Looking for performance tips - 1995 Grand Prix GTP

[GTP_MuNkY]

Last I read there was no chip available for the 95 LQ1. Ben was working on one but nothing ever came of it.

If you have any emissions testing where you are deleting the EGR and cat will kill you. So will a high flow cat. I had a Magnaflow high flow cat on my GTP and it failed emissions miserably, get rid of the cat and I passed with flying colors.
Here is a vid of my exhaust,
Walker Cat, 18" Vibrant resonator, 2 magnaflow mufflers



The problem with modding a 95 LQ1 is in the lack of tune ability, OBD 1.5 FTL!

[RedZMonte]

Thanks. I'm going to be putting a custom intake on soon. Any particular Magnaflow?

Not really.. 2.5" mid pipe and Y'ed into dual 2.25" or 2". any muffler shop should be able to get the right ones.. they are kinda short and for ease of install make sure you get a off-set inlet and center outlet. they are all straight threw design except the "Magnaflow XL" which is like a super turbo style..

Different tires make a world of difference.. They are kind of a odd size but i like the 235/55-16's on my stock wheels.. handle good but are wider and your speedo isnt off. and you also don't get the crowning and wear the centers out.. They wear very nice and handle better then stock by far.

S

[z34phoenix]

agreed! i run a 2.5" high flow cat, magniflow muffler, and a glass pack all in line, and then straight pipes to the back. has a very clean deep sound.

as for performance parts, if you go to my website that i have links to in my sig, you will see plenty of pics of me porting my intake manifold and TB. never mind what others have said before on this thread, there is power to be had here. your 95 will be harder to port as the TB is part of the intake manifold, but you can still reshape the inlet to the tb and how smooth it exits to the rest of the intake. if you dont feel comfortable doing this PM me and we can work out something.... as i have ported a number of tb's and intakes before.

deff do not do anything to the maf or you will suffer perf probs cause it will throw off the factory tuning.

a 180* stat is a good idea it helps keep engine temps down and keeps the trany cooler by keeping engine and engine bay temps down. should be 1st mod.

a good fender well intake is also key... i also have pics for this online in my website. again if you dont feel like throwing one togehter, (they are very easy to make) i can fab one up foryou.

its ashame you dont have a 96 or 97 cause then you would be able to get custom tuning... its not worth it for you right now but others have done an OBD2 swap so that they are runing the newer 96 pcm... (the 97 has a diff trany) this allows you to accept custom tuning that really makes an edge. very few people have done tuning with this engine and i am one of the few that have really put forth the time and effort to grabe every bit of power ican out of this engine.

as for exhaust. you do not want to go any bigger then 2.5" anything after that and you WILL loose tq. and we already are short in this department. a full 2.5" system is what this car needs... for flow and weight i went with a single muffler under the car. if i was going for full perf, i would have kept my shorter side exit but being a daily driver i needed a little quieter and livable... IE able to talk to friends and use phone in car. but for weight i would have kept the side exit.

deff wider tires will help. more traction... stock tires are 225.60-16 try a 245/50-16 or 245/55-16. i personally run a smaller dia tire on the car to get an edge in final gearing.

there is also a gear swap. by changing a few parts you can improve acc greatly with this... but its not something most people can do.


i have really taped out many of the possibilities with this engine... ifyou have specific questions PM me. you can also look of my websites for ideas as like said have done quite a bit with it.

[1995GTP]

Thanks. I'm going to be putting a custom intake on soon. Any particular Magnaflow?

[RedZMonte]

A couple more questions for you guys.
I'm looking to get a little louder sound out of the old girl. I don't know what to do with it. I don't want the stupid little bumblebee sound. I was thinking maybe straight piped. Anyone have any suggestions on getting a good sound out of my 3.4 DOHC? I'm looking for a low loud rumble.

Also, any truth to removing the EGR valve to increase power? If so, what do I need to do as far as capping off lines/vacuums?

Thanks!

Intake (makes more grawl) and exhaust. If you want a clean deep sound i would recommend 2.5" piping, high flow cat, Resonator (magnaflow) and dual Magnaflow mufflers.. I have the Borla on mine and its clean but a little on the quiet side. but Magnaflow, Borla, Dynomax Ultraflow, ect.. mufflers are all good. I personally don't like Chambered mufflers like flowmaster.

S

[1995GTP]

A couple more questions for you guys.
I'm looking to get a little louder sound out of the old girl. I don't know what to do with it. I don't want the stupid little bumblebee sound. I was thinking maybe straight piped. Anyone have any suggestions on getting a good sound out of my 3.4 DOHC? I'm looking for a low loud rumble.

Also, any truth to removing the EGR valve to increase power? If so, what do I need to do as far as capping off lines/vacuums?

Thanks!

[1995GTP]

Thanks for the great advice everyone. I love the car. Especially the part about stomping on my friends with imports. Ha ha!

[bszopi]

Pull the egr valve connector on the GTP, and delete the cat converter, that is good for at least 20 HP or more.

I think someone's butt dyno needs to be calibrated!

[4camv6]

Clubgp.com has a sticky for 88-96 mods, and the 3.4DOHC has its own section with mods listed with links to where to buy them.

I wouldn't stay over there for much more because if you ask about mods the SWAP response is all you will get.

I'd tell them right off, their 3800 II is nothing without a supercharger on top, a naturally aspirated 3800 is a granny engine in stock form.

it needs a supercharger to run with and beat a 3.4 DOHC

[4camv6]

Hey,
So I have a 1995 Grand Prix GTP with a 3.4L DOHC. I'm looking to add a few things to get some more performance out of it. I'm good with cars, but by far an amateur. I was wondering if anyone had some ideas for me or even knew where I could get performance parts for my car. Everything seems to be about the 3.8L these days. I put up some pictures of the car if you wanna take a look.Any advice appreciated. Thanks!
Corey

I have a '95 GTP 3.4 and it smokes my '01 Monte SS 3800. No contest- and the GTP is 6 years older and has 86,000 more miles on it.

the 3800 series II in stock form is an over-rated engine. what I'm gleaning is, one must pull the heads/intake/exhaust manifolds and replace them on a 3800 II, just to get it to run with a stock 3.4 DOHC- the stock 3.4 top end is already very, very good, right from the factory. More cams, more valves, better (hemi) combustion chambers, better intake/exhaust manifolds

Pull the egr valve connector on the GTP, and delete the cat converter, that is good for at least 20 HP or more. It will throw a code, just ignore it- I've been driving mine for 5 years with the CEL on, so what. But watch the tranny, the trans in those cars was "borderline" for strength from day one. My GTP trans let go at 178,000. Adding power to that trans 250HP and above, it becomes the weak link.

the 3.4 was a factory 280HP hot rod, that was detuned to 210-220 HP just to make that tranny live- when you push it back up to 250+ HP, the trans will fail with abuse.

[Lowerd1]

Clubgp.com has a sticky for 88-96 mods, and the 3.4DOHC has its own section with mods listed with links to where to buy them.

I wouldn't stay over there for much more because if you ask about mods the SWAP response is all you will get.

[timg]

Turbo, UD pulley, 2.5" exhaust, CAI (make sure the filter is in the fenderwell), nitrous, porting, etc.

Tim

[mn95gtp]

some help on places for parts

MSD makes blaster coils for it, Taylor makes an awsome set of plug wires, and NKG Iridium IX spark plugs.

www.andysautosport.com will carry a pulley kit, oil cooler, thermostats, fuel injectors, pressure regulator , and a fuel pump.

www.performancecenter.com will have a cat converter that adds horses, a MAF sensor for a true CA intake system, shocks for a better feel of the car along with a rear sway bar from ADDCO and they also carry computer chips from Jet, i believe you just have to tell them at what RPMs u want more or les fuel.

for a TRUE CA intake system and the cat-back exhaust with a larger diameter go to www.overkillengineeringmotorsports.com they also carry a large and very nice brake kit for our cars.

and now for the downpipe search this guy up and talk to him gpchris he can get you a larger downpipe for about 200 bucks and yes it does give u some horses back. for your headers there is nothing so i suggest a port and polish to also fit the larger diameter of 3". match your exhaust ports from the block to that setting if they can. port and polish the intake manifold and the valve valves. talk to your local overhaul shop and see if they cant make u some forged pistons. should run maybe 700 bucks for them. and ask what they can do for oversized custom cut valves and get some ARP rods and bolts as this SHOULD be enough to have to swap them out. i have heard something about LS6 valve springs. never tried it i also just heard it but worth a shot, cam shafts you will need a regrind and set ur exhaust cams to 13* retarded. ive also heard on the 7* retarded for the intake cams. upgrade your computer.

with all this i highly suggest running a higher octane fuel. no octane booster just real high octance fuel like 91 or 92 if u can get it.

[phantomgreen]

This link pertty much covers LQ1 performance options:

http://www.angelfire.com/extreme5/tu...lass/mods.html

[1995GTP]

Cool thanks. I PMed you as well.