Lately, I haven't had much success at the track. My 60ft times are suffering horribly. When I say horrible, it's REALLY bad. I haven't changed much. The new changes have been tires (Michelin PS2's) and Osiris Tune.

Before the changes, I managed 2.0-2.1 60ft's on crappy Eagle RS-A's which is probably the worst tire known to man according to reviews. With the new tires and tune, I cannot get anything better than a 2.4...don't laugh, I have a theory.

With the new set-up, it's simply spin city. I've tried 35, 30, and 25 psi. So far 25 is the best but not by much.

Also, when shifting to 2nd gear, it gets really dangerous. The tail wants to swing out to the left almost every time if I shift to second from redline. I almost lost it and almost kissed the wall on a few ocasions. This was never problem before the changes. With these issues, I'm simply forced to ease out of the line and shift carefully into second.

I've noticed that my PS2's like to be heated. I've never been a fan of heating street tires, but these simply like to be heated up slightly for some reason. I've tried avoiding the water box and launching with them cold with only a slight spin to remove rubble with no success. Without a slight burnout, I would simply have to launch from idle.

My theory is, is that my differential and subframe bushings may be worn. Although, I do not have the silicone streak on my rear diff, the rear differential bushing does have a crack. Also, my rear struts are also showing signs of wear. I also think the PS2's may have a sidewall too still for drag racing.

I would love to get a dedicated set of Drag radials for the track, but with the failing bushings, I think that will only mask or even worsen the problems with wheel hop.

Here's a video of my trouble. I launched from only around 2000-2500 rpm, while slipping the clutch out of the hole. No I didn't dump it which is probably what you guys are thinking. You'll see the wheel-hop once I shift to second gear. Since I heated the tires up, the tail didn't come out as much. Only slightly. My battery was low, so I didn't get anymore videos.

http://www.youtube.com/watch?v=PRrpf8KZM8E


Any thoughts?

 

thats really odd....

 

Mine does it often and I'm open diff, have 0 wear, and worn tires. Since you are using stock vlsd it could be the slip struggling to distribute power to both wheels after the 1-2 shift. Your powershifting correct? To test my theory if you are powershifting try a slower shifting technique but not so slow to effect your 330' times. Also another way is to start off at about 10 mph then go wot and see if it happens in first. Mine will wheel hop alot when doing that also.

 

i just watched your older videos and on one of the videos you made a perfect shift and there was no hop on the shift to second gear shift. It sounds like your foot is still on the gas while on the shift to second on the wheel hopping runs. I think you need to "lift" then shift. That's just my .02

 

hmm i think there is a program were you can do psi by gear. Meaning each gear will only go up to a certain psi. That may help with the shift into second. I would replace any worn parts and get a lsd and go from there. .02 of what is worth sense im not f.i

 

A time slip would be helpful.

 

I also have the dreaded wheel hop. I am going to try the SPL Front are rear diff and subframe bushings. May be add a diff brace after as well?

I am boosted so I thought I would short shift 1st and second and hit it in 3rd. The wheel hop pulled me hard towards the center of the track and then I got a noise in the Diff. right after. My 60 and 330 times are no better than a NA car. but I can trap at 119mph. 60 ft usually only 2.2-2.3

I have Tien flex with EDFC, RE50A 285's, I set the pressure to about 25lbs.
6MT with Carbonetic twin plate clutch and Carbonetic LSD.

Car is at the shop now to get the diff checked out. If there is no significant dammage I might spring for the Pro split axels. When I peddle it as above a NA car can beat me. If I try to slip the clutch I get wheel hop. I am very worried about breaking something like the axels so I don't practice much at all which I am sure would help some.

 

When I changed out my diff and FD I put in the SPL and whiteline bushings, I have almost no wheelhop now. Such an enormous change. With everything you've done Id attribute it to that.

 

Good to here OjiggyO

I was thinking about the whiteline as well but was not sure if they were needed if I go with the SPL. Plus I was trying to save on installation costs and hopefully put the extra towards the driveshaft shop pro axels.

Reading some other posts it sounded like DR's help to reduce wheel hop?

I want to hit 11's

Rich Christensen Arm drop is coming back to Cayuga this year it would be so cool to enter the ZR.

 

Gets some drag radials, inspect your rear suspension to confirm your theory. Replace worn parts. Crank it up to 3500 and pop the clutch if all is well (no wheel hop or spin), try 4000 then 4500,5000 till wheel hop or spin happens. I would get M/T ET streets, thats my

 

I have Enkei 9.5 x 18's RPF03's and was thinking about these.
MTT-3782R Tire, ET Street Radial, 265 /40R18, Radial, R2 Compound, Blackwall,
http://www.summitracing.com/parts/MTT-3782R/

Dont know if DR's will hapen this year but planning is good.

A set of smaller wheels for drag would be nice but i have Stoptech BBK front and back.

I'm getting an oil cooler and some gauges installed so must be carefull here on the budget.

 

The whiteline bushings are great for me, but your car is a monster lol. You have to decide if you want the super stiffness of the SPLs up front of the ease of installation of teh whitelines. Also if your front diff bushings are already toast the whitelines are useless for you. My car had 17k when I put in the whitelines so my bushings were still pretty much new.

 

i'm in your same boat get insane wheel hop sometimes seem work out for me is i don't wot right from the launch wait tell hit 8mph-ish to hit the gas here fun video me get insane wheel hop

http://www.youtube.com/watch?v=_89ngmCvxnw

 

^whoa! You just spun and hopped all of first gear and half of second. I guess were both in the same boat. What are you 60ft times with all the hop?

 

Here's a video of my rear bushing. As I lifted it up with a floor jack, I noticed lots of movement. Is this normal? Also, there are cracks on the top and bottom portion of the bushing. It also feels dry and flaky around the crack. Normal?

Video:
http://s55.photobucket.com/albums/g1...nt=Bushing.flv

 

beleive that that was 2.3

 

No bushing is dry rotten

 

Are the PS2s new or used? Check the production date - they get slick when they're a few years old.

 

Yes I got them used with 7/32 left. The production date is 4907 on both so they are a few years old.

I guess that makes sense. I can make them spin so easily compared to my RS-A all seasons.

So regarding my video above, is the movement of the rear bushing normal? Is it suppose to have that much play? I do not have the streaks on my diff cover btw.

 

I also had horrible wheel hop.. i noticed that my rear subframe bushing was leaking on exhaust, it busted. when they bust thats what makes it horrible. i JUST installed my SPL solid bushings today. heres my link to install and a few pics.... https://my350z.com/forum/brakes-and-...-installed.htm

I still have a little wheel hop but not as much as it was. thinking abt doing a diff brace. dunno what could eleminate it totally.
I use to hop all the time now if i practice i could launch without hopping.