Thread: Improve Performance

I'm looking for any ideas to help boost the overall horsepower of my GTP. Its a 2004. Its got the K&N air filter, new plugs/wires, and fuel filter. Any ideas for both cheap and expensive hp gain would be appreciated.

downpipe, rockers, 3.4 pulley, tune.

this will make it super fun to drive compared to how it is now.

Do all the mods first besides the pulley, you need to scan first before touching any pulley. Besides you 04 has got a Gen V so a 3.4 would most likely be to small, 3.5 would be a better choice but like I said, thats about the last mod you need to worry about.

Do a CAI of some sort first, Headers or a downpipe w/ u-bend removal, plugs and wires, a good tune (I recommend Overkill), 180 t-stat, and the the 1.9 rockers and 105# valve springs and retainers and then see where you stand via scanner. You should be knock free, if so then I recommend get a pulley system with interchangable pullies and start with a 3.5 and scan.

If you plan on installing 1.9 rockers, you better install some sort of valve springs or you'll be sorry down the road. Many guys have broken stock valve springs with them including yours truely. Do the valve springs or do not put in rockers at all, simple as that...

im running 1.9s (modded) on stock valve springs...no problems as of yet.

Something strange I've noticed people with higher mileage seem to be able to run 1.9's with stock springs and not have a problem wereas guys with lower mileage (under 60000) end up with broken springs,myself I ran 1.9 HS rockers when I was N/A with stock springs for a while I kept shift point at 6k and did'nt have a problem but if you plan on shifting over 6200 definatlely change your springs.

Stock springs get weaker over a period of time on 1.9 rockers, thats been proven many times on Clubgp. I've know of a couple people who broke springs in 15,000 miles then I know some who ran stockers a 100,000 on rockers. Its a gamble , you want to take the chance? Hey its your motor, don't ***** when a valve drops.

As for me. I ran my stock springs w/ 1.9 rockers for 60,000 miles. The spring broke at 140,000 miles on the motor. I NEVER reved it past 6k either so. Also my car NEVER showed any signs of valve float, it just happened all of a sudden out of the blue. Luckily I cought it before I had a major problem and dropped a valve into a piston.

Back in the day (about 6-7 years ago) rockers were a very common mod on these cars (been there, done that), more so than cams at the time. A rocker install was even featured in HPP (i have that issue). No one back then installed new valve springs, just the rockers and sometimes lightened or oil restricted pushrods. A few were smart and installed new stockers, most did not though. Well a few years later problems started showing up here and there, breaking valve springs. I followed the cases and I was an idiot and thought "it won't happen to me" and bragged how many miles I had and the 0 issues I had with my setup. Well my day came and I changed my tune complety I was luckier than the rest, no damage was done and I fixed my problem quickly and easily, others though replaced motors.

Those are the facts, take em or leave them. But i'll say this, with whats happened over the years, your an idiot for NOT installing valve springs and retainers w/ 1.9 Rockers. I was an idiot once, and I learned my lesson and somehow came out on top. My mistake could of cost me some $$$$.

Don't be a cheap ass, gets springs a retainers too. I think by the time I bought my CC 105#, CC Retainers, PRJ Viton Valve Seals, and PRJ Reusable Rocker Bolts, new valve cover gaskets i spent maybe $130? Alot better than a $1,000 Long Block! My math skillz ain't too great, but the valve springs are worth it. Why ruin a perfectly good working motor? Hell add in an OEM Timing Chain and Tensioner on a high mileage motor and your still on top, there cheap to get!!

I donno who else I need to convince, but I stated the facts and i'm right, take em or leave them. If you don't believe me, check some ClubGP archives otherwise don't be a cheap ass, get the springs and retainers at least or gamble with your motors life. Its up to you. Remember this, I was like some of you guys, I was against upgraded valve springs at one time. I'm sure you can find some of my old posts to back this up....

Originally Posted by BADAZGTP

I'll probably be running a XP hot cam, Parker was telling me about it, so what do you think I should run with that?

105# springs from PACracing.com with ZZP milled retainers and a stock timing chain.

IMO you can't go wrong with a new set of LS6 springs and LS6 retainers. They are easier on the timing chain and damper while being a more progressive spring, and end up having a higher open pressure than the 105's.

Whatever you do, just don't buy used springs....you never know what you're getting with those.