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Andy Hollis:

Tim Herron:

Personally, I'm just reporting what the caster ended being.  You can, however, add shims behind the radius rod sleeve to reduce caster.  However, not many wanting to do that.  You can also cut the radius rod sleeve a bit shorter which will pull caster more positive if needed.  However, this is a supposed no-no from what I hear in STS2 because you are modifying the radius rods position outside of an approved serviceable means (ie. modifying suspension attachment points)  Although I could be wrong.  Anyone car to clarify...

This would only be legal if you can successfully argue it as being an offset bushing (which is legal).  Is the sleeve part of the bushing?  The big washer? If so, modifying them would be legal.  Kinda grey, IMO.

There are other ways to achieve caster adjustment which are more clearly legal.  Think about it...

Personally, my Civics have always had caster that was pretty close side-to-side, so I just leave it alone.  Camber is another story...

--Andy

 

Tim and Andy, thanks for the responses regarding caster.  I'm not too worried about the absolute value at this time, just need to verify I don't have any significant caster split between the two sides.  However I will eventually be curious enough to compare and share my settings with others after I compete at more events.  The ST* class rules allow one to be a little creative on set-up and that is part of the attraction for most of us.

 Tim, I'll send you a PM about the KCR Midiv.  I am looking forward to participating and sharing some STS2 conversations.

 Thanks,

Steve  

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Steve Curran
'89 CRX Si STS2
"Zippy"

Andy Hollis:

Tim Herron:

Personally, I'm just reporting what the caster ended being.  You can, however, add shims behind the radius rod sleeve to reduce caster.  However, not many wanting to do that.  You can also cut the radius rod sleeve a bit shorter which will pull caster more positive if needed.  However, this is a supposed no-no from what I hear in STS2 because you are modifying the radius rods position outside of an approved serviceable means (ie. modifying suspension attachment points)  Although I could be wrong.  Anyone car to clarify...

This would only be legal if you can successfully argue it as being an offset bushing (which is legal).  Is the sleeve part of the bushing?  The big washer? If so, modifying them would be legal.  Kinda grey, IMO.

There are other ways to achieve caster adjustment which are more clearly legal.  Think about it...

Personally, my Civics have always had caster that was pretty close side-to-side, so I just leave it alone.  Camber is another story...

--Andy

 

 

What about cutting the radius rod bushing?  I just replaced the bushings on my 91 Si and when I put the new Energy Suspension bushings in I noticed grooves in the bushings.  If you cut out some of the grooves that would add caster.  

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Ryan K

Andy Hollis:

Tim Herron:

Personally, I'm just reporting what the caster ended being.  You can, however, add shims behind the radius rod sleeve to reduce caster.  However, not many wanting to do that.  You can also cut the radius rod sleeve a bit shorter which will pull caster more positive if needed.  However, this is a supposed no-no from what I hear in STS2 because you are modifying the radius rods position outside of an approved serviceable means (ie. modifying suspension attachment points)  Although I could be wrong.  Anyone car to clarify...

This would only be legal if you can successfully argue it as being an offset bushing (which is legal).  Is the sleeve part of the bushing?  The big washer? If so, modifying them would be legal.  Kinda grey, IMO.

There are other ways to achieve caster adjustment which are more clearly legal.  Think about it...

Personally, my Civics have always had caster that was pretty close side-to-side, so I just leave it alone.  Camber is another story...

--Andy

 

 

I completely agree with what you're saying Andy and my CRX as well as other's STS cars I've had on the alignment rack have been really close side to side as well.  I'm in the same boat as you, I feel if there's less than .3 degrees variance in cross caster, I leave it alone.  When I first installed all of the suspension components on my CRX, I was really happy with my caster at 3.1 degrees exactly on each side.  No worries at all.  

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Tim Herron
#195 STS2
'91 CRX Si

scarrie:

Tim Herron:

Can you tell me, does it seem to make any difference that you can tell running those staggered spring settings side to side?  Or is it still research at this point...

My input on setup for any car is almost worthless, as I'm still learning to communicate what the car does.... but I can definitely say that pre-spring change (practice runs @ dixie tour) the car felt entirely different without a passenger than post-spring change (hershey). if anything the difference /should/ be felt in left vs. right hand corners, and i can't comment on that, but i do know that post spring change it feels just as good without a passenger. (whereas before, i almost had to have a passenger to keep it straight). that COULD BE just me.

 

 

Carrie,

That's exaclty what answer I was looking for and I had been contemplating trying something to counter this characteristic for a while now.  I just didn't even think about trying this.  I guess I just wanted the guinea pig Ian to try it first as he's always willing to try the really weird stuff out.

It does make sense though and you're absolutely right about how the car behaves with a passenger vs. without a passenger.  It's something I've fought at local events now for quite a while.  I love how the car handles when I take a passenger with me but hate how under powered the car is because of the added weight.

 

Ian, has there been any drawbacks to this staggered "cross springing".  ie. any ill effects that have had to be tuned out due to this.  Obviously, just asking, please don't answer if you feel I'm prying into your secrets too much...

I'm just really interested in this and would like a little more ( OK, a lot more) of your insight...
 

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Tim Herron
#195 STS2
'91 CRX Si

redwhale240:

Andy Hollis:

There are other ways to achieve caster adjustment which are more clearly legal.  Think about it...

 

What about cutting the radius rod bushing?  I just replaced the bushings on my 91 Si and when I put the new Energy Suspension bushings in I noticed grooves in the bushings.  If you cut out some of the grooves that would add caster.  

Bingo. 

--Andy

 

Andy Hollis:

redwhale240:

Andy Hollis:

There are other ways to achieve caster adjustment which are more clearly legal.  Think about it...

 

What about cutting the radius rod bushing?  I just replaced the bushings on my 91 Si and when I put the new Energy Suspension bushings in I noticed grooves in the bushings.  If you cut out some of the grooves that would add caster.  

Bingo. 

--Andy

 

 

Actually, I don't believe this would work because when you tighten the radius rod nut, you draw the sleeve up to the washers, removing the bushing material will just soften the effective rate of compliance.  What actually moves caster is to actually move the rod for/aft with shims or sleeve cutting.

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Tim Herron
#195 STS2
'91 CRX Si

Tim Herron:

Andy Hollis:

redwhale240:

Andy Hollis:

There are other ways to achieve caster adjustment which are more clearly legal.  Think about it...

 

What about cutting the radius rod bushing?  I just replaced the bushings on my 91 Si and when I put the new Energy Suspension bushings in I noticed grooves in the bushings.  If you cut out some of the grooves that would add caster.  

Bingo. 

--Andy

 

 

Actually, I don't believe this would work because when you tighten the radius rod nut, you draw the sleeve up to the washers, removing the bushing material will just soften the effective rate of compliance.  What actually moves caster is to actually move the rod for/aft with shims or sleeve cutting.

 

Beware of the ES bushings for the radius rods.  Notice how the stock bushings are conical and soft.  Notice how the ES bushings are puck shaped and hard.  In my experience they basically lock down the radius rod and turn it into a spring.  If you account for the extra spring rate they provide, that might work out fine.  If you simply install them on your set up car it will exhibit understeer.  Ask me how I know.

 Oh, and just put the part that you cut off the bushing on the other side to achieve the desired preload...  I'm actually running a trimmed ES bushing (sanded conically) on one side of the crossmember and a stock bushing on the other side.  (<-- free speed secret)  Also, I don't think locking down the play in the wheel that the stock bushings provide is a good idea on street tires.  I think that with the relatively low level of grip that the tires provide, having a "buffer" or "damper" to abrupt inputs on the available traction the tires offer is a good thing.  It's not like we're roadracing on R-comps.  Some softness and compliance will probably keep the tires happier on the mixed bag of rough sites we run on.

Tim Herron:

 

Actually, I don't believe this would work because when you tighten the radius rod nut, you draw the sleeve up to the washers, removing the bushing material will just soften the effective rate of compliance.  What actually moves caster is to actually move the rod for/aft with shims or sleeve cutting.

The two bushing halves are free to move along the sleeve.  If you cut some bushing off of one half and put it on the other side, you have effectively moved the center of the bushing which is what locates the radius arm to the body.  By relocating the position of the radius arm to the body, you have effectively lengthened or shortened it.  That's the very definition of "offset bushing".

Do I have to engineer everything for you, Tim? 

--Andy 

Tim Herron:

Carrie,

That's exaclty what answer I was looking for and I had been contemplating trying something to counter this characteristic for a while now.  I just didn't even think about trying this.  I guess I just wanted the guinea pig Ian to try it first as he's always willing to try the really weird stuff out.

It does make sense though and you're absolutely right about how the car behaves with a passenger vs. without a passenger.  It's something I've fought at local events now for quite a while.  I love how the car handles when I take a passenger with me but hate how under powered the car is because of the added weight.

 

Ian, has there been any drawbacks to this staggered "cross springing".  ie. any ill effects that have had to be tuned out due to this.  Obviously, just asking, please don't answer if you feel I'm prying into your secrets too much...

I'm just really interested in this and would like a little more ( OK, a lot more) of your insight...
 

Heh, I'm glad to be the guniea pig of the group. No breakthrough's happen if everyone is a lemming :)

I have not noticed any detriments to the staggered setup so far. I finally put in the staggered rear spring this past sunday (the front spring went in before Cecil so that show's how fast I'm getting around to this) so I only have 1 event on it so far. That being said I did notice slightly less wheelspin on the exit of a tight right hander so I think there is a small effect there. I drive the car to work often and with the rear spring I almost feel like I get a bit of a rise out of that LR corner when I unload a front wheel over a bump, but I have not gone out and searched identical left and right hand bumps to test it on. It may just be my imagination since I'm looking for any handling changes on that corner. I have not nailed down the koni rebound settings adjustments either, they are still identical L and R, so that may be part of what I'm feeling.

One thing that makes a big impact in the CRX's is the static roll orientation of the chassis. Due to the upper control arms being so short if you have any sort of static roll in the chassis it will make huge differences in the camber angles in the front. Even if you can equalize the camber angles left to right each side will be at a different point in the compression-camber curve which means as soon as you look at dynamic movement you have differing rates of change on each side. I think this is mainly what causes the differences in handling left to right without a passenger. With a passenger I bet the car is closer to level and the camber deltas under movement align better left to right.

Once the car goes back on the scales I'll be able to see if I can get the chassis more level and still maintain the corner weights I want. Currently there is about 1/4in of difference (high on the right) and I think I can get that back to 0 and still maintain 50/50 cross weights while not having horrendous differences left to right on each axle.

Hope that all makes sense :)

Ian
 

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--CRX Addict
--Recovered Mini Addict

Andy Hollis:

Tim Herron:

 

Actually, I don't believe this would work because when you tighten the radius rod nut, you draw the sleeve up to the washers, removing the bushing material will just soften the effective rate of compliance.  What actually moves caster is to actually move the rod for/aft with shims or sleeve cutting.

The two bushing halves are free to move along the sleeve.  If you cut some bushing off of one half and put it on the other side, you have effectively moved the center of the bushing which is what locates the radius arm to the body.  By relocating the position of the radius arm to the body, you have effectively lengthened or shortened it.  That's the very definition of "offset bushing".

Do I have to engineer everything for you, Tim? 

--Andy 

I've run the ES front radius rod bushings for 6 years and never had a problem with them. I did full range camber/toe graphs for the CSP car with the ES bushings in there (and later with the offset delrin) and I can pretty much guarantee that the spring rate incurred by the front bushings for the range of motion that the SPSS3 Koni's limit to is almost nothing. I was able to droop about 3-4in below the droop limiter in the koni before I enountered any significant resistance.

You are much more likely to get resistance from the lower control arm bushings binding due to the inner mount bolt being too tight. Make sure you don't crank down insanely on both the front and rear LCA chassis mount bolts (and the rear hub mount bolts) otherwise the suspension can bind there.

Also be careful if you offset the radius rod bushing as while this will add caster it will also cause the LCA bushings to bind sooner. The best thing to do once you are done with the bushings is to run the suspension through a range of motion test. It should not take much more than the force required to lift the hub by itself. If it does, something is too tight.

thx

Ian


 

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--CRX Addict
--Recovered Mini Addict

Ian, as soon as I installed my ES radius rod bushings the car became pushy.  It was VERY apparent.  The first local event with these bushing in the car was my worst local event all year.  At a test and tune in Huntsville the next weekend, we started off with the car in it's pushy state.  Later in the day we removed the front ES bushing and installed the stock bushing.  BAM!  greatly reduced push and much more grip on turn in.  It was OBVIOUS and I can't even tell a difference in left and right handling w/o a passenger. 

glagola1:

Ian, as soon as I installed my ES radius rod bushings the car became pushy.  It was VERY apparent.  The first local event with these bushing in the car was my worst local event all year.  At a test and tune in Huntsville the next weekend, we started off with the car in it's pushy state.  Later in the day we removed the front ES bushing and installed the stock bushing.  BAM!  greatly reduced push and much more grip on turn in.  It was OBVIOUS and I can't even tell a difference in left and right handling w/o a passenger. 

Hmm, It's been so long since I was in a car that actually had stock bushings I can't say I remember the change over. It could be that the poly limits fore-aft hub movement and that movement was causing some sort of dynamic toe out under braking which would have helped in turn in.... Either way, I figure having less bushing based deflection is better for suspension kinematics. Once the bushings are in I can tune around what they give me.

It is definitely worth noting what it does to an already set up suspension, and something to keep in mind when changing over.

thx

Ian




 

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--CRX Addict
--Recovered Mini Addict

ibaker:

It is definitely worth noting what it does to an already set up suspension, and something to keep in mind when changing over.

we have a virgin 88 waiting for you to molest, you know...

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Carrie
'89 STS2 CRX Si (Thanks Ian!)
'88 STS2 CRX Si (it's heeeeee---eeere!)
'93 ES MR2 in L1 on occaision (Thanks Jerry!)

Perfect, you guys can test it out.  Also, I was running the HF bar all last year so my car was kinda pushy to begin with so the bushings just took it over the top.  I was also running 550 springs up front.  Yowza... How things have changed.

Keep your friends close. Keep your enemies closer.

My new ride...

This is the ex-Giles car. It doesn't have a title and since I don't have a tow rig, It won't see any action for a few months until I get that all sorted out. We'll see how it does against the Miata later this summer.

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90 Miata/89 CRX - STS2 #90/190

GChambers:

Keep your friends close. Keep your enemies closer.

My new ride...

This is the ex-Giles car. It doesn't have a title and since I don't have a tow rig, It won't see any action for a few months until I get that all sorted out. We'll see how it does against the Miata later this summer.

 

Very nice GC!!!  Those used to be my wheels btw.  I am glad to see them campaigned again.

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Mark Davis
1993 Toyota MR-2 White "Casper"

devomgd:

GChambers:

Keep your friends close. Keep your enemies closer.

My new ride...

This is the ex-Giles car. It doesn't have a title and since I don't have a tow rig, It won't see any action for a few months until I get that all sorted out. We'll see how it does against the Miata later this summer.

 

Very nice GC!!!  Those used to be my wheels btw.  I am glad to see them campaigned again.

Ha! I remember you having them on the Green Miata at the Peru Tour back in 05.

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90 Miata/89 CRX - STS2 #90/190

Gonna bring it to Toledo then?

 

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Mike Snyder (little)

Yes I still have it, 62hp at the wheels, more than I should have spent- any more questons?

Nope, we still plan on running the Miata at Toledo. We will have a bit of work to do to the CRX before it is ready to compete and the Miata is our priority. It will definitely see action at some local events this summer to get started.

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90 Miata/89 CRX - STS2 #90/190