Thought i would share my twin turbo firebird with you guys! I run two stock Buick Grand National turbo's blowing thru the stock TPI intake with a 58 mm throttle body. I run a 355 SBC, TH 400 with a transbrake and a 3.00 geared 9 inch rearend. best ET to date is a 10.23 @ 134 at 22 psi boost and a 9.75 @ 141.80 with a 100 shot of NOS thru a single fogger nozzle. It's a street car and still gets 20 mpg using a holley commander 950 engine management. You can get more info from the link below. It might take you 2 hours to read all of it but it's worth it! LOL How long till it grenades? (9.75 @ 141.50! 1.43 60' 616whp 692 torque)

 

I've seen that thread for a while now, your car runs damn good for what you have in it and the combo of the 3.00 gears and tpi intake is perfect. I like to see tpi being used in the rpm range it was intended for! I hope you get an 8.99 before the motor goes.

 

I like how you started out will low 11's as a goal and now your in the 9's...

I didnt have time to read all 26 pages...(can you blame me?) but is it still the original l98?

Hopefully ill have a chance to read your life story tonight...

 

22psi?
What's the static CR, and is it intercooled or water injected?
22 psi sounds like gobs of pressure there....
(I don't have time to read that 26 pages, but maybe soon...)

 

Very nice!

 

Do you have a picture of the engine bay? I am interested in checking out your headers. If you don't mind someone else looking at your technical know how from building something so spectacular.

 

Its intercooled, some kind of Freightliner intercooler if I read right. I think the compression was 8.8:1, cam was a comp cam 218/.454 (add for 1.5 to 1.6 rockers) and its maybe a single pattern, I didnt catch that either way.

Thats just awesome, I love it. I'd like to see some underhood pics too.

 

Thanks for the compliments guys! It's not the stock motor. It came out of a friends truck and has 150k miles if you can believe that! I think it's 8.7 to 1, runs a 99 freightliner intercooler and no meth injection. It was more of a joke to see how long it would go since i got the motor for free and now it wont blow up! It is .040 over with a sleeve, cast crank stock rods, cast badger pistons and the kicker is the heads. Stock 991 casting truck/van 1.72 intake small port 76cc heads! No porting and stock head bolts torqued to 85 ft.lbs. I will post pics of the headers tonight as im not on my computer now. Oh yeah, it runs a comp HE268 cam. 218 dur. @050 with 1.6 rockers. The cam is the only non-stock thing in it!

 

Great thread. Awesome job tuning that thing. What kind if ignition are you running on it? WOT timing advance? What did you set the WOT AFR at?

I am curious because I have the same style heads.

 

You are my new hero!

 

Ha ha, thanks! Im either a hero or really retarded for screwing this combo together! I run a crank trigger and the MSD digital 6 box with Holley commander running the show. I still use the stock distributor minus the guts to throw the sparks around from a blaster SS coil. A MSD digital window switch manages the nitrous system. 23 deg. timing at 22 psi with a 2 deg. retard on a 75-100 shot of NOS. A/F stays around 12.3 to 12.5 with or without juice. I know that sounds a little scary but i snuck up on it and havent cooked anything yet! The TPI is maxed out in terms of airflow cuz i usually run DART 200cc aluminum heads. The horsepower difference between the two? Maybe 10 dyno HP with identical curves throughout the range. In real life, they MPH about 3-4 mph slower in the 1/4 mile though. Weird. Here are some pix!

 

I just noticed thats a pix of the real motor that is supposed to be in the car. See the aluminum heads? Here is the GRENADE pix. I didnt even paint it in case people thought i was lying about it! LOL

 

I forgot the best picture. This one cracks me up!

 

very interesting combo that works really well using all stock components basically. i'm impressed.

 

Welcome!
I've read that thread 2 or 3 times, heh. Very cool, and thanks for taking the time to try exploding a stock engine. It's been very educational for all of us.
I'm hoping mine just hits low 12's on street tires, heh.

 

what headers are you using for the turbos? wastegates?...how do you like the header wrapping as opposed to the ceramic coating?

also, are your turbos infront of the fender wells?

 

I made my own from a hedman header weld up kit from summit. The turbos sit where the battery trays are on each side. I hate header wrap but it does seem to help with underhood heat. I think ceramic coating is probably just as good and will do mine soon! I run turbonetics EVO wastegates.

 

Hell yeah I'd imagine anything will be stupid fast running 22psi of boost (let alone 100 shot on top of that). What's awesome is that it is still together. I need to find myself a beater car and do something just like this.

 

hm, its anybody's guess. i say boost it til it blows. the basic thing is..detonation kills. if you keep that away you could go until you literally blow the mains out which is more of an rpm thing..

 

Why would you do that to a beater? Your car would be good canidate.

 

Yeah, everyone has a used small block laying in the corner of the garage. Throw one in and clean out the garage at the same time! The worst thing that can happen to the car is a dent in the crossmember when a rod flings out!

 

**** dude, your car is ****ing nice!!!

 

hehehe. I just don't want to turn my current T/A into a screamer. Low miles/great condition and all that. I already ruined one engine when my procharger grenaded and dumped metal into the oil pan. So, strictly show/cruise duty for it now.

 

22 psi, very very cool.

 

Yeah, my turbo's dont think so. The GN turbo's are way overcooked at 22-25 psi and i keep losing the thrusts on them. Time to upgrade and make 1000 HP!

 

Don't take that engine out until you see where it's limits really are.

This is why I love boost. Not only would it be impossible to get this power out of a stock naturally aspirated setup, but even if you could there's no way the naturally aspirated bottom end could take this kind of power.

 

No, the best part is you can run single digit 1/4 times and drive it to the track. No N/A engine could do that. (Im still at the 10 sec barrier, but i do drive my car to the track too) Turbo cars have awesome drivability.

 

Well heck ya, that too.

 

I hear ya on the driveability thing. I still get 20 mpg and drove 80 miles in the morning and went straight to the track and hit a 10.03. The next weekend i did a poker run and went another 70 miles and went 9.82! All i do is pour in 110 race gas out of my can in the back seat and air down the ET Streets to 12 lbs from 30lbs and thats it. I love the looks i get from all the full on gutted race car guys that run 11's when i leave the track idling smoothly and quiet! Sometimes i make sure they see me rolling up the power windows as i idle by just to mess with them a little more. Next time i should get into a discussion with them about how i have a little tiny rattle or vibration that just RUINS my whole driving experience and how my intermittent wipers act a little funny! LOL Am i having too much fun with this or do the rest of you guys do that too?
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We have a guy around here with a 68 camaro that runs 8.70's with a 540 big block and NOS and he DOES legitimately drive it everywhere but it cant be too much fun.

 

LOL!!! that is awesome.

 

Thats nuts. haha. Yeah, but you get my point. Most big inch, or high compression engines run pretty hot for street driving. But your right, it can be done. But it cant be fun. I like our true street cars.

 

Yeah, he doesnt have too many problems except it's hard on the roller lifters and valvesprings. He even hooked up an innovative wideband to tune thecruise and tip in response for the street. ON A 1050 DOMINATOR CARB. Heh heh. I am impressed with your numbers, Turboed TPI! In reality you have more motor than i do with better heads and a roller cam! Do you have some pix posted on here somewhere? I want to see how you did everything.

 

22 PSI. It sounds like you were spinning them pretty fast. What was the intake air temp. for that amount of boost?

 

Not that bad surprisingly. 130 deg. at the end of the 1\4 mile and 108 on a 75 shot. I got a lotta intercooler to help things out!

 

Thanks, I need more fuel (bigger injectors) before i start running more boost. I have some picture, but i have dial up and when i try and post pictures it doesnt seem to work, but i'll try.

 

Very nice job on the IC setup. No wonder you have that thing going so well. All that surrounds the block itself was set up to perform. Tuning that thing must have been fun.

 

It normally runs a 355 with dart 200 alum. heads, eagle h-beam rods and a steel crank but i overheated it and the ring seal went away. All my friends thought it would be cool to transplant a nothing engine into a well race prepped environment and tune it ragged edge and treat it like a REAL engine. We have been amazed how well it has held up with all the necessary support systems a purpose built car offers. I had a lot of trouble tuning initially with the commander 950 just trying to learn how to do it but now it's pretty cut and dried having some time on the car to get to know it's personality and preferences. I now work at a dyno shop so i get FREE dyno time! Yippee!

 

Your my freaking hero. I joined turbo mustangs bc of you.

And i especially love your convertor rated for 350 hp living through wheels up 9 second passes

 

More boost and nitrous!! TIME for 8's!! lol

YOur

 

Hell yeah! I should bolt on some better stock heads and see what it does.

 

NO if you turn bolts on that car bad thing's will happen! Delete this post entirely and take the car on Pinks, win you another car with a built engine so you won't have to spend any money

 

now theres an idea

 

Here's a pic, its not too good though

 

Nice lookin ride! Looks like ya had to lose the A/C to make room huh? There is a lot of crap packed under the hood of these things to make room for a turbo. I would have done a big single if i had to do it all over again since i dont even have power steering or a heater. I hate not having a heater since people think of it as a stripped out drag car. I made sure to keep the power windows, power mirrors, door locks, steering wheel controls for the stock stereo and the power hatch sucker downer and electric trunk release though.

 

Thanks man. Yeah, no a/c. Sucks too, because it still worked too. But with the intercooler and downpipe there was just no room for the condenser and evaporator. I still want to get an a/c delete heater box though, just havent got around to it yet. But everything else is still in the car. I even got a new trans am cd player to match the stock red instrument panel lights. I thought that was cool, because it looks stock and it says pontiac on it. I even have the stock shifter and stuff. Im all about stock apearance.

 

I remember that thread over at turbomustangs… somehow I missed it growing that big… I’ll have to dig through it.

I’m curious:
- what exhast are you running?
- What injectors are you running?

 

1 3/4 primary headers made from a hedman headers weld up kit from summit with twin 3 inch down pipes merging to a single 4 inch going thru a Dynatech 4 inch muffler that ends by the front of the torque arm. When i have to do emissions, i have a 4 inch mufflex system with a cat welded in that gets it out to the back bumper so they wont bitch when they sniff it. I run 55 lb. seimens deka injectors and so far they have kept up great! I would bet a turbo upgrade might run them out of capacity though. I eventually want 1000 hp when my wallet catches up! LOL

 

Huh… one of these: Dynatech Split-Flow Race Mufflers: DTC-76-014402 - summitracing.com ?

Do you have any sound clips or video of what it sounds like? Is it loud? I’ve never seen/heard on of their mufflers on a car before, but have wondered about them. Obviously it flows well enough if you're running 9's through one of them.

Do you have a 4” cat in the mufflex setup? Been wondering who makes a 4” cat (been thinking about modifying a smaller one for a simple bolt in for emissions testing)

 

No sound clips. Im sure it is a 1000 Hp capable muffler. It is a straight thru design with a center divider. I do not have a 4 inch cat. It's a couple of Catco converters cut and welded end to end to make a huge brick to pass emissions actually. If you find a supplier for 4 inch cats let me know. I removed the cat and went to weld a new section in one night and realized i didnt have enough pipe to do it so i drove it home with no exhaust. It wasnt loud at all but was a bit throaty and retarded sounding so i figured it wouldnt take much to tone it down a bit. The Dynatech made it sound PERFECT! I may extend the pipe back to the rearend to tone down some of the drone at 2500 rpm it has. The other reason for doing the system so short is the fact i lost 60 lbs. of race weight over the mufflex system. It was so quiet before that it almost got boring cuz if you wanted to honk on it for a cute girl, they wouldnt even notice! The new sound suits the car much better. Very sedated but has a mean big block growl at WOT! It's still the quietest car at the racetrack.

 

Sounds like a nice exhaust setup too. What RPM did you hit positive boost as recorded with the Holley ECM. I am curious because I have a H2D that is going on a 355ci in a pick-up truck with the same cam and free-flowing exhaust. The turbo(s) are different but it will give me some actual data to run through some calcs with.