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This is where I confuse everyone with my choice of words! IF I use a TPI intake paired with a custom grind of the Crane 227, AND use a lower gear ratio than my stock 3.42, I am going to zip to 5000 RPM in a heartbeat, am I not right? This is what I am trying to avoid! Does this make sense?
Well thats a combination of two things, increased torque And increased mechanical leverage. It will accelerate quicker for sure
but what you are hoping to do doesnt make sense because the lt1 intake can do the same thing as its making even more power. Hp and torque will accelerate faster period. The power band is just shifted differently in rpm range. Lt1 more top end the top end pull will feel alittle better. Little less low end torque peak slows acceleration at the beginning. This is where gear comes in to amplify the torque
Theres nothing wrong with pulling to 6000 instead of 5000.
You want short rpm range action, why wouldnt you want it to accelerate faster thru that rpm range?
Well thats a combination of two things, increased torque And increased mechanical leverage. It will accelerate quicker for sure
but what you are hoping to do doesnt make sense because the lt1 intake can do the same thing as its making even more power. Hp and torque will accelerate faster period. The power band is just shifted differently in rpm range. Lt1 more top end the top end pull will feel alittle better. Little less low end torque peak slows acceleration at the beginning. This is where gear comes in to amplify the torque
Theres nothing wrong with pulling to 6000 instead of 5000.
You want short rpm range action, why wouldnt you want it to accelerate faster thru that rpm range?
Well, it has EVERYTHING to do with my daily driving experience and the criteria I have set. I developed my driving style out of a need to help maximize fuel economy, so I was driving around town at 2000 RPM or 1500 RPM most of the time. Trying to drive at those RPMs on the expressway in sixth gear proves problematic when I start encountering mild inclines and then I feel the motor starting to lug. So, to address this, I definitely need an RV/Tow/Mileage cam with plenty of low end grunt. The Crane 227, to my surprise, is such a cam but with more muscle! However, I have another complaint about my LT1, the flat torque curve.
When I have launched from a green light or floored it onto the expressway, the car is not at all thrilling. I can squeak the tires from a dead stop while flooring it but the experience is dull. All that pull that everyone talks about, I just don't feel it! So, how can I experience a sudden jump in torque on the way to 5000 RPM? The TPI intake seems to be the simple solution paired with the right camshaft.
Yes, I can have a 4.10 gear ratio thrown on my car and maybe it would be fun for a little bit, but I speed shift to keep my RPM down while city driving and I would hate to have to shift into a higher gear just to drive around at 1500 or 2000 RPM in the city. Then with the highway, having a much higher RPM in sixth gear as opposed to with my stock 3.42 gear ratio.
So, once more, I have a stubborn sentiment with regards to how I want this car to operate. I want my cake and to be able to eat it too, a mild performance increase without sacrificing the fuel economy. Yeah, it may sound like making excuses but what need do I have to be trying to max out my tachometer to take advantage of the highest torque numbers possible? I hardly have enough road to gun it to 45/50 mph before encountering traffic at the next light! I have to be practical as well as safe!
You mentioned the LT1 with a deep (higher numerical) gear will zip you to 5000 RPM right away right? The taller (lower numerical) gear with the added torque of the TPI does the same thing! Lower gear, but more torque. It's the same. One does it via fluid dynamics, one via mechanical advantage gearing.
You'll never feel the RPM increase of deeper gears for the LT1. Sure, mathematically it's an increase, but without watching the tach....you'll never know it. ....and economy/gas price? It'll take you 20 years to recoup the cost of fitting the TPI to an LT1 and the cam swap.
You mentioned the LT1 with a deep (higher numerical) gear will zip you to 5000 RPM right away right? The taller (lower numerical) gear with the added torque of the TPI does the same thing! Lower gear, but more torque. It's the same. One does it via fluid dynamics, one via mechanical advantage gearing.
You'll never feel the RPM increase of deeper gears for the LT1. Sure, mathematically it's an increase, but without watching the tach....you'll never know it. ....and economy/gas price? It'll take you 20 years to recoup the cost of fitting the TPI to an LT1 and the cam swap.
....and if you're worried about that? Keep the motor as is, and get a t56 with custom .050 6th gear. Sell your t56 and you're half way there!
I hope no one thinks that I am seriously considering this intake swap for the sake of recouping what I put into it from fuel saving alone! No, but holding on to the car for another twenty years instead of trading up every ten years is what will save me money!
Yes, I will be researching if it is possible to tune the PCM for various air-fuel ratios under different loads from initial warm up using the proper stoichiometric ratio, to using a lean ratio for low load/cruising, to having a rich mixture for full throttle fun. I was also given the suggestion to tune for deceleration fuel cutoff, since I do downshift sometimes to slow the car down. It will net a small marginal increase but I am slowly gaining in fuel mileage! Pair this with building the motor with reduced friction parts like smaller low friction bearings, using a low friction ceramic coating on the piston skirt/bearing/valve stem/valve spring and crankshaft, low friction crankshaft seals, and a true roller timing chain. This is additional money but hell, it is a means to improve my LT1, on top of the optispark delete with LS1 coils per cylinder conversion. It would still be cheaper than swapping in a 2014 LT1 with accompanying transmission, electronic throttle, and necessary ECM.
I am going to hold on to my T56 transmission! Why bother with the TPI intake swap when I am messing with transmission gearing? If that is the case, the gearing should be higher to make my 3.42 ratio behave like it is higher ratio! I think I will content myself with the intake swap and all the other goodies to follow...
My point with the transmission is that you can run the LT1 intake, gear the car with 4.10 or higher, yet still have a really low 6th gear cruising RPM. which sounds like it was one of your concerns.
My point with the transmission is that you can run the LT1 intake, gear the car with 4.10 or higher, yet still have a really low 6th gear cruising RPM. which sounds like it was one of your concerns.
Yes. However, I really don't have the desire to use higher gears. This is why the TPI intake had me interested, especially when I looked into what gear ratios the TPI cars were using, which were not higher gear ratios but lower gear ratios! Despite this intake getting a bad reputation it suits my criteria and would optimize my LT1 for such criteria, shifting torque production down to lower and mid-range RPM while permitting me to cruise in lower RPM around town and even on the expressway, and with the right camshaft, not needing to shift out of sixth gear into fifth on minor inclines. If I am climbing a steep hill well that is another story!
Well you are dead set on this so no more discussion is necessary. Its not really the best way to complish your goals but to each his own.
Go aftermarket tpi stuff to get the flow. Else you will be making motor slower and weaker and not making it pull any better.
Cam only tuned lt1 lkely would get your cake and be full from eating it.
Well, I apologize for my stubbornness and I do appreciate your advice.
Yes, I plan on using AS&M big runners with whatever salvaged TPI system I end up purchasing. From there, I need to get the base modified to fit my heads by a machine shop, and they will need to add material to fill in the original holes followed by drilling the correct holes based off my LT1 intake which I will provide them, unless they have access to the specs and don't need the intake in person. Then, I have to ship the entire system out to get extrude honed. That should about do it for the intake unit. Then, pair this with the custom cam, and I should be plenty happy!
Yeah but at that time I was looking into throwing on a truck LS intake like the Chevy Trailblazer intake to help improve lower end torque. Again, I don't see how I can fabricate such an intake to work on my SBC style heads with reverse flow cooling! The only way to do it is to use LS style heads on my block but this requires some expensive one-off customization! The TPI intake by this point is much better and cheaper to modify to get it to work on my LT1.
Hey, I am not complaining, the TPI is perfect for my driving style and I am sure I will be happy with it's torque curve before it starts to drop off by the time I shift.
My question was if you wanted to use the ls1 truck intake the closest intake to that design in operation would be the first, HSR or superram, why are you set on the tpi? Now with the tpi base you could add the superam latter. Just wondering?
My question was if you wanted to use the ls1 truck intake the closest intake to that design in operation would be the first, HSR or superram, why are you set on the tpi? Now with the tpi base you could add the superam latter. Just wondering?
In order to use the LS1 Chevy Trailblazer intake on my motor, I would have required a totally new SBC block configured to use the reverse-flow cooling of the LT1, that can equip LS heads! I already contacted Bill Mitchell and unfortunately his iron block is only an SBC and he offers no LT1 version of the block. Besides, this would add significantly more money to get all the correct pistons, rods, crank, etc, to get this block functioning on top of LS heads with the intake, and then getting my stock emissions set-up to work with the LS configuration. So, I abandoned this idea.
The LS motor is a better flowing beast but I have nothing for my LT1 block that is comparable and will fit under the wiper linkage cowl that sits a third of the way over the motor from the rear!
The HSR intake is ten inches tall, I barely have enough room for nine inches height! The HSR intake will require cutting into the cowl bottom to get it to fit! Another problem, I am not optimizing for High RPM performance! The HSR loses the torque curve that the TPI intake provides for my application, and I don't want that! I am better off keeping my GM copy of the TPIS miniram if I want optimization for higher RPM.
The FIRST intake was on my radar, but the problem is that it does not offer an EGR provision, unlike the stock TPI! I have to be careful with aftermarket TPI products. Also, the plenum on the FIRST looks a little more taller than the stock TPI plenum, so fitment in my confined cowl area may be next to impossible! So this rules out the FIRST TPI intake.
The Superram? It lacks the low to mid-range torque that I am desiring from the TPI intake, as per the link! With the shorter runners it builds more torque after the TPI starts to drop off, this goes against the desired behavior for my build! In the chart on this link, the two graphs cross so it LOOKS like the Superram has more torque from the get-go, but that is the stock TPI curve!
Guys, He's posted this same cow dung over on the 'Vette Forum (and others). Don't waste your time; You will never be able to give this guy sound advice...that he will accept. No matter what you say that seems like a reasonable solution, he will come up w/some new, off the wall criteria for why it won't work....like this one, for example.
IF I use a TPI intake paired with a custom grind of the Crane 227, AND use a lower gear ratio than my stock 3.42, I am going to zip to 5000 RPM in a heartbeat, am I not right? This is what I am trying to avoid! Does this make sense?
Make sense? only to Phoenix97. Best of luck w/this one guys!
Just take your LT1, do every single bolt-on. And if you want more power than that, do a Lloyd Elliot, or Advanced Induction head porting package with one of their low duration performance cams.
It will drive like stock, make LOTS more torque everywhere, and give you all the go you are asking for when you want it.
I had a B-body cam iron headed LT1 with all the bolt-ons and it would send my 3750lb GTA down the track low 13's every time, even with a slipping transmission. The car was never dynoed but some math says it was probably making about 320-330hp and close to 400lb/ft at the crank.
I NEVER lacked for torque. And as for fuel economy? Once I swapped in a T56 I could hit 30mpg+ regularly. I hit 34mpg on the way back from Road America once.
Superram? It lacks the low to mid-range torque that I am desiring from the TPI intake, as per the link! With the shorter runners it builds more torque after the TPI starts to drop off, this goes against the desired behavior for my build! In the chart on this link, the two graphs cross so it LOOKS like the Superram has more torque from the get-go, but that is the stock TPI curve!
I think you might have that confused with the miniram. The superram is the inbetween of tpi and stealth ram. Its got long runners as well but not tpi long. It gives broader torque than tpi, more than stealth ram at peak. Hp is greater than tpi but less than stealth ram. Typically
This would be the best intake for you as they made it for lt1's back in the day with the only tpi style base for lt1 ever made
I think you might have that confused with the miniram. The superram is the inbetween of tpi and stealth ram. Its got long runners as well but not tpi long. It gives broader torque than tpi, more than stealth ram at peak. Hp is greater than tpi but less than stealth ram. Typically
This would be the best intake for you as they made it for lt1's back in the day with the only tpi style base for lt1 ever made
I have been trying to point this out without any success.
Guys, He's posted this same cow dung over on the 'Vette Forum (and others). Don't waste your time; You will never be able to give this guy sound advice...that he will accept. No matter what you say that seems like a reasonable solution, he will come up w/some new, off the wall criteria for why it won't work....like this one, for example.
Make sense? only to Phoenix97. Best of luck w/this one guys!
At least I am not encountering hostile comments jamming their philosophies down my throat. So please refrain from bringing those comments to this forum. I am sold on the TPI intake, and that is that! I don't see why you need to turn this into something for your own amusement, such an attitude results in giving forum members BAD ADVICE, for amusement!
I think this topic is closed but I appreciate all of your advice and help. I am sticking with the TPI intake. Thank you everyone.
There are a few folks like the OP that are looking to accomplish a very specific goal within a very specific RPM range. The problem he’s running into is the RPM band he’s trying to improve is more like the throwaway RPM band for most looking for increased performance. This including myself since I’m an automatic guy that runs 3,000-ish stall converters and not worried at all about gas mileage (although I do pay for more efficient stall converters). I have certain criteria I want to meet and the gas mileage is what it is – I’m totally fine with the old adage of you have to pay to play.
Instead of writing more of a book, I thought I would throw in a visual that pretty much backs up what most folks are telling you. I ran these on the less expensive and quicker/easier to use EAplus instead of EApro. Pro is more accurate, but Plus is still pretty close and perfect for showing a trend(s). Based on personal experience with a 355 and modified TPI as well as back up from the simulations, I do think adapting the TPI intake will meet your criteria. However, as seen on the graphs below, going with a 3.75 crank and good low friction pistons would give you much more in the off idle to 2500 rpm band you seem to be interested in and I believe it would cost less to boot. Throw in a small high velocity, high lift, modern hydraulic roller and it hurts nothing on the bottom end and adds considerable upper RPM performance for those times you would rev higher than 3000 RPM.
LT1 Stock - is a stock LT1
LT1 Stock TPI Intake is the stock LT1 with only a TPI with larger runners installed
LT1 3.75 Stroke - stock LT1 with 3.75 crank and good piston/ring package
LT1 3.75 Stroke w/Cam - adds a 206/212-112 high velocity and lift cam
As far as gas mileage – assuming the same overall efficiency, generally the more power you make the more fuel you’ll use. Whether that’s made with a TPI or extra stroke, it doesn’t matter. The TPI will make less power under 2000 rpm, but that’s due to the pumping loss of the long runners and if anything,,, you may end up burning more fuel in the lowest RPM range than you are with the LT1 intake. You more than likely will burn more fuel over 2000 RPM than you are now with the TPI, because it'll be making more power. That’s one of the main reasons GM went with the LT1 intake, that along with it being easier for techs to work on and it adding just enough HP so marketing could advertise a 300HP Vette.
As far as the 383LT1 using more gas, I do believe with the way you’ve described your driving habits, you would run more in an even lower RPM band with it than the 350TPI. Plus, I believe whatever small difference there might be in mileage, it would be well worth it and this is coming from who many people believe is the poster boy for the FIRST TPI.
Anyway, not trying to talk you out of the modified TPI, as said earlier I do believe it will accomplish your goals for the most part, just wanted to give you a visual of what other have been saying.
Am I understanding this chart, that it shows a stock LT1 w/TPI to improve low-end torque (orange hatching area) and the sacrifice of higher-end torque (black hatching) over stock LT1? Did I interpret correctly?
Am I understanding this chart, that it shows a stock LT1 w/TPI to improve low-end torque (orange hatching area) and the sacrifice of higher-end torque (black hatching) over stock LT1? Did I interpret correctly?
Thats midrange torque. Imo. The real off idle to 2000 doesnt change all that much. Theres no piston speed there so no real velocity in the ports so runner tuning isnt taking place
Thats midrange torque. Imo. The real off idle to 2000 doesnt change all that much. Theres no piston speed there so no real velocity in the ports so runner tuning isnt taking place
This is true, but I think less of an issue for a manual transmission.
As far as gas mileage – assuming the same overall efficiency, generally the more power you make the more fuel you’ll use. Whether that’s made with a TPI or extra stroke, it doesn’t matter. The TPI will make less power under 2000 rpm, but that’s due to the pumping loss of the long runners and if anything,,, you may end up burning more fuel in the lowest RPM range than you are with the LT1 intake. You more than likely will burn more fuel over 2000 RPM than you are now with the TPI, because it'll be making more power. That’s one of the main reasons GM went with the LT1 intake, that along with it being easier for techs to work on and it adding just enough HP so marketing could advertise a 300HP Vette.
Thank you. It is a convincing graph and it is enough to have me thinking about how best to pursue this build.
I really would like to avoid more displacement because off the bat I am using more fuel guaranteed. This was the reasoning behind why I am so adamant about the TPI intake, although I really need to understand the crucial differences between it and my stock LT1. I understand the TPI has a marginal reduction in torque production until 2000 RPM, but this should indicate that with less power production it is using less fuel, correct, despite that pumping loss you mention. Wouldn't a camshaft with improved torque right off of idle help address this issue to bring the TPI power production above the LT1 with the stock camshaft? After 2000 RPM, that same camshaft paired with the TPI torque curve should add to good torque production that will keep me happy even after it drops off after 3600 RPM yet is still producing better torque than the LT1 intake until 4500 RPM.
I will have this system Dynotuned with variable air/fuel ratios for the given demands on the motor from light throttle/cruise to full throttle/fun! I am not horribly concerned about the possibility that the TPI intake would result in more fuel consumption compared to what a stroker would result in.
Thank you again for showing me my options!
Last edited by Phoenix'97; 01-07-2018 at 04:56 PM.
You've already been explained these same options on other forums.
Originally Posted by Phoenix'97
Thank you. It is a convincing graph
Isn't it? But something catches my attention; This graph is very, very similar to the ones I posted on the 'Vette forums, that shows the LT1 making more LOW RPM tq than the TPI. Now, it appears the same is true even on an LT1 long block.
Additionally, look at what the stroker version does; exactly what you claim you want. Hmmm. Didn't someone recommend a stroker kit to you posts and posts and threads and threads ago?
You've already been explained these same options on other forums.
Isn't it? But something catches my attention; This graph is very, very similar to the ones I posted on the 'Vette forums, that shows the LT1 making more LOW RPM tq than the TPI. Now, it appears the same is true even on an LT1 long block.
Additionally, look at what the stroker version does; exactly what you claim you want. Hmmm. Didn't someone recommend a stroker kit to you posts and posts and threads and threads ago?
Did I also not make it clear that I am not interested in a stroker? Yes, my criteria SEEMS to fit the stroker set-up but I am not willing to "pay to play" for those torque numbers, in this case the fuel economy penalty!
The TPI does exactly what I expect it to do and exactly what I want it to do given my criteria using a mild build. I would LOVE to see the representation based on an LT1 using the Crane 227 cam paired with the TPI intake. This should pretty much give me what I am looking for. Yes, it is not as magnificent as stroker performance but for a mild build, it is all I could really look for when I do have my "fun".
Did I also not make it clear that I am not interested in a stroker? Yes, my criteria SEEMS to fit the stroker set-up but I am not willing to "pay to play" for those torque numbers, in this case the fuel economy penalty!
The TPI does exactly what I expect it to do and exactly what I want it to do given my criteria using a mild build. I would LOVE to see the representation based on an LT1 using the Crane 227 cam paired with the TPI intake. This should pretty much give me what I am looking for. Yes, it is not as magnificent as stroker performance but for a mild build, it is all I could really look for when I do have my "fun".
If you do this I would love to see the dyno results and hear if it met your needs or not. Good luck on however you do it.
^Me too. There is a pretty big audience who would like to see this thing run!
Originally Posted by Phoenix'97
Did I also not make it clear that I am not interested in a stroker? Yes, my criteria SEEMS to fit the stroker set-up but I am not willing to "pay to play" for those torque numbers, in this case the fuel economy penalty!
Did I not make it clear, posts and posts ago...threads upon threads ago, the fuel economy "penalty" that I paid when I went from a 305 to a sb 400?
The TPI does exactly what I expect it to do and exactly what I want it to do given my criteria using a mild build. I would LOVE to see the representation based on an LT1 using the Crane 227 cam paired with the TPI intake. This should pretty much give me what I am looking for. Yes, it is not as magnificent as stroker performance but for a mild build, it is all I could really look for when I do have my "fun".
Basically what i posted earlier the hot cammed tpi afr 180 head engine that i did. Crane cam is a touch smaller and the stock lt1 heads dont flow as well but the power curve would be somewhat similar. Just slightly lower numbers
Did I also not make it clear that I am not interested in a stroker? Yes, my criteria SEEMS to fit the stroker set-up but I am not willing to "pay to play" for those torque numbers, in this case the fuel economy penalty!
The TPI does exactly what I expect it to do and exactly what I want it to do given my criteria using a mild build. I would LOVE to see the representation based on an LT1 using the Crane 227 cam paired with the TPI intake. This should pretty much give me what I am looking for. Yes, it is not as magnificent as stroker performance but for a mild build, it is all I could really look for when I do have my "fun".
Kevin's use of the EA packages DO help to visualize changes (as they did for me during my build). Phoenix, you also make statements indicating you don't understand what's being communicated. Due to the repetition you've received those answers (in at least 3 forums), one has to wonder if you read, think, or consider what's being said. Other times, you word things so poorly, your meaning betrays what you're probably thinking....and you become combative when it's fed back to you.
(As an example, consider the first/last sentences in your response to Kevin:
"I really would like to avoid more displacement because off the bat I am using more fuel guaranteed. This was the reasoning behind why I am so adamant about the TPI intake....
and....
I am not horribly concerned about the possibility that the TPI intake would result in more fuel consumption compared to what a stroker would result in."
Do you see the apparent contradiction in your statements?)
I'm guessing what you MEANT was you think the TPI won't raise fuel consumption as much as a stroker? I'll assume this is true though it still makes me wonder if you missed that Keven (BADSS) pointed out the increased TORQUE of a stroker would allow you to drive/shift in favor of lower rpms -- more often. IOW, you could regain any mpg loss via low-rpm-driving. I would even point out the obvious additional torque BELOW the TPI advantage -- which you've HEAVILY LOBBIED FOR in our Corvette Forum.
When you ask what it takes to get X, you always say....but, but, "Y". Personally, I think you are too concerned over fuel losses to even consider engine modification. Again, if I give you the benefit of the doubt (and you are willing to have some increase in $$$ for HP/TQ, I think it's more likely your pay-to-play concern is with the cost of the stroker itself vs the fuel consumption. To those of us who understand the choices, that's really what it comes down to. If you're not happy with the lowest RPM response, you'll press the pedal harder and use up what you WOULD have it the engine were more "responsive" in giving you what you want. Make sense?
Kevin clearly stated (as Tom and others did in "our forum") that power is going to use more fuel...no matter how you go about it. Most importantly...and above all else is ALL of us have tried to convey the solutions that would make you happiest. For example, you can SEE how a stroker give the advantage you're looking for in 3-times the rpms. You get lower AND upper increases...in addition to mid-range. Why wouldn't ANYONE want 3 times the benefit -- if ENGINE BUILDING COSTS WEREN'T A FACTOR? And, you've never said this....it's ALWAYS FUEL, FUEL, FUEL.
Your OBSESSION about fuel shows a possible inner conflict on doing ANY mod in the first place. That's also been proposed. If not, I'm personally going to assume you want to keep engine building costs down (though you won't say it) and want to avoid pulling the entire motor. In OUR forum, we've understood THAT TOO...which is why we questioned when you wanted to CHOP UP a TPI to get it to fit where YOU claimed it wouldn't. You have been nerve-racking even when LOTS of people try to steer you to low-cost-mods and lowest-cost fuel consumption with highest FUN benefits.
You miss the bigger picture by being impervious to logic. People in all of these forums try every polite-to-bullying approach to get you to THINK. Too many times, it appears you don't. In this thread alone, you posted about two pictures incorrectly. You posted a pic of an HSR when bragging you wanted/needed a TPI. On page 1, you snubbed a pic of an LT1 TPI conversion. You didn't acknowledge it had the base but not the tubes you'd like. Both show a lack of recognition. Both show you aren't plugged in.
ANYONE posting in 3+ forums and being THAT aggressive should understand what they are talking about...or at least being willing to listen/learn. In AT LEAST your 4th visit to a forum, you still don't post pictures that show you even know you are LISTENING....that you understand. I posted an ebay for sale that you might pursue -- but it's WAY TOO EARLY since this project is
3 years into the future!!!
Who trolls 3 forums -- without LISTENING -- with THAT AMOUNT OF INTENSITY for a project 3 years into the future? Can you guarantee you'll feel the same in 3 years? Can you guarantee the car won't get totaled in a car accident? You drive it in the snow -- which means you won't have to be the fool that wrecks it. People are idiots in the snow.
If you finally want to "tone it down", I applaud a new approach. I would ask that you consider your target build-date and debate accordingly. I would also ask that you seriously debate and consider suggested options. You apparently have AT LEAST three years to plan -- which means you don't have to be closed-minded out this.
As I turn you back to this forum, Kevin, and whatever you choose to learn consider looking at what's presented. You asked to see a TPI with a 227 crane. Notice the difference between Kevin's performance-cammed and stock-cammed 383 setups. The difference gives you a reasonable clue to the bump a "cam" provides. Notice the difference is greater in higher rpms vs lower ones. That's true for ANY intake. Notice the AMOUNT of difference. The crane will be a bit more than high-lift 206/212 mapped for you. IOW, you can "add" the difference you see between the two 383 graphs to the LT1/TPI graph to get an idea of what it would be like with the Crane. Don't forget the difference if you set the cam adv/neutral/retarded too.
Just as a comparison I did a few things in the old Desktop Dyno application. Then exported the tables out to Excel so I could graph them there.
Food for thought. Just moving to a 383 really doesn't do much, you'd have to do all the bolt-ons otherwise the intake, heads, and exhaust would starve the engine. Torque would be pretty good.
A Full Bolt=on engine makes near the same torque (I personally think the sim is a bit high), but it basically makes more power EVERYWHERE. I had one of these in my GTA. You would NOT be disappointed, especially since you are talking about increasing it in the mid-range. Honestly, for your goals, do Full Bolt-Ons. CAI, Long-Tubes, ORY, Cat-back. HUGE gain in performance.
The 383's curve is self explanatory.
The Sims. Black = Flow charts for stock LT1 heads, B-body Cam specs, stock manifolds and intake approximations. Numbers are somewhat close to the real thing. Though torque is a bit high. PURPLE = Same engine, but with a bump in Intake flow and changed "manifolds" to Headers. ORANGE = Same as Black line, with displacement bumped to a 383.
Here is a vDyno excerpt from one of my drag strip runs. Its only from 3700rpm up to 6000rpm. This was with the trans that wouldn't shift correctly. Commanded at 5200rpm, but wouldn't shift until 6050rpm when it hit the rev-limiter.
Look at all that torque!
This was from the same run when the car ran a 13.3 @ 102. You can see how it falls off past 5200rpm fast. Don't look at the Numbers so much, but instead look at the curve. Just a solid flat plateau of torque till almost 5000rpm.
I'm guessing what you MEANT was you think the TPI won't raise fuel consumption as much as a stroker? I'll assume this is true though it still makes me wonder if you missed that Keven (BADSS) pointed out the increased TORQUE of a stroker would allow you to drive/shift in favor of lower rpms -- more often. IOW, you could regain any mpg loss via low-rpm-driving. I would even point out the obvious additional torque BELOW the TPI advantage -- which you've HEAVILY LOBBIED FOR in our Corvette Forum.
Why are you over in this forum AND AGAIN being combative with my choice to stick with the TPI intake?! Does more displacement not result in more fuel consumption? For city driving I can't have this! Since the general consensus is that more power is a direct result of more fuel consumption, I have to safely say that using the TPI intake with a rather mild build should result in less fuel consumption than a 383 using my stock LT1 cam. Am I not correct? You assume it is true so what is the problem?! Besides, with the right tune, I am sure I can negate the fuel cost for those times I do decide to go full throttle beyond 2000 RPM and use the torque curve provided by the TPI intake. So what is the problem here? You are proving to me that you only care about shoving your build suggestion down my throat as if it is only the correct choice! Respectfully, back off Sir!
Why are you over in this forum AND AGAIN being combative with my choice to stick with the TPI intake?!
Hmmmm....Members should stick to one forum? I never thought of that!
Just so you know, I joined this forum because the CorvetteForum doesn't have a particularly well-organized/robust tuning section. I RARELY post here but was drawn in by some guy trolling multiple forums and playing people AND forums against each other. Who might that be?
Like everyone else, I don't care if you decide to choose the TPI intake. After all, you already know I built my own 383 with one...which means I'll cheer silently if you ever DO IT and decide you like it better! That said...In your insane, take-no-prisoners, intense quest (carnage through several forums) makes me torn between your success and wondering WTF?
I will state this clearly to anyone reading. The intensity of your replies (especially from others coming here from other forums) is a result of the methods you've employed.
Originally Posted by Phoenix'97
You are proving to me that you only care about shoving your build suggestion down my throat as if it is only the correct choice!
You mistake the intent of myself AND many members in several forums. In my last post to you in the CorvetteForum, I specifically said there's no right answer to any build. It's personal choice. The ones who have tried to steer you to gears or a stroker HAVE listened to ALL of your goals.
Do you remember spending an entire week (in the CorvetteForum) saying how difficult and problematic putting a TPI under your hood would be? We ALL said gears and/or stroker because it logistically makes more sense. Does that mean we are badgering you?
The fact that you're seeing CONSISTENTLY so many suggestions for another approach doesn't mean people are wanting to shove their opinions down your throat. If I wanted to shove anything, it would be the suggestion to reread (even) this one thread to see how many points you missed the first time through it. Read it like friends trying to help...vs big brothers trying to beat you up.
Like me (coming to this forum because it has information not available in the CF), I hope you will consider the same. I've talked with several of the posters in this thread. They all know their stuff.
P.S...For the record, I'm seriously considering a swap to an HSR...or FFI one of these days. Everyone is right when they say NOT to ignore higher rpms!
GREGGPENN, all I can say is thank you for your advice, both on the Corvette Forum and here.
I don't have your engine building knowledge nor your experience with the TPI intake, but if you truly understand what I am about then let me explore what I get with this intake swap. Hopefully I can get everything together to have it done before I go hog wild on the engine build. I do need to see how this intake responds with my stock camshaft, although I will need a Dynotune for it.
I need to see how bad the fitment is because I doubt I will be able to fit a FIRST TPI with a plenum that does appear to be an inch taller than the stock TPI. Then I run into issues with trying to get an EGR system on the FIRST TPI.
So, thank you for your advice! Who knows, down the road, after 10 years with my then set-up, when I am older and I get bored, I may decide to throw a stroker in! We will see...
GREGGPENN, all I can say is thank you for your advice, both on the Corvette Forum and here.
I don't have your engine building knowledge nor your experience with the TPI intake, but if you truly understand what I am about then let me explore what I get with this intake swap. Hopefully I can get everything together to have it done before I go hog wild on the engine build. I do need to see how this intake responds with my stock camshaft, although I will need a Dynotune for it.
I need to see how bad the fitment is because I doubt I will be able to fit a FIRST TPI with a plenum that does appear to be an inch taller than the stock TPI. Then I run into issues with trying to get an EGR system on the FIRST TPI.
So, thank you for your advice! Who knows, down the road, after 10 years with my then set-up, when I am older and I get bored, I may decide to throw a stroker in! We will see...
NP....Lots of people have more building experience....even in THIS thread. My relevant experience is with the ownership and history of wanting much of what you specify. I started out with the desire to add headers and intake ONLY. By the time I looked into everything, I built a new motor...every nut/bolt.
Not to be a pest, but I have to ask if you even know (for sure) what a TPI is? Why did you post a pic of the HSR near the top of this page? Why didn't recognize the (superram) topped TPI at the top of page 1? We've covered these at the CF I thought. You've posted other things (at the CF) that also didn't pertain to the TPI. After linking you to an ebay auction of at LT1/TPI a couple of weeks ago, it seems odd you're making this error. If you're really looking at an HSR, that's a whole different ballgame. Have you looked at the FFI website to know what that intake really is?
Again....not trying to be an azz. Please confirm what you think an LT1/TPI is (for everyone's sake).
If you do this, and need a tune, swap to a 95 ecm to get rid of the obd2 stuff. It will be easier and cheaper to tune
I respectfully disagree, keep the 1997 computer and use Jet dynamic tuning software to tune it. It works well and you can scan it with HP tuners, or others.
I respectfully disagree, keep the 1997 computer and use Jet dynamic tuning software to tune it. It works well and you can scan it with HP tuners, or others.
My opinion.
Yes it works but costs 400$ while tunerpro is free and just need 20$ winflash
Does more displacement not result in more fuel consumption? For city driving I can't have this!
I left off with advising you to swap your gears. Like I said, it is the most feasible option for what you're looking for without even touching the engine. In terms of more fuel consumption with more displacement, that is not necessarily true. Bigger engines have the potential to always make more power, but they don't have to. It's more about air flow than cubic inch displacement, as even a 454 will run like a dog and use essentially no fuel if you run a broom stick of a camshaft, not to mention tailor the gearing to keep it away from the added torque that it does make. An L98 and LT1 both breath through a 48mm throttle body from the factory. The difference between the two is through a shorter vs longer intake tract, different valve events, and different cylinder head flow. This moves the power in your RPM band, that is all that it does. You can modify the LT1 to behave more like the L98 with a cam swap, and vice versa, though overlap comes into play with the L98 because it has a more restricted intake tract and will need a lot more duration in the cam, but that is besides the point, it will rev higher if you allow for it too. Bottom line is gearing out back will do exactly what you want in your situation, but if your bent on the intake swap, then go for it. Again though, it is way more feasible to swap cams in the LT1 to match the RPM band of the L98 as opposed to putting a TPI intake on top of an LT1. I think this whole argument is ridiculous... but in a good way, I guess lol.
Coming from originally having a stock TPI and currently t56 equipped ls motor, I do not see minor inclines really bothering a stock lt1 more than a tpi motor with same manual transmission. For a daily, I have no issues staying below 1700 rpm and keeping in 6th gear at 1600 rpm on minor inclines. Short 1 to 4 shift puts the motor at 900 rpm, which is just enough to slowly continue accelerating without bogging the motor. This is with ls motor, but lt1 has a bit better torque build up off idle. Just do not see a real issue to solve in the below 2000rpm range. Add some gears and maybe verify that the motor is tuned correctly if it struggles up minor inclines.
In terms of more fuel consumption with more displacement, that is not necessarily true. Bigger engines have the potential to always make more power, but they don't have to.
I already TOLD HIM THIS^ and even gave a real world example;
In reality the affect to economy will be minimal and dominated by how you drive it. I had a Trans Am once, like most TA's it had a 305 in it and would get about 24 mpg. Later, I installed a 400, and got....~24 mpg out of it. Mileage around town went down noticeably...but that was b/c fun went way up.
He don't listen though. I told him that three months ago.
Originally Posted by Street Lethal
Bottom line is gearing out back will do exactly what you want in your situation, but if your bent on the intake swap, then go for it. I think this whole argument is ridiculous...
It is ridiculous. And you haven't even scratched the surface of this one yet! Gears or stroker will meet the goals fastest/easiest/cheapest/best.
Coming from originally having a stock TPI and currently t56 equipped ls motor, I do not see minor inclines really bothering a stock lt1 more than a tpi motor with same manual transmission. For a daily, I have no issues staying below 1700 rpm and keeping in 6th gear at 1600 rpm on minor inclines. Short 1 to 4 shift puts the motor at 900 rpm, which is just enough to slowly continue accelerating without bogging the motor. This is with ls motor, but lt1 has a bit better torque build up off idle. Just do not see a real issue to solve in the below 2000rpm range. Add some gears and maybe verify that the motor is tuned correctly if it struggles up minor inclines.
I agree. In fact, I ALREADY TOLD HIM THIS, three months ago. He don't listen. He denied that his car has any problems...even though it apparently can't do what it should be able to EASILY do. Later, he comes back and ADMITTED IT HAD A PROBLEM. I'd bet that it has more/other issues too.
Don't remember where I saw it....Maybe his posts on the LS forum...linked to from our thread at the CF.
Anyway, Phoenix isn't running the stock GM motor anymore. It's a reman....I think by Jasper. Don't know anything about how they build to original spec. Who knows how it's setup for timing/compression?
Build a 396 cube LT1 with a 3.875" stoke and 6" rods, low end torque issue solved. I have run the "B" car LT1 aka Vortec cam in stock trucks, suvs and vans and HATE the cam. LT1 F/Y cam or LT4 cam improves the power EVERYWHERE in those engines. My 1997 Express van with a LT4 cam and 1.6 rockers in an otherwise stock engine would pull the same hill in OD the stock cam had to downshift to 3rd to climb. FWIW, 4L60E and 3.42s giving 2,000 rpm @ 70 mph. The factory cam fell flat on its face at about 4,000 rpm compared to the hotter grind that kept on pulling to 5,500 rpm. I have also run the 300 hp 350 Vortec marine cam and it was gutless too. The GM SPO 357 hp 350 cam ran much better. Basically that cam is a Hotcam designed to work with stock Vortec heads and the 9.4:1 long block.
01-05-2018, 03:17 PM
At this thread.
