Hey guys,
I have a few options to swap out my engine for some more cubes. This way I have a better platform to start on. My 327 is officially maxed out. Anyway, a nice 60,000 mile TPI w/ SLP runners, some aftermarket plenum(can't tell), etc. (the works on the intake). It runs hard and is pretty. Out of a 92 25th Anny.
Or a semi-built 330/350 from GM that I can go to town on. I'm excellent at porting/ matching and making the numbers flow. Then just throw a monster carb on it and run her. Question is>>>>>>(and try to leave the bias behind) Is a TPI all it's cracked up to be in the HP department when on the same motor you swap an intake and carb on it??
And......how much HP would you estimate the 60,000 mile, never beat on TPI putting out?
Thanks

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Alex (AKA chevyboy) '91 RS 327 stroker, trans-go shift kit>> manual valve body, cat-delete, MSD (ignition, coil, 2-step, timing retard/ advance),Flowmaster, complete Edelbrock suspension including shocks, struts and lowering springs. CRAGAR drag wheels. Lowered 2.25" in front and 1.5" in rear....Best E/T 12.84 @109 mph...(got spray?)plus more!!

 

back to the top>>>>>>>maybee someone can answer.

 

Let's try the top of the list again. WOW!!! You guys sure don't know how to make someone feel welcome. *Anyway, I'm sure many don't realize who's come in and out of this board nor realized who or what opportunities they've missed out on.*

 

I know there are more people out there with more knowledge than me but I'll throw my .02 in.
The 92 is a speed density system and the 350's on a dual cat exhaust system were putting out 240 hp. If it has SLP runners then the plenum is stock but he may have modified the plenum for these runners, I don't think you could put a superram plenum on it with them, but I could be wrong. If the intake manifold was ported or an aftermarket one then that is good. With that stuff you could, and I could be wrong, but I would say add 20 - 30 hp.
Now I said the system is a speed density system and although it is better than a MAF system it does not like MAJOR changes to the engine. Such as heads, cam even throttle bodies sometimes. This means you will need a new chip programmed each time you decide to do major changes ($300 or more) or do your own programming. Now some will tell you that you can do cam and head changes without a new chip and I agree you can but to get the BEST performance you need a new chip.
These car have great low end torque but go dead at around 4800rpms cause of air restrictions but porting and a aftermarket intake will let you get above 5000rpms.
Wil these cars get into the 12's in the 1/4 mile? Yes and you could cruise at 150 mph, gets real scary at 135mph! The only problem is parts are more expensive for TPI cars and you need to match up your parts for the best performance.
I LEARNED to like TPI motors and I haven't worked on a carb since the early 80's.
So how much the 60,000 mile, never beat on TPI putting out? Still the same as above 260 - 270 hp with the mods mentioned above.

Good Luck!

 

I dont know if this helps, but my buddy went from carb to to TPI (stock set up) on a GM HO replacement 350 (300 hp) and you could deffinatly feel it pulling harder in the butt dyno. I have heard that the TPI will reach a point where you just can't run enough air for big power. Regardless of tpi or not, fuel injection is more effecient and acurate than carb and therefore will give more power... IMO

 

You said that you want to run faster than before. I see that you ran a 12.8@109 In my opinion, if you want to go a decent amount faster than before, you are going to have to go miniram instead of an aftermarket TPI. If you don't you won't end up being much faster than your 12.8 If you build a 350 with great heads, high revving cam and the miniram intake, high 11's/low 12's would be very possible.

On the other hand going carb would be less expensive and you could probably acheive similar performance to what the miniram would give. It all depend on what you want.

In my opinion I like the miniram better. Just my opinion though.

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Jason D.
92 Z28

 

After building both a TPI engine and a Carbed car, I have to say that the bottom line is dollar per HP. You can make a carb setup function very well for performance and gas mileage. However, injection is king when it comes to the best of both worlds. You will notice that I said injection, not TPI, TPI is a good setup, but will run out of air around 5500 even with most aftermarket setups. It all depends on how radical you want to go and how much you have to spend. As you can see in my sig, I went fast for cheap.

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Black 89 IROC...Mods: 355, 10.5:1 comp, Big Solid Crower Cam, TFS heads, Victor Jr, Holley, and a 5 spd...