Just bought '86 GN, need advice

[Berman]

Ok, after trolling these message boards for a while I could not resist picking up this '86 GN I found for sale. I had been looking for a project car, was thinking fox body stang, then started checking out GN stuff. So here I am.

I need some advice. I picked up the GN pretty cheaply, but it needs a new turbo. I'm trying to get it on the road for as little $$$ as possible, but I am not hard on cash or anything. I just want to drive it a little before I start modding the hell out of it.

I know all the obvious stuff, change all fuids, clean intercooler, etc. What will I need to get it on the road? The new turbo, obviously, but what other parts? (part #'s would be great). I heard you're supposed to replace the oil line to the turbo, as well.

In addition to that advice, I need turbo advice. If I cannot find a cheap used stock turbo, what should I do? There's no way I'm paying $500 for a stock turbo when I can get an upgraded turbo for $650. And if I'm going to buy an upgraded turbo, it has to be the right one. I hate spending money twice when it is unnecessary.

The 'right one': whatever the most streetable, fastest spool up turbo that can run at least 120 in the 1/4 with all supporting parts. te-45? What about the ball bearing Turbonetics turbos?

What injectors and fuel pump would I need to run with this turbo? Blue tops?

Could I run the upgraded turbo with my stock fuel system if I turn the boost down to 12 psi maybe? This would be just for a few weeks. I'd hate to go buy a whole fuel system only to discover a week later that I need a tranny rebuild.

And yes I have read everything on www.gnttype.org It seems with similar money in the GN that I have in the LS1 it could be even faster. (the ls1 is a 12.5 @ 115 car on nittos with my crappy driving). Most logical people would play with one car and keep the other stock or nearly stock to drive. Not me I have to mod the heck out of everything I own. The LS1 is getting a 150 shot wet kit as soon as I get around to putting it on, I already have the kit.

So, advice please! One more question: I have the origional winder sticker to the gn, and it doesn't mention limited slip anywhere. Does this mean it's an open rear? Yuck.

 

[dconnor]

Ok as I said in the other post you should go ahead & do a Spring Cleaning on the car BEFORE starting in with the mods. It's best to have it in a good state of tune, that way you have a solid base (so to speak) to start with. Here are the 1st mods I'd recommend:

Freebie mods as listed in the recipes section of www.gnttype.org
Scan Tool www.turbo-link.com (check out the comparison!)
solid MAF pipe and K&N or S&B filter ( www.autophysics.com )
Walbro 340M fuel pump
Hot wire kit
Adj fuel pressure regulator
Fuel pressure guage
30/30 boost guage
adj wastegate rod
Thrasher 93 & 100 chips
test pipe w/ dump

With the above mods & the street chip you should have a solid mid 13 second car. With a xylene homebrew, stickies & the T100 high 12's would be a very reasonable goal.

A te-45 is a solid mid ten second turbo & will not work WELL until the car has A LOT more mods (built tranny w/~3200 rpm converter, beefed up suspension, intercooler, 3" downpipe, exhaust, ported heads, etc...) The stock turbo works well deep into the 12's so unless you plan on doing an intensive build SOON, just stick with that for a while.

Once you have the building blocks in place to start gunning for those 120mph passes, a good choice IMO would be the te-61 from John Craig with a PTE exhaust housing. I am running this on my car with an old art carr top-hat converter (9/11") with ~3200 rpm stall. It has excellent street manners, spools very fast & has plenty of gusto to pull 10.6~7's@125+ once I upgrade my car's heads.

As for injectors, 120+ mph is going to take a 50# minimum to be safe & bigger if you'd like room to grow later on down the road. 36# bluetops are only safe to around 115mph & mid 11's

Check your option code sticker in the trunk & look for G80 to see if the car has a posi.

Doug C.

One last thing, hunt around for a reputable TR vendor in your area and see if there is a local Buick oreinted car club. Having a local guru (or several) can be a big help!

 

[Berman]

Thanks for the advice! I was obviously going to do the spring cleaning first. I think I said that somewhere, maybe not.

I think I've found some stock turbos for sale, but I think you've convinced me to get my stock one rebuilt if I can't find a used one.

 

[Drthv8r]

Define "needs a new turbo". Is it just blowing/leaking a lot of oil? If so you can overhaul it. I purchased an overhaul kit a few years ago from John Craig for $75.00 and overhauled my stock 87 turbo. It's not all that hard to do, and it's still going strong. Something to think about.

IMHO ball bearing turbos aren't needed. Not much bang for the buck with them suckers...

As mentioned no G-80 on the trunk sticker=peg leg. Stock fuel system sucks, plan on purchasing a good adj. fuel pressure reg. along with a good fuel pump and hot wiring it. What sucks worse then the stock fuel system? 12 lbs. of boost on these cars...LOL.

Sounds like you're doing your homework and doing a lot of reading. This will pay off for you later. You can throw a lot of good money after bad with these cars. Plan on purchasing a good scan tool, you're gonna need it. Hope this helps.

Oh one more thing...Thrasher chips. Some like them, some hate them. I'm running one in my Turbo Regal and it works fine. The best $20.00 I spent so far with these cars, plus theft deterent to boot.

 

[Berman]

Originally posted by Drthv8r
Define "needs a new turbo". Is it just blowing/leaking a lot of oil? If so you can overhaul it. I purchased an overhaul kit a few years ago from John Craig for $75.00 and overhauled my stock 87 turbo. It's not all that hard to do, and it's still going strong. Something to think about.

There is a ton of play in it. The wheel moves around everywhere. Definately needs to be rebuilt. Nothing looks chewed up inside, so I would think the core is fine.

IMHO ball bearing turbos aren't needed. Not much bang for the buck with them suckers...

My only previous turbo car experience was owning a DSM. When you've only got a 2 liter engine and only a stick shift car, you need everything possible to spool up the big ass turbo you're going to need to make any power. The ball bearing turbos make those cars spool on average 500 rpm sooner.

As mentioned no G-80 on the trunk sticker=peg leg. Stock fuel system sucks, plan on purchasing a good adj. fuel pressure reg. along with a good fuel pump and hot wiring it. What sucks worse then the stock fuel system? 12 lbs. of boost on these cars...LOL.

Dammit, I got a peg-leg car. ****.

Sounds like you're doing your homework and doing a lot of reading. This will pay off for you later. You can throw a lot of good money after bad with these cars. Plan on purchasing a good scan tool, you're gonna need it. Hope this helps.

I'm going to buy Turbo-Link immediately. I use AutoTap for my LS1, I doubt it's that much different. Probably easier because there isn't all the dumbass obdii stuff.

Oh one more thing...Thrasher chips. Some like them, some hate them. I'm running one in my Turbo Regal and it works fine. The best $20.00 I spent so far with these cars, plus theft deterent to boot.

I was reading their web site last night and decided I'd try one of their chips. $25, what the heck. 'Custom' ecu's for LS1s are like $500. (it's a huge ripoff) I like the theft deterent too. On that topic I need to wire up a hidden fuel pump cutoff switch.

Why do some hate the Thrasher chips? Are they real agressive and cause knock on some cars?

 

[Jimn8or]

OK, I can't resist responding to this post...dconner has offered some good advice to you. I will only sway a little from his recommendations slightly. If your stocker turbo is hooped, you can have it converted to a TA-49 for the same money...more or less. This turbo will work excellent with your current converter. If you want to buy injectors once, and don't want to have your ECM modified, buy MSD 50's. These will be a little ragged to get your 120mph wish, but it has been done with smaller injectors than these. Above all, get at least one scan tool and follow the instructions given. Your GN will kick your LS1's ass within 1K.
HTH
Jim

 

[azgn]

when my GN was running 115 in the 1/4, the et's were in the mid to high 11's...get the picture?

You will get a much better et/mph out of a GN because of the 4 link suspension and instant torque.......

 

[Berman]

Originally posted by Jimn8or
. Your GN will kick your LS1's ass within 1K

My ls1 runs 12.5@115. I'll be truly impressed if the GN bests this for $1k. If I did big burnouts in the ls1 and had some suspension and a working clutch, I imagine the car could run an 11.

 

[Berman]

Originally posted by azgn
when my GN was running 115 in the 1/4, the et's were in the mid to high 11's...get the picture?

You will get a much better et/mph out of a GN because of the 4 link suspension and instant torque.......

Damn. I guess I've been thinking in LS1 terms, where everyone has silly mph and poor et. Except the guys with automatics and 3500 rpm stall converters. They run awesome.

 

[dconnor]

My TR ran solid 12.60's@110mph on the "stock" old combo & I was being held back by the hooker headers (they cause MAJOR lag in anything slower than a low 11 TR) the previous owner had installed and the fact that I'm not a huge fan of running my cars on the ragged edge. Ran around all the time with ~22lbs of boost, a Thrasher 100 chip & xylene homebrew mix in the tank. Not including those cruddy headers & tires (M&H G60 Racemasters) the car had right at $600 in go fast upgrades.

(warning bench racing about to commence!)

With a set of stock headers, VP c16 in the tank, a more aggresive race chip & 24+ lbs of boost I honestly think the car could have gone 11.9's@~112 or so!

Doug C.

 

[Jimn8or]

Stand-by to be impressed. Put some DR's or slicks on the GN with a K&N [cold air intake], proper 2 1/2" exhaust, a hot-wired Walbro 340and AFPR, a chip and a TA-49 and I'll let you drive the LS1 against me in your GN! Loser has to buy plenty Cervesa's! You will be absolutely amazed at what that little V6 does to 454's and 426's at the track, let alone all your LS1 buddies.
Welcome to 'Going FAST with class'
Jim

 

[Drthv8r]

Thrashers seem to work better with some cars then others. If you're going for the big numbers look for a custom chip burned by any of several people here on the board.

I've never tried a Thrasher race chip but the 92 chip works well for my mostly stock Turbo Regal. I mentioned the Thrasher as a good way to get your feet wet while you think about what you want to do with your GN. Hope this helps.


This run isn't out of the norm, I posted this in another thread.

A friend of mine on his 87 GN installed a K&N, adjustable FP Reg, boost gauge, JL Street Chip, (made the actuator rod adjustable), Cam-11, and with BFG Drag Radials ran a 12.7@105 MPH. The car was in a good state of tune. As posted before turning is where it's at.

 

[Berman]

Originally posted by Jimn8or
Stand-by to be impressed. Put some DR's or slicks on the GN with a K&N [cold air intake], proper 2 1/2" exhaust, a hot-wired Walbro 340and AFPR, a chip and a TA-49 and I'll let you drive the LS1 against me in your GN! Loser has to buy plenty Cervesa's! You will be absolutely amazed at what that little V6 does to 454's and 426's at the track, let alone all your LS1 buddies.
Welcome to 'Going FAST with class'
Jim

My LS1 is afraid of GN's after a guy with a really worked one put a hurtin on me.. Definately made an impression - maybe part of the reason why I bought one.

I can't wait I have a new turbo on it's way here, it will arrive sometime next week. I will do the 'spring cleaning' and immediately go to Gainesville raceway. Actully, I'm going to bring both my cars there - run one while the other cools down. Got a new clutch in the LS1, hopefully I can get in a couple good runs before it starts slipping. I wish I had known it's impossible to make a clutch that ****ing works correctly for the LS1 when I bought it - would have got an auto.

I think I need to fix up the interior of my GN a little before it's going fast with class..

 

[86brick]

The best advice I can give you for making these cars run is tunning and launching the car makes a world of difference! If the car is in a proper state of tune and you are getting decent 60' times(1.8's or better) you should have no problem running very low 12's to high 11's with just bolt on mods, however, some have run mid to low 11's with bigger converters, turbos, and more boost! Like somebody mentioned a scan tool is very important(I would suggest a Scanmaster to start cause it's pretty simple and you won't need a laptop). If you plan on staying with the stock D5 converter you should lock it up (by getting a lock up switch and manually locking the converter most guys see the ET drop by 2 - 3 tenths and gain 2 - 3 mph in the 1/4 mile). Also, I would replace the factory POS plastic timing gear and link chain with a high quality Billet double roller timing chain set cause if the factory POS timing chain goes you'll be looking to rebuild your LC2 motor real soon!!! Some guys have had them last close to 150,000 miles, but some have had it go at 100,000, so IMO it's well worth it to upgrade to the better double roller cause my buddies went out at 104k miles and if he would of spent the $100 to replace it the car would most likely still be running strong. Another mod that should be a no brainer is a tranny cooler to help eliminate heat cause that's what causes most of the 200R4's to break, so this is another mod to help with the longevity and durability which IMHO is very key, yet overlooked by some. Good luck with the GN and above all if you need any help or have any questions you should post them on this BB cause there is a lot of knowledge that can be given and most everybody is willing to help

Later, Steve

 

[Two Lane]

The advice on the timing chain is a must...what brand is considered best all-around for the 3.8?

 

[Berman]

You guys like one brand of timing chain over the other? I will replace this immediately as well.

 

[86brick]

Applied Technologies & Research, Inc. (ATR) sells a high quality double roller timing chain set for $90. If your interested their phone # is 864 -972 - 3800 or they have a website www.atrperformance.com. Make sure it's a Billet double roller (the best IMO). BTW, you do not use the tensioner with a double roller set.