New gn!

[87grandnational]

Hey guys, told you i was searching for a GN agian and i stumbled across a 84 hot air, hard top. I was thinking about buying it and restoring it back to original specs, or dropping an 87 drive train into it. Just a few questions.

- How hard would it be to set up an intercooler in the 84 gn?

- What times do the 84-85's run STOCK.

I know the stock boost is 12.5psi for the 84-85, but he has upped it to 17psi, it shows on the Aftermarket Boost gauge. A 4 1/2 psi gain. (40hp +/-). My question is this. When i get the car, a shop has a 3 inch hooker turbo-back? exhaust for the car (20hp +/-?). And a K&N Cold Air intake. (5hp? +/-). It has normal tires 245/60/15s.

After the dyno tuning and the stuff i put on it. I should be up to around 275whp and 360lbs tq. Shouldnt that put me in the low 13s if i can hook.

I plan on upping it to 19.5-20psi (to get hit that 300 mark). my gn had around 400-450 at 26psi, i bought it from a guy that did all the work but didnt tune it right.

It should have around 300rwhp +/- and somewere along the lines of 375-400lbs/tq after the tuning and upped boost.

Plus i plan on getting some streetable Drag Radials.

Do you guys think ill be able to hit 12s? The guy wants around 2500-3000 for it. i have 1,500 right now. dad is gonna help me out on the rest so we can keep the other car.

It right now has a bad exhaust leak which i already got my dad to agree to get the exhaust, and ive got a bit of money from my brother for a late b-day present to get the intake. and my uncle has some tires that will fit.

so yeah i SHOULD be high 12s capable with around 4k total (including the car) this will hold me over til i can get my new 87 w/t-tops gn

What do ya guys think?

 

[dragonational]

i dont know alot about gns yet but i do know that you need the fuel. I dont want to insult you b/c you probably know more about these cars then me. I would start with a new fuel pump and adj. fpr a good chip and all that stuff. Then worry about the intercooler and intake. just my 2 cents. Harry

 

[1QUICK85]

First off, I hope that car isnt seeing any knock at 17psi, does it have a knock gauge? On pump gas I cant see getting more then 15psi out of a stock setup?? Does it have any mods done to it?? If he has the boost turned up does he have an adjustable fuel reg. on it too??What kind of condition is it in? Mileage?
What kind/brand of cold air intake is it, just a filter?

From what I have read/heard no 84/85 has made it to the 12's on a stock turbo. If you can find a cheap 86/87 stock turbo that will be an improvement over the stock 84 turbo and you can dip into the 12's with it. I would start with the basics like dragonational said.........fuel upgrades, exhaust(cat-back, racepipe, downpipe, up pipe, make sure your stock headers have no cracks), 9in. K&N filter at least, something to monitor the engine and knock and to tune the b!tch with. Gauges or T-link.

You can find intercooler setups for the 84/85 cars on this board, used setups go for around $500, maybe cheaper.

But, if you want a 87 t-top GN then why not just save your money and get one of those? I hate to see ya buy a hot air and be disappointed with it.........I mean I know how some of the Intercooled guys think we give the turbo buicks a bad name.........bullSh!t......

Oh ya a stock "HOT AIR" runs mid to low 15's.......some have gotten high 14's.......depends on conditions, vehicle condition and driver.

 

[cool 84]

It seems like the hotair #s are all over the place. The first mods should be like an IC car. Fuel pump, regulator, up the boost, K&N, and chip.

I could run a solid 17psi on pump gas with mine without knock. After the IC and other mods I could only run 15-16 but with much more power.

An IC is a great mod to these cars. Spearco makes a kit but it costs a lot. I had the Spearco but decided to try the Ford Powerstroke unit and I haven't regretted a thing. You can do the whole thing for ~$450 and gain a ton of power.

My dad's hotair with chip, filter, 19psi, went 14.0@100mph on street tire, pump gas. Mine with only an intercooler and downpipe went 13.9@101mph with 14psi. I went 12s pretty easy on pump gas but never got the car to the track with racegas.

The 87 drivetrain is a drop in. You'll have to change the computer and wiring harness and adapt the powersteering along with some minor stuff like the vacuum reservior and battery cable.

 

[cool 84]

I would like to mention that I've gone 105mph traps on the stock turbo which is plenty for 12s, just always had old cheap tires.

 

[1QUICK85]

I was always under the impression or told that the stock turbo was just not capable of getting you into the 12's. I guess I have learned something new about our underdog hot airs.

 

[85 TR]

please tell me what you had done to run 105 mph in the quarter with the stock turbo i only trap 97 at 15 psi can our stock turbo handle more psi with ported heads and intake than 15 thanks.