Sharks

I ran my 86.5 5-Speed on the dyno last night and was somewhat disappointed with the results. Tried to scan the graph but I am not sure you will be able to see it.

Run Conditions: 44 deg F, 30.08 in-Hg, 28% Humidity, SAE 0.93
Max HP=239, Max Torque=249, Max Speed=140
Operator ran the car in 4th gear.
Car has H-Pipe, Chip, RMB, adjustable fuel, and K&N filter so I expected more.

Not sure what the deal is around 3000 rpm, but it looks like it is very rich.
SAE of 0.93? I thought it should be 1.01?

Please let me know what you think, this is my first time and have much to learn.

Herr-Kuhn

Don't sweat it too much. Correction factors and the like can take their toll on the results. I've never been a big fan of the dynojets. Regardless of what people say there are variances in the results. You are off like 20 or so HP...not the end of the world.

AO

Out of curiosity... I see his pull was made in 4th gear. Wouldn't this normally be done in 3rd? How does this affect results? Just curious.

mspiegle

you get a little more HP in 3rd.

Isn't 240rwhp for an 85/86 normal?

Bill Ball

85/6 US is rated at 288 crank. 4th gear can give lower numbers than 3rd.

In terms of fuel, this looks OK. At WOT it goes into a rich mode. I would have expected it to stay down around 11. Maybe the throttle switch is not working or you have too much slack in the throttle cable. Many people just check the cable adjustment from the throttle quadrant to the throttle housing but overlook the segment from the gas pedal to the quadrant. Slack there will prevent reaching WOT too. That leaves some HP on the table, but over all this looks about right.

A modest supercharger would relieve your disappointment.

James-man

My dyno was done in 3rd gear.

My 2800 torque spike is more pronounced than yours, but it does come back down about where yours does. My dyno was with chips and RMB.

While it is not supposed to matter that much, I wouldn't be surprised if it was starting in 4th gear that got you the results that you did. Starting by lugging the engine at 1500 in 4th - is this normal?

Sharks

I guess I should have had them do a run in 3rd gear too. I didn't know any better. The dyno operator said that ideally you want to run at 1:1 (5th gear) so you have the least amount of trans gear friction, but ran it in 4th as not to over speed the dyno. I just wanted to make sure that everything was running correctly before I installed the SC and I have something to use as a baseline.

I will be installing the J/E supercharger from Mike Spiegle's car soon (just waiting on a few more parts). Much more to learn ... should be an interesting spring next year.

Ketchmi

Our 86.5 5-speed did 246rwhp bone stock in 3rd gear. With just the X-over, no chips, rrfpr, or even an RMB it did 274rwhp. There was more to be had but we weren't there for that reason. I think we could have gotten it close to 300ish rwhp basically stock, just tuning.

BC

I ran my 89 5spd in 5th from 1000rpm to 6600rpm. I have the dynograph saved in my files somewhere. I wanted a full-run. It can't be considered a base run, since it was in 2001, and I would be dynoing the same motor rebuilt, but I'd like to see what my changes did to this specific motor.

I've digressed. That dyno line looks pretty damn familair to me. 928s seem to have that shape alot. Just higher or lower, and whether its a 2V, 4V with or without S4 intake.

Herr-Kuhn

Pulls are typically done in the gear that is closest to 1:1. In the case of the 3-spd AT that was 3rd gear. For the 5-speeds it is almost always 4th gear. I have to say, I am not a huge fan of the dynojet. It is just the industry standard for mods, so to compare you have to play the game. The better dynos load up the engine for longer periods.

BC

5th is closest to 1:1

Tony

thats the PITA im going throught with Darriens car right now. AS you may recall even stock he never had 100 OPEN on the throttle body.
Now with the SC on, i can get the TB closed...but then it wont open all the way. I adjust...i can then get it all theway open, but then end up short on the IDLE end and it not closign fully.

Shane

Sharks you should check your throttle quadrant for sure. Perhaps even your maf. Those numbers do look low.

Mine did its' thing with just chips.

GlenL

Those HP numbers look OK.

I think the A/F is too rich. Bad numbers from the sensor? Maybe someone has a comparable chart to post.

The SAE factor is less than one as the low air temps (44F) will give higher power than standard conditions.

The "best" gear varies. 5th would give the highest numbers but most dynos can't handle the speed.

Bill Ball

Tony:

You set the first segment loose temporarily and then set the second segment so the throttle JUST returns to the idle stop, with just enough slack that it seats fully and reliably no matter how slowly you relase the throtle. Then snug up the first segment. If you do not get WOT then pedal travel may be the problem. Is that adjustable? I haven't looked.