I am building a 92 350 with tuned port injection, my questions are that I want to run a good set of aluminum heads. I was thinking about the aluminum fast burn set. What is the best TPI runners to use? What is the best TPI intake to use? I am going to send the throttle body off and have it bored and polished. Would it be better to just buy an aftermarket one? Which brand? The camshaft will be changed to a comp cams, just don't know what size yet. I want to get 400 to 450 HP out of the engine. I also want to be able to get in the car and drive it 200 miles without worry of breaking down. This is my first TPI build and am I just dreaming? I might be cause I want to build this 92 camaro to outrun the new 2010 ss camaro. I know that I have a weight advantage already, but I can never have too much HP.

 

The TPIS runners and Bigmouth intake are the best flowing TPI set-up according to this dyno test. However, the FIRST tpi set up is said to flow the most but was not tested here.
http://compcams.com/Community/Articl...?ID=1737510521

 

the FIRST is also a completely new setup using none of your original parts IIRC

 

Sounds like a fun build. I am doing something very similar with my 92.

I haven't heard of people porting their throttle body. I do know that a 52mm throttle body will be plenty for a strong 350 engine. TPIS has them for $280 so I guess it depends on what a shop can do and for how much.

TPIS large tube runners and base are good and flow well out of the box. Other manifolds will need to be ported or extruned honed to flow on par with TPIS. Some people like the AS&M siamesed runners since it raises the rpm power band up some and you can modify them with more siamesing.

FIRST is the best flowing TPI system out of the box (around 300cfm). It includes new throttle body, plenum, tube runners, manifold and fuel rails. If you buy one, you will need different EGR valve than stock (if want to keep egr) and fuel pressure regulator (which you will want anyways). We actually have a group purchase going one where you can purchase a FIRST intake for $875. Seems expensive but compared to a full TPIS system at $1,180 it is a bargain. Check it out here https://www.thirdgen.org/forums/grou...ction-tpi.html. Either will work fine but I like idea of not having to port parts after spending that much money.

As you can see from the above comp cam article, large TPI systems can make lots of power on a 383. I believe the TPIS system made 460hp and 534ftlbs. Low 400's for HP is doable on a 350 with TPI system and good heads.

Fast burns are great heads but they are pricey and for not much more you can get a pair of AFR 180's or 195's. I like AFR more since they have great exhaust flow numbers which result in good exhaust/intake ratios. Either is fine though. Comp cam XFI268 / XFI280 or similar seem to work really well with a strong 350 TPI setup. You can search for XFI268 on this site as there are a few good posts about it.

Engine build will still be a good cruiser. Just need to tune computer no matter which intake you get. You may want to get a milder cam like XFI268 or less if driveability is a major concern. You'll reach a point with aggressive cams that while generating max power, will be hard to tune and vacuum pressure may get too low. People tend to go overboard on cam size.

Oh and if you didn't know this, with that much power you will need to upgrade transmission and upgrade or replace rear end depending on driving goals. Sighh, more money to be spent but car will be a beast.

 

That was some good information. On the build of the 383, why wouldn't anyone just use a 400 sbc? With those blocks, I have heard that you can stroke them to a 427. I don't think that I will go the route on having my throttle body ported. I found one on ebay that claims to be 58 mm and flow 1000 cfm. Would that be good enough for a 400 sbc? I don't know if I can believe that about the 1000 cfm.

 

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That is incorrect.

Stock TPI parts are rather long if you take the time to measure them. If you notice TPI parts are sold in a number of different configurations...semi siamesed (AS&M and SLP), LTR, and Superrams for example...usually the larger the tube the shorter the tube, by about 1". Also, alot of the aftermarket bases are short by about 1" compared to stock.

What does this mean? Runner length is important in a tuned port because it MUST MATCH the intake's cross section to remain tuned. The intake's length and cross section MUST match the engine size and peak torque RPM. In other words, it can be done but it's CRITICAL that it be a well rounded, well planned and well prepared package.
This is where most people mess up; they use someone else's ported stuff...hog it out... mismatch and loose the tuning effect...You CANNOT just hog out a TPI intake expecting optimum results because you were looking for cfm when you should have been looking for efficiency. Do not use shorter runners unless you plan on moving your torque peak up a 200-500 RPM. If you shift your torque peak up, your cross section for that engine (runner ID) must match as well and be consistant through the entire length of the intake runner. There are mathematical formula's online to help people looking to properly port a TPI intake (or any intake for that matter)

 

There are two top dog TPI aces on this board that put together an excellent 'sticky' just up at the top of this TPI tech board. Scroll up and look at what Kevin and Doc have done, have dyno'ed, and have documented for TPI air flow.
It takes a whole lot of extra cash to get the TPI system upgraded enough to support a 383. Some of us who live in SMOG dictatorship states such as California are limited to what we can legally do. The best bang for the buck is most likely an LS transplant with a Paxton.
TPI intake's require thousands upon thousands of dollars to support the big block power numbers you suggested you'd like to aim for. There's always the person who has access to the machine shop, the free set of AFR heads, and the 'alleged' dyno numbers that somehow never seem to get posted.

I'm sure I'll get mightilly flogged here for this post, but all kinds of people seem to be able to pull those kinds of numbers on paper, but read the article thread by some that have actually done it. Bring a calculator.

Don't get me wrong; I'm not trying to rain on your parade. I've got thousands tied up in mine and I still have to learn how to tune it! I don't want anything under the hood other than the TPI system, but it's been a steep learning curve and the car has been parked a lot waiting for me and my wallet to catch up!!

What did you think of the http://compcams.com/Community/Articl...?ID=1737510521 article? What they don't really talk about is that the factory TPI system was never meant to support anything bigger than the 305 engine, that's why it starts running out of air and power just after 5000rpm.

There's a gentleman on this TPI board (Michael) who occasionally builds and sells extra large TPI air lids. I've purchased one of those, and added the RAM AIR scoops that were designed by another board member. We have another 3rd gen member 'DOC' who designed a Mega MAF that's over 3 inches and can be used as a condom in an emergency situation. The whole trick with TPI, as you're probably more than well aware of, is the importance of air velocity speed. This is why we get that massive Torque reading instead of Horsepower. Go to to big of an Intake Valve (or using something bigger than let's say an AFR 190 head) and all that air speed stutters and stumbles. It's like having a girlfriend that just lays there every time; it's an okay experience, but you just don't know what you're missing.

Does that help?? Good Luck, Nitro-Nicky

 

Best TPI runner and base combination depends on vehicle application.

 

I will reccommend the SLP runners and be sure to open up the upper plenum remove casting flash/blend and smooth all bumps. We had excellent luck with this back in the early 90s when there was a VERY limited supply of aftermarkt support!

I also suggest to get those stock cast iron heads off of that motor they do not flow for crap even ported( some will argure) but not worth the expense get some L98 vette heads or some TFS heads and a stealthram or super ram along with 1.6 rockers and of course headers

 

Dont do anything before you check out this thread.

https://www.thirdgen.org/forums/engi...ml#post4599018

 

i have the first..... nice system.... fells great... when i break in my engine im gonna go for a dyno pull

 

What did you have to do for your PROM and programming etc when adding the FIRST?

 

nothin yet cause i installed the FIRST with a new motor.. i wanna break it in the first 500-1000 miles before i tune it....




hell i still have to weld a bung for the o2....

i have a wierd setup i guess..... i added long tubes.. FIRST.. iron vortec heads.

after the tune i wanna go to a dyno... and cry....

 

So you are going to run your engine for 1000 miles with the wrong spark and fuel settings .........?
One way to ruin a new engine