My Dyno Results

[SUN RA KAT]

Just got home from doing 3 dyno runs. The first run in 3rd gear was quite a bit lower than the other two in 4th gear, so I had them delete it from their computer. The dyno was a Dynojet & the figures below are SAE corrected.

Dynorun 002 Max Power = 431.9 Max Torque = 474.6
Dynorun 003 Max Power = 436.1 Max torque = 480.6

BTW, when I got home I had to step around several large packages in my living room from a Sean Roe in Florida. Does anyone know what these packages might be?

 

[KenH]

You mean you had a Roe SC on order? I must have missed that post

We will of course expect a complete 1st hand report for those of us who will have to continue to dream a little longer.

Someone needs to get their digital camera out and get some install photos posted. I'm getting tired of seeing the same 2-3 pics.

--- Ken

 

[LTHL VPR]

What mods are you using to make that power? Is your car stock?

We don't see cars making those power numbers unless they have headers, exhaust, no cats, filters and tubes. Is this your setup? If not, maybe our dyno is more conservative than I thought.

 

[SUN RA KAT]

Sorry about not posting my mods. LTHL VPR - good guess at my mods. Here they are:

Sean Roe Smooth Tubes with S&B Filters, Sean Roe VEC1, Belanger Headers, Random Tech Ultra High Flow Cats for engines over 525 HP, Corsa 3" Cat Back with 4" Tips.

 

[VPRGTS]

Sun Ra Kat, with your same setup my best is 426 HP
in an '01. VEC set for +8 , -20. Max HP was
421 with 0, 0 VEC settings.

Questions:

Did you change anything to get the bigger numbers on run 3?

What are your VEC settings?

Did you get air/fuel numbers?

 

[SUN RA KAT]

VPRGTS -

My VEC1 settings are +12/-20.

I got the -20 setting by very carefully doing WOT tests on my "closed course" on Route 42 between Spring Valley and Waynesville. It's hard to lean out WOT so only the left blue LED lights up & even with the heavy load setting of -20 I usually get the far right blue LED to light up. (Just as I slowed down to the speed limit on my last calibrating run a Sheriff's car went by me going the opposite way. Talk about Yellow Viper Luck!)

I got the light load setting of +12 by following Sean's instructions (yeah, I read 'em) for setting up the VEC1. Light low throttle response is very good at the +12 setting and settings lower than that have an easily noticable fall off in performance. I didn't notice much , if any improvement by going to +14, so I leave it set at +12. The amount of black soot on my back bumper didn't seem to increase from no VEC1 to having a VEC1 set to +12. The only downside to having a Yellow Viper other than bug splats showing up so well is the black soot showing up so well at the other end of the Viper. (Wash Me!)

Run #3 was done about 5 minutes after run #2. Nothing was changed.

I didn't get an air/fuel readout since it would cost more money and my Sean Roe Supercharger was supposed to come by the end of the week. Little did I know that while I was getting a baseline on the dyno, my Roe Supercharger was being delivered to my house.

I'm going to try and post the actual printout soon, but until then I can say that it was a very smooth curve for horsepower with a slight jump between 2500 and 2600 RPMs. The printout starts at 2100 RPMs because I wanted it to show my power from the low end where I do most of my Vipering. the torque curve was above 400 ft-lbs from 2500 to 5650 RPMs. It was above 390 ft-lbs from 2100 to 2500.

Max HP was at 5300 RPMs.
Max Torque was at 4250 RPMs.

 

[Jack B]

Just a couple of thoughts - The a/f ratio is the most important data you can extract from a pull. If he picks up the a/f info from the tail pipe it doesn't cost him anything additional. If he inserts his sensor in your forward O2 well, at tops it takes 15-20 minutes more.

Secondly, starting the pull below 3000 is far harder on the half-shafts and exaggerates the torque on a Dynojet. Dynjojet suggests starting the pull at 3000 rpm on high torque cars. If you try a pull from 2000 after you put on the sc, wear a flak jacket.

If I want to play with the numbers, I start the pull at 2500. When you examine a pull starting at 2500 and 3000, you will show a substancially higher max torque on the one that started earlier.

Good luck with the sc

 

[SUN RA KAT]

Thanks for the heads up! When I come back for my next dyno pull it will be with the supercharger and I will go for air/fuel, too. I probably will try some adjustments to the VEC1 to get the best A/F settings as well. I also will have the pull start at 2500 RPMs.

 

[Jack B]

Start the pull at 3000 and make sure each following pull starts at the same point, otherwise, peak torque and the rise to peak torque will differ (inherent to Dyno's). The same applies to peak readings, don't go much beyond 5000. It is not giving any significant data beyond that point

The dyno is not a perfect tool for comparing one-time peak readings, it is tool that is very good for comparing the diff between successive pulls when each starts at the same point.

Make sure you have him record the coolant temp on each pull. In general, hp differences can be linked to coolant temp. When you are comparing curves, look at more than the peak numbers. I recently did a pull that showed a 25 hp improvement, however, at many points along the curve the new setup showed 50-60 hp difference. That was my sweet spot in A/F.

One last item, have him put his a/f sensor in the forward O2 well and have him give you a file in additional to the hard copy.