StuartW Posted July 6, 2011 Share Posted July 6, 2011 Hi there i have the HKS front Drag suspension. It is adjustable but i would love for you to please clarify how i do this correctly on my road Legal Toyota Supra Drag car, I am guessing i have Hypermax? it says HKS Drag Damper on the bottom and they have anodised purple top hats, There seems to be a gas type shrader valve on the bottom and a small brass and larger steel adjusting nut on the top, i would like to know if they are adjustable for rebound and compression? if so how do i turn the nuts? I have mailed HKS europe and USA with no reply and can find the instructions/downloads section but nothing in there about these Thanks in advance... Stuart Quote Link to comment Share on other sites More sharing options...
Homer Posted July 6, 2011 Share Posted July 6, 2011 Any use Stuart? Theres some responses which explain how they are adjusted. http://www.supraforums.com/forum/showthread.php?225072 Quote Link to comment Share on other sites More sharing options...
StuartW Posted July 7, 2011 Author Share Posted July 7, 2011 Cheers for that Homer, I found my old SF log in details and ended up on the forums til 1am!! Not sure if i actually took in any info or was just bemused with just how many 1000+hp Wheelie poppin stock lookin road legal drag supra's are members on there ;-) The concensus is to soften rear AND front which i have not tried yet....Wheelie time for me soon?! :-/ Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 7, 2011 Share Posted July 7, 2011 The Scraedar valve is just for re gassing with nitrogen, leave that alone. (I can re gas or check pressures if needed) The adjuster is in the top of the stem. Not sure, but I think they are just adjustable in one plane which affects bump and rebound. The Drag shocks have hardly any bump in the rear dampers, and hardly any rebound in the front, to promote weight transfer. In other words the bump / rebound curves are heavily skewed on each end of the car for this specialist application. The problem with the MKIV is it has such a steep camber gain curve on the rear suspension a lot of asquat gives a lot of negative camber, killing tyre contact patch area, even if you start with some positive camber. It's probably a far from ideal IRS for drag racing. Quote Link to comment Share on other sites More sharing options...
StuartW Posted July 7, 2011 Author Share Posted July 7, 2011 Yep, thats why my drag Supra is Back Halved with 9" ford solid axle and 4 Link so positive camber on squat is not an issue. I only have the HKS drag shocks on the front as my car is still OEM floor pan from the back of the seats forward. On the rears i have invested in Some Penske Double adjustables. I think in time i will also invest in a suspension logging set up as well. HKS europe have just replied with some interesting info; "Thank you for your enquiry, Unfortunately our knowledge of HKS Drag suspension is very limited. It is an old discontinued obsolete product that was only officially available for the Japanese market and was never part of HKS Europe’s product range so we have no experience with it and do not support it. However we expect adjustment will be similar to that of the current range of Hipermax III. Ride height is most likely adjusted by loosening the lower locking ring and rotating the spring platforms up or down using ‘C’ spanners. Dampening will be adjusted by either a small adjustment knob on the bottom of the damper or by a hex type allen key bolt on the top shaft of the damper and we believe it will be for compression only. Rebound is not adjustable. The larger brass nut on the top holds the top mount assembly to the damper and is does not adjust any dampening rates but may allow camber adjustment if the top mounts are adjustable type. The valve at the bottom is the service fill point for the Nitrogen gas inside the damper and should not be tampered with. I have attached an instruction manual for the current range of Hipermax III suspension which should be similar. Hopefully this will help you. Regards, Nathan Dodson Product Manager HKS Europe Ltd www.hkseurope.com" Cheers Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 7, 2011 Share Posted July 7, 2011 If you valve the Penskes with minimal back bump and a moderate amount of rebound it should be OK. I have little interest in drag racing, but maybe your dampers have a slow speed bleed on the bump valving, this should be an area of interest I run triple adjustable Penske's on one of the Zeus race cars, they have been superb. I also have a good damper man who can advise on valving, but I doubt he's got much drag race experience. Damping is damping though.... Good luck, don't blow it up! Quote Link to comment Share on other sites More sharing options...
Kirk Posted July 7, 2011 Share Posted July 7, 2011 (edited) The problem with the MKIV is it has such a steep camber gain curve on the rear suspension a lot of asquat gives a lot of negative camber, killing tyre contact patch area, even if you start with some positive camber. Just to jump in here. (sorry stu) Chris is there a way to minimalise this on the stock arms and adjusters with moderately stiff shocks or would it need some 'special' bits to limit this? Edited July 7, 2011 by Kirk (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 7, 2011 Share Posted July 7, 2011 No, it's a function of wishbone lengths and angles. Running much below stock ride height makes the curve MUCH steeper though, hence abnormal inner tyre wear on cars lowered very much at all, even when the geo is reset, static camber wise. Quote Link to comment Share on other sites More sharing options...
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