Blackdog36

iTrader: (3)

Yes, you read the title correctly. I recently went through the mental thought process and didn't find many discussions in favor of a 383 TPI build so I wanted to share my thoughts. My reasoning which I'll explain below is that my TPI combo will be a very well matched, make more torque and horsepower at a more streetable rpm range, better suited to my intended driving style and be very strong in the 1/8 and the 1/4 mile. The TPI build will also be a little more unique and fitting to my cars history. Although I understand why a lot of people swap in LS engines, they are becoming very common.


Since I first bought my Camaro over five years ago, I loved the TPI intake and wanted to build up my engine with it. Soon I purchased a FIRST TPI intake and had plans of a 350 build. The build then escalated into a strong 383 TPI build. For this I am storing the stock drive train and installing new aftermarket parts. The thought of doing a LS swap never fully crossed my mind until recently. I decided to look into the swap since I am getting to point of buying many 383 build specific parts. There is a local LS part out shop so I inquired with them what a LS3 pullout would cost. In comparing the 383 TPI build versus LS3 swap, the LS3 swap was $1,300 more. My interest really peaked in the LS3 swap since they make high horsepower numbers with just a cam upgrade, tune ability and ease of maintenance.


I knew performance wise what my 383 build would do by looking at similar dynos especially the “Ten Times Torque” article where Super Rod magazine dyno compared ten TPI intakes on a 383 engine. From the article, the TPIS extruded honed system produce over 450 ft-lbs of torque over a 2,500 rpm range. I believe a FIRST TPI 383 build is closest to this intake and would produce the same if not a little higher numbers do to its larger flow capacity (280-300 cfm) and shorter runner length (21.5 inch overall with cylinder head). From a harmonic calculation, FIRST peak torque would come in around 4,400 rpm versus 3,900 rpm of the TPIS system. I transposed the TPIS system dyno numbers into excel, moved the numbers up so they peaked at 4,400 rpm and bumped the numbers up 2.5% to account for extra flow from the FIRST TPI build. The resulting numbers are shown in blue on the attached graph.


For the LS3 build, I found an engine dyno article at Engine Labs that compared three different cams on a stock LS3 engine. I chose dyno results from the second cam since it produced good gains and did not get into gray area of piston to valve clearance with the third and most aggressive cam tested. Dyno results are shown in green on the attached graph.


The results are what you would expect from each engine. The LS3 build makes a peak of 530 hp at 6,500 rpm and more than 450 ft-lbs of torque from 4,100 to 6,100 rpm or over a 2,000 rpm range. The horsepower curve is similar between both until 4,800 rpm where the LS3 engine takes over. Conversely, the TPI build has a tremendous torque advantage from 2,900 rpm to 5,300 rpm or a 2,400 rpm range. I realize that both engine dyno articles were done under optimal conditions, i.e. on an engine dyno with an electric water pump. This will yield great numbers that will not be realized once they are setup in a car. However, the differences in where power is made and by what magnitude would still be the same between each setup. Overall the dynos and chart help me compare each engine type and make a decision.


Okay now for me to explain several of my arguments made at beginning of this post.


Point 1 – TPI combo will be a very well matched system


I will be building a 383 four bolt block with AFR 195 heads, Comp Cam XFI 280 or similar and slightly ported FIRST TPI intake. This will allow me to maximize power from the 3rd wave harmonic at 4,400 rpm. Horsepower will peak around 5,300-5,500 rpm. The resulting torque boost will be significant.


Point 2 – TPI build will have more power


As noted previously, the TPI build will make more torque over a larger rpm range and slightly more horsepower in the mid rpm range. I know that the LS3 build makes more horsepower overall in the upper rpm range but that is not everything as I will explain further below.


Point 3 – TPI build will have better more streetable rpm range
Both builds start out at the same horsepower and torque levels around 2,750 rpm. However the TP I build will make more of each (especially torque) up to 5,300 rpm. This will make a TPI car more fun to drive around the streets without having to wind the engine up very high every time along with less stall and gearing required. The TPI engine will also experience less wear and tear. Yes I know LS engines can take high rpm's : )


Point 4 – TPI build will be better suited to my driving style


I like mashing the throttle from a standstill or slow roll and having all hell break loose. The TPI build will provide me with constant enjoyment on the streets where most of my driving will be.


Point 5 – TPI build will be capable in both 1/8 and 1/4 drag strip


I will be purchasing an upgraded 4L60E transmission to work with my Strange S60 rear end. The S60 has a 3.73 gear which will have me passing end of the 1/4 mile at around 5,400 rpm. This is right around peak estimated power level. Also, this paring or rear end gear with transmission gearing will have my shift points at very good locations within the TPI power band. From an online calculator, I determined that my shift points will be at the following rpm's: 1-2 = 2,900 rpm, 2-3 = 3,300 rpm, 3-4 = 3,800 rpm. Also, I would be crossing end of 1/4 mile near my max mile per hour of around 112. Engine power along transmission and rear end gearing would work very well. I figure I could do mid to high elevens in the 1/4 and high sevens in the 1/8.


There is a 1/8 mile drag strip half hour from me that I would go to the most, maybe ten times a year. The 1/4 mile drag strip is an hour away and I would only go there few times a year. So most of my strip time would be at the shorter track where the TPI build would be more competitive.


I know that the LS3 build would trap higher miles per hour due to more horsepower but doesn't mean that it would be quick time wise or as consistent versus the TPI build. I think the TPI build will surprise a lot of people and be able to hit steady times.


Either build will still offer plenty of performance. Overall I know that the TPI build is better for my goals and will make me satisfied once finished.

TTOP350

iTrader: (8)

I like a lot of your points, however, I think the S60 may be overkill for this build

Blackdog36

iTrader: (3)

Yes it is but I got it for $2,350 delivered with S-trac differential from Carl at Central Racing Parts : ) Great price versus what other swap in rear ends would have cost.

Blackdog36

iTrader: (3)

Forgot to upload graph comparison.

PAFORM350

This is a great thread. I will be following closely. I too thought about swapping the TPI our for something LS and just like you said "it is getting common" not trying to knock the LS crowd but if it came with a TPI why not leave it right? My engine developed a knock. So I purchased a 1991 Corvette engine with 40 something thousand miles on it. Engine is perfect as one would expect from such a low mileage piece. I'm just contemplating what to due with it before I install it. Cam, head work, intake. I'll probably wait and see how your build goes.

Mongoose

iTrader: (2)

Subscribed

ezobens

Always interested in sharing and comparing information with others planning to use a FIRST TPI on a big inch SBC.

Subscribed!

MMroc86

Great thread. Im going with a similar build for the same reasons.

https://www.thirdgen.org/forums/engi...rst-t-p-i.html

I'm working on purchasing our first home right now so its all on hold, but should be moving along again in a few months. Im gonna keep an eye on this thread.

Blackdog36

iTrader: (3)

I'll make a separate post on my engine build. My build is going to be almost the same as what gbayfisher did a few years ago. He has a nice long post about it. There is a member named TA on corvette forum that is running really good times on a modified 383 TPI. See his stats in this post. I came across a post of his detailing his upgrade journey and track performance, just can't find it now. I just want this thread to be a discussion about why a thought out TPI build can still be worthwhile.

I will admit that for any TPI build you still should be upgrading stock components like better flowing runners at a minimum. Yes Stock unit can make decent power as shown in the Super Rod article but if you are going through the effort, small changes can be beneficial.

Also, I am going with a far from stock TPI unit and going all out on my car restoration which is going to cost a lot of $$. Other people may be in different circumstances on what parts they have or what they can readily get a hold of.

Here are some LS counterpoints which are valid.

1) You are spending all that money. Why not get the best engine you can and be able to go faster. Your TPI build will be maxed out when done, no easy way for more power. LS has stronger internals so up the cam or add light boost down the road.

2) I can do LS swap for less money so it will make more sense financially. Junkyard 5.3 turbo or LQ stroker swap.

3) Tuning is so much easier with LS, everyone knows how to do it. You will have to find someone to tune your car or learn it. This will take time and you may never get it 100% correct.

Orr89RocZ

iTrader: (20)

Becareful. Alot think they can tune them. Some arent so good

Javier87z28

iTrader: (1)

Subscribed!!

dabomb6608

iTrader: (3)

Looks like a good plan! I love my FIRST on my 406!

Orr89RocZ

iTrader: (20)

Any dyno or track times?

dabomb6608

iTrader: (3)

Unfortunately no, took it once to the track and found out real quick the stock clutch didn't have the guts to hold. I was trying to keep the T5 together by slipping a little off the line. It was getting weak anyways so I wasn't expecting anything more.


Installing the TKO 600 I just got sometime in the next month or so. Already have a new Spec 3+ Clutch that I installed after that track trip. Will be taking a trip to the dyno and track late spring/early summer.

TTOP350

iTrader: (8)

Would love to see the dyno numbers on that 406 with the 1st on it..

seiplentz

iTrader: (2)

Good luck on your build. I considered an LS as well and I am going with a 383 and xfi 280 cam as well!! But I have a HSR that will allow it to pull harder up top.

antman89iroc

I built a 414 SBC. I already had a HSR intake and TKO trans. I am very happy (usually) with how it runs but I can't help feeling at times like I should have gone LS. I thought I was saving some $$. But in the end I had to change a lot more than I originally anticipated. Injectors, throttle body, fuel pump, computer system, complete exhaust, cooling etc. There are still other things like rear end that will eventually need to be upgraded. Now there is a valid point about not doing what everyone else is doing and our cars did come with SBC's so it's a natural fit. But there is still a part of me that thinks I would have been better with the more modern technology. Also, my combo wouldn't pass any type of emission testing, which for now isn't a problem since my state doesn't test. But someday I may need it and an LS can make the power and still retain emissions.
When it comes to burning rubber, there's more than enough torque for it. I don't think you'll have any problems. And your combo's target range is better for the street. The reality is my big CI motor can likely make 500HP but spends most of the time in the 2-3500 RPM range.
And black dog's point about tuning is correct. I have not found anyone who can tune the original computer. I had upgraded my stock computer and have been tuning it for a few years before building this motor. Since I have gone with the EBL flash and recommend that approach. Still, the local dyno shop who is a "local legend" for tuning LS's will only rent dyno time to me and "help" but just looked confused when I told them what ECM I'm running. And kinda giggled when I mentioned something about swapping chips- like I was running 3 strombergs and lake pipes!

Street Lethal

iTrader: (16)

I would like to see dyno numbers too. Considering a similar build...

Z28FAST1

Seems like you've done some research and ready to drop a good amount of $$$$.

IMO and experience, a max effort 383 TPI doesn't hold a candle to a cam-only LS3.

http://ls1tech.com/forums/dynamomete...24-timing.html

**This is to the wheels.


Only argument I understand about sticking with TPI is for nostalgic reasons. Performance wise its hard to beat technology. Either way its your money. As long as you have fun with it.

antman89iroc

This makes my point exactly. While my combo is still very streetable it has taken over 6 month to get it close. Now I'm ready for some warmer weather so I can finish the tune. If it weren't for the people on this forum helping me out I don't know where I'd be. And still not making the power of an LS.
There's another wrinkle, my combo is well, my combo. If anyone ever had to work on my car without my input they would be lost. Various year part systems- mix matched components and a basically unknown ECM system. An LS swap is going to look familiar to anyone not in love with the 80's.

Street Lethal

iTrader: (16)

You call a stock LS3 and a custom cam with lobes spec'd by Patrick G technology? You do realize that there are prehistoric carbed 383's with heads and cam turning the same RPM and making more power than that out there, right? You may have a point about TPI being a deterrent, but I wouldn't classify that cam only LS3 as great technology...

Z28FAST1

Compared to a max effort 383 TPI yes. 383 will needs aftermarket block, aftermarket heads, aftermarket intake(upper and lower), aftermarket valve-train(roller rocker/hydraulic lifters/chain), aftermarket oiling, aftermarket pan, etc etc.

LS3 technology has you covered on all of those upgrades.

Sure I believe you about a 383 carb set-up but then you're giving up throttle response, fuel econ, cold-starts, ease of tune-ability etc. etc.

Funny tech scares some people, look at the C7Z and all the hate from prior generation vette owners.

PAFORM350

Stay with the TPI and never give it a second thought. There are a ton of other swaps and engines you could choose. I personally love the fact that when all is said and done my car will have the engine design it was born with a TPI. I guess all that really matters is that YOU will be satisfied with YOUR car, the way you wanted it I applaud you

Street Lethal

iTrader: (16)

Tech scares some people? I've owned countless LSX cars including a ZO6, as well as a Nissan GTR, and the only thing the last two did differently were wreak havoc on my wallet. I am very familiar with the LSX. I am down to two projects now, a GTA w/TPI, and a C4 vette with LT1, and although considered old tech, they get the job done either way. I will give props to that LS3, but GM chose to hold back from giving the 3rd gen any real power, and it wasn't due to lack of technology, just poor decision making. You can't compare an engine that breathed very well from the factory with one that didn't. With all things being fair and equal, there is no real gain that I can see. In respect to the supercharged ZO6, one could order a Camaro from the factory through Motion back in the day and run 11's guaranteed, stock. Had Motion slapped a roots blower on it from the factory, and we're talking easy tens, maybe even nines from the factory. Chevy chose not to up until the last decade, big difference.

antman89iroc

I have no problem with the decision to build SBC. The only issue with the 3rdgen is the tuning. Carb and dizzy is a different kind of tuning. I don't regret building an EFI small block but you do leave a little on the table for the level of modification for each design. I do feel that a LS3 with only a cam change and the required ECM is light years ahead of what gm put in our cars. Comparing it to a dart block, afr head, aftermarket everything EBL controlled small block the gap gets narrower but still behind. The only part of my engine that is gm is the accessory brackets and starter bolts. Everything from the intake to the oil pan, water pump to the clutch is aftermarket. That's what it took for me to make a powerful very streetable engine that compares to a cammed LS.

Street Lethal

iTrader: (16)

Antman, General Motors made very poor decisions. They should have never of stopped making Pontiac engines for one, as the Pontiac 400 should have graced the GTA, but with fuel injection. They also should have graced the Iroc-Z with high revving engines like the DZ302, but also with fuel injection. They had the means, just not the common sense, as their focus was only on cost savings. The LT5 was already in development in 1985, and yet some 3rd gens were still getting 4 cylinder Iron Duke engines. GM has had a very strong racing background, they knew what they were doing when they under powered those ridiculous LG4/L69/LB9/L98 engines, one only need to look at the cam specs they chose, as well as runner diameter, and cylinder head flow. It's not that they didn't have the tech, they detuned them deliberately...

Edit: Will give you an example of GM's poor decision making. In 84-86, the V8 in the Corvette came with iron heads with 2.02"/1.60" valves with 76cc, although the actual flow was down because of poor porting (624 heads). In '86 they then changed over to an aluminum 1.94"/1.50" cylinder head, two different versions of them (128 & 113 heads), both with cc in the 58-64 range. Perhaps if GM combined the two, and went with aluminum 2.02"/1.60" valves with 58cc from the getgo, and perhaps went with more lift in the cam (LS3 comes with 204/211 551"/525" @ 117 LSA, compared to the L98's 207/213 415"/430" @ 117 LSA), not to mention larger TPI runners instead of essentially choking the engine up top, you would see what I mean...

Orr89RocZ

iTrader: (20)

Ls3 is best bang for buck. Doin a lq4-9 shortblock with ls3/l92 top end is verrry popular and dirt cheap. 450-500 whp depending on transmission

Most sbc builds are with automatic trans. Vettes with manuals have much lower drivetrain loss so always dyno pretty well.

383 can make the power as a cam only Ls3 but its gonna take more money as u need big heads and bigger cam to turn tad more rpm to get the power

Street Lethal

iTrader: (16)

LS3 also comes with 10.7:1 compression from the factory, that is over one full compression point compared to an L98, which is an automatic 4.5% increase in horsepower with both engines being identical everywhere else. Now, add the larger displacement factor over the L98, the tremendous increase in stock cylinder head and cam specs, better flowing intake and throttle body, and it's an obvious it will make more power in every area. Perhaps it is the best bang for the buck, but nothing new in terms of technology, it's still; air, fuel and spark...

Orr89RocZ

iTrader: (20)

By tech it has a more complex efi system than old sbc efi. That can be overcome by upgrades but does cost more

Lsx has 15 deg heads from old racing technology but shrunk down port size to make them streetable. Port shape itself is improved to get flow while keeping emissions and driveability

They has shaft rockers for superior valvetrain and larger cam core for better stability.

Just improved old tech applied inthe right areas
Only real tech thats new is variable valve timing. But not many seem to run bigger vvt cams. They saythe lifters are weak

antman89iroc

I agree with most everything you said. Especially about the Pontiac 400- I would have loved to see the EFI version of that engine. The "homogenization" of the GM products was the beginning of the end for the BOP lines. It made brand/model differences basically just options. Even though the Buick badge has survived (for now) it's basically just GM's answer to filling the nitch between Chevy and Cadillac.
But keeping it all in a time perspective, we were just reeling from the late 70's power plants. I think the first car I saw with a "HO" badge on it after 1975 was the Citation X11 lol. Do you remember how excited we were when a Holley carburetor reappeared on the Mustangs? The fact that we were getting anything that resembled performance was better and the mfgs took advantage of it to get their bottom lines back. While they have always had technology held back I don't think they had figured out how to merge performance with the emission requirements in a cost effective manor. I feel the LS was the first (GM anyway) time an engine was designed with emissions in mind. And computer technology was a factor too.

But I digress and apologize to the OP about jacking this thread. It's more about HIS decision than what we think about it lol. I look forward to hearing how it turns out.

ezobens

It seems we are getting a bit off topic here-
This is not an LS vs SBC discussion, this is a SBC / TPI discussion.

I think most of us can agree that the LS motor is far more advanced than the old SBC but that's not the topic of discussion.
It's also easy to dismiss GM as making "poor decisions" sitting here 30 years in the future- Unless you were working for one of the big 3 during that time, you have no concept of what was involved.
Yes, the bottom line was always (and still is) the determining factor but you have to also look at the technology available 30 years ago. Fuel economy and emissions were the battle cry of the day and is largely responsible for the "poor decisions" made and the low horsepower (compared to today's standards).

The demise of the Pontiac V-8? GM was no longer able to get the design to pass ever tightening emission standards for a reasonable investment based on units produced.
That is also why the Olds V-8 stuck around as long as it did- It was much easier to meet emissions requirements for the time.

Even foreign manufacturers had a tough time in the 80's and 90's.
I have an 86' Mercedes 560SEC, which was their flagship coupe of the time and listed for well over 60K (in 1986!!). Peak HP from that 5.6, all aluminum, OHC, fuel injected V-8?
248 HP in US emissions trim, 300 in Euro trim. Doesn't make the old L98 seem all that bad now does it?

Making a V-8 produce 500 HP is the easy part (relatively speaking) and anyone with a few bucks, minimal technical skills and a basic Craftsman tool kit can do it in their driveway by just buying bits from a catalog.
OEM manufacturers on the other hand have to adhere to standards beyond belief from a safety, durability, economy and emissions standpoint where as the aftermarket is more or less free to do and sell whatever they want no matter what a POS it may be because their only standards are self imposed (unless you are talking safety related equipment required by specific racing sanctions and organizations).

Would I have loved to see the Pontiac V-8 live on? Hell yes, but that's besides the point.
GM is in the business to make money and it can't if it loses it's *** building cars that comprise of less than 10% of their total sales. The C7 would not exist today if it didn't make money for GM.
Yes, bean counters run the world but is that a surprise?

Street Lethal

iTrader: (16)

It's not really tech though, because an OBD1 will do the same exact thing. If you mean "more refine" compared to a prom based ECU, then that boils down to personal preference, because in the end the fuel is still being consumed through controlled spark and fueling. This is why a carbed 383 with worse heads will make more power, just not as refined. It has nothing to do with 15* cylinder heads, and everything to do with their 2.165" intake valve and better flow heads, which cannot be compared to a 1.94" intake valve and poor flowing cylinder heads. Destroke a 400-SBC down to 377, add a 2.165" valve and port it thoroughly, a custom cam based on RPM range with miniram, and it will annihilate an LS3. Yes, not cost effective because the 400 didn't come that way from the factory, but it's all relative. All; air, fuel and spark...

Street Lethal

iTrader: (16)

.... lol, go back to sleep. GM did that to save cost, thus why the Pontiac and Oldsmobile brand themselves are both now gone. What they tell the public is very different than the decisions being made in house. You wanna play, you gotta pay, and they knew what was coming from the other foreign manufacturers abroad. Emissions standards have to do with combustion control, not engine size, nor engine design. Every choice they ever made was to reduce cost, and increase profits. Its a business.

anesthes

iTrader: (12)

Since this is a TPI thread, and it's starting to go full-retard, I'm moving it to the TPI forum for another moderator to deal with.

-- Joe

antman89iroc

Guilty. Sorry balckdog, I didn't mean to get so far off topic. Rather, share my experience with my SBC build and thoughts on the LS. Using it as a comparison in performance and what I had to do to get there. Why, technology and what GM had for breakfast when they designed the L98 or LS engines doesn't really matter.
My combo with 414CI, HSR intake I chose a 236/242 (@0.050) cam on 112 LSA. If I had it to do over again I would likely close that LSA up to 108-110 and maybe even a little less duration. So, if I were building a 383 I would probably use AFR 195 comp ports and a 230/236 cam on 110. The reality is my street motor "runs" at around 2000-3000RPM for 80% of the time and the long duration cam with wide centers takes a bit of the efficiency away at that range. While CI gobbles up cams it is still good practice to chose cams based on where it usually operates rather than strip times or dyno #'s.
I would defer to First TPI builders experience too since mine is with HSR.

Mongoose

iTrader: (2)

As far as the subject of tuning what about the EFI Connection 0411 conversion for the SBC engines? Would that not be a viable solution albeit a more expensive one?

Orr89RocZ

iTrader: (20)

Thats what i run and it works well. Allows modern hp tuner guys to work with oldschool motors



Tpi seems to be only worth while when using first tpi parts.

I got a bone stock 305 car that all i want is to upgrade the runners so i can pull 500 more rpm and everyone wants an arm and my two legs for them. 450$ for the edelbrocks now. Slp siamesed on ebay bring 400+.
Base is 400+ now. Entire first tpi with throttle body is 995. And its bigger and flows more. Cant beat it

antman89iroc

Did it allow you to run COP? I have been going through a discussion about ignitions systems and COP solves a lot of those problems. Not to get off topic but in regard to OP's build. If I had it to do over I would be very tempted to go this route. One of the "pluses" to the LS swap is getting an ECM that tuners recognize and this would be a good compromise. The computer doesn't know the vintage of the hardware it's controlling. And during the build is the time to make the changes (reluctor, cam sensor, TB etc) for the ECM.

Edit: I'm interchanging COP and CNP and I guess that is incorrect. One coil per cylinder is what I mean.

Blackdog36

iTrader: (3)

I don't dismiss the power and draw of an LS swap. Just in comparing the two different engines for my situation and goals, the FIRST TPI is what I am going with. Like most things, it will come down to financials in comparing two decisions. Will be different per each individuals situation.

I did look into EFI conversion a while back especially since they are located hour and a half from me. The conversion cost would be expensive plus speed density harness requires extra effort. See my post below. Not worth it in the end when you have a great tuning product like EBL P4.

https://www.thirdgen.org/forums/dfi-...24x-420-a.html

Street Lethal

iTrader: (16)

... looking forward to your results with the FIRST system. Just finished swapping engines myself, and I downloaded the LT4 spark table into the EBL-P4 just to see how the new engine likes and responds to it after a few VE learns. I'm not running a FIRST though, but a siamesed Tuned Port Injection system. Am leaning towards a FIRST, but like some of the others in this thread, am very curious to see your results with it beforehand...

Orr89RocZ

iTrader: (20)

Yes i have a coil per cylinder, the ones from the gm trucks. No ignition probs even up to 28 psi so far

ezobens

Perhaps you are the one sleeping?
We're both saying the same thing-

"GM was no longer able to get the design to pass ever tightening emission standards for a reasonable investment based on units produced."
IE cost reduction.

If GM felt they could have made a "killing" in profits by having the Pontiac V-8 pass emissions, they probably would have figured out a way-
But by the 80's no one could afford to certify 400+ cubic inch engines for passenger car use for the couple thousand (maybe) units they would potentially sell so the answer was obvious.
It's the same scenario of why the 450+ cube engines disappeared from car lines in the mid-late 70's.
If you think cubic inches and engine design has nothing to do with emissions produced, than obviously you have no idea what you're talking about.

Street Lethal

iTrader: (16)

Clearly we are not saying the same thing, and you are being absolutely delusional to think that cubic inches effect the amount of emissions in combustion. Perhaps in a poorly tuned engine it will, something you might be familiar with since you got your thumbs up looking for a ride, perhaps? 14.7 or 14.2 is stoich depending on where you obtain your fuel, it is not a setting to make a catalytic converter happy, it is your target for maximum efficiency. More cubes take in more air and thus we supplement with more fuel. By your logic though, if I run 80# injectors in my 383, and tune the duty cycle down to match air intake I will have increased emissions? Give me a break. Widebands don't lie lol. Or perhaps you think a boosted 350 at 15-psi which would equate to a 700 cubic inch engine would have less emissions than a naturally aspirated 454 simply because it is a 350 engine to start with lol? Air is air my friend, we tune fuel and spark to it, nothing more nothing less. An WB O2 reading of 14.7 in a 350 and an O2 reading of 14.7 in a 454 is the same reading, you think an O2 sensor knows that its a big block? O2 sensors measure oxygen, period. The only reason why it is against the law to swap larger engines into vehicles is because of the chassis structure, it is a torque issue, and the engine must come in that vehicle to begin with, or a newer vehicle of its' kind, and must maintain all of the emission "devices", and this is enforced in some states to deter engine swapping...

Buy yourself a clue...

Edit: Incidently, cubic inches doesn't cause increased emissions, overlap does...

ezobens

Wow..
So you think emissions is solely a function of A/F ratio and if you maintain 14.7, the emissions produced are exactly the same regardless of CID and engine design?

You're right.. Clearly, I'm the clueless, delusional one..

Street Lethal

iTrader: (16)

Here's a clue for you, and don't worry, it's on the house. There is a REASON why larger engines will idle SMOOTHER with cams that are too big for a smaller engine. Hmm, would you like to know why that is? Nah, research it on your own. The only thing a larger engine will do is use more fuel to satisfy the more air it is taking in, that is it. The exhaust itself is just as clean as the smaller engine when running the same cam characteristics tailored for its' cubic inch displacement. I'm done with this conversation, believe whatever you want...

anesthes

iTrader: (12)

You will never have any. Those coils have builtin IC's that take care of dwell and batt compensation. It really is a great setup.

-- Joe

anesthes

iTrader: (12)

CAFE requirements are what killed the large displacement engines in the 70s and 80s.

There is a bit more to emissions than just air fuel ratio and camshaft sizing. Biproducts of combusion differ due to port shape and size, velocity, compression ratio, etc. Also, the 70s and early 80s used carbs. The mid and late 80s used primitive ECM's with a single narrowband 02 sensor.

But anyway, by 1980 CAFE standards required passenger CARS to get 20mpg to be sold in the united states. Trucks were 16 for 2 wheel drive, and 14 for 4x4. Larger trucks (over 8500lbs) are exempt, which is why you see your ford 460s and GM 454s in the larger 1 ton trucks.

By 1985, cars were expected to get 27mpg which just wasn't possible with a large displacement engine and the available engine controls/tuning.


Now going back to emissions, this is a bit trickier. You have two types of measurement when it comes to emissions, you have your parts per million. This is where a small and large displacement engine will be the same if tuned properly, and what Rob is trying to say.

However, manufacturers beginning in 1977 were not regulated to parts per million, but rather grams per mile of pollutants. Obviously an engine that was displacing more volume, and expelling a higher volume of exhaust would have more grams of a pollutant than a smaller displacement engine. (even though the ratio of pollutants to air was the same).



-- Joe

antman89iroc

The EBL is a good system. My car is an 89 so I want with the standard Flash. If yours is 90+ the P4 is easier. And since they're both flash systems there's no more swapping chips. May not sound like a big deal but it is. Not to mention the ECM gets to go back in place while tuning. Like I said before I've been tuning this motor for 6 months (be nice don't laugh) and when I started I had the stock ECM with a burner. The EBL is Soooo much better.

dabomb6608

iTrader: (3)

So if running a 3.0L car at 14.2-14.7 AFR puts out x amount of emissions. Then a 6.6L car running at 14.2-14.7 AFR would mean getting the same amount of emissions out the exhaust? Just because they both are running at the same AFR doesn't mean the quantity of emissions is the same. Otherwise we would be running the same size exhaust as a 3.0L.


But we don't we have to have big exhaust because our motors are putting out more air. More air means that we need more fuel to meet that ratio. More fuel means more emissions in that air.


So yeah the percentage of whatever they measure at emission places (don't know never been to one) out the two exhaust pipes in the above examples might be the same. But there would still be more emissions. Its like a 15% of 100 doesn't equal 15% of 1000 kind've situation. 100 being the volume of exhaust coming out the 3.0L engine and 1000 being the 6.6L engine.


I'm not trying to bust your ***** on this or call you out. Just curious if how I view the situation makes any since? Maybe we are just viewing it from different meanings of what we are defining the emissions as...

dabomb6608

iTrader: (3)

Back to the original topic though and bringing in some experience with my setup, I really enjoy the FIRST Intake. It is hard however for me to know how much difference it alone made. Because I went from a 406ci with a "RV" cam/stock 400ci smog heads/stock TPI setup/EBL Flash tune all the way to how it is now 406ci with XFI 280 flat tappet cam/FIRST Intake/Performer RPM heads/EBL Flash. I did all the changes at once...to save down time.