the parts for my car are all over the country right now being made or worked on or whatever....but pretty soon i'll have to hit the dyno. big power cars get a little tricky. at what power level do you end the dyno session with and finish up at the track?

i had a 1178whp mustang on my dyno that had more traction than a 500 horsepower civic. last year my car got into the mid 600's and was still holding....but i dont know how much more it had left. i had to take the fenders/bumper etc off for the dyno and dyno on slicks which i HATE doing.

any tricks/secrets to get the power to hold?

 

225 bfg's and 4th gear pulls, starting around 4k work well run the tires around 15 pounds and allow time for tires to cool if you are making multiple pulls...

 

why did you have to take the fenders off?

 

the slicks grow a lot on the dyno...and since the car is strapped down so hard in the front it doesnt lift..... the tires would grow more than the amount of tire/fender clearance i had.

 

what i use to do at jg was just grab the fatest guys around and hop on the door sills

 

yikes......a car isnt worth killing somebody. maybe i'll just duct tape bowling ***** to the core support.

 

good to know

 

maybe you should strap the car down better.

 

the car was strapped down fine and holding power just fine.....my original question was at what horsepower level does it START becoming a problem.

 

we hit ~820 on 28 inch slicks and didnt have a problem.(20psi of pressure in the slicks)

 

nice....pretty big tire though. ive never had anything bigger than a 25 on my car. i have a set of 24.5's that ive used on the dyno. the dyno tears up slicks real fast.

i dont really care about the numbers....i just want to make sure the timing is in check before blasting down the track.


what turbo was that on? just on boost?

 

CFT posted a vid of the coupe making 749whp and it was on bfg's (or similar tire and appeard to be 225/50's). I didn't see them having traction issues at all. If I knew how to post vid's I would post it.

Phil

 

Which dyno are we using? Our Dyno Dynamics has slight problems with independent rear sus cars with over 600 fttq but other those cars its fine upto 1200hp on street tires. i rec changing dynos.
but to answer your question , it will vary with power output , avail traction, dyno brand, strapping and such. try to strap the lower control arms down instead of the body of the car this will help. but on a dyno jet i dont think you can.

 

With dyno dynamics it comes down to the strapping. You shouldn't have any issues when strapped in properly. Even with independant suspensions front or rear. The key is you want to prevent the suspension from moving to much and lose traction. Solid axle rears are a piece of cake.
We had over 1000hp front wheel drive hp on our dyno without slip.
We had to make blocks that locked up the control arms so there wasn't any tire movement.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo-charged &raquo;</TD></TR><TR><TD CLASS="quote">i dont really care about the numbers....i just want to make sure the timing is in check before blasting down the track.
</TD></TR></TABLE>

Joe,

I always leave a little room on the timing and test it at the track. You'll find sometimes that adding the extra couple of degrees won't show up as much hp gain on the dyno but at the track it'll pick up quite a bit. This is due to the fact that with the extra timing the motor accelerates faster and will net you faster et's. So basically keep your eye on your trap speeds and keep adding timing until you can't go any faster.

 

we use VHT when it starts smoking tires on the dyno

 

Put some D-rings in the floor closer to the front of the car so they pull more down than away. On a dynojet they are about 6ft out and don't do much on holding the car down. 2 more short straps in addition would help.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Enzo-Racing &raquo;</TD></TR><TR><TD CLASS="quote">With dyno dynamics it comes down to the strapping. You shouldn't have any issues when strapped in properly. Even with independant suspensions front or rear. The key is you want to prevent the suspension from moving to much and lose traction. Solid axle rears are a piece of cake.
We had over 1000hp front wheel drive hp on our dyno without slip.
We had to make blocks that locked up the control arms so there wasn't any tire movement.</TD></TR></TABLE>

i call bs on 1000hp fwd cars!

 

how you strap down is key, plus 4th gear pulls are a must

P.S. over 600 bHP is when is gets tricky


NOTE: I'm speaking of dual roller dynos, single rollers are not a problem.

 

all you big hp ballers. Do you have have trouble with excessive wear and shear with your slicks on the rollers?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by VE junkie &raquo;</TD></TR><TR><TD CLASS="quote">i call bs on 1000hp fwd cars!</TD></TR></TABLE>

Yeah i guess your right. What do i know.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SpeedDreamz.com &raquo;</TD></TR><TR><TD CLASS="quote">all you big hp ballers. Do you have have trouble with excessive wear and shear with your slicks on the rollers?</TD></TR></TABLE>

You will chew them up pretty quick.
As was stated earlier if you have to use them make sure you give them enough time to cool off in between pulls.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Turbo-charged &raquo;</TD></TR><TR><TD CLASS="quote">

what turbo was that on? just on boost?</TD></TR></TABLE>

gt42R, around 40 psi, 83mm ls/vtec. stock 1gen b16cams. in the hotrod coupe in my sig.

 

would you be willing to post the graph? ive been searching and searching for 42r dyno charts but havnt been too impressed for the most part. this one sounds promising

 

send a pm to 2.0coupe. he has the charts