Another car seems down on power thread
 

Ok so my car seems down on power.

I just got it put back together and it has the same, I just rev without making power above 4500 or so. I had figured it was the opti, but a new one is in place and the same thing. Tired valve springs, well replaced those too, stamped steel rockers well those are roller now. When I 1st put my car back together 2 years and 5k miles ago it ran very, very well. I added exhaust and that seemed to choke it a little but not that bad. Then I added ZR1’s and nittos and the car could only manage 102 traps down from 106-107 with full exhaust in the same air???. But it had been losing steam before that. I changed the wires and plugs 106’s to 104’s added an Acell 300+ and still no resolve. Hence why I tore it back apart and changed some stuff to no avail. Did a compression check: looked better then I would expect from a 120k short block. I mean the car would spin new GSC’s from a roll, through 2nd (auto). Now I can’t get a squeak out of cold nittos. I know my converter is stock, but I don’t feel that is the whole problem.

Set up
Stock heads, 218/224ex, stock tb, 1.52 pro mags, csr pump and double roller, cai, Edelbrock shorties, cat co 3 inch cat (less then 500 miles), flow master single 3 in and out, 3.42’s out back and a Madz28 tune. Have two chips one for emissions and for not. ( been running the emissions tune)

I am running 24lb injectors, a newer regulator and adjustable hat, and a stock fuel pump w/ about 50k and 5 years on it with a new fuel filter. But all of this has been sitting for a while. The car seemed to run better with lots of fuel pressure 53 psi or so, but then idle quality was bad at best. I am suspecting a lazy fuel pump, but haven’t been able to get to a dyno or a long enough gauge to see in car while driving. What should the dip be in pressure at WOT, its set at 43 now.

Sorry for the length, but I had nothing better to do at work :D

Re: Another car seems down on power thread
 

Do you have the stock cat still on the car?

I would guess clogged cat or else check the compression ratio.

Re: Another car seems down on power thread
 

Nope its a Catco and its new, also checked the compression within 5%

Re: Another car seems down on power thread
 

There should be NO dip at WOT.
It likes fuel pressure probably because the injectors are to small to make the HP it is capable of.

Get a tune and that will solve your FP issues at idle and ya can set the pulse width for upper RPM'S and probably drop the FP.