TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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I have a 87 Pontiac Trans Am, and recently I've been building a strong street setup while staying within a budget (married with one child).
I started with a 69' 4 bolt main block bored +.040, torque plate honed, align bored, true decked, with block filler.
The bottom end starts with an eagle ESP crank, Eagle I beam rods, Speed Pro hypereutectic pistons wth teflon skirt coating, clevite bearings, and total seal gapless TSS street rings. Melling standard volume oil pump, 7 qt circle track pan w/7 trap doors, baffle and windage tray. The cam is a Crane 270H flat tappet with .450" lift, 218 duration, and 106 LCA. The Heads are GM performance parts L31 vortec heads (cranking compression was 200PSI). Proform true aluminum roller rockers, stock valve covers. SDPC votec intake, stock runners, holley fuel regulator, accel 26Lbs injectors, ported upper plenum, stock throttle body for now, cold air kit, and 160 degree thermostat. The ECM EPROM was burned specifically for this combo. Long tube headers with 3" collector reduced 2.5" into a flowmaster muffler.
My desktop dyno 2000 results are 344HP @ 5000RPM and 425Ft-Lbs @ 3500RPM
I thought this engine would make more power then it did. Does anyone have any input or any other dyno results?
Try one of the 268 duration cams. Comp Cams and Lunati have some good ones and supposedly work best with vortec heads. All aftermarket tpi components would be best.
1) stock runners/plenum. you need aftermarket bigger runners and port the plenum and should port the base to really get the flow that the motor wants. 383 really needs air, and that setup is not getting it done.
2) i highly doubt that combo will pull to 5000rpms with that cam and runner setup. more like 4200. i'd look for a slightly bigger cam. 383 needs more cam. what u got there seems more like a good 350 TPI setup.
Comp Cams recommended cam with .464" intake & .470" exhaust lift 262 intake & 270 exhaust duration @ seat to seat with 133.5 LCA. I have not run the engine yet, its been in the car for some time now. I'm almost finished building a hot 700R4 tranny then I will be ready fire it up. At first the estimated power numbers were impressive over the stock baseline, but as I read more engine build up articles I soon wondered if my combo was worthy of being called a 383 stroker. If I pull the camshaft backout with the motor being in the car I'm going with a roller. As far as induction the SDPC vortec intake flows very well. The stock runners and TB are eventully going to be replaced, but they are quite pricey. The upper plenum is ported, and MAF sensor has screens removed.
Last edited by StrokerTransAM; 11-06-2006 at 09:17 PM.
As far as the desktop dyno, the program assumes the induction system is adquate and suitable for the power output the created engine combo presents. It only measures induction flow (carb/throttlebody) in CFM. I tried from 600CFM up to 800CFM with very little improvement in power output.
idk about the 106 lca either...thats tight!!! i'd try atleast 110-112. but you definately would benefit from roller cams. they generally make better power all around.
and you definately need runners/plenum port. stock runners dont feed stock 350's...let alone a cammed heads 383. it is abit pricey but well worth it. else get vortec holley stealth ram and be VERY pleased. thats a nice 383 combo
The heads aren't helping you either if they are the stock regular vortecs. Yes, they flow much better than a smog or iron L98 head but that's not saying much. The vortecs have a small port and small valves. You have to look at the cam, heads and TPI together as a system and match them. The TPI is going to define your engine as a high torque low-end monster so don't expect it to breathe well up top. Knowing that, you don't need heads with huge ports but something that flows very well in the low-mid range will be nice and the cam needs to complement that. Sticking with a stockish TPI intake look for heads/cam that will breathe low to around 5200 RPM on a 383.
Polecat I submitted your recommended bumb stick into my desktop dyno as a Hyd flat tappet, 230 duration @ .050, .480" lift 110 LSA, and 106 ICL. The results were 352HP @ 5000 and 413Ft-Lbs @ 4000 with the overall torque numbers down, but power was up very slighty over the entire powerband.
I have pretty much stock vortec heads and a budget (hence why me and many others have bought the vortec heads $250 each)so, I don't want to have to get the valve seats remachined to accept larger stiffer springs. I don't really want to push over past .490" of lift.
Does anyone have HP and Torque numbers on their own 383 power houses, within the normal realm (no aluminum blocks or cyls, valve lift over .550, 10.1 CR, and etc) Maybe Mr. Gaskets desktop dyno is in accurate does anyone else have any experience with this softwere???
You should try a search. Here is a 383 vortec tpi setup. Note he is using a better flowing intake. TPI in general dont flow very well except maybe the Superram or the HSR. The vortec superram and hsr 383 engines seem to get you around 350 rwhp.
This is a at home desktop computer engine dyno simulator. As far as induction goes in terms of this softwere from Mr. Gasket, all intakes in the same catagory are created equal. You have a choice of single or dual plane, tunnel ram, individual runners, TPI, SFI, or forced induction. Not if you have a SLP, edelbrock, holly, weiand, dart, and etc intake. If you make 500HP with a dual plane intake the software assumes that the actual dual plane intake you might intend to use is matched to the simulator power results. I already know I'm going to have to buy runners and a throttle body to start getting the air flow I need, thats a givin.
Even with the aftermarket LTR intake you will still be at the 350 hp level. If your fine with that then it should work. If you want more power expect to change the intake completely.
Gunner823....
As far as cylinder heads go the vortecs are a great head.
They maynot be as compared to a set of AFR 195 eliminator alunimum heads or etc. I have the flow numbers of the vortec heads as well as many others.
As for the price fully assembled brand new it can't be beat.
The average valve sizes in street rods is 1.94/1.50 or 2.02/1.60. 175cc intake port is found on many other good flowing heads; Edelbrock performer 60909 heads, Trick Flow 23 degree 3030003 heads, and etc.
Shaggy56
As far as changing the induction, I have thought about it. Is it really worth tring to get a tpi to deliver any desent power?
and yeah i cant see you gettin much more than low 300whp range on aftermarket TPI and stock untouched vortec heads on the 383. and i dont think it would make power over 4500-4800rpms. that aint bad tho! thats good power. the torque is whats gonna be unreal!!
just dont expect a whole lot from TPI. with a bigger cam and runners, you'll be happy with that setup.
my buddies carbed LT1 cammed,vortec headed 350 in his 83 shortbed chevy pickup made in the neighborhood of 330-350hp. ran mid 13's all day long. and thats a MILD CAM.
Machining the heads to fit a Z28 .500 to .550 lift spring is not much of an additional process. Matter of fact, SD already makes some ready to bolt on. Dollar per dollar, the Vortec is the heads to have for a mild 350, or 383. The 383 isn't going to be a high revving engine any how.
The Luntai cam mentioned will stay under the .500 lift, has a tight LSA and a nice idle.
If you don't change the springs, that limits you even more with nothing more than a .450/.470 lift.
Either way, the 383 will be fine, just the stock TPI will limit the engine.
Thanks for the info, and suggestions. I hope this combo makes me smile. I'm not expecting 500HP or anything just a strong street motor on a budget. I still have to set the suspension up to try and make the best use of the torque output and the rearend to handle it.
Maybe you can be the first to get one of these and look what it says. The prices are around what you would pay for an aftermarket tpi setup.
Quote:
This is an up and coming option of the FIRST® manifold designed to fit the Vortec heads. Pattern development has been done. We do have some castings to be machined. We are hoping to have all the development done soon. It has taken a lot longer than we had hoped, but as soon as it is done, we will post it on the web page. The top manifold is the original and the lower is the new Vortec head design
Thanks for the info, and suggestions. I hope this combo makes me smile. I'm not expecting 500HP or anything just a strong street motor on a budget. I still have to set the suspension up to try and make the best use of the torque output and the rearend to handle it.
do you have subframe connectors? Once you do a bigger cubic inch SBC, you'll never go back down...
Last edited by Polecat; 11-07-2006 at 01:57 PM.
Reason: spelling
TCI recommended the Saturday night special lockup converter..... 2000 RPM stall speed.
Transmission has B&M trans kit with street/strip valve body modifications, .500 boost valve, 13 vane pump, the beast sun gear shell, 29 element sprag, and deep pan.
I wasn't trying to say the Vortec heads were a bad head, they aren't, for the price. But from your post it seemed you were disappointed with the power estimates of your desktop dyno. Fast, cheap, reliable, out of those, pick two, because you can't have all three. If you want 400+ hp out of a 383 with a TPI set up you'll have to go with AFR or similar heads or have your vortecs worked over to the max which would cost you a bunch of money anyways. There are performance vortec heads out there that have larger intake/exhaust valves and will accept higher lift cams but again, you'll pay more than $250 a piece assembled for them.
I've spent the better part of six months researching and asking the same questions you are, and the conclusion I came to was I also wanted a 383 worthy of the term "383 stroker" and that's why I bought AFR 180s. IT definitely pushed back the "completion date" but you have to consider also how important being happy with your finished product is to you.
Your 100% right. Maybe "down the road", when the car is finished from all the other upgrades I have planned for it. I'll purchase a set of high flowing aluminum heads. I plan on purchasing the new FAST TPI complete manifold setup that Shaggy56 brought to my attention to make the most of the vortec headed 383ci motor. I'm going to do my research first, but I hope they will provide the air I need to feed my large cubic inch mouse motor. Like most gear heads, we're always searching for more power, and never satisfied for long.....either too much motor or not enough car???!!!
Dont underestimate the power of vortecs. I will post a link of someone running the stock vortecs heads and he had nothing done but a little port cleanup. Its a carb engine but its running great. I disagree about the major work having to be done to vortecs for them to perform. The times he has is with nitrous but that engine is easily a high 11 low 12 second with all motor.
yep i agree... should be really easy to make 400hp with a 383 and vortecs.
and as far as the converter is concerned, i'd like to see you go with something abit more than 2000stall. stock is 1600 or so. so why spend extra money for 400more rpms? get a 2500 and be very happy with that. i got a 2800 on my L98 that is near stock, and i'm very satisfied with that
If I remove the muffler option on the desktop dyno with just headers the motor improves alot.
355HP @ 5000RPM and 441Ft-Lbs from 2000 - 4000RPM with 86% volumetric effi. vs. 344 @ 5000 and 425 @ 3500 with 84% volumetric effi.! I hope the dyno's version of a muffler is maybe a turbo muffler, verses the true flow potential of the many mufflers like dynomax, magnflow, or flowmaster???
Last edited by StrokerTransAM; 11-07-2006 at 04:18 PM.
Pay particular attention to what Dirt Reynolds and Gary Penn have to say. Dirt started the thread, Gary was at the top of GMPP when the Vortecs were designed. A lot of current thinking is moving to moderate (~0.500") lift with longer duration to take advantage of the flow characteristics of the Vortec design. It's a hot thread, currently 10 pages. I've been pursuing the Vortec info for months, I already have a V/HSR in the closet, now ready to buy E-Tec 200's to go on a planned 383. I expect to be commited to the whole package by January or so.
__________________ My grammer is poor and my spelling sux, but I know what the Caps Lock button does, and I know when to punctuate!
wow thats a great thread. didnt know those cars were making that much power on those heads. but i do wonder how they would compare to a set of aluminum heads like trick flow, AFR, dart etc
thats a full gutted car and only trappin 113. very good times for whats done but normal street car would be goin mid 12's at 110-111 on that setup. not a bad budget setup.
i'd want a car that traps near 118-120 and then add some spray for more
They're a pretty good head for a factory head, can push them pretty far.
Yep, Pony Killer did well with that setup, and note he did it at under .500" lift! But also note the thread is three years old, probably why I didn't find it searching here on my TGO homepage. Still, I've not seen anywhere else the depth of discussion as provided by Gary Penn on the nasty site. Well worth reading.
Its amazing how well the vortecs have lasted the test of time. Its great to see guys having the same results no matter where you go. Its never a hit or miss thing either. I knew it was a big deal when I read some circle track guys talking about how great they are because they are starting to be able to run them in classes that previously didnt allow them. They said they are getting some astronomical power numbers that they have never seen before.
Wheelspin, thanks for directing me to nastyZ28.com........awesome and very informative artictcle. I can't believe the vortec heads can deliever so much with some tweaking.
Everything that everyone has suggusted to me is making me realize that I should have asked questions along time ago concerning the stroker theory, fuel injection, head characteristics, and camshaft selection. The creative wheels are in motion.
Not sure yet, but I'm thinking the "low" lift with high duration, probably one of the last things I spec out. Definitely going to talk to "Cam Master Jay" at Camshaft Innovations: Camshaft Innovations - Home
Looks like he will be carrying the RHS Vortecs soon, though I'm leaning hard toward the E-Tec 200's. My focus is straight line performance.
I was reading that Nasty Z thread and thought it was pretty neat they got 300 cfm out of vortec heads but then you hear every other guy say how you cant improve vortecs. Lots of internet bs floating around lately its hard to find the real facts. I know those circle guys mentioned power numbers in the 600+ hp range but from reading that thread I totally believe it now. Very nice.
like they said, vortecs only seem to flow to near 500 lift...then its pointless to go farther. so keep it relatively low lift...480-500 and go abit bigger on duration
like they said, vortecs only seem to flow to near 500 lift...then its pointless to go farther. so keep it relatively low lift...480-500 and go abit bigger on duration
Where did you get this info? I was reading a royal purple writeup and they gained like 70 hp going to a bigger cam. The only thing they mention about .490 lift is the springs and guides cant take more but it isnt difficult to correct.
Dont underestimate the power of vortecs. I will post a link of someone running the stock vortecs heads and he had nothing done but a little port cleanup. Its a carb engine but its running great. I disagree about the major work having to be done to vortecs for them to perform. The times he has is with nitrous but that engine is easily a high 11 low 12 second with all motor.
I would think with the FIRST TPI, Stealth Ram, or Superram you could easily make 400 hp with vortecs.
That was with my old 350. I'm running a 383 now with the same heads and cam. Car has run a best 11.59 on the motor and 10.85 with 125 shot. Our valve work determined where these heads are making the best power...right around .400 - .550.
Where did you get this info? I was reading a royal purple writeup and they gained like 70 hp going to a bigger cam. The only thing they mention about .490 lift is the springs and guides cant take more but it isnt difficult to correct.
i dont have the exact links anymore but all the flow data i seen show .500 lift being the best and no more flow was gained afterwards goin to higher lifts.
Where did you get this info? I was reading a royal purple writeup and they gained like 70 hp going to a bigger cam. The only thing they mention about .490 lift is the springs and guides cant take more but it isnt difficult to correct.
BadAssNova, thanks for the input, and welcome to TGO! Any comments on the aftermarket vortec derivatives? RHS and Edelbrock have some out, and word is there is a new Motown 215cc currently being advertised.
I'm currently in the part selection phase of an sbc gen1 383ci V/HSR.
Last edited by Wheel Spin; 12-04-2006 at 12:33 AM.
BadAssNova, thanks for the input, and welcome to TGO! Any comments on the aftermarket vortec derivatives? RHS and Edelbrock have some out, and word is there is a new Motown 215cc currently being advertised.
I'm currently in the part selection phase of an sbc gen1 383ci V/HSR.
I've heard a lot of good things about the E-Tecs. A friend of mine did the article in Chevy High Performance that tested the GM Bowtie Vortecs against the standard GM Vortecs. The stock Vortecs made better power up until .500 or so, but the Bowtie Vortecs kept making power beyond that. I've got a friend here that runs the RHS Vortecs on a 355ci nova and he's running 11.60s, but his race weight (3000#) is also MUCH lighter than mine (3400#).
I'll be using Edelbrock E-tec 200cc heads with my new 355 build. Along with a Edelbrock Vortec base, AS&M runners, matched Plenum, XFI268HR13 cam, 1.6 rockers and eventually a custom chip to go along with the rest of my mods. Should be a pretty stout motor.
I deceided to get rid of the TPI system all together. Which parts are listed on ebay, so if you want or need any TPI pieces here's your chance. I'm going with a air gap intake, street avenger 670, MSD HEI, and Comp solid lift camshaft.
