So, I have an appointment on Monday, July 28th for three dyno pulls at a local shop here in N. Virginia. The dyno is a MD-AWD-IMP.

Here are my current mods:
VMS ECM/TCM tune
VMS HSRK
Rotofab CAI
Magnaflow cat-back

I am thinking about exchanging my modded-ECM with my stock-ECM for one of the pulls.

I have a couple of questions:

1. Do you think this would cause any problems?

2. Do you think I should do this in any particular order or just let the car cool down between each pull?

This is the first time I have ever done this, so any insight would be nice.

Thanks,
Robert

Leave the Vector ecm in it. Most cars benefit from a drive cycle or 2 after ecm tuning or replacement.

Leave the Vector ecm in it. Most cars benefit from a drive cycle or 2 after ecm tuning or replacement.

I've noticed that. I haven't posted anything, but both times the tune was changed (1st swapping the ecm and then flashxpress), the first drive I did the "this doesn't feel bad, but it's not like I expected".

The next day, however, man it was different.

I just chalked it up to being mildly insane.

:wink2:

Dats what it iz!

So, if I run the first two pulls with my modded ECM (obviously that is how I have been driving it), then put in the stock ECM, you think the stock pull would be under rated compared to driving the stock ECM around and then pulling the dyno?

So, if I run the first two pulls with my modded ECM (obviously that is how I have been driving it), then put in the stock ECM, you think the stock pull would be under rated compared to driving the stock ECM around and then pulling the dyno?

Yes. The best time to check stock is when its stock. Unfortunately I am not much on patience either! LOL

You should run the stock ecm 1st , the dyno should be able to show you where the timing is on the pull,and should also chart your air/fuel ratio. this what will change on the tuned ecm,also HP will increase when the motor is leaner and more timing is available

You should run the stock ecm 1st , the dyno should be able to show you where the timing is on the pull,and should also chart your air/fuel ratio. this what will change on the tuned ecm,also HP will increase when the motor is leaner and more timing is available

Will this make the second pull, with the tuned ECM, show more power/torque?

Will this make the second pull, with the tuned ECM, show more power/torque?

It better. Just don't do it on a hot motor. Give it time to rest between runs if possible.

The dyno should have large fans in front of the car to add cooling,if you have any GRRRR8 mods be sure to place a fan in front on driverside to get as much air as you can directed at the intake. And yes it should make a decent increase in HP

I will scan in the dyno results when I get home, but the results are rather poor. My best run was 310.2 rwhp/337 rwtq. It was 85 outside when we ran. The engine was cool, and we had two large fans on the front of the vehicle. :(

I will scan in the dyno results when I get home, but the results are rather poor. My best run was 310.2 rwhp/337 rwtq. It was 85 outside when we ran. The engine was cool, and we had two large fans on the front of the vehicle. :(

Something aint right!

Mustang DYno I assume?

Did you switch ecms while on the dyno?

Meetings all day:(

It was on a Mustang. I noticed that the HP @ 50 MPH differed then what VMS is using. They entered 13.39 and VMS used 13.8. Do you think this could skew the numbers?

Did you switch ecms while on the dyno?

Charlie,
I did not. I left the VMS tuned ECM for both pulls. I only did 2 pulls.
-Robert

Charlie,
I did not. I left the VMS tuned ECM for both pulls. I only did 2 pulls.
-Robert

I think the dyno calculations are off as far as initial set up. How does it run to you?

I think it runs great. A lot stronger then stock and not just a few hp's stronger as the dyno sort of suggests.

I think it runs great. A lot stronger then stock and not just a few hp's stronger as the dyno sort of suggests.

Something screwy.

Settings on a mustang dyno can be adjusted to yield different results. Any A/F readings?

-Brian

Settings on a mustang dyno can be adjusted to yield different results. Any A/F readings?

-Brian

No A/F data. Does anyone know how a wrong "HP @ 50 MPH" initialization would effect the outcome? I can't find my scanner (just bought a house), so I will have to take pictures of my results. Will post soon.

Here are my two dyno sheets using a poor man's scanner (my camera).

First Run:
http://www.oweninfo.com/pictures/g8/dyno1.jpg

Second Run:
http://www.oweninfo.com/pictures/g8/dyno2.jpg

Well at least you have a pleasent shaped torque curve.

13.80 is the proper number to enter on mustang dyno

torque curve looks real nice. Don't get worked up over the dyno numbers. Take it to the track and see how it does.

-Brian

I plan on going to the track in the next couple of weeks to see how she runs. I plan on running against my buddies LS2 goat.

Let us know how she handles.

Eating goats causes indigestion,so I'm told, but go for it anyhow

310 on a Mustang dyno is closer to 330 on a dynojet. Your numbers aren't off too much, I wouldn't worry about it. Track times are where you'll find out how well it's really running.

310 on a Mustang dyno is closer to 330 on a dynojet. Your numbers aren't off too much, I wouldn't worry about it. Track times are where you'll find out how well it's really running.

What bothers me is that VMS is pulling 332 with the same mods on a Mustang dyno but I have a cat-back exhaust on top of their mods. I think the initialization parameters are wrong or something.

VMS, Can you talk to the "HP @ 50 MPH" parameter?

WEll thats alot better than mine
I pulled only a 292hp 314 tq :( stock with rotofab intake

VMS,
Hope you enjoyed your vacation. Can you do me a favor and talk to the "HP @ 50 MPH" parameter on Mustang dyno's? I do not believe the person who pulled the dyno's on my car had the right parameter. How would this change the numbers if it would?
Thanks,
Robert