The Strut thread - Koni / Illumina / Tokico / Carrera / Bilstein / Ground Control

[ProjectSR20]

I have actually talked to the guys at technotoytuning and they seem to know their stuff. I would not be the least bit worried about buying something from them.

[Mikelly]

I'll probably end up with the 8610s. I will need to replace the rear struts as my new Tokico Premiums on the rear have on that has failed, and I had to "resize" the fronts for a little custom top hat experiment I was trying...

 

Mike

[johnc]

I have actually talked to the guys at technotoytuning and they seem to know their stuff.

 

Can't tell that by looking at their TC rod. Again, as discussed many times on this site, shortening the TC rod pivot length increases bind in the front suspension and affects the camber gain in bump designed into the 240Z's front suspension. It hurts rather then helps handling.

[JMortensen]

Can't tell that by looking at their TC rod. Again, as discussed many times on this site, shortening the TC rod pivot length increases bind in the front suspension and affects the camber gain in bump designed into the 240Z's front suspension. It hurts rather then helps handling.

I'll say it again, my TC rods with a similar design allowed me to run a lot more caster, and I think that the caster more than offset the camber gain or the increased dive. By a very large margin. I'm sure that anyone who uses Mike Kelly's or AZC's control arm and TC rod would back me up.

 

EDIT-I guess I should also state that I am redesigning the rear pivot to get rid of the shortening of the TC rod. I agree that shortening that rod is detrimental, but the increased caster is HUGELY beneficial.

[katman]

I'll say it again' date=' my TC rods with a similar design allowed me to run a lot more caster, and I think that the caster more than offset the camber gain or the increased dive.

 

snip

 

I agree that shortening that rod is detrimental, but the increased caster is HUGELY beneficial.[/quote']

 

I haven't ever done a back-to-back with caster being the only variable, but I have never found the need to add any more than stock on our 240Z's or BMW's that we race in ITS, and there isn't anybody out there beating us. Years ago we started out in the "race cars need more caster" mode and couldn't tell the difference between weekends with more and weekends with stock (never did a same day test). When I took over the BMW suspension program at ARC/Sunbelt I removed the ton and a half of caster that Ground Control had recommended, however, the plethora of other changes I made would negate any conclusions about the contribution of caster to transformation of those cars from undriveable to ARRC champs. I just don't see more caster being necessary for good handling on a 240/260/280Z. I could be wrong. I usually agree with everything else you say.

[JMortensen]

Might be a road course vs autox thing too, but the front end will ACTUALLY TURN IN at an autox if you have more than 5 degrees. I did have an instructor who drove my car with 3 degrees at a road course say to me: "This car is great at the road course. How the hell do you autox it???"

 

Ground Control recommended 3 degrees last time I checked with them for what that's worth, but my own experience is that doubling that works a LOT better.

[Mikelly]

Steve and Ian were very successful with their setup at many autoX events. They were running over 7 degrees positive caster. The added benefit in the front was less static camber, which in their case made for a better contact patch on the front tires.

 

I'll be playing around with mine this spring and summer and will be able to tell you what works better, more or less...

 

Mike

[katman]

Might be a road course vs autox thing too' date=' but the front end will ACTUALLY TURN IN at an autox if you have more than 5 degrees. I did have an instructor who drove my car with 3 degrees at a road course say to me: "This car is great at the road course. How the hell do you autox it???"

QUOTE']

 

Interesting, what front toe do you run? Turn in on low speed corners can be an issue, but a smidge of toe out usually takes care of that for us.

 

When I built Chet Wittel's first ITS 240Z he took it to a few autox's to get more familiar with it, and being former Atlanta Region BSP champ he did very well with it, so not unusual for a properly set up road race 240Z to also autox well.

 

Looking forward to Mike's tests.

[JMortensen]

I ran anywhere from my street driving setting of 1/8" toe in to 1/4" toe out. Car sucked until I added the caster, and that was with slicks.

[johnc]

Another variable in this caster debate is tire size. When I ran 275/45-16 S04 Hoosiers on the front I got rid of a lot of caster (down to 4) which helped even the tire temps out. I also reduced camber from 3.5 to 3.0 in front. Back when I was running 225/50-15s I had a lot of caster (about 7) and camber to make the S03 Hoosiers work.

[JMortensen]

As long as we're comparing, I was running 5.5 degrees with a 250/45/15 Yokohama slick that is kind of a hard compound, I'd say simlar to a Kuhmo but I never did have a durometer to check it against anything else.

[tube80z]

Steve and Ian were very successful with their setup at many autoX events. They were running over 7 degrees positive caster. The added benefit in the front was less static camber, which in their case made for a better contact patch on the front tires.

 

I ran a similar amount on my car using bias ply slicks (13" FA fronts). In the motec seminar it was pointed out that caster is very tire dependent. Claude's example of how to think of a tire was as a number of interconnected springs. If you coilbind any of them you slide the tire. Some tires need a lot more caster than others.

 

Claude told us that one car they run uses 29 degrees of caster. The trick in testing this is to also realize that you'd need to change the caster trail as you increase the angle to test just caster. And the trail will change with tire diameter. It's the caster trail that leads to increased steering stiffness as you add more caster.

 

Cary

[clarkspeed]

OK, let me pull this sticky post back to the original topic. I have some updated info on struts.

 

I followed the Katman's advice and went with Bilsteins. I like to be a little different and I think a non-adjustable strut more closely matches vintage racing intent. I was also swayed by this post and Katman's posts on the IT forum. In addition the Bilsteins are cheap and the Carreras are no longer available.

 

The full part number on the box is F4-P30-0032-MO. This is the "sport" shock used for 75-84 Rabbit and others. From Bilstein website:

 

SPORT

For the performance-minded driver, Bilstein “Sport†shocks deliver absolute mastery of the road surface. Designed to push a car’s suspension to it’s performance peak, these super-firm shocks are well suited for use with special

springs, anti-sway bars or other suspension upgrades.

 

Measured data (by me with +/- 5% tolerance) is as follows:

Shaft dia: 1.315

Shaft dia. at top: .550

Shaft length: 8.5 to top of gland nut

Body dia: 1.519

Body length: 13 to top of gland nut

gland nut is 1/4 thick

Overall Length: 21.5

Stroke: 5 - 5/16

Color: Bilstein Yellow

Gland Nut (240Z) - p/n B30-629

Gland nut - 48mm x 1.5 thread

Cost: $99 ea. + $15 gland nut

 

The gland nut was a sticking point. P/N 450424 gland nuts listed earlier in this post are no longer available. Bilsteins take a special nut that has an oil seal. The closest replacement is p/n B30-629 with the correct threads but too long. You will need to order this nut and cut about 5/16 of the threads off to get correct fit. I did it carefully with a cut off wheel and a little sanding. I will try to get a p/n for a 280 (52mm x 1.5) nut at a later date.

 

So far, Bilstein has been a good company to work with and future re-valves are indeed $65 ea.

 

Of course, as detailed in earlier posts, cut a spacer to fit into the bottom of the tube so the gland nut tightens up within 1-2 mm's from the strut housing, but not bottoming. I used 3/4 pipe. And depending on what you are attaching it to at the top, you may need to drill out or obtain a bushing for correct fit to your camber plates or spring perch.

 

As I build this one up in preparation for the Walter Mitty, I will try to post a static alignment thread.

[zed240au]

hi just a question here ive been running std strut length bilsteins with 1" lowered std heavy duty springs for many years quite happy with this but wanting more camber adjustment i have now bought arizona z camber plates and coil over kit with 250 ib springs

 

my question is will the camber plates and coil overs drop the overall height or do i still need to section struts to get the lowered look as well as full suspension travel

 

mick

[clarkspeed]

The answer is: it depends. Camber plates let the strut rod extend further and the 240 struts are already a little shorter, which helps a lot. Again, shoot for static ride height around mid-point of strut travel. If you slam it, you will bottom out the struts.

[driftz240]

i found a good short stroke for the 240z

tokico hts 102 built for the ae86 cut 40mm case

these things are crazy good...but japan only, can be ordered from a few places, sometimes on ebay...about 350 for a front set... and support higher spring rates than johnc would reccomend....lol

[JMortensen]

Can you show us a shock dyno graph, or are we supposed to take your word that they're "crazy good"?

[driftz240]

you should take my word for it.....

you guys seem to devote alot to shock graphs, what if you build the ultimate suspension via the numbers and what all the graphs and wheel weights , corner balanceing say they should be and you dont like how the car feels...

if you want a dyno graph im sure its out there someware, maybe www.club4ag.com , im sure gabe tyler from t3 "techno toy tuning" can vouch for the hts as being a awesome strut since he builds alot of ae86 enthusiast "such as myself".

"I MESURED AND I WENT ASFAR AS TO DROP ONE IN A 240Z FRONT STRUT CASE, ITS A 2 INCH SHORT STROKE AND WAY BETTER THAN ANY ILLUMINA OR MR2 STRUT YOU CAN FIND...WITH MUCH BETTER RANGE OF ADJUSTMENT..JUST OFFERING AN ALTERNATIVE TO THE GRIPEING YOU ALL DO ABOUT WITCH STRUTS SUCK....IF THE GUYS ARE LOOKING INTO WHAT CARTERAGES WILL FIT WHY NOT MAKE A LIST OF THE ONES KNOWN TO FIT....MAKES SENCE..ALL IVE LEARNED IS WHAT SUCKS....LOL

HERES WHAT I HAVE FOUND WITHIN 1 HOUR OF PLAYING WITH STUFF I HAD LAYING AROUND FROM OTHER CARS

240Z FRONT SHORT STROKE

1 .88 MR2 REARS, 2 INCH SS. STRUT ROD NOT GONNA FIT TEH MOUNT WITHOUT 5 MINUTES OF MODIFICATION, KYB AGX MAKES THEM IN A 8 WAY ADJUSTABLE, TRD MAKES ALL OUT RACE SHOCKS FOR THIS ALSO,WITH MANY DIFFERENT VALVING COMBOS, ILLUMINA FROM SAME MR2 WILL WORK

2. TOKICO HTS, "THE BEST DAMN DRIFTING SHOCK FOR AE86 PERIOD...

VERY ADJUSTABLE 40MM SHORT STROKE

3. KYB AGX 95 MR2 FRONTS 4 WAY ADJUSTABLE, WILL BE A 30.8MM SHORT STROKE, SAME ON ALL MR2 STRUTS MINOR MODS WILL BE NEEDED TO THE UPPER HAT.

4. 95 MR2 KYB-AGX REARS WILL BE A 1 3/4 SHORT STROKE IN THE REAR THEY ARE 8 WAY ADJUSTABLE , ILLUMINAS FROM THIS MR2 WILL FIT SAME..

I WOULD RECOMMEND IF YOU LOWER OR SHORT STROKE A CAR YOU REPLACE WHAT YOU CUT OUT BELOW THE STRUT IN THE FORM OF BUMP STEER SPACERS OR ROLL CENTER ADAPTERS AS SOME FOLKS CALL EM..TO GET THE SUSPENSION GEOMETRY BACK TO SAFE RANGES.

SINCE THE REARS HAVE THE STOOPID PINS AND NO WAY OF REALLY GETTING THE SUSPENSION GEOMETRY CORRECT AFTER LOWERING /SHORT STROKING I WOULDENT GO CRAZY WITH THE LOWERING, OVER 2 INCHES SEEMS TO LOOK LIKE IT WOULD BE OVER KILL TO ME, BUT WHAT DO I KNOW...

anyway, i really like this site, its very informative but some of teh gripeing on here makes me not wanna hang out in here,alot of bashing other peoples ideas...alot of people think there way is the best way, the whole beauty of being a car enthusiast is doing different stuff than the other guy, and in racing if everyone ran the same suspension, dampers, spring rates / camber settings it would be totally gay, every driver is different, its apples and oranges with driver feeling vs shock dyno graphs.... i admit im no shock engineer, but i am a driver, i know what i like and what makes the faster times for me and what im driving, it takes more time than saying this shock and this valving is what will make your car fast.......sorry to rant great website...but some people need to relax abit....

[driftz240]

More shock q's. Ok, so I got ahold of the oil shocks I was looking for and needed for an upcoming event. My next question is this: What spring rates are they valved for? I mean you can alway run any rate you want, but what are the ideals?

Next, in the tech section it states this about the HTS:

"45 way adjustment at top accommodating 2.5 to 15kg/mm spring rates, low-height AE86 stoke"

Now a friend of mine who knows a lot about suspension was going over the shock dyno below. It's for the HTS. Now he didn't see how it was possible to be rated for such a high spring rate if you rate the force kg/m and the time in sec? I think. I'm no shock master by any means that's for sure.

 

Corey

Auto racing is an addiction cured only by poverty

1987 GTS Coupe currently ???

http://www.splparts.com

Yeah, The HTS things were right out of a manufacturer's touting of the HTS, written back in the 80's. We have used them for 4kg/mm rates and up to 10kg/mm ratings. They are pretty usable for these ranges but the more important factor is whatever the rate of the springs you use, the character and the balance of the valving between compression and expansion is the key to making your car handle the way you want.

We've seen the HTS to be variable effectively on the compression side but somewhat lacking in range on the expansion or (rebound). Keeping this in mind, it is effective for places that need a fast reaction to initial inputs but not in places where a certain behavior is needed to be maintained. Taka likes to use stronger shocks to control the expansion rates since compression amounts and speed can be somewhat controlled by the spring rates itself.

On the 45 way adjustemt...I guess with the valve controls being a infinately adjustable analog curve, you can pick 45 different places on the shocks but generally, it can turn 7 times and the range being what it is, I'd like to think of the HTS as a 7 way... as breaking it up into 45 settings is virtually useless in such small increments unless you are making a graph such as above?

 

Remember, shocks controls the "speed" or "response time" of suspension against a load, and springs and assist springs like sway bars, adjust the "amount" of suspension movements.

 

[driftz240]

thread from club4ag. posted above, dyno graph fo ya,