Frustrated New GN owner


Jul 6, 2007
Me again.... yeah I'm whining...please bare with me...

My Dad came over today first time to show him the GN.... everything is going well I show him under the hood and etc... we take it for a ride.... so far so good right... well the T-top starts to sqeak... It gets worse really loud then both sides started... inbarrassed... I turn around and after smoothly gettign to 55 mph and punch it ...... I don't think he could tell I floored it even.... It picked up speed about liek my 96 Chevy ex cab work truck... Id doudt it was any faster....
My Dad said not bad for a little V6....

It hit 14 to 15 psi boost sounded fine just did not put you in the seat... at all...

I dreamed of owning one of these things after seeing one wax a vette back in 1990 at the local race spot ..... Now I have a 77 Trans-am that runs mid to low 11's and I race allot of cars Cobras 03,04 and LSX F-bodys, Lightning trucks etc... Win in the TA most times but the GN would gets it ASS handed to it by a Pick-up with a cat back I think !!! I need to inspiration that this car can perform and not cost 10 grand to get it in the 11's !! I am just miffed... I read about cars running 11 with 21 psi.... I know my stock turbo was putting out 19 until I screwed out the waste-gate to lower it fear detonation and the car feels better .... It runs well 25 mpg or so and it sounds fine etc... just is not ripping when you put the pedal down like I thought Grand-nationals did... no wheel spin or anything from a dead stop pump without power braking it first.... I told my local car guy friend about it and he called it a Buick Turbo Turd....Man Id like to spank that guys ass at the track with this Turd...
You must be reasonable....

A stock GN is a low 14 sec car. I'm sure it does feel slow coming out of a 11 sec car.... You have practically no mods... and are running on pump gas.

For the least $$.... get some tires... a scantool....and some C16 and a test pipe. You could probably work your way down to the lower 12's pretty quick.

Otherwise.... establish a set of realistic goals.... and buy the parts necessary to put you where you want to be. Read alot... and ask questions.... study other peoples combos... and what they run and what boost did it take to run that ET.

Look at my sig on my new combo.... that is 10 sec parts on pump gas all day... with tuning, traction, and decently cool air.

Good, Fast, Cheap ...... Pick any two.... because you can't have all three together....
My car was like that before I got everything in the right order.
The most impressive thing I every did was changing injectors. I guess after 16yrs & 100,000 miles they were not flowing good but all sensors were in spec.
1) Make sure all sensors in spec
2) All vacuum hoses are new & zip tied
3) All exhaust leaks fixed
4) New plugs & plug wires
5) Adequate fuel delivery
6) Chip update
7) Good IC & turbo hoses, t-clamped
On my stock car, I also run alky & a LN IC.
I can leave from idle and as soon as the boost hits, it starts going sideways.
I can be going 40MPH and floor it and it will squeel the tires.
This is no 11 sec car but I feel it pretty good.
scanmaster??? you'll need one or some other form of data collection. You could be getting "knock retard" which isn't good. The computer could be pulling timing to keep from damaging(and you still are) the motor. You could do the basic tune up(plugs,wires,coil, fuel filter) and "see" if it's better. I wouldn't go WOT until you get a scanmaster.
Any exhaust work done? Loose the converter if its still there...HAve you looked at your headers to make sure they are not cracked like many stockers do....that will hamper performance quick like. Is your spring cleaning done and all vaccum lines replaced? Look at all intercooler and turbo connections closely for cracks etc...An all stock gn will spin the tires with no brake petal action, you have a problem affecting performance terribly, My Gn has some heavy mods done...but right now with the turbo at only 14-15 psi this car is absolutely silly once the turbo spools, all over in first, second and most of third with a good set of tires...dont be discouraged, they take some work and some tuning but the juice is worth the squeeze, A six that will rock most eights........Imo
Dam, in the time it sook me to type that you had three replies.... guess im pokey, and were all thinking the same thing, and tell your Slow Buick Turbo Turd buddy to come visit me....Lol

For less then 3k you'll have her running 12's. get the following
1)ScanMaster-used 175-200,
2) DR's-new 300,
3) larger injectors 60lbers 300+,
4) TurboTweak Chip -90 ,
5) larger Turbo -900,
6) DownPipe-300-400,
7) AFPR- 150,
8) Razor alky kit.-450 ,
9) Walbro 340 fuel pump -100,
10) driveshaft loop 50-100
..... no way you need to put 10k into it. You'll still have enough for weatherstripping for your t-top. And if you buy good quality used stuff, people go bigger and faster all the time and sell their stuff with low mileage fairly reasonable, you will save even more. There's people on here that are honest and sell quality parts so shop smart. Dollar for dollar you won't find a car/engine that has the increase in power from bolt-ons as an LC2 equipped Regal. Don't be down you'll have her running hard soon. Once you do all the basics spring cleaning and add bolt-ons... Your turd will be heard!
I went 11.98 @113mph with less than $1k in my first GN. (pair of slicks, K&N, fuel pump, chip, test pipe and race gas)These cars are 20 years old and they require upkeep like any other car and many don't get what they should. Go to and do thier "spring cleaning" list and make sure everything is what it should be then start with the mods.
Thanks, I'll go thru the Spring cleaning list although most of it I know has been done... It has a new MAF ( GM ) New Coil Pack and Wires + PLugs... New Boost solenoid and vacuum hoses all look good. No detectable exhaust or boost leaks and that would show up as a loss of boost wouldn't it ? The Boost comes up quick, very little lag btw.. It seems to be working right except there is a feeling of loosing power at high RPM's It feels like all bottom end and mid range and just before the shift it just goes flat.

I am going to get the OBD1 upgrade for my AutoXray 4000 that should give me all the stuff a scanmaster would right ? I want to same for a power logger so I can trend the data next year.

I used to have an old OTC 2000 I was able to tune and dial it in. Only problem with those old devices is they take a frame maybe 3x's a minute(exaggerating but not by much they're pretty slow). I was more inclined to tune with the EGT I had on my other car that was stolen. You'll be able to get in the ballpark though.
How many miles does the motor have? Have the valve springs been changed? Weak valve springs will make one nose over pretty hard.
same thing I was thinking. If she has some miles on her you are probley due for a new set of springs. All the boost in the world is useless if the valves are not sealing up. Daniel Ray

Does the car have the Cat still on it and stock air intake(hose)as they are restrictive. When I have to get emmissions done, I have to put the Cat back on and talk about chokin her out.
Motor has 54000 miles...
Has a new aluminum inlet tube and K&N filter. All new blue hose adaptors.
Cat is gutted and has new 2.5" pipes y splitter to dual magnaflow mufflers.

At 55 I punch it and it shifts back into third I guess at about 65 and seems to pull harder right at the shift ... I have not really been watching the dash led tach so I don't know for sure but I think it is shifting about 5000 rpm in automatic. Also does it matter is the shifter is OD or not ?

It did bark 2nd one day if that means anything.
I agree with most of the above...

While you may want to smoke the tires off the car right away, a small bit of prevention (ie: basics), will take you a long way and prevent you from smoking something else...

You have to let the car breathe and you have to feed her properly (fuel). Once you have these things handled, you can add the bigger turbo, FMIC, etc...

Below are a few things that I have found useful in my own endeavors...( Bear in mind I am not a drag/street racer but I'll put my car up against nearly anything on the street- Took on a crotch rocket the other night. Startled him that I was still staying with him...:cool: Anyway...

1. Scanmaster is necessary to see if all your stuff is running right. The OTC is kind of a Pain because you have to scroll throught the menus and check the book. The scanmaster is right there for you to read with a quick push of the button. ($200 used)

2. If the car has higher miles, do the springs ($40 from Kirban)

3. Also, consider a timing chain (it's probably time for that as well) I like a nice double roller. Cloyes is a good brand.

4. Get a downpipe asap! (THDP is very popular but hard to find cheap-$300-400 is about right)

5. Loose the cat (my car was really slugging along until I yanked it and then the car came alive) I use a custom test pipe with and electronic cut-out for the nice effect:biggrin:

6. Get larger injectors 50-60lb minimum. ($250-300)

7. Get Alky-you can get a used SMC kit here for about $250 or buy the newer progressive kit from Razor for $550.

8. TT chip tuned for the Alky

9. Don't forget a nice big intake- (ideally one that sucks in COLD air and not the HOT air inside the engine bay) I like the KB one but it's hard to get) You can check with Mark @ TR Custom Parts 84-87 Turbo Regals, 94-6 Impala SS, 93-up F Body Cars, Olds G-Body Cars he's got a new one for about $145! It's very nice.

10. The Dutt Neck is a quick and easy mod (welding required) - More breathing for the car.

11. Plenum spacer (equalize air distribution)- $20-40

12. Larger Bell mouth for the stock turbo.

13. Liquid filled fuel gauge (mounts on the fuel rail and lets you properly set the regulator) $20

I suppose that's a good start for now. There's more you can do but this should keep you busy for a while. I don't think that's $10k but it will add up quick. BTW, once you do the above the car will really smoke the tires. Then shop around for something a little meatier. I slapped on some cheapo ($65 a tire) Futura 295/50/15's on one of the cars and they're not too horrible hooking up. They are not Drag radials but they won't be nearly as pricey.

Good Luck and tell your car guy friend to be careful when speaking of the Darkside. He obviously doesn't know what he's talking about (btw, don't let him touch your car);)
You must be reasonable....

A stock GN is a low 14 sec car. I'm sure it does feel slow coming out of a 11 sec car.... You have practically no mods... and are running on pump gas.


I think the above is right on target. My car feels strong, but when I took it to the track it ran 9.1 sec in 1/8th mile. I had the boost set at 18 psi. This is with a stock turbo, injectors, downpipe and cat. I had race gas in it too. Only mods are stretched intercooler (dut neck) and Hooker exhaust, and LT-1 MAF and translator. I also had new MT ET Streets. So this week I'll install a Meese downpipe and lose the cat. I was talking to Nick Micale and he said that sounded ok for what I had. So don't despair- your car is probably fine. Most people will agree that you can run 12's with stock turbo and injectors. Just do the downpipe, dut neck on intercooler, race gas, and wait for a cool day. Oh, and get a chip, too.

I ran 9.20's (1/8) when mine was bone stock except for decent tires..... I started with some bolt-on's.... and worked my way down to 8.32 in the 1/8.... still on stock boost...

Add alky... and 1st trip out... went 8.0's... 1.71 60' time... this was a 12.65 in the 1/4.... on about 21 psi boost on the stock turbo.... 3" THDP with a decent exhaust. It had alot more in it with tuning and a better 60' time...

Be patient... talk a little... and listen alot.... set your goals.... and get the parts necessary to get there.... then tune.. tune.. tune. Find a local that is knowledgeable with TR's and enlist his help.

If you beat the bushes..... you'll find a wealth of "hand-me-down" parts that can make your car much stronger.... and it will be much easier on the pocketbook.
I think the most important thing to do first is to ensure everything is working properly before you worry about mods. Make sure there are no boost leaks and that your headers are not cracked(these two things alone can really hurt performance). Next get a scan tool to ensure that all sensors are properly operating and that the car is tuned right. Sometimes the headers can have very fine cracks that you'll miss, mine did, but when I ran some sea foam through the motor white smoke was rolling out of my headers and not just the tail pipes.
I would get the Comp 980's from Full Throttle for about $33. If the valve springs are original they need to be changed. You should easily be able to get in 12's with stock turbo, injectors and downpipe and elbow. You wont need a downpipe until you get in to the low, low 12's. It was proven years ago at the Nats(and I had the same results on my car) that a 3" dp will give almost no performance increase on a 12 second car. A good K&N, decent exhaust or a dump, a chip, sticky tires and either alky or race gas(whichever you choose) and a turbo Buick with no mechanical issues should easily be well into the 12's.