wheel hop

[automec1062]

does anyone else have bad wheel hop on hard starts (drag racing) if both tires hook they hop . doing autocrossing and street racing and hard launch's really bounce the front end .

mike

[brad]

Wheel hop can be reduced by using stiffer spring,550# front, 600# rear, adjustable shocks, siffer A arm mount bushings and proper tires. Our best time in 1/4 with classic 900 is 13.9.

[automec1062]

proper tires ? will just stiffer shocks help ? what did you have done to get a 13.9 ?thanks for the advice
mike

[brad]

Shocks will help but not solve the problem.
Tires are alittle tricky, Michelins are not the best they will hop if tire pressure is to high. Try running about 25 to 27psi.
What di we do. 1986 900s, 2dr, auto, no turbo with an Aerocharger turbo added, stock intercooler, water injection, remove interior and just about every thing else, weighted 2400#, change springs, Spax shocks,
Set caster and camber to 0, set toe to 0. That is the basics.

[automec1062]

i have cooper crobra's 205/55/15, when autocrossing they have 55psi in them , but normally at 36. impressive to get it down to 2400 lb. .planing on better bushing's , also looking at 17" wheels .
how much boost did you turn it up to ?
mike

[brad]

We were running 15psi+ with 10:1 compression ratio.

[87SPGIN]

thats not a whole lot of boost did u tear engine down to replace with turbo pistons or keep them N/A? i have run 22lbs through my 87 spg everything stock except a borla exhaust, apc mod, nology wires and intercooler fan.Wasted all the v-6s there but trans wasted me.

[Keith]

87SPGIN,

thats not a whole lot of boost

I think you'll find it is quite a lot with a 10:1 cr.....

[87SPGIN]

oh so then you want a higher compression ratio ie(10:1) when running the high boost numbers or well running high boost numbers in a higher compression setting will produce more power?

[Carl Hernandez]

the lower the compression ratio of the pistons the less chance of knock at high RPMs.
This is why if you were to put the 7.2 pistons from the pre-APC 8v in a 16v car it would boost into the red w/o any mods.

[87SPGIN]

well then why isn't that a common performance mod geez though i have heard of compression being too low to blow off your intake? maybe old wives tale? anyway if thats so wow i have no problem with doing that :wink: but how do they compare with 16V pistons what are differences anyone know? what are the after effects i guess is the question. You would obviously want to go with a rising rate regulator to compensate how about AMM does it have to change or need to be adapted?