12.5 quarter

[drd21968]

well heres the question.my previous grand national was all stock and it was in the kind of shape where mods would have likely hurt its value.i have purchased a gn for a third of what my other cost,so im not worried about hurting the value of this car and i would like to get into about a 12.5 quarter mile time.i kmow that its not too hard with these cars.whats the best combination.car needs body work while im at it more power will be nice

 

[Dewey]

I think with the kind of power you're talking about I'd count on putting a fresh transmission in it if it doesn't have one already. That being said, sticky tires, alky, DP, and some injectors on top of the basics like a fuel pump, hot wire kit, cold air kit, and exhaust and you'd be real close.

 

[GNDriven]

When I get a new GN the mods are...
1. New fluid changes (oil, coolant, trans,)
2.Basic tuneup (sparkplugs, wires, etc)

Then before any mods to power I do

3. Front end kit from SPT (poly-graphite, tire ends, ball joints, etc)
4. Front end Bushings
5. Rear end bushings
6. Body bushings
7. Transmission mount
8. Motor mounts

In that order, FORGET making power until the chassis is not moving around like a belly dancer. Then any extra power you make will feel really good and sound.

 

["Turbo-T"]

Well my car ran 12.61 at 109 on 24 psi with all of the stuff listed below in my sig plus a crappy 2.00 60 ft not from spinning but from bogging...oh the tires I used were M/T drag radials.

 

[pacecarta]

well the car in the pics isnt stock ..looks like youve already got a turbonetics turbo with turbonetics external gate on the exhaust housing, that turbo could be a t44 a t60 or even a t66
but still on a stock maf and fuel regulator
is there a cam , any port work on the heads ?
test pipe ?
how does it idle/run ? blms o2s
what chip/injectors?

if :
the converter is matched for the turbo and spools
trans isnt slipping
the ignition is working properly
the cooling system maintains the temp around 170s (160 thermostat)
injectors arent too small
fuel pump is upgraded
the gate maintains boost properly without creeping up
and the engine is sound

all i see you needing

some race gas and ACr42ts plugs or alky and ACr43ts plugs
a turbo tweak chip for the combo (id the injectors and the turbo first)
an adjustable fuel regulator
60#injectors should cover the turbo you have
shift kit and trans cooler if it hasnt already been done
a scanmaster
some sticky tire like MT et street radials (and a driveshaft loop)
and if you can tune you should be well past the 12.5 goal and most likely 11.5s or faster with the boost turned up
and ps ..I'd replace that cheap flex upper radiator hose

 

[kshef]

good tires, good fuel, more boost

12.5s is too easy on a stock turbo/intercooler/motor

 

[Pronto]

I'ld pull the engine and put a sbc in it so it will run 12.5. No sense running the TB since is will be faster than that.

 

[Red C5]

Run at it as is and see where you're starting from.

 

[drd21968]

thanks for the responce man you guys can tell a lot just by the pics.i havent even picked it up yet.i will see what i have and post more pics first of the week.i paid a forth for this car as my other gn.it needs work ,still i got a great deal.i just want to make it run with my other cars.and honestly if i could do it without breaking engine parts,it would be amazing to see the gn run with my viper.i have a typhoon i just picked up forged pistond,rods,scat crank.it broke the crank.how bad are these cars to break internals,i havent got the typhoon back together yet, i dont want another broken turbo v6.

 

[87granny]

Read my sig it does 12.5 at 109 without pushing it and i found out 3 times at the track that i can't drive for $hit so no pinks for me :biggrin:

 

[scojack_2001]

thanks for the responce man you guys can tell a lot just by the pics.i havent even picked it up yet.i will see what i have and post more pics first of the week.i paid a forth for this car as my other gn.it needs work ,still i got a great deal.i just want to make it run with my other cars.and honestly if i could do it without breaking engine parts,it would be amazing to see the gn run with my viper.i have a typhoon i just picked up forged pistond,rods,scat crank.it broke the crank.how bad are these cars to break internals,i havent got the typhoon back together yet, i dont want another broken turbo v6.

Congrats on the purchase. Ive been beating on my car since I bought it in 2007 and havent broken anything (major) yet. The only real thing that let go was the original posi. As far as I know, its still a stock motor. Only did valvesprings and a timing chain to it.

I ran mid-low 12s all day long on the stock turbo/IC/convertor setup. Basic upgrades only.

 

[GNregistry]

Lots of Fun and Fassst for simple bolt on mods, 0-60 in 3.5 seconds

Fixer Uppers are fun...

Pick your budget, acquire parts... study your car...
my GN cat converter looked like a pottery class....
Brakes, Exhaust, Fluids, Ride are essential for 12's, 125 mph

I purchased my GN as daily driver and drove it until the bumper fillers needed replacement... check out my signature and mods, links etc...

106,000 miles, stock rear end - added HR Super Sway Bar, HR Upper and Lower Control Arms, Air Bags
May 2010 Updated to 245/50/16" Kumho Street Tires, quarter mile back to back at Bowling Green 12.49 @ 109, REMOVED FLOOR MAT for next 1/4 mile pass, 60' - 1.806, 12.396 @ 108 mph, 1/8 mile 7.900 = 88.88 mph
TA 49 Turbo, FMIC, 60 inj, RJC PP, no alky yet...

Same Car. Same Track = 87 GN Bowling Green, KY 1/4 mile
Prior to HR Suspension on stock grand national, 60' = 2.3 - 2.7 May 2009
Added HR Suspension 60' = 1.80 in Oct 2010

$1,100 for HR Suspension upgrade 2.3 - 60 foot time for stock rear end down to 1.80 60 foot time on 245/50/16" STREET TIRES...

What I wished I had changed immediately -
coil pack, spark plugs, wires, pcv valve, maf/translator,

always check quality of fuel and air...
turbo buick.com is all you need...

2008 Original 88,000 miles GN, Bad Brakes, Bad Turbo, Yet Solid Body
2009 13.2 @ 105 mph -- 60'=2.3-2.7
2010 12.39 @ 108 mph -- 60'=1.806
2011 shooting for 11's and/or 60 foot 1.7's wth street tires...
MT Drag Radials mounted on rims and waiting for chance to Race...
Add Razor Alky... and see what happens in 2011.....

 

[Razor]

Get a scanmaster first. Watch for knock. Thats why you get a scantool. If you try listening for it.. you'll blow the motor up.

Start on the scantool.. setup the engine parameters and confirm things are working as should.

Then you can start flooring the car and as long as there is no knock.. you have a green light to tweak it out.

From there.. sticky tires, boost, chips, octane, etc.. and get it figured out. This cannot be accomplished without a scantool.

 

[drd21968]

well the car in the pics isnt stock ..looks like youve already got a turbonetics turbo with turbonetics external gate on the exhaust housing, that turbo could be a t44 a t60 or even a t66
but still on a stock maf and fuel regulator
is there a cam , any port work on the heads ?
test pipe ?
how does it idle/run ? blms o2s
what chip/injectors?

if :
the converter is matched for the turbo and spools
trans isnt slipping
the ignition is working properly
the cooling system maintains the temp around 170s (160 thermostat)
injectors arent too small
fuel pump is upgraded
the gate maintains boost properly without creeping up
and the engine is sound

all i see you needing

some race gas and ACr42ts plugs or alky and ACr43ts plugs
a turbo tweak chip for the combo (id the injectors and the turbo first)
an adjustable fuel regulator
60#injectors should cover the turbo you have
shift kit and trans cooler if it hasnt already been done
a scanmaster
some sticky tire like MT et street radials (and a driveshaft loop)
and if you can tune you should be well past the 12.5 goal and most likely 11.5s or faster with the boost turned up
and ps ..I'd replace that cheap flex upper radiator hose

well sir it sounds as if you have played with the gn and know your way around.thanks for the advice, and yours is the plan i am going with.

 

[machinegun]

The answer to this question will be as varied as the people on here.

I personally have gone mid 12's with little done to the car.

So here is my recipe.

Do the spring cleaning on gnttype.org

This will ensure your drive train is in good condition.

Next ensure that all suspension components are in perfect working order.

Next ensure your transmission is in perfect working order.

Do all this before doing anything else, once complete here are my items.

Good scan tool, without it you have no idea what the car is doing.

good quality boost gauge, needed to tune.

Fuel pump and hotwire kit. Although not technically needed it is one item that can really save your bacon.

Remove the stock exhaust and replace with a good quality one. The hooker with aerochamber mufflers works very well and is reasonably priced.

Cold air kit, get rid of the stock air box.

Adjustable wastegate to tune the boost

Adjustable fuel pressure regulator to help tune.

A good chip, Turbo Tweak, Red armstrong, Max effort all make good chips.

If you can gut the CAT.

Some sticky drag radials would help but you can do it on street tires

Everything else with a good tune will run mid 12's

Next is tune and practice.

Again follow the first items in this list. The primary components must be in good working order and your goal will be easily attainable with very little in expense.

Hope this helps.

If you are near me you are welcome to stop over anytime, I will be more than happy to help.

 

[machinegun]

I never looked at the pics but if that is the car you have, depending on what is done if there is a matching combo of turbo, fuel mods, chip, trans that with tunning and fuel I bet will be in the 11's.

I guess I would really need to know what you have though.

 

[Heg87t]

Add your location to your signature information. You may have a knowledgeable board member near by that can lend you a hand.

 

[kshef]

12.396 @ 108 mph, 1/8 mile 7.900 = 88.88 mph
TA 49 Turbo, FMIC, 60 inj, RJC PP, no alky yet...
/QUOTE]
thats stock turbo/intercooler MPH...run the wastegate rod up a few more threads

 

[87granny]

well sir it sounds as if you have played with the gn and know your way around.thanks for the advice, and yours is the plan i am going with.

He's a Jedi master when it comes to GN's he touches your hood and it's .5 faster:biggrin:

 

[drd21968]

well i think 12.5 may be a little conservative.i think i will go with the advice here and from my recent research,11.5 seems to be possible without breaking anything.if i can get this out of the car,i will be very happy.picking it up saturday,i will have pics and a real look at the car monday.thank you all for the advice i have already learned a few things,regards,don :smile: