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Time slip and dyno sheet don't match (need advice)

Posted: Thu Oct 30, 2014 7:37 pm
by Jdm1027
Is something wrong with my comb.
Motor made 574 hp and 572 tq on engine dyno. Motor is 418 sb mopar stroker motor. It is in a 72 challenger street car with stock rear suspension, 3.55 gear and a reworked converter from ptc roughly 3800 stall. A competition 727 from tci. Car weighs 3800 with me in it. The best time so far is 7:44 @91 mph in the 1/8. With a 26x10 slick on it. 60 ft times are 1.6. I am looking to try some caltracs on the rear but I just don't feel the mph matches the hp.

Re: Time slip and dyno sheet don't match (need advice)

Posted: Fri Oct 31, 2014 11:25 am
by Jdm1027
I am new to this site is this the place to post such a question??????? Thanks

Re: Time slip and dyno sheet don't match (need advice)

Posted: Fri Oct 31, 2014 11:39 am
by Dave Koehler
The more knowledgeable will chime in but the numbers they give you are corrected.
Are you running at sea level on a 60 degree day with no humidity? If so then I think you are missing some HP or there is an anchor in the car.

Re: Time slip and dyno sheet don't match (need advice)

Posted: Fri Oct 31, 2014 12:40 pm
by Baprace
Try this link from Stan Weiss, he has some formulas that help estimate horsepower.

http://users.erols.com/srweiss/calchpm8.htm

Re: Time slip and dyno sheet don't match (need advice)

Posted: Fri Oct 31, 2014 3:39 pm
by Jdm1027
I ran the nmbers on that site and on wallace calculator and they both estimate about 410 to 425 hp at flywheel. Am i loosing that much power from stock suspension. Shouldnt my mph be up even if my times were slow??

Re: Time slip and dyno sheet don't match (need advice)

Posted: Fri Oct 31, 2014 3:58 pm
by Dave Koehler
I'll try this again. Check your UNcorrected HP numbers from that dyno sheet. Those are more realistic, particularly if your dyno and your dragstrip are in the same local area.

Re: Time slip and dyno sheet don't match (need advice)

Posted: Fri Oct 31, 2014 5:41 pm
by Jdm1027
Sorry, All I recieved was corrected numbers on my sheet,

Re: Time slip and dyno sheet don't match (need advice)

Posted: Fri Oct 31, 2014 6:26 pm
by Kevin Johnson
Jdm1027 wrote:Sorry, All I recieved was corrected numbers on my sheet,
Josh, is your dyno in Philippi? You can look up the weather on the day you tested there or wherever the dyno is and try to calculate backwards to the uncorrected numbers. Check the elevation and weather at the track as well.

http://www.wunderground.com/weather-for ... lippi.html

Re: Time slip and dyno sheet don't match (need advice)

Posted: Sat Nov 01, 2014 10:23 am
by thedynoguy
just call the dyno shop and get the uncorrected numbers...

Re: Time slip and dyno sheet don't match (need advice)

Posted: Mon Nov 03, 2014 10:06 am
by John Wallace
I'd say your MPH matches the ET great. So does the 60'

Now the ET/MPH are for a 465/470 HP engine.

So, you're not using a 100HP somewhere.
Could be as these guys are saying is the weather/dyno numbers are making your HP numbers higher than what you raced at.

If you are at sea level in 70º calm weather when you ran those times, then you should be running faster.
(possibly 6.9's in 1/8th)

Re: Time slip and dyno sheet don't match (need advice)

Posted: Thu Nov 06, 2014 10:27 am
by fdicrasto
Did the shop that built the motor also dyno the motor ?

Re: Time slip and dyno sheet don't match (need advice)

Posted: Thu Nov 06, 2014 3:25 pm
by Jdm1027
Yes sir, I emailed them to get the uncorrected numbers but have not heard from them, He is the one telling me something is wrong with my comb and I should be turning better times. I just thought that with 3:55 in the 1/8 and stock suspension with old worn out air shocks that was what was hurting my times.

Re: Time slip and dyno sheet don't match (need advice)

Posted: Fri Nov 07, 2014 8:48 am
by Stan Weiss
Jdm1027 wrote:Sorry, All I recieved was corrected numbers on my sheet,
Can you post a copy of your dyno sheet?

Stan

Re: Time slip and dyno sheet don't match (need advice)

Posted: Fri Nov 07, 2014 9:54 am
by Jdm1027
dyno.jpg

Re: Time slip and dyno sheet don't match (need advice)

Posted: Sat Nov 08, 2014 1:18 am
by Stan Weiss
Jdm1027 wrote:
dyno.jpg
That is the only information on your dyno sheet?

Stan