I went back out to the track today and had an absolute ball. One of the Speed World Challenge GT Corvettes was out doing some last minute testing before this weekends event in Denver. Those things are LOUD - and the sound of that thing passing me was unbelieveable.

Many of you may be interested in my impressions of some new Mugen suspension busings I put on the car before today. I have the Front Compliance set and the Rear Trailing Arm set.

- Turn-in and corner entry was sharper
- Mid-corner stability and predictability was improved. I felt like I could really trust the car in the corner more than before.
- For some reason I had quite a bit of understeer at corner exit. I'm not sure if this was the bushings or something else. But they are the only thing I have changed and the balance is not the same on corner exit for sure.
- I didn't notice much difference under braking - maybe a bit more stable at threshold.

Overall I am very pleased with the bushings - and I know the car needed a bit of a refresh. Now I need to get the balance back to where I like it.

 

You let him pass J00 ??

Good to hear the money was well spent, I have thought about doing my caR's bushings and now that I have heard a good thing... I need to see how bad mine are in the next few weeks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flux &raquo;</TD></TR><TR><TD CLASS="quote">IMany of you may be interested in my impressions of some new Mugen suspension busings I put on the car before today. I have the Front Compliance set and the Rear Trailing Arm set.
</TD></TR></TABLE>

Definitely on my list of things left to do

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flux &raquo;</TD></TR><TR><TD CLASS="quote">- For some reason I had quite a bit of understeer at corner exit. I'm not sure if this was the bushings or something else. But they are the only thing I have changed and the balance is not the same on corner exit for sure.</TD></TR></TABLE>

What could be responsible for this if the bushings were the only thing you changed?

If you could explain a little more what you mean by understeering at the <u>exit</u> I'd appreciate it. I think that many of us would consider the exit the point at which you'd normally be aimed at the next event, whatever it is (straight, next turn, whatever).

RJ hasn't mentioned understeer with his, and the Mugen bushings were on my list of things to do in the down time. LOL... But you might have just changed my mind!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by George Knighton &raquo;</TD></TR><TR><TD CLASS="quote">What could be responsible for this if the bushings were the only thing you changed?</TD></TR></TABLE>

Interesting way to put that query, are you saying he was driving differently George, or that you don't understand his perception of the goings on after the install?

Maybe more rear bar or spring rate is in order to counteract the increased front roll stiffness. Just my guess though.

And yes, I was under my car this weekend and am also considering bushing material upgrades/updates.

 

how hard were the rears to install??

 

rear trailing arm busing is easy once the old is removed. couple big washers and a long *** bolt to 'press' in.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">Interesting way to put that query, are you saying he was driving differently George, or that you don't understand his perception of the goings on after the install?</TD></TR></TABLE>

[OT] I just now "got" your avatar, Ed, and how wonderfully appropriate it is Sorry I can't make the WVa meet - hope to see you at the We-Todd expo. [/OT]

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">

Interesting way to put that query, are you saying...?</TD></TR></TABLE>

I'm saying I don't understand what he means by understeering at exit and since I was thinking about doing this, I want to know exactly what he means.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chad &raquo;</TD></TR><TR><TD CLASS="quote">how hard were the rears to install??</TD></TR></TABLE>

20 ton press and 2 inch pipe

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by George Knighton &raquo;</TD></TR><TR><TD CLASS="quote">

I'm saying I don't understand what he means by understeering at exit and since I was thinking about doing this, I want to know exactly what he means. </TD></TR></TABLE>

I usually divide the corner into 3 sections: entry, mid-corner and exit. When I refer to 'corner exit' I am referring to the point where I am tracking out and on the throttle again (accelerating). This last session (with the new bushings) the car was very prone to understeer (the thing wanted to go straight off the track) while trying to accelerate out of a corner. Previously the car was very neutral.

This is a track I drive ~3 days/month and I am very, very consistent in my times (all laps in a session within .2) so I don't think it was a different driving style. I am guessing what happened is that I had the car set up the way I liked it with the worn bushings and the new bushing and my suspension are playing together differently, hence the different dynamics. I'll need to do some sorting again.

I wouldn't avoid the bushings becasue of this. The bushings put things the way they should be and I jsut need to get the rest of the suspension components to work within the new environment.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flux &raquo;</TD></TR><TR><TD CLASS="quote">I wouldn't avoid the bushings becasue of this. The bushings put things the way they should be and I jsut need to get the rest of the suspension components to work within the new environment.</TD></TR></TABLE>

Does that bushing help control the camber? Maybe you ended up "fixing" the rear camber on the outside rear, which gave you more rear grip?

If it's camber or toe, yeah, sounds like something you'll have to dial around..

 

Was the car aligned to the same specifications as before?

 

Why is everyone assuming the RTA Bushings are causing corner-exit understeer? What about the compliance kit in front?

Without any investigation, people are going to NOT use the RTA Bushings because of this? :shakes head: No one, including Flux, even knows what is the cause... at least not at this point.

It could be a million diferent things. Maybe some adjustments need to be made to tire pressures (as a simple start) or something else now that there are new bushings and this new (i dont even know what it is, lol) compliance kit. new vs old bushing... big differences.

Chris - who sighs at jumping to conclusions with very little data.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Reid &raquo;</TD></TR><TR><TD CLASS="quote">Was the car aligned to the same specifications as before?</TD></TR></TABLE>

Actually, I was just about to edit my post after sitting here and thinking about it. The car has not been alligned after the bushing install and there may be a weird toe issue happening... but I wouldn't think it would be too far off. I would think an alignment issue would impact all aspects of driving rather than just corner exit...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris N &raquo;</TD></TR><TR><TD CLASS="quote">Why is everyone assuming the RTA Bushings are causing corner-exit understeer? What about the compliance kit in front?

Without any investigation, people are going to NOT use the RTA Bushings because of this? :shakes head: No one, including Flux, even knows what is the cause... at least not at this point.

It could be a million diferent things. Maybe some adjustments need to be made to tire pressures (as a simple start) or something else now that there are new bushing and this new (i dont even know what it is, lol) compliance kit.

Chris - who sighs at jumping to conclusions with very little data.</TD></TR></TABLE>

You are right - I do not know exactly what is happening. All I know at this point is that something is happening and it is the direct result of the new bushings.

It may be as simple as an alignment issue or it may be that I need to go back and make other suspension adjustments to compensate for the new bushings.

Either way, to me the bushings are a good thing. I was not jumping to conclusions with very little data - I was stating what was happening with the car. A full day at the track (not just 3 20 minute sessions, more like 5 30 minute sessions) after installing a new part on the car is a pretty good piece of data if you ask me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flux &raquo;</TD></TR><TR><TD CLASS="quote">Actually, I was just about to edit my post after sitting here and thinking about it. The car has not been alligned after the bushing install and there may be a weird toe issue happening... but I wouldn't think it would be too far off. I would think an alignment issue would impact all aspects of driving rather than just corner exit... </TD></TR></TABLE>

I guarantee the rear toe is off.

The rear is most likely toed in too much.

 

I agree with Reid, check you alignment (prop to much rear toe out) and go from there.

Since where talking about Mugen bushings here, I might as well throw thoughts in. Back in February I replaced my RTA, Front compliance, and any other bushing I could press out with Mugen ones. After that put the car back on the scales, gave it an alignment, and drove down to VIR then next day. Over all the car felt more solid, turn in was improved, mid-corner felt the about the same, and on exit the car would just rotate on throttle. I didn’t feel the car understeer like Flux mentioned. It was money very well spend in the end.

What I found weird was after I installed my roll bar, the car was all understeery everywhere. However the car needs an alignment pretty bad, but lazyness owns me.



Modified by canuckr at 11:54 AM 8/12/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Reid &raquo;</TD></TR><TR><TD CLASS="quote">

I guarantee the rear toe is off.

The rear is most likely toed in too much. </TD></TR></TABLE>

I think you are probably right.

 

Bringing this back to give it some closure and answer some questions left unanswered (for future searchers).

Went and got an alignment today and the rear toe was in fact WAY off on one side of the car. This lead to the terrible understeer I experienced at my last track day.

The good news - one more thing crossed of the list as I prepare for the SCCA national time trail event next month.