Why won't car E.T. ?

[Bigblok71]

I need some help figuring out why my car is soooo slow ? I am a newbie to the Turbo Buicks so be gentle. I am an old school big block guy. I have recently purchased a 1987 GN all orig. 30k mile car. When I bought the car it had a JET chip and was completely stock other than that. I have just installed a 3" cat back exhaust and a cold air intake. Went to the track last week and realized I have lawn mowers faster than this car. I have new BFG 255's on the rear and was able to leave on 5lbs. of boost. Car went 14.50's @ 93mph. with a 2.0 60 foot. I know slicks will help but the 255's hook a lot better than stock. temp was 92 degrees and a lot of humidity. HELP. HELP.

 

[HelloBozos]

You spun!!....If on 93 octain only ,an under 15 lbs boost.You''ll only gain ET hooking up better....Want to "go fast"? , Loose the "Cat", Add race fuel, Turn the boost to 19-20 lbs,An Last, get sticky tires,You'll drop a Full Second of your times if not more!!!!

Enjoy!

 

[scgnx2]

Those numbers are pretty much what a "stock" GN ran back in the day.
These cars are completely different then the big blocks. So, you have
alot to learn. The good news is you found this great website. Some of the
most knowledgable Turbo V-6 guys are here. Do some searches on tuning, etc.
You'll get the phone book. Get a scanmaster to start and tune the car as is, before
you do anything. I would not race the car further without knowing the readings for
O2's, knock, BLM's, etc.

 

[Mr.Spool]

these cars need boost and at 15psi and a 2.0 60ft that's around what it should do.put more boost into the motor with the proper upgrades and leave on boost using drag radials and 12 second passes are easy to reach for very little money.

 

[Bigblok71]

The car didn't spin leaving on 5lbs. I increased to 6lbs. next pass and it wouldn't hook. So you guys are telling me with no chip and exhaust and cold air this thing would be lucky to run 15 O's ???????????? If I junk the old school JET chip,,, and get a test pipe,,, and install a TT chip can I see any gains ? If not I don't want to spend any more money on this car ? The reason I went to the track with these tires is I want the car to go as quick as it can on street tires w/o using drag radials.

 

[we4Mateo]

The car didn't spin leaving on 5lbs. I increased to 6lbs. next pass and it wouldn't hook. So you guys are telling me with no chip and exhaust and cold air this thing would be lucky to run 15 O's ???????????? If I junk the old school JET chip,,, and get a test pipe,,, and install a TT chip can I see any gains ? If not I don't want to spend any more money on this car ? The reason I went to the track with these tires is I want the car to go as quick as it can on street tires w/o using drag radials.

Test pipe will help but look at it this way. With a big block you are used to, you get good mass air flow and thus good power just by starting the engine up. The only way to get more mass air flow out of a turbocharged vehicle is by increasing boost. The V6 will make the power, but that's the fun part, figuring out how to get the mass flow numbers up when you don't have an abundance of cubic inches to work with. The factory airbox may not have been a restriction yet though so you may not have realized the gains from that yet bu you will! It's all about the combo. Get a TT chip, a scanmaster to adjust the TT chip and monitor the motor, and increase the boost safely by using a little race gas or alky and go nuts! These cars are a reward when you get them figured out, but you can't turnkey a stock TR and expect to go fast like you can in a big block car. It's like a science experiment every time you drive a TR.

 

[whitehot1]

You have a good stock gn to start with so you are doing good. Now do a few mods to go fast and you will like the car more.

160 degree thermostat,60 lb injectors with matching Turbo Tweak chip,new performance fuel pump and hotwire kit,K&N open air filter,adjustable fuel pressure regulator,scanmaster,sticky tires.

 

[big reazon]

x2 to what whitehot1 said

 

[bison]

I've turned one of these from a mid 14sec stock car to low 12's in one day. Fuel pump, chip, slicks, 24psi/26*, 110 octane, a little practice launching. The car ran right where it should for 92* air and almost stock. All the above was done with no other issues like bad wires, plugs and all grounds clean and secure.

 

[John Larkin]

Now do a few mods to go fast and you will like the car more.

What he said. They are kinda doggy stock, fun but not real fast. You're going to have to spend some more money. Decide on a goal, buy once, be done. More money is wasted on upgrades than anything in my experience.

 

[UNGN]

What others have said, but the next mod is a "Test Pipe" to replace tha cat.

If the car has a new, hotwired fuel pump (the stock pump has got to be long dead), make an adjustable wastegate actuator, add some race gas for knock insurance and crank in a few lbs of boost and it will be easily in the 13's @ 105.

Only Run the car in D, never in OD and tune for best mph, forget ET until you get some sticky rear tires.

The Stock turbo, fuel injectors, intercooler, rear axle, etc. are all fine to 12.0@110 mph (with a race gas mix and sticky tires) and you really don't don't have to buy a lot of "bolt ons" Other than a good K&N and Free flowing exhaust to get there.

A good race chip like an old "Thrasher 108" with TC lockup is a great Stock injector race chip...people probably still have these in their glovebox they''ll part with for $20, and a FP regulator. If the injectors are still stock don't spend a lot of money on a chip for them.

Get a good chip if/when you upgrade the Fuel injectors (if switching to E85 or wanting to run faster than 110mph in the 1/4)

 

[Bigblok71]

Thanks guys for all the input. Can anyone tell me,,, if I already have the 3" exhaust and cold air set-up and I put in the (test pipe) (160 thermostat) (Walbro 255) (Hot wire) should I add this scanmaster ? AND do I have the TT chip made for these mods ?

 

[SIXBANGR]

Thanks guys for all the input. Can anyone tell me,,, if I already have the 3" exhaust and cold air set-up and I put in the (test pipe) (160 thermostat) (Walbro 255) (Hot wire) should I add this scanmaster ? AND do I have the TT chip made for these mods ?

yes and yes.

 

[GNONYX]

What others have said, but the next mod is a "Test Pipe" to replace tha cat.

If the car has a new, hotwired fuel pump (the stock pump has got to be long dead), make an adjustable wastegate actuator, add some race gas for knock insurance and crank in a few lbs of boost and it will be easily in the 13's @ 105.

Only Run the car in D, never in OD and tune for best mph, forget ET until you get some sticky rear tires.
The Stock turbo, fuel injectors, intercooler, rear axle, etc. are all fine to 12.0@110 mph (with a race gas mix and sticky tires) and you really don't don't have to buy a lot of "bolt ons" Other than a good K&N and Free flowing exhaust to get there.

A good race chip like an old "Thrasher 108" with TC lockup is a great Stock injector race chip...people probably still have these in their glovebox they''ll part with for $20, and a FP regulator. If the injectors are still stock don't spend a lot of money on a chip for them.

Get a good chip if/when you upgrade the Fuel injectors (if switching to E85 or wanting to run faster than 110mph in the 1/4)

This maybe a dump question since I haven't race as of yet, but leaving the it in D and running at 110 miles would that damage or heat up the tranny? Also why not leave it in OD for the extra gears? Thanks

 

[scojack_2001]

This maybe a dump question since I haven't race as of yet, but leaving the it in D and running at 110 miles would that damage or heat up the tranny? Also why not leave it in OD for the extra gears? Thanks

That bogs the car down too much and actually slows you down. Leaving it in Drive for that short of a time wont hurt anything. Besides these motors with stock cams only spin to 52-5300rpm anyway.

Id do everything everyone else said except for maybe the 60s. I dont think you need those just yet. I went 12.40s on the stock original 28s with alcohol on DRs. Stock turbo/intercooler/converter/downpipe & elbow through the exhaust. That was with all the other basic support mods (fuel pump/hotwire/regulator, etc..) Thats on a non alchy TT street chip as well.

Ported turbo, IC, and plenum it went 12.0s all day long. Was soooo much fun.

 

[scojack_2001]

Oh, and the first time I raced my GN on street tires. It went 13.40s at like 104ish at 20psi.

I have gotten a 1.85 60' time out of a true 275/60/15 BFG Radial T/A before.

 

[Red C5]

I've never had good luck with BFG tires at the track. Also figure at only 5psi, you're not making much power, especially when you're used to a big block that's got tons of torque down low. These cars have plenty of potential but they do take a bit of figuring out. Congrats on the low mileage find.

Peter

 

[UNGN]

This maybe a dump question since I haven't race as of yet, but leaving the it in D and running at 110 miles would that damage or heat up the tranny? Also why not leave it in OD for the extra gears? Thanks

Shifting into OD @ WOT will do more damage than any heat build up running in drive and will doom you to 93 mph 1/4's (as soon as it shifts itself into non close ratio/out of the power band OD, acceleration is over).

If you had the power to run 125+ then shifting into OD @ 123 mph might speed you up. At 93 mph, its only hurting you.

 

[GNONYX]

Shifting into OD @ WOT will do more damage than any heat build up running in drive and will doom you to 93 mph 1/4's (as soon as it shifts itself into non close ratio/out of the power band OD, acceleration is over).

If you had the power to run 125+ then shifting into OD @ 123 mph might speed you up. At 93 mph, its only hurting you.

Thank you all for the info