My Mustang GT on Mustang Dyno Results
03-02-2010, 05:17 AM
#21
3rd Gear Member
Thread Starter
Join Date: Apr 2008
Location: Merritt Island, FL
Posts: 996
I agree with Marc. While it could just be dyno, I wouldn't expect that big of a difference between dynos taking into account all the mods you have done since. You're at a 20-30 wheel horsepower difference, and you've done quite a bit since. How did the air/fuel numbers look on your last dyno?
I forgot to mention that the original dyno is a couple hours away in Tampa. I went there for a concert with my friend, and a former co-worker of his started a dyno/tuning shop Proven Power. I got 3 pulls for $30. If I go down to Tampa, I'll try and make an appointment to get dynoed, but that may or may not happen.
Also, the weight that was entered into the Mustang dyno was 3400. Which I feel is a pretty reasonable weight for the car. Marc S what was the weight that was entered in for the 326 hp I see in your sig?
03-03-2010, 05:49 AM
#28
3rd Gear Member
Thread Starter
Join Date: Apr 2008
Location: Merritt Island, FL
Posts: 996
3350 sounds good. Figure I'd ask to see if that is a possibility for the number difference (aside from cams, UDPs, and dyno tune). It might just be different series or model dyno or just because its a different dyno. I don't know.
On the A/F ratio, the manager said that my A/F ratio was a bit high for what he typically likes to see, so in between pulls, I used my handheld tuner to add fuel at WOT. But it only resulted in a loss of power (~8rwhp at 2% increase), and you could definitely smell a difference. This is the tune that Brenspeed sent me, and it seems to be pretty good for an email tune.
Also, I got the new Muscle Mustangs and Fast Fords, and the camshaft swap article shows a dyno pull with the A/F ratio around the 13 mark. It might not be too uncommon to have A/F ratios like this then.
On the A/F ratio, the manager said that my A/F ratio was a bit high for what he typically likes to see, so in between pulls, I used my handheld tuner to add fuel at WOT. But it only resulted in a loss of power (~8rwhp at 2% increase), and you could definitely smell a difference. This is the tune that Brenspeed sent me, and it seems to be pretty good for an email tune.
Also, I got the new Muscle Mustangs and Fast Fords, and the camshaft swap article shows a dyno pull with the A/F ratio around the 13 mark. It might not be too uncommon to have A/F ratios like this then.
03-03-2010, 07:47 PM
#29
1st Gear Member
Join Date: Dec 2008
Location: Washington
Posts: 70
Your A/F does not concern to much me for a N/A engine. I like my tunes to be in the 12.8-13.0 range though. Like I said earlier, the MD you used might just read low. You stated the manager has a GT500 that dynoed at 391 HP. That's why I provided my GT500 dyno numbers as an example. If his stock GT500 reads 10% lower than my stock GT500. Then maybe your car would be closer to 295 HP on the MD I use and trust. My GT made 297 HP before the cams by the way. At the end of the day dynos are only tuning tools and number don't mean crap. But it would be nice if you knew for sure his MD dyno just reads low.
03-03-2010, 08:24 PM
#30
4th Gear Member
Join Date: Jan 2005
Location: Florida
Posts: 1,190
mustang dynos are typically about 10% lower than dynojets. even that being said my guess is that you didn't gain anything from the headers. I know that Kenne Bell has done a lot of exhaust tests with the 3V motor and different header, x pipe, and exhaust combos and they've only gain with exhaust past the 550whp mark.
in order to have a good test you can only change one variable at a time. by changing parts and dynos in the same test you don't know if the part or the dyno changed the numbers. even when guys only change headers and go back to the same dyno they usually change the tune. again they're changing more than one variable at a time and it's more likely the tune changed the power. when kenne bell did their test they stuck with the same timing and AF ratio through all the combos and the power stayed the same.
in order to have a good test you can only change one variable at a time. by changing parts and dynos in the same test you don't know if the part or the dyno changed the numbers. even when guys only change headers and go back to the same dyno they usually change the tune. again they're changing more than one variable at a time and it's more likely the tune changed the power. when kenne bell did their test they stuck with the same timing and AF ratio through all the combos and the power stayed the same.