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Discussion Starter · #1 ·
i went to Mustang Magic yesterday with Jim V. to dyno my car and make sure everything was running ok. to make a long story short, i drove for 1 1/2 hours and parked the car for about 1/2 an hour for a little bit of a cool down. hooked the car up to the dyno for 2 pulls . my first pull netted a "whopping" 429 rwhp and 433 rwtq. my second pull was back to back and was an even better 419 rwhp and 431 rwtq. keep in mind that i just ran 11.69 @ 120.01 with this power. something dont make sense.

i was wondering how everyone gets there dyno #'s . do they just drive to the shop and throw it on like i did? do they ice , do they have cooldowns? any secrets or tricks? im not saying anyone isnt putting down the #'s they are saying . i know they are, im just wondering what could be wrong with my car? i also changer the fuel filter ( it was fine), and did a backpressure test to check my cats ( they were fine also). everyone was dumbfounded about why my car wasnt making power. and how am i running the times im running with that little power.

before anyone says belt slip or spark blowout. the dyno sheet showed my power curve was solid as a rock and smooth as can be. just very low #'s . any ideas , would be very much appreciated . and details of how you dyno. thank youin advance guys.

p.s. Jimmy V. jumped on the dyno right after me to make sure the dyno was ok, and netted 469 rwhp and 478 rwtq. so it was fine .

p.s.s. Jimmy V. drives like a little girl!!!!!! 470 rwhp and his best was 12.03!!! :lol ;)
 

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The Ubiquitous Jimmy V.
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p.s.s. Jimmy V. drives like a little girl!!!!!! 470 rwhp and his best was 12.03!!!

LITTLE OLD LADY:D

I resemble that remark....;)

I'll get my 11sec pass OCT6th at ATCO...
 

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Just imagine what you would do with REAL numbers like I have?

John, when I dynoed, I had a cooldown, but when the car was strapped on the dyno, there was little if any cooldown between pulls.

You got me confused man, maybe a techie will chime in and give some better advice.
 

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That is def. some low numbers, evidentally the car was heatsoaked or something, did it feel lazy on the way to the dyno or anything. I know its hard to do but I would forget about it, man your car is running over 120 like it nothing and that tells me its making alot more than what the dyno indicated!! I will be interested in what if anything you find though, keep us updated!
 

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The Ubiquitous Jimmy V.
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John went low 12's with initial dyno of 449,,then 11.80's with 439 now he ran 11.69 with 429..That really does not make sense..
 

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Night Trains Daddy
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If it traps 120...I wouldn't worry about it

I had three back to back pulls after a 1 hour cool down

Third pull was the highest 455 and 470
 

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The Ubiquitous Jimmy V.
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stlblack03 said:
If it traps 120...I wouldn't worry about it

I had three back to back pulls after a 1 hour cool down

Third pull was the highest 455 and 470
Is it true you dyno higher with Solid Axle...??
 

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Night Trains Daddy
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Never dynoed with the solid in. It was IRS and Mac 3" catback, now I have solid and Bassani...I'll dyno again soon.
 

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The Ubiquitous Jimmy V.
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2 guys i know ,,1 dynoed removing IRS and added solid axle..He gained 8rwhp..The other was n/a car that added IRS he lost about 7 or 8 RWHP
 

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Discussion Starter · #11 ·
i dont know guys, the only thing i can think of is heat soak. but i would think a 1/2 hour cool down would be enough. maybe not to cool the car down fully , but atleast get rid of any heat soak.
 

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I know everybody here in Colorado uses ice on the blower. I pull it in, they hook up the big fan and I ice the blower for about 15 mins. The weird part is, my first pull is ALWAYS the worst. Maybe that big fan blowing on it helps cool the engine and blower in general down, but, later runs are always higher.
 

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Don't worry about the dyno number. You probably were down due to heat somewhere. For reference, My car as it went at Bowling Green last year put out 441 SAE, when it went 11.72 @ 120.37 on F1's. I later added some stuff that got the dyno # up, but I don't belive it ever improved track performance.

I've done some things that have improved the dyno number, but it doesn't seem to show up at the track. True I ran some better times after BG, but the weather ( and Drag Radials) was enough better that I think I could have ran the same number in the same trim that I registered the 441 rwhp.

I think whatever improvements that show up as a good dyno number when the car has been cooled for a pull, are lost by second or third gear, or maybe even by the end of the burn out.

JT
 

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if you tune has a little too much timing it will be down on power when the motor is warm. Otherwise you can expect it to be down 10HP, maybe 15HP when it's hot. But with a half hour cool down it shouldn't be that hot. Another thing to consider is outside air temp, humidity, and altitude. Those can play a part in dyno numbers.

Brian
 

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Did someone say "heat soak"? Try the Heat Exchanger, I love mine.
 

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Build a chiller. A heat exchanger will not get the colant as cool as ice can or below ambient temp. Plus, you will have to run a fan on it to do any good. My chiller put out 503 rwhp SAE and 550 rwt with one hour cooldown sitting in the sun with one bag of ice on the blower and no fan. The air temp inside the shop was 88 degrees. Even the rubber hoses were sweating. We forgot to put a fan on the engine to provide more air for the intake when we made the pulls. The intake had to draw in air on it's own. That may have cost me 10-15 rwhp. The chiller made peak HP gains of 20 and nearly 30 on torque. It had net gains of 30 down low.
 

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We all compare peak dyno numbers but thats not what its all about. I have personally compared my dyno results by 100rpm increments to a car that made more peak H/P and T/Q than mine and mine was 8-12 H/P & TQ ahead through the entire range up to about 5200, so its not all about peak numbers at all they are just what everyone wants to see !
 

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Discussion Starter · #18 ·
thats a very good point trey. but we layed mine and jim v.'s dyno over each other , and his was alot higher the entire way up .

i was told that it was probably heat soak. i drove to the dyno for 1 1/2 hours in traffic. and when i could , igot on it a little. so i guess 1/2 hour cool down wasnt enough. i was told that the block will actually get hotter in the first 1/2 hour of cool down.
 

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Yes Venomous I agree that in the 1/2 hour that it sat there that everything heatsoaked more so than if you would have drove it right off the street onto the dyno. Did you let it cool with hood down or up?
 

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Discussion Starter · #20 ·
it sat there with the hood down. so i guess it was just baking..
 
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