I have been away from 3rd gens since Novemeber of 1999. My car was totalled and I proceeded to get a 1969 Firebird 400 (which is now for sale) Anyways...I had an 1988 IROC 305 TPI w/ 700R4 with full exhaust, K&N filters, full accel igntion and 3.55 gears. The question I want to present is that of a cam for the 350 TPI ws relatively small. I know the engineers at Chevy made the 350 TPI cam on the mild side (1990 IROC 350 TPI 202/207 .413/.428) and that the intake was the major restriction in making lots of HP. I know the TPI ran out of steam at around 4400 RPM or so but it made gobs of low end torque. Being an engineering major I sometimes look at things and how to make them better. If an SLP cam (51002) 206/214 .470/.490 and aftermarket runners and intake base with ported plenum and modified chip could this engine theoretically make close to 300 HP and over 350 ftlbs of torque through the stock exhaust manifolds, dual cats, and exhaust? I know that when duration increases in camshafts the powerband moves along with it but the TPI suffers up high. My theory is as follows: Since the TPI suffers up high why change the duration of the cam and increase lift where the TPI will suffer. Why not keep the duration low to keep the torque but open the valves FARTHER to make power. To me it seems this could help people keep the low end grunt the TPI is famous for and also get some much needed gusto all the way to redline. To me if my theory is true, this "new" 350 TPI could maybe run with the LT1 and not be far from the LS1. I know I may be talking out of my @$$ but I just thought I would share my thoughts.

 

Actually that is a very good idea, but it has been done. The LT1 and LT4 are pretty much what you just said, they have higher lift and a mild duration(.470-.480s, 205/207,203/210), making a decent amount of power with good driveability. Im not too sure about the LS1, which I believe moved the powerband up significantly(and is much faster).

Now, get rid of the restrictions of the stock tpi setup on any 350 with a decent cam and you will outrun any stock LT1.

I think that these cams are perfect for a daily driven 305, while a 350 needs to breathe better than the stock intake can allow. This means that a more aggressive cam could show more improvements with a better flowing tpi setup.

One more thing...with decent parts I think the torque and horsepower numbers should be much higher. I could see a 350 with a tpi setup, a mild cam, decent exhaust and heads making 350hp and 380ft/lbs at the flywheel. That would be more than the LT1, but still less than the LS1. I say that using my car as an example, Im running with LT1s with 45 less cubes using the LT4 stock cam and 1.6rrs. However, I would like to switch to a higher duration cam later on to compare.

[This message has been edited by rezinn (edited November 15, 2001).]

 

Well, my car is set up similar to what you said. I do have stock heads and exhaust manifolds with a better intake. If I have my car done by this weekend (Blew a head gasket) I plan on going to the strip to see what I run. So I guess I can kind of put your theory to the test, through me.

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88 Formula 350
Upper and Lower SuperRam, 1000 CFM Accel Throttle Body, ZZ4 cam, 24# Motorsport Injectors, Larger Gutted Mass Sensor, Homemade Cold Air induction, Custom Burned PROM, MSD 6a box, MSD Distributor, Accel SuperCoil, Taylor 8mm wires, TB Bypass, B&M shift Kit, 160* Thermostat, Flowmaster Muffler,

 

How much for the firebird?

-- Joe

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1989 Formula 350 4-bolt mains, Forged .030 TRW pistons, SLP 51010 Roller Cam, Comp-cams roller lifters, Summit 1.5 roller rockers, World Products Sportsman II
2.02/1.60 heads, Edelbrock TPI Intake, Cloyes Double Roller, timing chain, Mellings oil pump: 13.5 @ 100.23 MPH

Since close of track : Ported SLP runners, Ported Plenum, AFPR, Autometer 100lbs gauge, A/F ratio gauge.

http://www.joesperformance.com

-- Joe

 

The car is 7500/obo. I have made a webpage with some pictures. http://albums.photopoint.com/j/Album...1809&f=0&vt=vp

If you have any questions please e-mail me at cakes12@hotmail.com
Thanks for your time Brian