power?

[shellboy]

how much horse power will a stock tIII ,plus 40s and three inch exgaust no cat. with the stage 4 calibration at 20 pounds of boost make?

[turbovanman²]

Whatever the dyno says, ;)

Almost impossible to guess, dyno is your best answer.

[shellboy]

i see. i just bought a 91 spirit with 88000 miles and i want to go a little faster. just wondering what to expect. 280 maybe? take a guess for me .since i have no clue..

[stereo]

Faster than stock, always a good thing.

[shellboy]

would any one else like to guess?

[Lotashelbys]

275ish at the crank

[Turbo3Iroc]

275 or so at the crank sounds reasonable, The stock turbo is pretty much done at 20 psi and will not hold it up top. Put a front mount on it and you will see better gains.

[shellboy]

thanks for the info guys!!

[turbovanman²]

275ish at the crank

You think so, on a stock turbo?????

Whats that, about 260 at the wheels.

[Dr.Evil]

say the average fwd drive train loss is around 15%, 275bhp = 233.75whp. I dynoed at 240whp/250wtq on 95 octane spiking to 20PSI, droping all the way down to 10PSI, on a mustang dyno last spring in the vegas heat. Besides the good gas I had a fmic, 3" dp, 2.5" catback, stage 3 cal w/ +40's. Couldn't figure out why it wouldn't hold 15+ on the dyno. It was fine all day on the freeway, just didn't like the dyno I guess. I was pretty happy with those #'s for how it was acting. I can post up the chart if anyone is interested.

[turbovanman²]

say the average fwd drive train loss is around 15%, 275bhp = 233.75whp. I dynoed at 240whp/250wtq on 95 octane spiking to 20PSI, droping all the way down to 10PSI, on a mustang dyno last spring in the vegas heat. Besides the good gas I had a fmic, 3" dp, 2.5" catback, stage 3 cal w/ +40's. Couldn't figure out why it wouldn't hold 15+ on the dyno. It was fine all day on the freeway, just didn't like the dyno I guess. I was pretty happy with those #'s for how it was acting. I can post up the chart if anyone is interested.

Sure, post up the dyno sheet, :thumb:

[overlordsshadow]

226.25 whp is my guess. +20bhp with a decent fmic.

[Dr.Evil]

Clicky here for my dyno chart (http://70fastback.ws/dyno_big.jpg)

[Lotashelbys]

You think so, on a stock turbo?????


I think he might get close to that. I really cant complain too much about a stock turbo. On one of my 91 TIIIs I have a stage 4 cal and 3" mandrel bent S/S exhaust and a Precision front mount and the stock turbo will spike at like 23-25PSI and hold as much as 19PSI at 7K. Must be a good stocker huh....

[turbovanman²]

I think he might get close to that. I really cant complain too much about a stock turbo. On one of my 91 TIIIs I have a stage 4 cal and 3" mandrel bent S/S exhaust and a Precision front mount and the stock turbo will spike at like 23-25PSI and hold as much as 19PSI at 7K. Must be a good stocker huh....

Yep, mr horseshoe up his wazzoo, lol! :nod:

BTW, we'll see what my almost stock newly aquired 91 RT will do next summer at the strip, ;)

[GLHSKEN]

John Fleck just went from 96mph to 101.3 in the 1/4 by adding a front mount. Stock tiny turbo... would guess a 3100 lb car makeing at least 275 to the wheels

[turbovanman²]

I'm leaving mine mostly stock. I'll add a 3inch dp to the already 3 inch system, TII IC, +20's and a stock cal for now. Its for the wife, don't want to kill her yet, :evil: :nod:

[Turbo3Iroc]

Ken, The stock turbo maxes out around 275 with "all of it" I'd guess John is around 240 - 250.

I trapped 103 -104 at 14 psi with a front mount, 105 at Cecil. I know the Daytona is slicker. Car dynoed 250/280 at the time.

Jackson, you have an exceptional stocker there or a restirctive head or intake (I doubt the latter).

Simon, a stock Spirit R/T makes a great DD! I only have a 3" exhaust on mine because I needed something with a cat on it.

[turbovanman²]

Simon, a stock Spirit R/T makes a great DD! I only have a 3" exhaust on mine because I needed something with a cat on it.

Thanks, :D I might have to make it an auto for her though.

[Lotashelbys]

"Jackson, you have an exceptional stocker there or a restirctive head or intake (I doubt the latter).


Probably a combonation of both. The stocker is off a low milage unit that ran M1 all its life and the head is stock except for Ti retainers and a good VJ and a stock intake:D

I think its that I/C that lets it do what it does. Lets say on a 90 degree day the intake temp was like 110 degrees after a few hard runs. I have no way to measure the temp before but you cant touch the S/S pipe:thumb:

[GLHSKEN]

Ken, The stock turbo maxes out around 275 with "all of it" I'd guess John is around 240 - 250.

I trapped 103 -104 at 14 psi with a front mount, 105 at Cecil. I know the Daytona is slicker. Car dynoed 250/280 at the time.

Jackson, you have an exceptional stocker there or a restirctive head or intake (I doubt the latter).

Simon, a stock Spirit R/T makes a great DD! I only have a 3" exhaust on mine because I needed something with a cat on it.


Kelly, he was running ALL of it (20 psi). Plus the car is loaded with air and more than likely goes 3500Lbs through the traps. 101.3 was his trap on street tires... He would be up 1-2 mph with slicks..

Too bad he didn't stay at my house Friday before 'Palooza. He could have whipped up on the mustang on the way to the track as well.

[moparzrule]

I'm not understanding why the stock turbo is only capable of 20 PSI. The stocker is larger than a stock T2 turbo, the T3 is a 60 trim and the T2 is a 50 trim. The T2 has done 28 PSI before, the T3 should be able to do atleast that! Is it the stock wastegate actuator or something?

[moparzrule]

Clicky here for my dyno chart (http://70fastback.ws/dyno_big.jpg)

Dude your A/F ratio is 9:1, practically flogging the thing out! You would have made 20+ more HP just by taking up to a normal A/F ratio like atleast 11.5:1.

[bansheenut420]

I'm not understanding why the stock turbo is only capable of 20 PSI. The stocker is larger than a stock T2 turbo, the T3 is a 60 trim and the T2 is a 50 trim. The T2 has done 28 PSI before, the T3 should be able to do atleast that! Is it the stock wastegate actuator or something?
I have wondered the same thing. And I am willing to bet its due the the high flow of the dohc head. My s70 falls off on top and I am not running over 13 psi. And its not from a boost leak. Its from some good flow.

[turbovanman²]

I'm not understanding why the stock turbo is only capable of 20 PSI. The stocker is larger than a stock T2 turbo, the T3 is a 60 trim and the T2 is a 50 trim. The T2 has done 28 PSI before, the T3 should be able to do atleast that! Is it the stock wastegate actuator or something?

From what I remember, and I could be wrong, is the head flows so well, thats all the turbo can put out as the engine is using all of it. A 8 valve head is a big restriction so causes more boost.

I used a TIII turbo on my 8 valve motor and with a small restrictive IC, slightly ported head, wastegate locked, it could get 23ish psi and I hit 29 psi on the dyno? :wow1:

[Turbo3Iroc]

Kelly, he was running ALL of it (20 psi). Plus the car is loaded with air and more than likely goes 3500Lbs through the traps. 101.3 was his trap on street tires... He would be up 1-2 mph with slicks..

Too bad he didn't stay at my house Friday before 'Palooza. He could have whipped up on the mustang on the way to the track as well.

Yea so he's right there then.

Matt, boost is relative to intake restriction. These 16V heads flow well in stock form. When I still had my stocker it would peak up around 22 and then fall off to 16 but as Jackson showed there is variances in that also. I haven't quite figured out why that is yet.

[moparzrule]

Oh I know what boost is, but as long as the wastegate is shut the turbo should keep spinning faster until it blows up before it just can't produce any more boost. I think your wastegate actuators are at fault or something because it just doesn't make sense.

[Turbo3Iroc]

Remember these heads don't have the exhaust restriction either. I literally wired my wg shut and the boost still falls off up top. Remember by the time these cars were made Chryco was also concerned with drivability. When the turbo maxes out on these cars its from maximum velocity and the compressor wheel can no longer pump the air in as fast as the engine can use it.

[moparzrule]

I understand what you are saying, what I'm not understanding is why the turbo isn't overspinning and blowing up. The turbo spins faster to make more boost, if there's no wastegate there's nothing to stop it from keeping on trying to fill the intake in cannot fill. Thats what doesn't make sense to me.

[Turbo3Iroc]

Oh, I'm not sure but they don't last so long overspinning them like that either. For a stock turboed car I'd recommend max boost be set at the max it will hold to redline or 1 or 2 psi over that. Racing the car wasnt all that fun in all of it mode with the peaky power band. I'd end up shifting at 5200, I even went to the 24.5" slicks to keep in in that band longer.

[moparzrule]

Probably making a good bit of heat too!

[Dr.Evil]

Dude your A/F ratio is 9:1, practically flogging the thing out! You would have made 20+ more HP just by taking up to a normal A/F ratio like atleast 11.5:1.

Yea I know, thats they way the Stage 3 cal is I guess. I was thinking of getting an afpr and turning the FP down to help with the a/f. So for now I'm just running a meth/small n2o shot combo and not even worring about the a/f, and it pulls good. I would like to lean it out a little for just normal street use and pick up a few extra HP.

[Pat]

I understand what you are saying, what I'm not understanding is why the turbo isn't overspinning and blowing up. The turbo spins faster to make more boost, if there's no wastegate there's nothing to stop it from keeping on trying to fill the intake in cannot fill. Thats what doesn't make sense to me.

Compressor efficiency drops like a ton of bricks when you get that far off the map, so more compressor rpm doesn't mean it's actually putting more volume out of the turbo.

My stocker was good to hold about 16 at redline in my old red car.