Thread: Opinions For Performance Upgrades

Hey guys, I have a 99 4dr. GTP with 94k miles on it. I bought it in 2009 with 83K so I don't drive it a lot. I am finally ready to dive into some real upgrades and $ for the car. Currently I have K&N CAI (came with car), 3.4 pully, 3" downpipe with cat and plog. I mostly know what I what to do, but some will be this year and the rest will have to wait till next year. So my plans are full 2.25" intercooler, headers (ZZP or WBS), port supercharger and lower intake mildly within commonly agreed upon recommendations, port heads to open up slightly to smooth transitions, blend bowl areas to increase flow into combustion chambers and highly polish exhaust ports and combustion chamber for heat flection and to resist carbon buildup, ported TB, VS cam or 1.9 rockers (keep flip flopping on this one) and a Overkill PCM from Will. I like the GTP because it is a great mix of power,performance and comfort. So I want to retain a stock or at least near stock drivability and try to keep gas mileage near what it is now.

So for now I'm trying to decide what would be best to do now. I think I can swing either the intercooler or the headers and rockers or cam now and the other will have to wait. All choices will include PCM tune. I have considered doing the rockers now and upgrading to a cam later. I have 2 daughters both with GTPs so I can pass parts down to one of them.

* intercooler, porting and cam
*intercooler, porting and rockers
* headers and cam
* headers and rockers

Would love to hear some opinions. The car ran a 14.65 at 93.8 mph at Bristol Dragway in TN with just the CAI and has ran 14.48 at 95.4 mph with the 3.4" pully, downpipe, colder plugs and 180 thermostat ( all runs with 110 octane and normal track prep for the car). I think I will pretty happy anywhere in 13s.

I would recommend the cam first because its less work

Get a way to scan for knock (Aeroforce, Torq App), and get it tuned. That 180* stat won't do anything for you with the stock fan settings still in place. And you want to run the hottest spark possible, not the coldest.

Take a good read through this post if you haven't already and it should help- http://www.grandprixforums.net/threa...00-Powered-Car!!

Cam with intercooler or cam with headers? Plan on getting both but one is going to have to wait till next year probably. I was leaning towards the intercooler, thinking I would be ok for a bit with the downpipe and plog no more than I really drive it. And it's mostly driving normally except at the track and occasionally showing up a teenager in a compact whatever.

Originally Posted by FordMan77

Get a way to scan for knock (Aeroforce, Torq App), and get it tuned. That 180* stat won't do anything for you with the stock fan settings still in place. And you want to run the hottest spark possible, not the coldest.

Take a good read through this post if you haven't already and it should help- http://www.grandprixforums.net/threa...00-Powered-Car!!

I plan on getting the Aeroforce Interceptor to monitor and maybe later looking into HP tuner. Have a friend with a Tech 2 thats how I have been looking at it so far. But do want to be able to check it anytime. Also I do plan on getting a PCM from Will at Overkilled.

Originally Posted by blueguy

You need a live feed scanner while you're driving.

Not something you hook up while you are sitting idle or revving it at the shop; unless it's the uber expensive handheld one.

I agree need the Aeroforce for full time monitoring and am ordering today. The Tech 2 is the scan that was standard issue to all GM dealers until the new Can bus interface modules came out I'm thinking around 2005 or 06. I worked in a GM dealer from 98 til 05 or 06 so I left about that time.

Agree with GTPower, cam and IC with your plog and dp will feel awesome. No reason not to go with an xp, drivability feels like stock under normal driving, just bump the idle up a bit if you don't like the lopy-ness.

Thanks for the input guys. So I think I'm sold on doing cam & intercooler now along with port work and PCM. So now to pick a cam, the choices seem to be VS cam (ZZP), S1X (intense) or XP (ZZP). I think the XP may be a bit more than I need or am looking for now and also looks like it will cost a bit more overall with getting all the recommended stuff to go with it. The VS seems to be a pretty good choice since I am looking to maintain similar fuel mileage to what I'm getting now and wouldn't take more than $60 set of springs to go with it, although I would probably go to the LS7 lifters as well. But seems like a lot of people are running the S1X cam and really like it. It looks to be in between the VS and XP and may be a good fit for me. So what do you guys think? Also who makes the S1X cam for intense?

Thanks for the input guys. I have the Aeroforce scan gauge ready to go in as soon as I can get some free time and decent weather. And I am going with the VS cam and intercooler, probably from sseilmnop.