Same Stuff You've Heard For Years.. but,

[gnman87]

I've been dabbling in Turbo Regals for a LONNNNNNG time now. I had an 86 GN for 7 or 8 years.. and never really achieved what I wanted with it.. I've had my current 87 for a few years now.. and after a crank replacement and cam upgrade.. (not to mention lots of chrome) I still can't make it do what it can.

I've ridden in TRs that do exactly what I've heard they can do.. so, I know it's not a myth or folklore.. but, I'm really leaning toward selling this car.

Please check my sig for all the upgrades on this car.. The only thing that's kinda foreign to me is the alky set up. Here's what I know about it.. the chip is burned for it (jay carter alky chip at 22*) and it kicks in at 11psi boost.

I'm running about 16-17 psi boost now.. and I still get 3-6 -- sometimes more -- knock retard. I'm running a ton of fuel pressure .. but, still the car -- in my opinion -- is slow.

I've got a 95 Viper too.. this car would SMOKE my GN. I've also got a supercharged 98 Vette.. No contest.

With the upgrades I've got in my GN.. I would assume I should be well over 400 horsepower.. the same as the Viper.. I'm just not feeling it.

I know I'm not the only frustrated GN owner out there -- but, I also know there are a ton of very satisfied ones.

Yes, I've read all of the recipes.. I was around for the old #BuickGN channel on IRC. I've been shooting the **** with you guys about these cars for years.. and know an aweful lot now.. I'm just really a ****ty tuner.. or I've got my second lemon. I'm guessing it's me.

Can you guys do me a favor and just step by step help me to diagnose this damn thing? I'll take all advice..

BTW, don't tell him .. but, my dad has an 86 T-Type.. stock stock stock -- I'm quite sure he's smoke me in a race.

thanks for your patience.
jp

 

[suicide six]

Scan tool readings?if not get yourself at least a scanmaster.

 

[gnman87]

I have a scanmaster

mounted on top of the ac/radio area. You want all of the readings? I can give you all the idle numbers.

I also have turbo link .. but, haven't run it in a while. I'll get you some numbers and report back.

jp

 

[SloGN]

i think the stock turbo and ported elbow is holding the car back. with the cam you have you should upgrade to a turbo that can keep up. i have a gt61-52e with a 3" terry houstan down pipe. what type of intercooler do you have. if it's a stock you should at leat get a duttweiler big neck for it to some more flow thru the intercooler.

 

[Geoff87]

never really achieved what I wanted with it

I still can't make it do what it can.

First you have to define what the above means.......

You say that you've read all of the recipes.... Are you following any of them? If so, which one?......

Do you have any 1/4 Mile ET goals? If so what are they? Any 1/4 mile passes? It's kind of hard to quantify anything using a butt dyno...

Run some higher octane gas, or get an alky kit. Then crank up the boost!

 

[turbo2nr]

16-17PSI with stock heads, stock turbo, stock ex. elbow is going to feel pretty darn slow compaired to a viper. About a 13sec car on street tires.

Please tell me you at least have removed the cat.

Better down-pipe! Bigger turbo, alky, more boost, more cow-bell! Maybe heads/roller cam. You should be able to spank that viper and still get better gas milage.

 

[gnman87]

butt dyno --

good stuff.. but, you guys know as well as I do that it's a pretty good guage. It doesn't do what I know it should.. and feels slower than my dad's stocker.

I have alky
I have a 3" downpipe
yes, cat is gone.. running a test pipe
yes, duttneck intercooler. I can't crank the boost much higher.. as knock is my chief perfomance problem.

I know it's tough to diagnose just hearing my moans.. I know a lot about this car.. but, seem to suck at tuning it.

Anyone in San Antonio Texas who can tune these things?

jp

 

[gnman87]

p.s.

with the mods I have (listed in my sig) I should be eating the Viper for dinner... easily.

jp

 

[INTERCOOLED]

I agree with the fact that you are limited with the stock turbo. You have updated the DP, injectors, etc. But you have to do something about the turbo, especially a rebuilt one. I know that they are expensive, but that would be the next smart move.

Back in the day, I was running a TE-44 with a similar set-up and running low 12s, easy.

 

[wiked87gn]

you also mentioned above that you are running a ton of fuel pressure,(how much fuel pressure) running to much fuel will slow the car down because is running to rich, while the car in park and running take off the little hose going to the fuel pressure regulator and read what the gauge says set it at 43psi line off and forget it about it with the line on it should be around 36psi., At WOT the readings on your scanmaster should be around 760-790 range anything above 800 on top of 3rd gear is considered running rich, like they said before bigger turbo like a TE44 or TA60 to match your 3,000 convertor, a torque strap to prevent the downpipe hitting the frame creating false knock, turn up the turn on point for the alky to at least 14psi, making it come on to early will bog the car down, tune, tune, tune and you should be able to spank your viper in no time.

 

[Fuelie600]

Let's not change any big parts for now. First thing I would do, would be to install a fresh set of plug wires and spark plugs ( gapped @ .032 ). Second, is to remove the intercooler, and flush out the oil that has built up in it from the stock breather hose. You state that you run 16-17 psi---verify that you have enough fuel pump, as the original might be tired. With that amount of boost, you should see 60 psi FP at WOT in third gear. Start with this, and report back with your findings, and Scanmaster readings. Brian

 

[VadersV6]

Without data its hard to come up with any ideas. "high" fuel pressure isnt very good data. I have about 42lbs at idle, line off.
As far as the basics go, have you ever done a compression or leakdown test?
If you block the PCV valve line, do you have alot of blowby coming out of the valve covers?
A slow spooling turbo can make a turbo car very dull. The difference between the stock boost solenoid and my own boost controller is dramatic. The boost comes up so quick that if I had to lift the throttle when it starts boosting, i wouldnt be able to pull my foot fast enough. It goes from 0-20psi in a heartbeat (at half throttle), while with the factory boost solenoid, it spooled slow as hell. I have a completely stock exhaust, with a smaller than stock cat, an extrude honed stock elbow and stock DP. The car still MOVES. It runs out of steam at higher rpm's, but thats valve springs. You need a bigger turbo. You need to make absolutely positive that you have no exhaust leaks before the turbo.
How active are your O2 crosscounts?
Is the cam sensor working properly/adjusted right? Is the crank sensor tight and not moving around? Do you have any weak firing cylinders? Pull a spark plug off each coil post while its idling and see how dramatic of an rpm drop you get with each one.
What are your spark plugs telling you? Not the color of the porcelain, but the color of the flat steel area that the ground electrode is welded to.
Assuming you have no exhaust leaks, what are your WOT O2 numbers? You may have rich knock. You really need to be patient and gradually tune the car right. Dont make 5 tune changes all at once. Do 1 at a time, write it down, and think about WHY this change happened, how it happened, and use that info to make your next move. You need to have more control over your tune. Thats why I love the extender chip. You can do so much with that chip for so little money. If I were you, I would ignore the alky for now. Get the boost up to 16psi, and dial the tune in. Go leaner and leaner till you start to knock. Richen up a little bit it gradual steps until it just goes away. Then set up your alky to turn on at a high boost level. This really smooths the transition between alky off to alky on. Keep the boost at 16, and watch the O2's when you go WOT, and wait to see what happens to them when the alky kicks on. Adjust your WOT fuel in the lean direction until the knock comes. Then richen it up just till it goes away. At that point, write down what your O2's are. Dont worry about some magic O2 number that people throw at you. That factory o2 sensor sucks, and the numbers will variate alot from car to car. Its good to spray the alky at full pump voltage to get a good spray pattern, and tune WOT fueling around that. This is easy with the extender/LS1 MAF and extender combo. Next, up the boost a few psi, and do that whole tuning procedure over again. Keep doing this dance until you're at the boost you want and you dont get knock.
How are your BLM's?
Is your EGR working? Is the EGR solenoid working? Is the backpressure in the exhaust forcing the EGR valve open when you go WOT?
Have you jacked the car up and checked for dragging brakes? Mine were dragging severely after swapping my rear end.
You sure your converter isnt locked when you go WOT?

 

[GN1]

i still agree bigger turbo and if you dont have a after market fuel pump get one also make sure that torque converter matches tour turbo if it doesnt there might be part of your problem

 

[Paul Clark]

Like what VadersV6 said - unless the timing in the chip would make things a bit dangerous - I'd start off tuning without the alky.
You should tune to get 16 or so lbs. of boost with no knock on 93 octane.
Then start turning up the wick.
It's all there someplace. Just gotta find it.

 

[gnman87]

Great stuff guys

a few things..

no EGR -- took it off.. and blocked the hole. No leaks.. not an issue.

took off the pcv and tube to intercooler -- got the small breather there now. not leaking oil there.

The intercooler is clean as a bell.. it's only been in for about 1000 miles -- since the crank and cam.

Plugs and wires? Will do. Haven't done them yet.

o2 cross counts change a lot. WOT 02s always over 800 sometimes 850-870
I was told to NOT look at this with the alky as that screws those numbers up.

line off fp? high.. I turned it up to try to stop the knock. I think it's 40-41psi line off right now.

I kinda feel like turning the alky off.. and going to 15 psi to get a stock starting point..

also running a 22* alky chip right now.. but, have a 97 octane thrasher available.. and casper's thumbwheel for 36# injectors. What would you guys do there?

thanks for the help.

jp

 

[blackstallion]

I agree with the lack of data. Have u tried checking for a wiped cam lobe.?

 

[gnman87]

brand new cam

I'm not thinking that's it.. it's brand new.

I will bring more data tomorrow.

jp

 

[bison]

Have you done a compression or leakdown test? Your cam is way wrong for the stock heads and turbo. A 200-200 would have been a better choice. The 3000 stall is hurting your performance with the stock turbo also.You need to determine your cause of knock. Feed us some data. Fuel pressure @17psi, O2 readings, TPS voltage, and plug wire resistance and plug gaps would be nice info. Has the fuel filter ever been changed? Put in a fuel pump and remove the restriction in the sender asap. Hotwire the pump also. The stocker is barely adequate for the stock configuration. I raced 2 vipers with my old GN(which was stolen shortly after) that was pretty much all stock including the turbo, and i won by a couple car lenghts in both instances. The car went 12.40 with a 1.8 60'. Anyway that was back in 97. Post up some data. Theres an answer for every problem.

 

[TURBOTWIN2]

Where you at, Man?

Anyone in San Antonio Texas who can tune these things?

jp

Are you in upstate New York or San Antonio, Tejas right now?
If in San Antone, PM me, I might can help this weekend.

 

[SloGN]

a few things..

no EGR -- took it off.. and blocked the hole. No leaks.. not an issue.

took off the pcv and tube to intercooler -- got the small breather there now. not leaking oil there.

The intercooler is clean as a bell.. it's only been in for about 1000 miles -- since the crank and cam.

Plugs and wires? Will do. Haven't done them yet.

o2 cross counts change a lot. WOT 02s always over 800 sometimes 850-870
I was told to NOT look at this with the alky as that screws those numbers up.

line off fp? high.. I turned it up to try to stop the knock. I think it's 40-41psi line off right now.

I kinda feel like turning the alky off.. and going to 15 psi to get a stock starting point..

also running a 22* alky chip right now.. but, have a 97 octane thrasher available.. and casper's thumbwheel for 36# injectors. What would you guys do there?

thanks for the help.

jp

first off you need to get the o2 #'s in the low 800's to 760's range. you could be getting knock due to the fact that the car is running to rich. how fresh is the o2 sensor?. Alky will kill an o2 sensor over time. when you replace it get a denso sensor.