My Dyno Nightmare

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Old 10-22-07, 09:40 AM
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My Dyno Nightmare

Its been sometime since i posted stuff here .....went to dyno saturday .....Horrible
started out with 389@8 psi running pig rich , i am talking 10.0 A/F here .....horrible , just as i started to lean the thing out ...we started to to get some electrical problems (couldnt read RPM`s ) for some reasons , when we finally got around that (dyno needed another RPM input or something) i said **** it , i am going to do the tune to 10psi ,
So i did a baseline run @ 10 psi , and netted 405WHP but ith an A/R of under 10.0
So now i am going to lean it out a bit to get it running ......nobody noticed that the dyno strap was touching the exhaust ..............
Shure enough .....strap melted and broke ......so here i am in fourth gear @7000RPM suddenly not on the rollers anymore ....i never knew i could react that quickly
Nothing happend to the car , thanks to the quick reactions of both me and the dyno operator , and thank god for the extra safety strap .....but believe me when i say i almost stained my leather seats brown

needless to say i stopped dynoing for that day as everyone was to shaken up , but i will be going later to the dyno again to lean it out ...
Quick question also i noticed my car was spinning on the dyno because there was a bunch of rubber in the back of the dyno , is this normal ?....if not should i put weight in the back of the car ?.....that will also make the reading not be acurate right?

comments are welcome
Old 10-22-07, 10:40 AM
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Wow.... glad you and the car are ok..... very scary for sure.
Old 10-22-07, 12:46 PM
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Sounds stressful. I'm glad the motor held together though. Any dyno session you can drive away from is a good one. Regarding the rubber, I had the same thing happen with my 2 rotor when the car was out of alignment.
Old 10-22-07, 12:52 PM
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That would be very scary, one of my biggest fears while dynoing. If you were spinning on the dyno they should have some DET handy to spray on the tires.
Old 10-23-07, 11:15 AM
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Originally Posted by felix_is_alive
Its been sometime since i posted stuff here .....went to dyno saturday .....Horrible
started out with 389@8 psi running pig rich , i am talking 10.0 A/F here .....horrible , just as i started to lean the thing out ...we started to to get some electrical problems (couldnt read RPM`s ) for some reasons , when we finally got around that (dyno needed another RPM input or something) i said **** it , i am going to do the tune to 10psi ,
So i did a baseline run @ 10 psi , and netted 405WHP but ith an A/R of under 10.0
So now i am going to lean it out a bit to get it running ......nobody noticed that the dyno strap was touching the exhaust ..............
Shure enough .....strap melted and broke ......so here i am in fourth gear @7000RPM suddenly not on the rollers anymore ....i never knew i could react that quickly
Nothing happend to the car , thanks to the quick reactions of both me and the dyno operator , and thank god for the extra safety strap .....but believe me when i say i almost stained my leather seats brown

needless to say i stopped dynoing for that day as everyone was to shaken up , but i will be going later to the dyno again to lean it out ...
Quick question also i noticed my car was spinning on the dyno because there was a bunch of rubber in the back of the dyno , is this normal ?....if not should i put weight in the back of the car ?.....that will also make the reading not be acurate right?

comments are welcome
Like Cmonakar said, if the car is put on the car a little sideways, your tires will fight each other and loose some rubber. Where are you located? A dyna-pack tuner in your area (check www.dynapackusa.com) will allow your car to be bolted direct to the dyno. I am not sure if we are close enough, but would gladly let you do pulls on ours
Old 10-23-07, 11:55 AM
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Who ever stapped the car down should get fired. They need to check that kinda thing out. I never trust other people to do it right. I walk around the entire car and check every strap to make sure it well connected and tight. Just like in rock climbing if you guys ever do that kind of thing, never trust someone else to tie you off.

As far as spinning on the dyno, more wieght won't cure the problem. Try stickier tires, strapped down tighter, or make sure your car is aligned properly. Spinning on the dyno makes it less accurate then having more wieght on the rollers.
Old 10-23-07, 11:55 AM
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damn double post
Old 10-23-07, 03:25 PM
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thanks for the replies guys ...phew ...i am still trying to shake it off , i`ll be going back to the dyno maybe later next month , i am swamped at work
and this time i will check every strap myself
i decided to attend to my bumpsteer issues before i get more power out of this thing becaus , honestly its bugging me a bit , car drives nothing like it used to and with this new power potential ,i think its very dangerous

GTO thanks for the offer ...altough i am a little too far from you
I will however post the dyno sheets as soon as i get them of course
Not shure how much power i should get when its done but we`ll see
Old 10-23-07, 03:40 PM
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Originally Posted by felix_is_alive
..
Quick question also i noticed my car was spinning on the dyno because there was a bunch of rubber in the back of the dyno , is this normal ?....if not should i put weight in the back of the car ?.....that will also make the reading not be acurate right?

comments are welcome
at 405 whp, you were not spinning a thing. The guy who straped your car down is to blame for this one.
Old 10-23-07, 10:46 PM
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I agree, you werent spinning the tires at 400hp. We have had cars at 700HP+ with no problems. Just about every RX-7 we dyno will have a strap touch the exhaust. Just make sure they have a shield next time to protect that. Sounds like the car is going to make some good power once tuned. Good luck.
Old 10-24-07, 05:24 PM
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good save. glad this didn't turn into a worst case scenario. regroup and go back to it. it was obviously one of THOSE days - i'm sure we've all been there at some time or another.

good luck.
Old 10-25-07, 03:03 AM
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Glad to hear the car didn't get hurt (or anyone in the way)!
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