Top end power

[crue98]

On my 94 5.7 I find that the low end power is pretty good. It gets up and goes pretty quick and have quiet a bit of torque. But when it gets aroung 55-60mph it loses the power that it had. I was wondering what I could do to keep the power that I "think" I need. Maybe a different chip or a different cam, or intake. Let me hear some of the things you would suggest or what you know works by experience.

[Charlie in TX]

To get more power at hi rpm you need to free up the intake/ex. Or a 150hp shot of NOS will wake it up.

[crue98]

I thought about looking for a Edelbrock performer intake. I'm looking at all the options. I have also been looking at Vortec heads also so I will have to wait to find out what intake to get. Next month I'm going to the muffler shop and getting the cats off with a set of duals with muffler put on. Would a different cam do much? I saw in JC Whitney that they have Flow Tech headers for $170 or so. But those help low end torque don't they?

[02denali]

well the removal of the cats is going to give some top end. but it is going to kill your low end. unless you are going to put in an x pipe to keep some torque i think you will be dissappointed. i think a cam and iuntake will help out. a stall is going to be needed soon. to. good luck with it.

[crue98]

Thanks for the info. I'll take these into consideratrion. I've heard that the TBI engines need to flow so the high flow duals really help it out. I'll have to ask my muffler guy about the putting a x pipe on.

[357mag]

The stock cam on TBI motors quits breathing at around 4500 rpm. If you want more top end, you MUST change the cam to one with more intake duration and more lift and you should get a better flowing set of heads. If you want to keep decent low-end, keep the duration @.050" under about 212* or so. Don't waste your money on an intake manifold if you aren't changing cam and heads. The only thing you will make faster is getting your wallet out, because you spent all your money for no gain. High flow duals won't do much if you can't get more flow on the intake side. And, don't forget, you'll have to burn a PROM to match the new flow numbers. Adding headers without adding more fuel will cost you power, because you will be running a lean condition at WOT. If not compensated for, you'll end up burning a hole in a piston or two.

[crue98]

The stock cam on TBI motors quits breathing at around 4500 rpm. If you want more top end, you MUST change the cam to one with more intake duration and more lift and you should get a better flowing set of heads. If you want to keep decent low-end, keep the duration @.050" under about 212* or so. Don't waste your money on an intake manifold if you aren't changing cam and heads. The only thing you will make faster is getting your wallet out, because you spent all your money for no gain. High flow duals won't do much if you can't get more flow on the intake side. And, don't forget, you'll have to burn a PROM to match the new flow numbers. Adding headers without adding more fuel will cost you power, because you will be running a lean condition at WOT. If not compensated for, you'll end up burning a hole in a piston or two.

 

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So you're saying to change and the cam and if I get headers to get a different chip to compensate for the change in flow for the engine? Also not get get a different intake b/c it's a waste of money. I know I'm going to get the duals, probably in the next few weeks, then maybe a different chip. I'm just like getting info on different kinds of setups that I'm looking at. I don't really want to through a lot of money into it. I'm just looking for a litlle power

[357mag]

Do a search of CARCRAFT magazine, starting around the April or May issue. They did a bolt-on exercise on a 93 TBI truck. They didn't do any internal engine mods, but they came up with some fairly respectable numbers on the dyno. Also, take a gander at the tech board forums at www.thirdgen.org. There is a plethora of TBI info on that site.

Also, the OBD 1 ECMs are not conducive to step at a time mods. You must program a chip after every major mod. Methinks it would be better to get all your parts together, install them and have a chip burnt for your particular application.

 

Good wrenching,

Tim sends

[crue98]

Thanks man I'll check them out.