I have an opportunity to put the Daytona on a chassis dyno next Saturday. A friend of mine who owns a shop. Is having a dyno day for his customers. He stopped by today and ask if I wanted to put my car on it. Would this be a good idea? Can you run slicks on a dyno? Jim

Pump the air pressure up in the slicks.. a loose
conv give you some iffy numbers down lower

Put some tiny radials on it and over inflate them. The slicks will hurt the #'s.

Why do the slicks hurt the numbers?

I wouldn't run slicks on a chassis dyno. Best bet is to get some good radial tires and fill them to the max sidewall pressure. Then you can strap the car down hard to keep it from moving around.

If you have a high stall converter in there then the numbers will be weird anyway. Might not even be worth the hassle of running it on a chassis dyno.

I had the Hoosier QTP's on my dart when I dynoed it and an 8" vert and it showed 478 tq and similar hp running hi 9`s at 3200 lbs. which seems off to me and others I talked to about it.

Don't run the slicks. If you're lucky, you will have junk tires when you're done and lower numbers than expected. If you don't get lucky you may be in the market for new quarter panels. When they cinch down the tires hard, it takes away the tires ability to"grow" and all the pressure and expansion hits the sidewall creating a ton of pressure and heat.
Grab some wheels with radials on them and run good pressure and you'll be happy you did.

I guess some of you have money for extra tires.. I
ran on the slicks each time on the dyno.. and the
quarters are still there.... but my junk was only
high 8s

Nah I just ran a cheap takeoff wheel on my trans am that was larger diameter than the race wheels but with a stock tire was still very similar overall height. I got that info the first time I was going to chassis dyno. I was ordering some bias ply MT ET Streets and between what the tire manufacturer told me and what the dyno operator said I listened close. My take offs for running the dyno were less than 50 bucks and I didn't want to take a chance of a slick blowing out a sidewall.
The manufacturers advice made sense, wrinkle walls aren't designed to balloon way out. The sidewalls get overstretched and the wrinkle wall rebound is affected in the future. Since then I've seen some single digit cars completely frag a set of slicks on chassis dynos. At the end of one or two runs they're coming apart.
I'm not knocking your advice. In fact I've read your feedback with great respect over the last several years .
I'm just paranoid about safety I guess.

IF I didnt have other tires then I would run the
slicks.. but if I did I would change over.. I put
cars on dynos everyday for 25+ years.. you dont have
to have them pulling down so hard it hurts things..
its all in the angles of the straps

If you're looking for accurate numbers don't bother with a converter. Like others said it makes things weird. Can't help on the tire situation but if you can put a wideband in the exhaust it would be worth seeing how your tune is. Might be some useful data there.