Improve top end performance?

[-Jayson-]

well i just started getting into racing this summer when i bought my 2001 Cavalier Z24, i know most you will think its a joke, even more so when i tell you its an auto, bit a for a 20 year old with an OUIL on his liscense it works out alright. Anways heres a slip from my first time ever at a track, i was in my cavalier. It seems to do really well on my 60ft but after that it just seems to slowly die. The car stock is rated at 150HP @ 5,500 RPMS and 155lbs TQ @ 4,400 RPMS. I usually launch around 2k RPMS. Also being i was such a noob, i never adjusted my front air tire pressure to gain traction so i did slip some off the start. IT was also a hot high 80s low 90 degree day. But my main problem is once it gets into 3rd gear at like 70MPH the car just falls on its face. Keep in mind the car is stock right now and when these times were run.

Reaction: .552
60FT: 2.312
330FT: 6.753
1/8th ET: 10.314
1/8th MPH: 68.47
1,000: 13.466
1/4 ET: 16.174
1/4 MPH: 83.63

Im pretty sure with the right tire pressure and cooler day high 15's are well within my reach, but i think the area i need to work on most is my trap speed, what are some of the best ways to gain high end power without losing low end tq?

[JekylandHyde]

Intake and exhaust are always the first steps ...

You may want to read this:
http://www.jekylhyderacing.com/StoryTweakHorsepower.htm

[TechX]

Are you shifting or just leaving it in D? Air flow is very important in the highend. Like said about intake and exhaust.

[-Jayson-]

i have intake, but im skeptical of exhaust, what kinda HP increases could i see with a fulle xhaust setup?

[beyondloadedSE]

Originally Posted by -Jayson-

i have intake, but im skeptical of exhaust, what kinda HP increases could i see with a fulle xhaust setup?

Id say if you did headers and a full catback exhaust, your looking at 10 hp.

[big1]

Where you live isn't stated.If it's legal in your area you can also go with a low or no back pressure "CAT". This will improve exhaust flow.
You stated the horsepower and at what RPM,but you didn't say what torque and at what RPM. This RPM determine's your shift point's if your manually shifting.
At what RPM are you crossing the finish line ?

[-Jayson-]

umm i did state TQ, but again its 155lbs @ 4400 RPMS. about the finishing RPMS, im not really all that sure, last time i was at the track was june. Its prolly close to 3,000-4,000.

[-Jayson-]

well i figued id work on getting RPMS to get up faster so i ordered a few things. Not sure how long shipping is, hopefully they will be here by next friday.

RSM Racing 2.4L Alternator Pulley
RSM Racing 2.4L Crank Pulley
RSM Upper Engine Mount Insert

[SuperchargedGS]

with going with headers and a catback exhaust you with loose a noticble amout of torque so keep that in mind. try a larger throttlebody, cam will help a lot in top end also. try this website www.mantapart.com

[chevytrucks92]

Well, I don't know about for a 4-cylinder or V-6, but adding headers and exhuast sure won't make ya loose torque in a V-8, lol.

Anyways, it would be alot of money and alot of work, but how about a new intake (not air intake)? This would go much further with improving flow then anything else, lol (aside from head work).

[-Jayson-]

well after i get the light weight pulley, under drive pulley, and motor mounts paid off, im gonna look into either a 59MM throttle body or i was thinking about porting and polishing the head.

[chevytrucks92]

porting the heads will help alot, but if you do that you need to get your intake matched, and you need a header. If not then you will just bottlekneck your improvements.

[SuperchargedGS]

if you get your heads P&P, intake manifold and a larger throttlebody then you could get a catback and header. I wouldn't want to loose what torque I have though which in your case is 155. I had a clogged muffler that was only letting a bout an inch of exhaust out of my car. I scaned it and it had 440 FT.LB. of torque. I got the muffler fixed and now I only have 370 FT.LB. but I gained big top end from it.

[Rod&Custom]

You don't go from 440 lb.ft. to 370 from a clogged muffler. Anyway who leaves a stock muffler on a 440 lb.ft. torgue monster(and 1 muffler to...). You can't pull that past us. You get the BS.

[SuperchargedGS]

OK, i was just going by what the tech 2 scanner said. I don't have a stock muffler. its a dynomax super turbo and it went bad. the back plate of the muffler was bent over the outlet hole and only about one inch of gap was showing. when I scanner the car it showed 440 FT.LB of torque and when I put a new one on it would only show max of 370ft.lb. I have a full 3 inch exhaust from ported manifolds with a supercharger, 1.8 roller rockers, custom computer, smaller supercharger pulley, P&P throttlebody and a cold air intake. I am not B.S.ing