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I've always heard that every dyno will produce slightly different numbers too. You can have the same car pull baselines on 3 different dynojets and get 3 different sets of numbers.

Oh I know that cars will pull different numbers based on every environmental variable known to man. Even the same car on the same dynojet will pull different numbers every pull. I'm not saying they wont. I'm saying that Dynojet is usually the accepted dyno for having the most accurate results.

Edit: Roman's car put down 2 different numbers on 2 different pulls within 20 minutes of eachother on the same dyno.

Maybe the rollers have more or less surface area in contact with the tires? I don't know. Maybe I'm wrong and tire-to-roller friction doesn't vary; it's just something I read.

There is, of course, also the difficulty of trying to get repeatable performances from an ECU that's always trying to learn from its sensor feedback.

Nah, as long as the rollers are spinning the same speed as the wheels, then tire contact doesn't make a difference. I have seen (video) a GNX spin it's tires on a dyno. I've also seen (in person) a Supra spin on the dyno. You won't get peak numbers that way, but you know you've got to much power if you can light them up on the dyno.

The GNX put down more than 1000whp (before spinning off). The Supra put down (what was measurable) just under 1000whp. Had it not spun off, he would have probably put down around 1050 or so. The Supra actually scared me when it was on the dyno. It just kept getting louder and when he was spooled up, the back end just squatted. It was nuts. He lives in Virginia and his license plate explains it all. "1000HP"

BAC5.2 wrote:Laurel - What dyno was he on? TurboXS is right down the street from me, and they put 230 down at the wheels on their dynojet. It's been a little while since I saw the graphs, but I believe the peak number was 230.

Was on a Mustang dyno at Fame Automotive in Redmond, WA.

Not sure what the corellation to the Dynojet would be, but the other stock STi they ran a couple months before was within 1-2 hp of mine on the same machine.

I've heard bad things about the Mustang dynos, but that's just heresay.

As long as it's consistant, then it does it's job of being a tuning aid.

It could have read 10hp, as long as it was consistantly off, it would serve its purpose properly.

i'm gonna dyno my car on the mustang one once it's tuned.

BAC5.2 wrote:As long as it's consistant, then it does it's job of being a tuning aid.

Precisely. . . which is why I mentioned that. Plus, the guys that work at Fame seem to be the best around, short of driving 180 miles to Portland in order to let PDX Tuning do it.

mustang dynos are good for real world numbers. they put friction against the rolers to simulate the real world. dynojets put out numbers as if the car is on air. also most dynojets are 2wheels only.
im also curious if hp numbers can be taken on a track run. because we have awd traction shouldnt be a problem. does anyone have a or have access to a g-tec or similar device?

You guys all have valid points, as for comparison, wheels, etc. SO, in two weeks WOOHOOO, I am going to Portland to PDX and having my bone stock 93 SS dyno'd AND my 01 2.5 RS dyno'd to have comparison numbers. That way I can calculate the differences between factory specs and have an idea on the loss to the wheels, and see what the dyno puts out for that specific model.

Then we start the buildup on both cars.

June 5th I will post what the results are.

http://bbs.legacycentral.org/viewtopic. ... 3668#63668


The dynojet at axis measures a stock wrx as 155whp. It is well known that dynojet's seem lower than others. It puts resistance on the wheels using eddy currents.

The straps do put more pressure onto the rollers, not that it matters much.

MK

mTk wrote:The dynojet at axis . . .

If I had known you were going to Axis, I would have made extra effort to drop in. Gotta represent the old school turbos.

ah damn, you live semi-close by? I made a thread a few weeks back about the dyno day. I was definitely a hit, the impreza guys loved my car.

MK

mTk wrote:ah damn, you live semi-close by? I made a thread a few weeks back about the dyno day. I was definitely a hit, the impreza guys loved my car.

MK

Oh yeah, I'm in St. Louis. I know Ron, John, and Mike. I've been to the shop many times, but just have not made the trip to the dyno location.

I totally would have stopped by if I had known another Legacy was going to be there. Let me know if you come to STL again, I'll take you on a couple roads I know...

Definitely will do!

MK