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View Full Version : 240sx Coil over, and Suspension Advice Please.



Jason M
04-24-2005, 11:43 PM
My name is Jason Merritt. I'am building a 1989 240sx, and I'am hoping for some suspension related advice from. What coil over/ spring shock combo's are poular and or competitive in IT? Is there any major suspension issues with the 240 that should be addressed (weak spots) that produce major gains? (What are the must do suspension mods for an IT 240?)

Machines240
04-25-2005, 12:27 AM
well most people will say do the rear suspension bushings because there is alot of stock rubber in the rear suspension the new bushings are a must.
for shocks, koni, advanced designs and bilstein or of the best quality.
also an LSD is a must.

if interested, a couple threads up, i have for sale Nismo hard rubber rear bushings and LSD,both new.
if interested, let me know. http://ITForum.ImprovedTouring.com/wink.gif

jamsilvia
04-25-2005, 09:27 AM
Most definitly do the rear subframe bushings. Those make the biggest difference I've noticed.

joe

Jason M
04-25-2005, 08:30 PM
There are soo many inverted mono tube coil over set ups for the 240, are any of thoose really track worthy? (KTS, JIC FLTa2's, silk road, Apexi N1, ZEAL Super function) The only downfall to all those JDM coil overs seems to be some customer service issues, and all of them adjust compression and rebound together. Would the extra strength of a 45mm inverted strut (JIC's)(16way adjustable) on a McPhersion strut suspension system be better then a flexy strut that is doulble adjustable?

Machines240
04-25-2005, 10:18 PM
well most of the JDM stuff doesnt have sufficient shock settings for slick tires.
even the top of the line endless super functions are only recomended for use with semi-slicks. but you could have them revalve to your spec and spring rate as long as the shock is beefy enough.
for a real track car, id recomend a real racing developed shocks.

its300zx
04-30-2005, 03:33 AM
f interested, a couple threads up, i have for sale Nismo hard rubber rear bushings and LSD,both new.
if interested, let me know

http://splparts.com/Parts/NissanShared/Sus...ame/default.asp (http://splparts.com/Parts/NissanShared/Suspension/Subframe/default.asp)

I highly recommend these. The stock rubber bushings are pretty much worn out on all 240sx's nowadays. I have the aluminum spacers on my street car, but on a racecar I would definitly go with the solid bushings. It takes a lot of work (don't get me wrong) to put these in, but they are worth it.

erlrich
04-30-2005, 08:35 AM
Originally posted by Jason M:
There are soo many inverted mono tube coil over set ups for the 240, are any of thoose really track worthy? (KTS, JIC FLTa2's, silk road, Apexi N1, ZEAL Super function) The only downfall to all those JDM coil overs seems to be some customer service issues, and all of them adjust compression and rebound together. Would the extra strength of a 45mm inverted strut (JIC's)(16way adjustable) on a McPhersion strut suspension system be better then a flexy strut that is doulble adjustable?

Jason - I'm not at all familiar with the JDM offerings, and I'm sure with the new rule allowing threaded coilovers there are many more choices than when I started building my car, but here are a couple of observations I had: 1) if you're building an IT car, keep in mind that the struts/shocks are limited to two (2) external adjustments; 2) you'll probably be running spring rates in the neighborhood of 450 - 550 lbs. in front, and 275 - 350 lbs. in the rear, so before you buy anything make sure they can handle those rates; 3) the suspension bushings are generally thought to be the weak link on these cars, the 'trick' setup is to replace everything with spherical bearings. SPL parts or West Tek can help you out there (I can personally vouch for SPL's products - they are good quality and their customer service is excellent).

Earl

its300zx
05-03-2005, 03:00 AM
The new ITS rules are really nice for those of us not running b18's. My z31 is running custom spring rates (ers) and custom mated dampers (koni) just talk with some other racers with s13's and ask their spring rates/dampers and you can either have tein/kei office/ jic, etc mate your dream coilovers to whatever spring rates needed.

Trust me. You did good choosing an s13 over a z31

turboICE
05-25-2005, 11:12 AM
Originally posted by erlrich:
1) if you're building an IT car, keep in mind that the struts/shocks are limited to two (2) external adjustmentsWhat does this mean? Does it mean you can have compression and rebound adjustments which would be tow? Or does it mean you can only have two adjustment settings (hard and soft)? Because there are dampers in many cars that have infinite settings since they do not have keyed/notched/clicking setting points. Softening or hardening a damper with no notches effectively has infinite settings.

Konis have more adjustability range than most 8 setting JDM dampers for instance.



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Ed.
240SX ITA

x-ring
05-25-2005, 03:31 PM
Two adjustments, rebound and compression for example, not two adjustment settings. Within the rebound adjustment (for example) there is no limit on the number of setting positions.

(edited for spelling)

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Ty Till
#16 ITS
Rocky Mountain Division

[This message has been edited by x-ring (edited May 25, 2005).]

PFM Racing
05-25-2005, 03:39 PM
Jude and I are also building a 1989 240SX for ITA. We have replaced all of the rubber in the rear with Delrin. There are pics on the website.

As far as coil overs, we are using Ground Control.



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Jennifer Rudder
PFM Racing
http://www.pfmracing.com

turboICE
05-25-2005, 09:00 PM
Originally posted by x-ring:
Two adjustments, rebound and compression for example, not two adjustment settings. Within the rebound adjustment (for example) there is no limit on the number of setting positions.Thank you for your response.
That was my read as well but elrich's response lead me to seek confirmation. That would mean JIC FLTA2 with their 16 adjustment settings are legal without modification to the strut body now that threaded body struts are permitted.

I have found with the 2005 rule update that the Japanese brand coilovers are a much better performance value than the exorbanant amounts GC is asking for their "recommended" Advance Design set up. When I called, trying to sell me that set up, they claimed Koni's would be fine if I didn't want to be competitive. The responses from them pretty much turned me off to GC immediately, they must have thought I had a BMW racing budget. Of course I called in mid-2004 when GC was the only viable alternative for the S13.

My many track experiences in multiple cars on JIC's will lead me to build with them. 10/8kg on smooth tracks and 9/8kg on rougher surfaces.

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Ed.
240SX ITA

[This message has been edited by turboICE (edited May 25, 2005).]

jamsilvia
05-26-2005, 12:23 PM
Originally posted by turboICE:
I have found with the 2005 rule update that the Japanese brand coilovers are a much better performance value than the exorbanant amounts GC is asking for their "recommended" Advance Design set up. When I called, trying to sell me that set up, they claimed Koni's would be fine if I didn't want to be competitive. The responses from them pretty much turned me off to GC immediately, they must have thought I had a BMW racing budget. Of course I called in mid-2004 when GC was the only viable alternative for the S13.


I've driven a friend's BMW with the GC setup. They are pricey - but DAMN, are they nice. They soak up the harsh bumps like nothing, and still provide great control in the low speed transitions.

I don't know what other people are doing with their GC's - but the front of the 240's will have very little travel without a shortened strut, when lowered.

I was running them with the KYB AGX's (heck, they're cheap!). With the rule change, I went with SPL's coilovers (again, cheap - I don't have a BMW budget either).

joe

turboICE
05-26-2005, 11:49 PM
With JIC FLTA2RS dampers, travel is maintained for all ride heights. On all applications I have driven with them they have performed excellently and are affordable. The bigger problem is finding wheels with the proper offset hence my collection of K-1's.

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Ed.
240SX ITA