Put the TTA on a dyno Sunday...

[Scott89TTA]

A friend of my son put together a Dyno Day this past Sunday. They needed some more cars so they asked me and some of my buddy's to come as well. Turned out the word got around and they had plenty so it ended up costing us $40 each for 3 pulls. Couldn't pass it up even if the car wasn't running its best.

First off...my TTA is stock except for Grumpy's MAF pipe and a K&N. I just added an adjustable waste gate actuator and installed new plugs. The car definitely runs better then it did but still needs new plug wires...they are at home waiting to be installed. At least one of them will arc if you get anything near it so I'm sure the others are close or just as bad. My car needs the typical Spring cleaning as I know there is some oil in the IC as well. On my Dyno plot I am guessing that either my plug wires and or valve springs are killing power above 3800 rpm since the hp slowly falls off and the torque falls off pretty fast after 3700 rpm. I guess the best thing is my air fuel ratio is pretty solid right around 12.

Am I on track with my assumptions or is my plot normal or am I way off

Here's my plot...

 

[72firebird]

I just looked at my dyno graphs and my car starts to drop in torque around 3,700 rpm but the power continues to increase all the way to 5,100 rpm. Of course I have some mods but maybe that'll give you something to compare it to.

 

[DaJoker]

I am very interested in seeing some numbers after the "spring cleaning" is done. This would be a good example to see how much difference it really makes. PS Thats a pretty impressive torque #, factory rating was 340!!!!

 

[2QUIK6]

Mine bone stock dyno'd at 235 rwhp and 304 rwtq. Torque began to fall off at 4200 rpms while hp held fairly steady up to about 4800rpms.

 

[1quick1]

Hi guys, I'm new here, found this thread by a seach.

Very timely info for me.

I've been in a discussion at another forum as to the stock RWHP on GN's and TTA's.

I've always loved both cars, but it seems in my thread a few overzealous folks have a slanted idea of the HP these cars make stock.

I contended 250 RWHP would be a stong running TTA, the local TTA "expert" was claiming they would dyno RWHP 280/380 TQ, which I find totally way too high.

I understand Scott89TTA that your car may need a bit of fine tuning to get it to optimum power, but I think the peak is probably pretty close to max, it's just not holding out over the upper RPM range, due as you might think, possible tired springs, weak wires....

Any input as to bone stock dyno numbers for the TTA or 86-87 GN would be appreciated as web searches have proved close to fruitless for stock numbers/dyno charts.
Thanks guys.

 

[chris718]

i believe that for what is done to the car that is pretty close to what they make un modded.a slight increase in boost will yield additional torque through 4000 rpms imo.tailpipe air fuel ratios slightly richer might increase power slightly due to their cooling effect on the intake,pistons and cylinders.it is always wise to use the dyno after mods and record data.one thing i hate is speculation.there are things in life we cant measure,this however is not.great knowledge is gained thru the use of a chasss dynamometer.

 

[Scott89TTA]

As soon as I get the Spring cleaning done, the new wires and valve springs installed I'm going to go back for another pull before I start any of my planned mods. I'd like to see HP come up a little...if the factory claim of 301 hp is true then ~240 hp at the wheels should be stock with a 20% drive train loss. I don't think torque loss to the wheels is the same as hp...if so then I'm doing better then stock on torque with 325 compared to the factory 340. I'm only lossing ~4.5% torque to the wheels. If 20% loss applies to torque as well then I'm putting down about 390 lb.

We'll see next round...

Scott

 

[1BADDAM]

HP is not measured on a dyno, torque is. HP is a calculated based off torque.
This is why all dyno number HP & TQ cross at 5250 rpms

 

[72firebird]

HP is not measured on a dyno, torque is. HP is a calculated based off torque.
This is why all dyno number HP & TQ cross at 5250 rpms

Yup HP= (torque x 5252)/rpm

 

[89ICBM]

Any input as to bone stock dyno numbers for the TTA or 86-87 GN would be appreciated as web searches have proved close to fruitless for stock numbers/dyno charts.
Thanks guys. [/QUOTE]



Hi, someone on this forum posted an article from a turbo magazine that I believe was from 89. I don't remember the exact name of the mag but it had 'turbo' in it. I also don't remember the exaxt numbers but I do remember that the TTA was 40 hp more than the GN and 20 hp more than the GNX. It seems that the GN was 220 hp, GNX was 240 and the TTA was 260 hp. You might be able to do a search on this forum for the thread.

 

[Scott89TTA]

Any input as to bone stock dyno numbers for the TTA or 86-87 GN would be appreciated as web searches have proved close to fruitless for stock numbers/dyno charts.
Thanks guys.

Hi, someone on this forum posted an article from a turbo magazine that I believe was from 89. I don't remember the exact name of the mag but it had 'turbo' in it. I also don't remember the exaxt numbers but I do remember that the TTA was 40 hp more than the GN and 20 hp more than the GNX. It seems that the GN was 220 hp, GNX was 240 and the TTA was 260 hp. You might be able to do a search on this forum for the thread.[/QUOTE]


I have seen that as well...the 40/20hp difference over the GN/GNX was do to the different heads used on the TTA (better flow and combustion chamber). Also it was noted that the TTA was advertised at a lower 250hp do to the 89 Corvette being advertised with 255hp. The TTA easily beat the Vette and GM put it on their dyno to reveal the TTA having 301hp.