Finished up the Greenville, SC Dyno meet this morning. We had 2 928's (mine included), a C-5 vette, a Civic Si, a '68 Impala, and a turbo RXC-7. Good group of guys, but wish we had a better 928 showing.

Anyway, with this being my first experience at the dyno, I wanted to post my results for help with interpretation. Honestly, I didn't know what to expect, but expected better than this: best run was 201 HP, 210 torque. My 86.5 is mainly stock, with RMB and supposedly Autothority chips. I'm going to confirm the chips in a while.

It was humid and warm, but damn 201/210???

I'm not looking to increase HP/torque at this time, but spec would be nice. Any suggestions?

 

Was the c-5 stock and what was it's numbers??

 

DO you have the dyno graph to post?

 

I assume you're talking about HP and torque at the wheels? What kind of dyno were you on?

 

There's something wrong with those numbers. You should have 288 HP at the flywheel and about 225 to 230 at the rear wheels. What was the other 928 and what HP did it show?

 

The C-5 was "slightly" modified and put out 391 HP. I thought my ears were going to bleed during those runs.

HP and torque were at the wheels on a Dynojet.

I have a graph and trying to figure out how to post it.

 

Here it is...

 

With an AT you would have to disconnect the bowden cable, the kickdown under the gas pedal and make the run in 3rd. I bet it downshifted during the run and it was over before it began. Happened to us many moons ago before we figured out the above courtesy of the rennlist. Once you do the above you would then manually put the car into 3rd..hold at 2000 to 2200 rpm...and when the operator flags you..you hit it...and hold it till around 6200 rpm...

Lets see the graph...I've seen 85/86's do 280 or so to the wheels...

later,
Tom
89GT

 

This was in third gear. Hmm, could that have something to do with my "lower" numbers?

 

3rd is what you want...since in D..you would be spinning the dyno at over 200mph..and the dyno jet won't hold data above 200mph...(haha.don't ask me how I know )..

Graph looks normal...just low...odd...was the pedal floored?....did they record a/f ratio.?..

later,
Tom
89GT

 

It's supposed to be in 3rd gear for the dyno run. I did a dyno run today, too. 88 S4, bone stock. Had to disconnect the kickdown switch and I had a totally goofy looking run because when I hit FT, it screwed up all the parameters.

Stock numbers: 260 - 262 at the wheels. 4 runs. Very consisent. Will post slip soon. Waiting for shop to email it to me.

 

Incorrectly adjusted throttle linkage? Something under accelerator? Slipping tranny or failing torque converter (highly unlikely for this)? Green wire retard loop plugged in?

 

Thanks guys, I think I know what happened.

The above graph is the 6th run. The previous 5 were a combo of 2nd and 3rd gears runs that down shifted at some point (kickdown activated), messing up the run. On the 6th run (the one above), I was reluctant to floor it b/c of reasons listed above. Thus, low numbers.

I guess I should have checked here first on "how to run a dyno", but I thought it was just floor it and look at the graph.

Next time, disconnect the Bowen and kickdown, and run in third. Simple!

 

Sucks being a newbie.

 

Chris
Your #'s are low for a properly running stock 86.5...typically they run at least 230+ whp.....if you were running less than full throttle combined with letting off the gas early (since your power flattens out at about 5200rpm) could explain it......or you could have a slack throttle cable causing the WOT switch to not activate.....which could cost 20whp too?