Next size up from stock turbo?

[csmwiese]

I'm looking to upgrade my turbo to the next level, but I'm only looking to get into the 12's, nothing major. What is the next size up from stock that will get me there? I have a 23 row SLIC, Adj fuel press reg, cold air, no cat with a cat back system, street TT chip, 3 inch down pipe. My 1987 Grand National only has 29,000 miles on it i want the stock look, just a little faster

[Slow91z]

Stock will get you WAY down in the 12's some have been 11's, but pushing it HARD.

I don't know what you have done to it so far, but if you aren't running 12's with it then a turbo should not be on your list yet.

[hflwyo]

I agree you should be able to run in the 12's the way the car sits.

[jasjamz]

I'd think a TA-49 is the next size up in turbos. If your car doesn't already have a Fuel Pump Hotwire Kit, add it and a Scanmaster to your list. Oh... and Beautiful Car!!

[csmwiese]

[quote=Slow91z;1968590]Stock will get you WAY down in the 12's some have been 11's, but pushing it HARD.

I have yet to read about someone running WAY DOWN in the 12's with just a cold air, exhaust, down pipe. SLIC and a stock turbo. I could be wrong, so if there is some one running WAY DOWN in the 12's with just that stuff only let me know. I have not taken my car to the strip and I have run in the 12's with other cars and this does not feel like it's there yet. Let me know, I want to hear from someone who ran there car at the strip not I raced a buddy or ......my car should run.

Guys, I'm just looking to add a couple of bolt-on's to get quicker with out cutting it up or hanging a bunch of guages or wrenching on it every weekend on a 29,000 mile GN.
Maybe your my car is faster then I think, I am a new GN owner and you don't get that same sound/feel you get from a V-8.

[Smokin-6]

I ran 12.70 with the stock turbo & intercooler. My setup was similar to yours. I ran 110 octane and 22lbs of boost, this was with an old ATR pitt bull chip, stock trans and stock injectors. Is your car tuned properly? I think SCOJACK has run 11.98 with the stock turbo. Have you replaced your 20 year old valve springs?

[SPOOLN]

Buy an Akly kit so it will make your stock turbo more efficient. Then you won't have to worry about knocking the motor.

[RUQWKNF]

I agree with the stock turbo being capable of running low 12's.

Here is what I did back in the beginning with my first Turbo Buick.
Back in '95, I took my stock motor, stock turbo/stock intercooler '86 T-Type, to a best of 12.09 @ 109 with these mods.

Stock intercooler with the trash screen removed from the shroud and ported inlet and outlet necks, stock turbo with a stage 2 inlet bell, motor was stock with new valve springs and a double roller timing chain, both valve cover breathers, Kenne Bell plenum and 65mm t-body, 3" downpipe, 3" test pipe, with stock cat back, Super Turbo mufflers with turn downs, 36# Blue top injectors with a CPP Mini Mag race chip, Bosch external fuel pump with no intank, adjustable fuel pressure regulator, Magnacore 10mm wires, ATR air fuel ratio gauge, 160* t-stat, 3" MAF pipe, 9" K&N cone filter, dual rear air bags, Scanmaster, 26x10 ET Drag slicks on Pro Star wheels and VP C-16 leaded race fuel. This run was done on an E-brake lauch at 14psi and running 24psi. Motor had approximately 89K original miles and good compression.

The stock Garrett TBO-348 turbo is capable of safely supporting 370-375 flywheel hp when pushed. Some have actually gotten more out of it with alky and or nitrous. But, you run the risk of not only overspeeding the rotating assembly, but the charge temps are out of site at boost levels past 25psi.
The main reason you won't read about people taking their stock turbos deep into the low 12's is, most people don't realize that older posts from way back when, get purged from the system. And if those who have run those numbers with a stock turbo posted about it a long time ago, there's a good chance that their post is MIA now. I know pretty much all of my old posts from '98-'00 were deleted when the site crashed, as well as others that were purged.

There were a bunch of good posts that were done about low 12 second combos over the years. But you are correct, it is very hard to run low 12's with a bone stock car. As you can see with my own experience, it takes a carefully selected combo of parts to realistically run low 12's. There are some ringers out there that have done it with very few parts. Typically those are cars with very low miles (5000-15000 miles) and were never abused. The stock injectors become a serious restriction on reaching low 12's. Especially when you do the math. 28.5# injectors x 6, x 2 = 342 rough flywheel hp. When you take into consideration drivetrain losses, you'll be lucky to put down 300-320 rear wheel hp. Not too mention the weak stock fuel pump with inadequate wiring from the factory. It takes roughly 360-380 rear wheel hp to run 108-110 mph in the 1/4 mile with a full weight 3650# Turbo Buick. Obviously it takes less if the car is lighter.

The biggest things your combo needs are a intank pump with a hot wire kit, larger injectors with corresponding TT chip and a Scanmaster so you can tune it. Now, throw on some sticky tires and some high boost launches with race gas and 23psi and you should be in the low 12's. At least 110 octane with 25-26* timing in all gears under WOT. Don't forget to change the fuel filter, fresh plugs and a new O2 sensor. I'd recommend 50# Delphi injectors and start out with the fuel pressure set (hose off at idle) to 42psi. Watch for .800 - .750 on the O2 Mv at the end of the run and no more than 3* of sustained knock retard.
Hope this helps and sorry so long winded.

Patrick

[Mr.Spool]

csmweise,i would purchase an alky kit from alkycontrol.and i would be very carefull about seat of the pants estimates.i can tell you the alky will cool the intake charge and supply the fuel needed so you don't have to upgrade the injector's,intercooler,or turbo to achieve the 12 second passes you want.but i will tell you the car will wake up drastically when the boost is raised.we installed a walboro fuel pump,alky kit from alkycontrol,tt chip,and raised the boost to 22psi and the trans lasted a week

[87Regal3.8SFI]

Originally Posted by SPOOLN

Buy an Akly kit so it will make your stock turbo more efficient. Then you won't have to worry about knocking the motor.

Ditto

[UNGN]

[quote=csmwiese;1968696]

Originally Posted by Slow91z

Stock will get you WAY down in the 12's some have been 11's, but pushing it HARD.

I have yet to read about someone running WAY DOWN in the 12's with just a cold air, exhaust, down pipe. SLIC and a stock turbo. I could be wrong, so if there is some one running WAY DOWN in the 12's with just that stuff only let me know. I have not taken my car to the strip and I have run in the 12's with other cars and this does not feel like it's there yet. Let me know, I want to hear from someone who ran there car at the strip not I raced a buddy or ......my car should run.

Guys, I'm just looking to add a couple of bolt-on's to get quicker with out cutting it up or hanging a bunch of guages or wrenching on it every weekend on a 29,000 mile GN.
Maybe your my car is faster then I think, I am a new GN owner and you don't get that same sound/feel you get from a V-8.

My car ran 12.26@110.5 with only a K&N, dump (a good exhaust would work, too) and the stock intercooler. My 60 fts were lousy 1.800's, too.

The trick is to run a high timing, lock up chip like like a Thrasher 108 with high octane gas.

[86george]

Originally Posted by csmwiese

I'm looking to upgrade my turbo to the next level, but I'm only looking to get into the 12's, nothing major. What is the next size up from stock that will get me there? I have a 23 row SLIC, Adj fuel press reg, cold air, no cat with a cat back system, street TT chip, 3 inch down pipe. My 1987 Grand National only has 29,000 miles on it i want the stock look, just a little faster

I think what everyones trying to say is that the stock turbo will not keep you from the 12's and a slightly bigger turbo alone will not put you in the 12's. There's a few things you can do that help and still look stock.Fuel pump and adjustable pressure regulator. Ajustable wastegate and boost controller.You'll need 20-21 lbs boost on 110 gas.A open dump tube exhaust helps.Some launch friendly shocks and air bags.Sticky tires.A lock up switch for the tcc so you can lock the converter clutch in third gear at about half track.Work on your brake-boost-launch skills and you should see 12's. Have fun. Thats a very nice clean car you have. George

[TLIMITED]

I would start with what you got,do some tuning and for sure a tire that will hook,airbags and boxed control arms.You will not see a low 12 without good 60ft.times.

[csmwiese]

Thanks Guys for all your info. Clint

[bernie01851]

you need a hot wired fuel pump new fpump adjustable fuel presure reg
k and n air filter scan master and allky thats all lol

[Clark6]

you have everything according to your post,........ that car is too clean to be riding it too rough. jmo.

1) put in some 110 oct race fuel at 21 or 22psi of boost.... hot wire the fuel pump as someone stated
2) mickey thompson 275/60/15 et street drag radials or slicks would be better 26x8s for your rims you already have or better yet i'd just mount them on a lighter aluminum set.

Now with what you already have just put those 2 things suggested on your car & get a (((scanmaster))) regardless of course.

go to the track and practice i guarantee you a hi 12 with what you have now. remember you have some adjustability in your chip if its an up to date tt chip.

the tires will be your biggest gain but dont sneak & go out there runnin on 93 octane only & tear up that pretty engine.

[gs462]

buy a TA 60 it is capable of going low 11's with a stock TC. no downsides to this turbo whatsoever.

[BREAKIN IT]

I ran 12.31 @108 totally stock with a chip and some sticky tires. Has to be tuned real well. High timing chip with race gas helps.

[87Regal3.8SFI]

Originally Posted by Mr.Spool

we installed a walboro fuel pump,alky kit from alkycontrol,tt chip,and raised the boost to 22psi and the trans lasted a week

When you blew your tranny were you running slicks?