What should it feel like

grandwazoo

New Member
Joined
Dec 27, 2003
Okay, generally trying to beleive the adage, "There is no such thing as a stupid question..." here is my attempt at one:

I have had my GN for about a year, and have had it Streetable and licensed for about 6 months. I never had a turbo vehicle before, and have had primarily various Lt1's prior to this.

Never was a hardcore gearhead or racer, but this car is my latest passion.

My car was a basket case when I got her, put in alot of time and love. Car currently has the 2 3/4 dual exhaust from fullthrottle speed, Blue-top injectors, air bags, Billstein shocks, new springs, and a TA49 turbo. In addition it has a big aftermarket "mystery cam".
I have no idea what my 0-60 or 1/4 mile times are.

So here's the dumb question, "What should a good Grand National Launch feel like?" When I am cruising, and lay into it, BANG!!! turbo kicks in and off we go, no complaiints, and no loses. But from a stop, without brakeboosting, when I floor it, the launch feel less than prestigious, kind of a drag. When the turbo kicks in, wheels spin, pulls to the side, eventually grabs meat and things start to feel okay.

The other nite at a stop sign, a new 05 GTO pulled along side of me, and when we took off he got the jump on me, my turbo kicked in, but I still had wheels spinning at 45 mph. Yes, I understand that traction is where it is at, and I need to buy street sicks if I want this problem to go away. But I also would like a little more gusto before the turbo kicks in.

I think maybe I just don't understand the Beast yet and I am so used to the way an LT1 or a small block feels that I am just expecting the impossible.

Please do not misconstrue this as a complaint, I love my GN, I am awed by it's power. I just don't think I really know what it should perform/feel like, and since it was such a basket case, I cannot be sure there is not residual performance losses from the previous owner.
 
spring cleaning

i would do this because you shouldn't have any lag with a ta49 and look at the chip you are running...may be rich causing slow spool.....As far as your traction goes air bags and a set of stickys will help cure that........................................................Bob
 
Originally posted by grandwazoo

So here's the dumb question, "What should a good Grand National Launch feel like?" When I am cruising, and lay into it, BANG!!! turbo kicks in and off we go, no complaiints, and no loses. But from a stop, without brakeboosting, when I floor it, the launch feel less than prestigious, kind of a drag.

Without boost, it's just a 3.8L engine towing a 3,500 lb car around. So yes, the performance is just that of a 3.8L towing around 3,500 lbs. :)
 
Also keep in mind what converter stall you are running. These turbos like RPM's to get things rockin, even with a 49. Do you have a stock converter? If so that may be why you get "lag". My GN was not a rocket off the launch with no boost, but as soon as the needle registered on the boost gauge.... yummy! Think I'll keep her!

Squid
 
Re: spring cleaning

Originally posted by Super6
i would do this because you shouldn't have any lag with a ta49 and look at the chip you are running...may be rich causing slow spool.....As far as your traction goes air bags and a set of stickys will help cure that........................................................Bob

Yeah, it is time to have a chip programmed, that is next on my list (after a bit of cosmetic work.

As far as the airbags, already have them, and the stickies....well, yes I should get them, just debating between Nitto's and the BFG's.

For some reason I am hesitating on the Drag Radials, I have a superstitiion that as soon as I put them on I will start getting speeding tickets.
 
Re: Re: What should it feel like

Originally posted by bruce
Without boost, it's just a 3.8L engine towing a 3,500 lb car around. So yes, the performance is just that of a 3.8L towing around 3,500 lbs. :)

This is the answer I was most expecting.
 
Pull the dust cover off and make sure you have the right convertor in it. If it's stock it should be stamped with "d-5" around the outer edge.
 
Where at in st. louis are you from?
Im over here across the river in Granite city.A couple buick guys over here.Gateway opens saturday(i think)you going out there?
 
make sure you have a fuel pump, hotwire kit, adj. fpr and a fuel gauge!

removing the cat or running with a dump pipe before the cat can free up some HP too. you dont' want any restrictions in the exhaust at all. a restricted exhaust can hurt turbo spool up as well.

scantool and a boost/vac gauge helps to make sure your IAC and TPS are set right at idle and to make sure you don't have any other problems.

the "mystery" cam could also be hurting you on the bottom end giving you some lag. this concerns me a bit, do you know the cam was turbo buick specific?

best thing to do is find some GN people in your area and take them for a drive or let them drive it and they can give you a better opinion if its running properly or not.

check out gnttype.org and make sure all your spring cleaning is done to the car before you really get serious about racing it a bunch.
 
If it has a "big" cam, that would make things worse. Now it is 3.8 litre engine pulling a 3,500 lb car, and the big cam might be killing the off-idle torque. The turbo Buick doesn't need a real big cam, and if you have one, then you may need a looser than stock converter, to overcome that off-idle bog. Once you get the bog problem fixed, then the traction problem will be more obvious.
 
Also, what exaust housing is on your TA-49? I know it's a .63, but is it a Garrett houseing or Precision? You'll get more lag off of the line with the Precision housing, but once you get to 8lbs of boost, it's instant spool the rest of the way. Your big cam is causing lag too. I say get an aftermarket torque converter (3000 - 3200 stall is my opinion) and prepare to drive sideways. :D
 
It is the Garret housing on the T49.

Diferent Torque converter seems to be a concensus....

I guess the next thing is to ask myself how much day-to-day drivability do I want to sacrifice to have a killer launch.

I'm greedy, I want the best of everything at the same time, speed, launch and drivability. Then again, driving sideways sounds good
 
Warm apple pie

I almost replied with that. :D

If you have a Garrett housing you should not be experiencing any more lag than a stock GN. Your problem is most likely that camshaft.
 
Theres nothing wrong with your car, it just needs to spool up. Next time you race, make sure to have sticky tires. Push the brake down hard, and give it some gas. Don't light the tires, just give it a couple psi of boost. Let go of the brake and mat it. Say goodbye to whatevers in the next lane. My car leaves hard from a light if I spool it up. Hell, I beat my buddies chevelle so bad it took him half a block to catch me. I left on 2 lbs and never gave it more than 1/4 throttle. I was breaking in the motor still.

You're just used to off idle torque, which turbo cars for the most part ain't got.
 
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