Thread: Lotsa Questions - MODs Mostly

Hello.

Going from a 2000 GTP to a 2004 GT...I know, I know...it is newer not necessarily better. I'm not a body guy and couldn't keep up with the rust on the 2000.

I have been searching the forums and I found some items and wanted more info and I question I couldn't find an answer to:

1. 180* Thermostat - Why? Cooler? Any other bits of wisdom are appreciated.
2. K&N Cone Filter - Is this just a matter of removing stock air box and slapping the cone filter in place?
3. This GT seems sluggish after the GTP...no mystery there...feels like the tranny needs to shift later, like the 'Performance Shift' in the GTP. Is there a mod that a weekend mechanic can do to squeeze a little more out of the tranny?

This is my daily driver so I need mods to be tried and proven.

I still have the GTP, so if there is anything she can give up for the GT, please suggest. Other than the obvious, like drivetrain swap, remember weekend mechanic.

Thanks! in advance.

First off, congrats on the 04+, welcome to the 7th gen club. Lol

180 tstat is only good if the engine is heavily modified and needs to stay cooler to prevent detonation.

K&N filter can be slapped on, but the best choice is a intake that can keep the filter from bouncing around. I made mine out of 3 inch PVC. Seems to work fine.

There's very little the GTP has to give up, the entire drivetrain as a whole won't work without a large amount of modification.

http://www.grandprixforums.net/threa...00-Powered-Car!!

That's 90% of the information you are looking for. You can keep some of the engine parts for a top swap, but you would need a Gen 5 supercharger. The Gen 3 supercharger on the GTP now would need modification of the PCV system in order to work.

The heads, valve covers, harmonic balancer, ignition coil bracket and tensioner with all of the bolts, studs and nuts, idler pulley and bracket, and possibly the injectors, can all be used for a top swap.

If you keep the 04 N/A for now, ZZP has a Front and rear PLOG if you want to spend the money, but headers will be needed, albeit more expensive, if you decide to add boost later.

For the trans, a TransGo shift kit will tighten up the shifts and make them feel more solid and snappy, but if you want the trans to hold up to more power, you will need hard parts and a good amount of money for those stronger parts.

A good tune will be what wakes up the car the most, ordering one from a company doesn't really give you what you want. There's a number of people on here with tuners, find somebody nearby and convince them to tune your car. That's the quickest way to get the most out of the car.

Suspension upgrades are also something you will want, cornering and braking sucks on stock GPs. Here's another link to read and learn yourself: http://getoverkilled.ca/wbodytech.html

Good luck with the GT.

Originally Posted by SgtMarshal

you could just take the airbox off and put an open cone filter on the end of the throttle body. my car is a 2001, so it doesn't look the same as yours, but the idea is the same.

Not quite, 04+ has the MAF in the middle of the intake, not inside the throttle body like yours.



Our MAF sensor is inside that black tube with the connector on the side. It needs to be part of the intake, either with couplers or a intake tube designed to hold it in the center of the airflow so it measures correctly.

I tried that myself, it flopped around and kept hitting the connectors for the PCM. After one of the clips cracked, I decided that was a bad thing.

That one is a good example. LQ4 MAF is substantially shorter than the stock 04+, but that 45° aluminum elbow is what I was trying to get the point of, if it's not a rigid intake or braced somewhere, it's going to cause problems.

You don't want to stick the filter directly on the MAF, if you don't care about proper/laminar airflow across it then go ahead.

Mine needs to be closer to the TB, but it works for now. Lol

Not really.


My stock MAF on my truck is built into the air box neck coming off it, it's as far away from the throttle body as it can be and it makes no difference. I'd say it's over 20+ inches away at least. As long as there are no leaks between that and the intake manifold, it doesnt really make a difference if it's closer or not.

I was saying to have a longer run between the filter and the maf, since it's got a 90° and 45° elbow between the two. Not exactly a smooth airflow across the maf. Lol

Thank you Gentlemen.

Wow. A wealth of knowledge!

Since she will never be the GTP...I think I have to accept her for what she is...but that doesn't mean lipstick on a pig is a bad thing.

I think the 'lipstick' for this will be the K&N filter, I will ponder the how and where from the info gathered here.

The trans tune, I will table.

You guys mention a 'tune', is this reprogramming the computer?

Thanks again, this was awesome!

She could still be a "GTP", you can slowly collect all the parts and mods you would need, install them one by one, then take a Friday off and use the 3 day to install the full top swap.

The tuning is computer reprogramming, the computer in our cars controls the engine AND transmission. Tuning will increase the performance of both, and is best to do with a laptop connected to the car itself, not just a "canned" tune from a company that mass produces them.

I think the trans tune you are referring to is the shift kit, it's fairly simple to do and will also preserve your transmission while making the shifts feel more solid and quick, not so much sluggish and meh.

There's other things that can be done, comfort, aesthetics, upgrades to certain systems, and the all important suspension and braking upgrades. Making the cat look good, feel good and handle corners like a boss is almost as rewarding as going fast. Lol

I was trying to get him to stay away from canned tunes, Marshal...

Lol but Will knows what he's doing, that would be the only canned tune I will run in a GP.



Now if e talk canned tunes in general, it's better if you get the canned tune in the car when its new. Like with a 2015 car, there is almost no differences between one fresh from the factory and one with 10k, engine and trans wise. Less that could be slightly off in the canned tune.

A GP with 100+ thousand miles? So many things could have happened to that car, nobody can know how it truly affected everything.

Excellent, well thought out advice.

"...look good, feel good and handle corners...is almost as rewarding as going fast" Agreed. I'm not looking to go fast...I'm looking to GO. That 'sluggish, meh' is unacceptable.

Sticky wrote an excellent how-to on the shift kit. It is something I will consider.

PCM swap, too scary a job a weekend mechanic and for my daily driver.

I took apart air box to check fitting for K&N...found a mouse house in the forward box area. Cleaned the ****e out of the MAF and I'm pretty sure I got some giddy-up back.

Next, wires and plugs, thoughts?

Suspension is pretty lame. Those front sway bar links are toothpicks! So advice on shocks, links, bushings is appreciated.

Thanks again, enjoy the day!

Originally Posted by WarStryker13

Suspension upgrades are also something you will want, cornering and braking sucks on stock GPs. Here's another link to read and learn yourself: http://getoverkilled.ca/wbodytech.html

already gave you the info. lol

Yes, you did. Yes, you did. Thanks!

Answers in bold for you...

Originally Posted by 71GP2000GTP

Hello.

Going from a 2000 GTP to a 2004 GT...I know, I know...it is newer not necessarily better. I'm not a body guy and couldn't keep up with the rust on the 2000.

I have been searching the forums and I found some items and wanted more info and I question I couldn't find an answer to:

1. 180* Thermostat - Why? Cooler? Any other bits of wisdom are appreciated. - Because even though without a tune, the highway cruising temps will still drop to 180*~. It helps to keep things a little "cooler" and not get so heat soaked. It'll help more so with a tune...see transmission answer as well; because if you do a 180*, with a drop-in high flow filter, a catted downpipe to open it up a little, the shift kit, and a tune...it'll really help the car out. Not much...but it'll be worlds better than it was.
2. K&N Cone Filter - Is this just a matter of removing stock air box and slapping the cone filter in place? - Yes. All this talk of "smooth airflow for the MAF" is crap. Been there. Done that. Doesn't make any difference either way you do it.
3. This GT seems sluggish after the GTP...no mystery there...feels like the tranny needs to shift later, like the 'Performance Shift' in the GTP. Is there a mod that a weekend mechanic can do to squeeze a little more out of the tranny? - Skip the shift kit; unless you want to screw with it. If you're in there for a pan drop and filter change; then do it. If not...get the car tuned. Regardless the tune is where the transmission comes alive.

This is my daily driver so I need mods to be tried and proven.

I still have the GTP, so if there is anything she can give up for the GT, please suggest. Other than the obvious, like drivetrain swap, remember weekend mechanic.

Thanks! in advance.

If it was me; I'd leave this car alone. Rip the powertrain from the other one. Scrap it and find a clean body to swap it in and mod that. L26, unless going turbo...you're not going to benefit from anything on that damn thing. Hell a heads/cam full bolt-ons L26 probably wouldn't crack 225 horse to the tire. It's not worth the trouble. These motors just don't make power N/A for beans. OR; find a cheap turbo kit for it. That L26 will take a little bit...toothpick factory rods. It has been the weakest of the Series II/III 3800's across the board when modding. Trans will go if the motor doesn't...but if you top swap it, keep a stock pulley, toss headers on it with a small cam or some rockers...it'll be a decent street car: boost + high compression.