Wasted by GTP

[Self]

Originally posted by fatninja19
I'm quit unfimiliar with nitrous.... does the engine get loud when one squeezes?

Yes, but not because of the nitrous...It may get louder because the nitrous accelerates the car faster and runs it up into a higher RPM quicker, which would make it loud. But the nitrous itself doesn't make and "noise" or anything like that.

[HiFlow5 0]

Last year when I went to the track, there was a GTP running 12's. With the stock pulley he was running high 15's low 16's I believe, but once he swapped the pulley he was running high 12's very low 13's. Depending on how well he hooked and shifted.

[Cbass]

Well, you can't just swap the pulley and expect to pick up a few seconds like that, you have to have the engine flowing well enough or you'll be blowing head gaskets all over the place.

Like I said, porting, exhaust, a chip would help also, and a small blower pulley. Simple math, the smaller the supercharger pulley, the faster the supercharger will spin. The 3800 S2 SC uses the M90 twin screw type blower, which developes good boost at low rpms, and off throttle idles, making for good fuel economy.

The downside is, the GTP is fairly heavy, and it's front wheel drive...

[HiFlow5 0]

Originally posted by Cbass
Well, you can't just swap the pulley and expect to pick up a few seconds like that, you have to have the engine flowing well enough or you'll be blowing head gaskets all over the place.

All I know is that he swapped a pulley, and lost a few seconds. I don't know what else he had done for mods, but I witnessed his runs first hand. I don't remember the exact times he ran, but its was a big difference. I think it was high 15's to mid 13's, the more I think about it.

[pontiactrac]

What year RX-7? I know GTP's were fast but damn, RX-7 is pretty mean too. Pully swap is a definate possibility, one of the most frequent upgrades usually done first, makes quite a difference. The think that suprises me is the fact that it was sooo loud. I'm familiar with hearing them alot but didn't think they were ferocious in sound. He had to do something. If you would like to know more about their 1/4 times and such, i know a really good site of a few GP tuners and what they run. Don't know if that guy was runnin about the same.

http://www.migpc.com/Members/members.html

[Self]

Originally posted by pontiactrac
What year RX-7? I know GTP's were fast but damn, RX-7 is pretty mean too. Pully swap is a definate possibility, one of the most frequent upgrades usually done first, makes quite a difference. The think that suprises me is the fact that it was sooo loud. I'm familiar with hearing them alot but didn't think they were ferocious in sound. He had to do something. If you would like to know more about their 1/4 times and such, i know a really good site of a few GP tuners and what they run. Don't know if that guy was runnin about the same.

http://www.migpc.com/Members/members.html

The Rx7 is a 95. Yea this supercharger was DEFINITELY aftermarket or at least upgraded. I was walking to my car just yesterday and a GTP passed me going full out. The supercharger whine on it was minimal to non-existant The one we raced in the Rx7 most definitely wasn't stock.

[pontiactrac]

Originally posted by Self


The Rx7 is a 95. Yea this supercharger was DEFINITELY aftermarket or at least upgraded. I was walking to my car just yesterday and a GTP passed me going full out. The supercharger whine on it was minimal to non-existant The one we raced in the Rx7 most definitely wasn't stock.

Yea, it couldn't have been stock with such a sound. There is a company called SLP that makes performance parts for a few GM performance cars, you probably know of them with your z/28. I just today put on a new SLP CAI air box, and i definatly notice a big difference in sound. Kinda had me worried for a minute there. I could imagine that the supercharger would have been even louder. Did the GP have a twin air scoop hood? If he did it could have even been a Grand Prix GTX which im not really that familiar with. They are a pretty rare find.

[DRSully]

Hey guys. I am a GTP owner. The whine of the supercharger gets loud with light modification. Once you do a cai you notice the whine. If you go to a smaller pulley then it screams. I get many weird looks at wot. The whine is much louder at higher rpms. You don't really hear it in first too bad, but it screams through second. GTP's typically run mid 14's bone stock. There are some freaks that run low 14's, and some slow ones that run high 14's. If someone is in the 15's they are doing something run. There are some GTP's with the same mods as mine that have broke into the 13's. If you have money to spend they are good for twelves all day. There are some in the low 11's, but I have not seen a 10 second one yet. The stock pulley is a 3.8. With a couple mods you can go with a 3.4. A couple more and then 3.25 and so on. You have to open up the exhaust though or you will just be stacking the boost. Some people get as small as 2.8 with their pulley. There are even some running a little smaller than that. The M90 is a belt driven roots supercharger. You have full boost very easily with no lag. This creates some traction issues, but once you get good at a rolling launch you can really surprise some people. They make for great little sleepers, so look out for one in a neighborhood near you.

[ChaosStarter]

Hey, what's up guys. I've been on the board just reading for a while now, but never registered. I also own a GTP. 1999 to be exact. Check out my sig, that's what I read with JUST a K&N. A lot of the people over on ClubGP call my car a freak because of what I've done.

A smaller pulley is on the way, then I'll start fooling with the exhaust a bit. By throwing on a FWI or CAI, you can really hear the S/C scream. However, like others have said, it only gets louder with smaller pullies.




Oh, and to correct something someone said earlier. They are Eaton M90s, but they are not twin-screw, they are roots-type superchargers. Similar, but close.

[TheDirtyLittleMan]

Yes, it has an Eaton M90 blower, which is running at a conservative 8psi... same story with the Thunderbird SC, which also had a 3.8 liter supercharged V6...

i never knew that the ford and gm v6 was the same

[DRSully]

Originally posted by TheDirtyLittleMan


i never knew that the ford and gm v6 was the same

They aren't. There are several differences between the two. I know a kid that has a lightly modded super coupe, and it does not keep up with the GTP. I think the Ford engine has some good horsepower numbers, but is a little weak on the torque side. Also the GTP is only running 6lbs of boost from the factory. Once you do a pulley swap you are more in the 8-10lb range.

Take care,

David

[non sequitir]

Ford and GM 3.8 V6 the same? Right.

The 3800 Series II is actually a Buick engine, and its "ancestor" is the 3.8L V6 engine that powered Buick GN's. Of course, those Grand Nationals were turboed instead of blown.. and GN's ran 13's stock in the 1980's http://www.gnttype.org/

DRSully, I believe the boost is 7.5 max at 6k RPM, with the stock 3.8 pully.

[JewbaccaGTP]

The supercharger is pretty quiet on the GTPs. If his was whining loud, he definitely had replaced the pulley to a 3.25" or less (from 3.8" stock). Our cars are very easy to put in the 13s. Intake for $300, exhaust/new downpipe for $600, new pulley for $70, shift kit for $100, you're talking high 13s for around a grand, or so I'm told. My new pulley and intake are going on in the next week or two, I'll keep everyone posted as to the upgrade if you're interested. I'm told that the 3.4" pulley I'm getting alone could increase boost from 8 to 10psi and up to 20 hp. I meant that it is 8psi stock and goes up to 10, not that it'll give me 8-10 more psi (just re-read that and saw how it sounded).

[DRSully]

The whine on mine is very noticeable and I only have a 3.4 pulley. I think open cones make it much more noticeable. I have heard of some GTP's getting 7.5 lbs stock, but I thought must stayed around 6 and sometimes 7. It may take some $1k to reach 13's, but some do it for much less. There is a thread running on www.clupgp.com right now about someone that has $150 in mods and is running 13.9. That is in a four door as well. I know everybody does not get there that easy, but it seems like we have quite a few like that. A guy that used to own a GP is over on the forum as well. He ran 13.5's with nothing more than a couple hundred dollars in mods. The potential is great for these cars. It is all about the right combination. You should expect 9-10 lbs. with a 3.4 pulley.

Take care,

David

[Scott Anderson]

Hey, I have a 98 GTP. My best time (in my sig) was done with $300 dollars in mods. People that know GTPs know that with Race Gas/Low tire PSI/no spare/no jack and a 2.00 60' I would hit 13.7s easily.

My mods:
$70 - 3.4 S/C pulley
$225 - Used 1.9:1 INTENSE Rockers
$5 - Local used Fenderwell Intake.

The Scream of the supercharger is EASILY heard after JUST an intake. A stock one is Very quiet/muffled/choked!