Drag Launch
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From: Kingston, Ontario, Canada
Drag Launch Hoping to hear from Madman Racing as I purchased their Fbody valved AFCO double adjustable rear shocks. Appreciate input from others as well. They suggested I start with rebound 24 from full tight and compression 11 from full tight. Single adjustable QA1 fronts at 1 from full soft. I had those settings on this run. Could not hook with 15 llbs cold in Pro Bracket Drag Radial. 60ft in 1.65 range. I started the nitrous at 60% with a .4 build to 100% which was no better. 3900 llbs car with 800-815 rwhp on 300 shot. Track was not well prepped. Suggestions on better settings for local track? I'm inexperienced with these double adjustables and when it would not hook I really didn't know what to adjust next.......
When I went up to Napierville Dragway, which is well prepped, later in the week, I ran 1.385 sixty on same shock setting on way to 9.65 at 141 mph. I did add air to the tires starting with 16 llbs cold at Napierville. Suggestions appreciated.
http://vid615.photobucket.com/albums...psc2zbvely.mp4
When I went up to Napierville Dragway, which is well prepped, later in the week, I ran 1.385 sixty on same shock setting on way to 9.65 at 141 mph. I did add air to the tires starting with 16 llbs cold at Napierville. Suggestions appreciated.
http://vid615.photobucket.com/albums...psc2zbvely.mp4
Last edited by CanadianEh!; Jul 23, 2016 at 02:16 PM.
I think you first problem is the tire pessure should be 18-20. I'm not sure how many clicks are on you shocks but my rear viking have 19. I run rebound 5 from full loose and compression 15 from full loose. My car is 3740 and makes about 650 on a 250 hit and does 1.40-1.44. I run 18 psi on not so great tracks and 20 on nicely prepped tracks.
In the video the tire looks balled up and not planted. I believe tire pressure for you should be around 20.
I also believe you mean you started the nitrous at 60% with a .4 build to 100%. If so this is not a very long progression. At this point I would slow the nitrous down to start at 30%, build of 1.0 to 100%
I know this seems long but you have to get the car going down the track so you can find what shock changes work. And start bringing in the nitrous sooner until you find what changes it likes. Take lots of notes in a log book.
In the video the tire looks balled up and not planted. I believe tire pressure for you should be around 20.
I also believe you mean you started the nitrous at 60% with a .4 build to 100%. If so this is not a very long progression. At this point I would slow the nitrous down to start at 30%, build of 1.0 to 100%
I know this seems long but you have to get the car going down the track so you can find what shock changes work. And start bringing in the nitrous sooner until you find what changes it likes. Take lots of notes in a log book.
Thread Starter
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From: Kingston, Ontario, Canada
Thanks for the feedback. Since I read your post I've done some research online which validates what you are saying - 18-20 psi is where most are running this tire. With my heavy 3900 llb car mine should likely be on the higher side of that. Likely need to hit the tire harder with the additional psi as well. Only one way to see if she likes it - should be able to test it out next weekend. Thanks for the feedback - much appreciated!
Suspension wise it looked pretty good, no squat and very little separation. But I agree the tires looked like they deformed pretty badly. Some wadding up is normal, but those looked a little over done. Radials like higher pressure, they are really kind of an opposite mindset than traditional wrinkle wall slicks. I always got the best performance out of my MT radials at around 17psi in a 3000lb car. Heavier car will likely need more pressure, so 18-20 does not sound like an unreasonable place to start
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Glenn ***
Sales Tech
www.bmrsuspension.com
813.986.9302
Find a Quality alignment shop near you!
Thread Starter
9 Second Club
iTrader: (4)
Joined: Aug 2009
Posts: 317
Likes: 4
From: Kingston, Ontario, Canada
**Updated Track Results** Thanks for the feedback. Since I read your post I've done some research online which validates what you are saying - 18-20 psi is where most are running this tire. With my heavy 3900 llb car mine should likely be on the higher side of that. Likely need to hit the tire harder with the additional psi as well. Only one way to see if she likes it - should be able to test it out next weekend. Thanks for the feedback - much appreciated!
**Update**
Initially I tried going to 17 psi with fronts 1 from full loose and rears with compression at 10 from full tight (22 total clicks) and rebound at 14 from full loose (44 total clicks). Blew the tires off on poorly prepped track.
I tried a number of shock combinations at 16 psi on different outings and tracks but was stuck in the low to mid 1.40 - 60 ft range. This weekend I was watching another car running M/T E/T Pro Radial was running 26 Psi and was adjusting to 20 psi as he was not hooking in the heat. He was hooking after that. Seeing the psi he was running I decided to go 18 psi but adjusted the rear shocks to 7 from full firm on compression and 5 from full soft on rebound to hit the tire harder. Wow! The car left harder than ever before with a 1.35 sixty in the 83 degree heat! That was a personal best.
My next option is to increase psi until sixty falls off then tighten rebound until sixty falls off. Not really sure which one I should try first? Also on poorly prepped tracks is it better to reduce psi first or loosen rebound first? Input welcome!
Last edited by CanadianEh!; Aug 21, 2016 at 11:50 AM.
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From: South Lyon, Michigan
Separation on a radial is what the tire and car will like.
Remember with a radial they don't like wheel speed off the hit. They want to be dead hooked and pouring the power to it.
When it comes to radial tire racing, tuning to the track is very important. We normally run our 275 pro's at/around 17psi (single 88 or 98mm turbo car) and we see 3-5" of separation off the hit and holding 1-3 down the track. 1.14 is pretty normal for our radial tune up, low 1.20's when we have a slick tire setup on the car.
Remember with a radial they don't like wheel speed off the hit. They want to be dead hooked and pouring the power to it.
When it comes to radial tire racing, tuning to the track is very important. We normally run our 275 pro's at/around 17psi (single 88 or 98mm turbo car) and we see 3-5" of separation off the hit and holding 1-3 down the track. 1.14 is pretty normal for our radial tune up, low 1.20's when we have a slick tire setup on the car.
