So a local place was doing two dyno pulls for $40 and I had just switched my pulley with a 178. So I figured I'd check out how good my car is running.

Every thing was good and I turned out to be the last person they dynoed. They did a porsche gt2, targa, various supras, and various other cars.

Since I was the last person I decided to run some errands and what not. I let the car sit for a good hour before I got on the dyno, but the supercharger was still kind of hot. No big deal, I just wanted to get an idea what the car would do with the new pulley, no tune. I had made 282 on mustang dyno a few months back.

So I put it in dyno mode and did the tranny reset. Will once they get it on and strap it down they go for it and I you could see the car struggling. They tell me that the traction control is still on and that I have not taken it off, but you could see all the warnings on the screen for abs and etc off. So they try it again and they are saying the rear brakes are stuck. They keep blaming it on the traction control. By this time the whole place stunk of burnt brakes. They finally look at the straps and they notice that one of the straps was strapped to the brake line, which was causing the brakes to engage.

So they do another run, mind you this is like the 4th or 5th try and the car comes out with 259 whp. I told the guy that this can't be because I had dynoed it before and I had 282 stock and now have a pulley and new HE. I know the HE doesn't make any hp, but I figured the new pulley would make a bit more. The guy had the nerve to tell me that the other dyno run was messed with to give me higher numbers, but the numbers seem right for stock at 282.

On my last pull I only made 264whp and 272 wtq. I'm figuring that the car was extremely heat soaked and that was one of the reason for my low results.

Does any one know of any thing I can do to check on my rear brakes, they seem to be fine, but they still have that burnt smell. I did feel like the rear brake was still engaged for a second, but it seems to be fine. What should I check and do you think there is any thing potentially wrong with my rear brakes?

I'll post some pics later.

 

Put the car up and check the hoses-pull a wheel and see whats left of the pad (and how much transfer you got on the rotor now)-
worse case-you needs rear lines and pads-
sorry to hear about a crappy experiance!

 

I had a similar experience. I still don't know exactly what was wrong but my passenger side rear brake was glowing red. That was with the fuses pulled. (SRT-6, no dyno mode) 219 hp. Much later I went to another dyno and had problems again. 240 something. Finally I went to a dyno day and everything went smooth. Still low numbers (Mustang dyno) Around 290 hp. Then we did a dyno 1/4 mile. 12.7 at 108 which is correct. I love to read dyno numbers but I'll tell you what, they really don't mean much to me anymore. Now I agree more with those that say that dyno's are a tuning tool more than anything else.

Les

 

Sounds exactly like what happened to me. That burning smell is your parking brake going up in smoke. The only way to fix this is to replace your rear rotors. Check you parking brake and get the shop to buy you new rear rotors. Of course your whp numbers will be much lower than you expect if your parking brake on durning the dyno. Since the shop admitted placing the strap around your brake line, they should help you out.

 

If you're not tuning, there really is no point of putting the car on a dyno. Dyno's put a lot of strain on the motor.

 

I put my car on the dyno for the benefit of forum members. (Crossfire and C32 AMG) I wanted a baseline and to document results of future modifications. I come to find out that butt dynos can be as accurate as real dyno's depending on if a butt head is at the dyno controls or not. With the unreliability of the dyno numbers my desire to document gains from changes went out the window. I think data logging is as valuable as dyno time for tuning. Mostly, IMO, dynos are for entertainment and then for tuning, if you can find a tuner worth the trouble.

Les

 

I agree 100%! I have never found a tuner worth the trouble, so I've always done all my own tuning. Well ,I have to take that back. Dan Craigen at DC performance in L.A. is good. He tuned my viper and wants to tune my C55. Other than that, I've done all my own tuning (on the crazy custom engines)

Mike

 

I will definitely check that out this weekend, I've been due for a change in my rear rotors any ways.

I signed a waiver that states that they would not be liable for any damages on my vehicle if any thing were to happen to while in their possession. So I'm pretty sure I do not have any recourse, I was just really disappointed that I wasted my money.


I had done a baseline dyno in the past to see how my engine compared to stock in the past. I wanted to see if the addition of the renntech pulley would make any difference. I know on my butt dyno my car seems to have a bit more get up an go, I just wanted to see actual numbers. I figured that I should have been in the 290+ range with the pulley since I dynoed at 282 with out the pulley.

 

It didn't ruin my rotors or pads so yours should be OK unless they were almost gone anyway. I attended a dyno day a few weeks ago as a spectator and they had water sprayers and fans galore. On the regular customers cars they put a fan on top of the motor as well as the big fan in front and were spraying the radiator and intake manifold. No ice, but you get the idea. For me it's better not to help the numbers, use the same dyno everytime with the same dyno operator if possible. Unfortunately for me, it took 4 dyno sessions to find a good one with trained personnel. You are in the 290 or 300 range with the pulley, depending on the dyno and operator. I've heard of around 330 with a pulley. But some peoples 330 equals your 290.

Les

 

damn sorry to hear that. thats why i watch them like a hawk when they strap down my car.

 

You really have made my day with your quote, I guess I was just needing reassurance. At least now I have an excuse to change the rear pads and rotors.

I really thought nothing of it, I figured if they could do a gt2, they could do my car with out a problem. I will check from now on.

 

they probably figured the guy with the gt2 has enough money to sue them to bankruptcy..lol.

 

Here are some pics:











Here were some of the cars that they dynoed:









New interior pics: