Just wondering how much HP guys with stock fuel systems are making? Either TBI or TPI. I am running a TBI pump and lines with my 406....never seems to run too short on fuel....haven't had time to work the bugs out to be for sure.

 

The stock system, both tbi and tpi, is good for around 600hp. On most cars the stock pumps are good for just about anything streetable.

 

The TBI pump will NEVER support 600hp. They will not develope enough pressure for port injection.

At carb fuel pressure levels they are adequate for mild engines. Raise the pressure and they won't be able to keep up.

 

The tbi pump will support 600hp on the tbi setup. Of course it wont work on a system designed to run at over twice the fuel pressure.

 

More pissing in-the-wind contests.

The TBI pump is the same as the TPI pump. The only thing that changes is the pressure, which is done by the FP regulator.

Go to any parts place online and look. The replacement numbers are all the same for both engines.

 

Sorry thats not true. I don't care what aftermarket replacement pumps are listed. The stock pumps are different.

GM lists the 25168719 EP386 for TBI and 25116163 EP241 for TPI.

If what you say is true than none of the TBI folks would have trouble with maintaining 20psi or more.

Try and dead head a stock TBI pump. It won't produce near the pressure a TPI pump will.

 

EP386...... that's the AC Delco that three different places I've seen list for the TPI. Why would they do that if it didn't work with TPI?

 

I won't argue because I am not 100% either way. But I didn't think they were the same pump. I didn't even believe the stock TBI setup has a FP regulator. If it does then it had to be in the TBI unit itself. Not only that, but if you ever turn a TBI pump on not hooked up to anything, there is no 45 pounds of pressure coming out of it. I will have to look at those part numbers. The only way i can see it making 45 pounds is just by constricting the flow. But I don't know if you could do that and still meet fuel demands. Interesting topic.

I also didn't know about 600hp, but I think its possible. Mine is feeding probably close to 500hp. Of course that is not dyno proven power, only what I would estimate.

 

It does have a fuel pressure regulator in the TBI unit, I had the gasket leaking from it.

 

I`ve gone 11.20`s @ 120 with the race wieght at 3850....you need at least 550 at the back tires to do that...so my stock tpi pump, mind you it came with the car in 1985, is feeding the carb just fine apparently

 

TBI and TPI pumps are not the same. Period. TBI pumps support 9 to 12 psi and TPI pumps push 40+. They are however interchangable. That is why you may see the same part numbers for them. However, you cannot use a TBI pump with TPI but you can use a TPI pump with TBI. TBI pumps can support gobs of power on carb set-ups (low PSI) but can barely supply enough pressure on a 200hp TBI set-up (medium pressure). TPI injectors won't even work with a TBI pump. If you have a modded TBI set-up the fuel pump is one of the first things to be changed or you will never meet the pressure demands at high rpm's and engine load.

So cliff notes.

TBI pumps are not the same as TPI pumps
TBI pumps can support high HP carb set-ups
TBI pumps cannot support high HP TBI set-ups
TPI pumps can be used with TBI set-ups and are needed (or equvalent pump, ie Walbro/Holley) with heads and cammed set-ups.
A TBI regulator will keep the pressure right where it needs to be and send the rest down that amazing thing called a return line when multi port fuel pumps are used.

 

:werd:

 

Ive got a proven 422 bhp with Holley Stealth Ram and my standard TPI pump doesnt seem to have a problem.I do have a new Walbro one though,ready to fit should there be a problem

cheers
PM