Drivetrain MTH Dyno Results

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Jan 17, 2005 | 05:17 PM

#26

ATSTodd

Thread Starter

1st Gear

Joined: Apr 2004

Posts: 43

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From: Near Dallas, Tx

Quote:

Originally Posted by greatgro

1 - The evaporation of water on the intercooler can make a very big difference on the dyno and since no other MINI dyno techs do this, these numbers aren't comparable at all to anyone else's dyno.

I'm not trying to make my numbers comparable to anyone elses. I don't care what anyone else made at the flywheel on XXXX dyno. Thats not the point of a dyno. I think this has been beaten to death in other posts but the purpose of a dyno is to tune cars and to evaluate different modifications. Are you sure other Dyno techs don't do this? Maybe they should be. If i see the torque curve drop suddenly near the end of a run i know something made the car unhappy and made it pull timing and add fuel. Since i can't actively adjust the timing i have to influence it in other ways, like cooler intake IAT temps.

Quote:

Also mods that great more heat (pulleys, ECU programming to run leaner) are going to benefit greater from the extra cooling than a car in stock form.

The intercooler dosen't get more efficient because you add a pulley.

If you put more heat into a system you need to get more out of it to show any gains you might have made. Ideally you want the exact same IAT and A/F ratios with and without a pulley to see exactly what difference the pulley made. Without extra cooling the mods will likely show less power than they should due to the extra heat they create. The question then becomes, How much cooling do i need? The limited amount of datalogging i have done indicates that the ECU actively retards ignition timing and increases fueling as the intake temps get hotter. In third gear, on the street, WOT, near redline I was seeing IAT's just over 140F, starting temp was 95F I think. It probably was a bit hotter but my datalogger has a VERY slow sampling rate.

On the dyno, in fourth with a squirrel cage blower Very close to the I/C I saw IAT's climb to 156F at redline from a starting point of 93F. with water spray only the IAT's made it to 142F starting at 97F ,and with both waterspray and the fan: 120F at redline started at 86F. Looks to me like the water spray is the way to go to ROUGHLY approximate street driving as far as IAT goes. Still need to get the water temps stabilized because they also have an affect on timing and fueling. This was all done with ambient air temps in the mid 60's.

Quote:

So that will throw off your readings of how much power a mod made. Same car and same dyno yet b/c of the cooling factor, the mod may show more power than it really makes.

The converse is also true. Not enough cooling will probably get you LESS power. see above.

Quote:

2- There is no SAE correction factor for forced induction so different dynos using different correction factors also make comparisons impossible.

Again i'm not trying to compare my dyno with anyone elses. However, Dynojets seem to read generally higher than the Mustang dynos from the very limited amount of information I have seen on Mustangs. NONE of the 5 correction factors our dyno has compensate for forced induction. I am not aware of any dynos that do compensate.

Even so, most dynos still show a stock MCS in the 140-145 whp range.

Don't forget the 05's are geared shorter in addition to a little more hp and are supposed to be several tenths quicker to 60. I don't think they're underestimating the power these cars make at all. Those figures sound right. :smile:

The '05's Definitely feel faster.:smile:

I'm not trying to be an as$, I promise.

Todd

Jan 17, 2005 | 06:09 PM

#27

ATSTodd

Thread Starter

1st Gear

Joined: Apr 2004

Posts: 43

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From: Near Dallas, Tx

Quote:

Originally Posted by Mugami

The stock number being that high is why i stated impressive. On a local Dynojet so far we have tested 3 MCS with 15% pullies and the MTH programming. no cooling on the IC except a fan. All three pulled 178 hp at the wheels which is equal to about 200 at the crank. using the 12% drivetrain loss. Also did a JCW that was retro fitted with the 210 upgrade kit. it pulled 188 hp equaling to 210 hp at the crank.

The important part about these results done by ATSTODD isnt the numbers themselves in comparing car vs car. (different dyno's can give different reading of the same car) But the gain which is important since it was done on the same dyno in approx same conditions.

If i may ask Todd are you getting A/F readings when your doing the pulls. if so i would like to see them for the stock run and after you switch to the 15% pulley. We are going to be getting intouch with Franz on our finding to see if he can fine tune the setting for our area. So i would like to see the comparison

Thanks a bunch

Yep, we always use the wideband. I 'll send them to you if you like. be advised that the ignition timing was being retarded a bit in certain places and probably a bit more fuel was being added as well due to high IAT's. So not sure if you will want to use them for actual tuning.

Todd