SUPERCHARGER!

[grandprixgtp_91]

im hoping to push around 375 - 400 hp and i hope to run the 1/4 in low 13's.

Jake

[dykz34]

With that kinda HP you should be good for 12's--traction permitting of course.

[grandprixgtp_91]

that would be good, but im not sure. all i know is that i want to run as fast as possible!

[phantom505]

What boost are you planning on? You would need to run 12-13 psi to hit those numbers (crank) at the mid range band. I think you would have to start at about 15 psi to achieve it. At the low end you'll have shit loads of torque, assuming your cams are conducive to use power at that point. I know part of the problem of the roots 3400's is that the power band is in the wrong spot for that cam.


I read this from someone's post:

"Turbo's are much higher maintenance anyway. Due to the high temps, they practically need there own oil cooler to not melt-down under any prolonged conditions. They receive so much heat from the exhaust system plus they are spinning so fast there is a huge amount of frictional heat developed within the bearings. At least with the supercharger you only have the bearing heat to worry about. Also since the Blower design (commonly) is much better at dissipating heat that helps too. "


I can't believe the number of misconceptions there are about turbos. I hate to break it to you, but if you tap the engine for oil it changes with every oil change. They are less maintenance than a SC. Much less as a matter of fact, no needing to change a second oil reserve here. to make that even less true do you realize how much from friction an SC gets? Over about 8 psi you are dying to heat soak without a SC. Just look at the GTP's with and without an IC. Did I mention the fact I never run hotter than the stock system?

Roots are great 0-35MPH. To me that's just a cheap thrill. Over 4000 RPM they fall flat on their face. Let me guess, it's just a fluke that the fastest of pretty much every GM engine happens to be a turbo... Besides that, aren't the DOHC's high winders? I would go centrifuge if you absolutely insist on a SC, but the turbo is better in that range anyway.

And for those of you that think turbos don't have no low end power, tell to the crew in my car that burned rubber through 3 gears with me. They just have the equivalent of NA WOT at the bottom, which is still a huge improvement.

[Lyle's GTP]

Holy shit! People get down-right bitchy when it comes down to the Supercharger vs Turbocharger debate. From that last post, you would think the guy was sponsored by Turbonetics or something. HaHa

Lyle

[grandprix34]

try telling that to all those L67 guys who havent replaced their M90. Personally, I want to s/c the LQ1 with the M90 and be as fast as possiible.

Whatever poweradder you choose to use, lets just watch and see it take hold. No use holding fellow DOHC back because of some company sponsorship...lol

The way I figure, simple as shit, is if the pushrod 3800 90* can get 40 horsie's out of the M90, the DOHC should be able to see better figures....thats without modifying the rset of the system (ie. exhaust work, headwork, larger plenum/tb, NAWZ, etc.)

[Lyle's GTP]

Let me guess, it's just a fluke that the fastest of pretty much every GM engine happens to be a turbo...

I guess so, if you ignore the fact that GM has used the supercharged 3800 in all sorts of cars since god knows when. I would even venture a guess that there are more supercharged 3800's out there, than all other GM turbo's combined. If true, that would be a hard fact to ignore. Even if you talk to most mechanics, it's one of GM's most reliable engines ever built.

Lyle

[Norm '88 GT]

I think the Buick GNX made 245hp. The new GTP with a roots blower makes 260hp and has stiffer emissions to adhere too than the 17 year GN(current Series II has been on the market for 7 years). Besides the Eaton roots blower is the most inefficient of them all compared to centrifugal and Lyschom, most of which don't have almost 200F motor oil running through them. Or even cooler running than using their own oil reserve to lubricate gears, or a kevlar belt like my Powerdyne. Talk about cool running. Remember too that a centrifugal blower uses a compressor wheel similar to the turbo compressor side. The lyschom or twin screw is the most efficient of all belt driven superchargers. The C32 AMG uses a twin screw blower at 14.7 psi on a 3.2L 3-valve motor that makes 350hp...hello Mr. Vette.

[Gemmer]

Yea, a prix with those numbers would be in 12s, if your in a fiero, you should have nothing to worry about 1/4 wise

[phantom505]

Let me guess, it's just a fluke that the fastest of pretty much every GM engine happens to be a turbo...

I guess so, if you ignore the fact that GM has used the supercharged 3800 in all sorts of cars since god knows when. I would even venture a guess that there are more supercharged 3800's out there, than all other GM turbo's combined. If true, that would be a hard fact to ignore. Even if you talk to most mechanics, it's one of GM's most reliable engines ever built.

Lyle

Yeah, and GM has YOUR best interest at heart. So yes, it's an easy fact to ignore. And I can find an expert witness that will support almost everyhting too.

Also, you people actually believe you'll get more horse power than the theoretical numbers? Those numbers are based on maximum efficiency. Just becuase you have a DOHC doesn't mean you're going to make more power at a given boost level. Air in equals power out. It's simply chemistry folks.

How old is the Buick GNX? What was it's stock boost level? How easy was it to mod? Let's get the WHOLE picture here.

And Lyle, yes, I STRONGLY support the use of turbos. Because I was correcting someone (you by chance?) doesn't mean jack. It means what it is... a correction, clarification, whatever. Roots blowers are crap. Centrifuges are only slightly better, but most people don't know how to use them properly. The only style worth mentioning is the twin screw. However they cost a bunch and aren't that friendly to tune. The simple fact that a SC eats about 10% of the power it generates should indicate to anyone that it can't be as effecient.

I was told people here were a cut above other sites. Judging by the lack of objectivity here I can see this forum is just like every other one. Here's some conventional wisdom from the 70's that hasn't been shook yet... most of which is more or less an outright lie now:

NO REPLACEMENT FOR DISPLACEMENT
ROOTS BLOWERS ROCK
TURBOS LAG AND HAVE NO TORQUE

and my favorite:

GTPs ARE FAST

They just happen to have a crowd willing to spend money.

None of which makes ANY sense to me. I just know I put down more torque and horsepower at the same boost level on stock 3400 versus a Roots or a Centrifuge. To be exact about 30 wHP and 50-55 wTQ (at ~5 psi).


It's easy to be a lemming.

[brian89gp]

And its easy to disagree with you, very easy. Even if someone agree's with your thoughts, its still quite easy to disagree. Every single post you make it seems like you are trying to sell a turbo without actually selling one.

Just becuase you have a DOHC doesn't mean you're going to make more power at a given boost level. Air in equals power out. It's simply chemistry folks.

Yes it does. Air in = power out. The DOHC flows much more air then the 3800, hell their gen3 CNC heads that cost $2k flow just about as much as a stock DOHC head does.

[Lyle's GTP]

I'm not posting anymore arguments here. It's pointless.

Lyle

[grandprixgtp_91]

well all i know is that someone told me that if installed properly and tuned right the m90 will give me an extra 100 hp maybe a little bit more. then with my rebuild and tuning the engine up as much as possible i hope my DOHC will have 375- 400 hp, i just hope my getrag and clutch can handle it. i would have put a turbo on my car also but due to the fact that i got an m90 for $150 canadian i chose to go with that. i have no problems with turbos and i like the sound they make but i want the low end power a supercharger gives, thats is where the DOHC lacks power. now i gotta figure out the electronics and fuel and ill be all set in a few months! today i started sandblasting my getrage tranny ill post some pics when its done.

Jake

[Cotton]

what i want to know is who compared the Buick GNX to GTP?
the "step down" Grand National was the fastest GM car in 1987 (besides the GNX)
yes, faster than the Corvette.
Damn sure faster than a supercharged Grand prix.
But take that as encouragement, the mighty Buick of the late 80's was also a 3.8L
If you see an all black Regal today, beware, there have been many performance add-ons around for a long time, they will have you for LUNCH!

[grandprixgtp_91]

im hoping to solve that problem with this m90!