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Discussion Starter · #1 ·
I was wondering about this style of thread.

The purpose would be for people wanting to get into some form of motor sport in their MX-6 who would like further information about what those of us that are doing it use and the experiences we have had with different set ups.

I can see it being very useful both for beginners and for the rest of us to share our knowledge.

So without further ado. My set up.

I'll list modifications. Power mods arent so relevant but for the sake of completeness i'll put them in.


Car: 1992 2nd gen MX6 4WS

Type of events - Hillclimbs (short, reasonably technical road course style)
- Motorkhana (think mini autocross. VERY technical, very tight)



Power
KLZE, CAI, headers

Comments: nice increase in power


Suspension/Wheels/Tyres

Currently lowered about 1" on pedders spring/struts at the front and stock rear (need to fix)
Whitline 18mm rear sway bar
front and rear strut bars
Camber bolts front and rear (about 1.75deg front and 1deg rear)
17*7 5zigen fn01rc's
225/45 Federal 595RS

Comments:
When I first got the sway bar I loved it, felt that it made the car a lot more neutral with the rest of my set up. It also increased the lift off oversteer a fair amount. However, since I have gotten used to the increase in lift off oversteer I think I would like to try a bigger bar.

Camber - LOVE front wheel camber. Not so sure about rear wheel camber with the 4WS. Havent had it for long and whilst it has increased the cornering traction, straight line stability has dropped a lot.

Tyres - I initially tried some second hand Kumho Ecsta V700's. They were pretty good but didnt last long at all. The Federal's I have now grip much better than the Kumhos ever did and so far have lasted 8 months of track and daily drive. I would say still over 50% tread. Grip has decreased a little but not huge amounts.
Having said that, I would prefer to be running 225/40 or 225/35 as I have noticed a little less acceleration from the increase in diameter. The increase in grip from 225 is worth it though.



Brakes
Front slotted with Lucas TRW pads, rear stock

Comments: I used stock everything for a while But wasnt too happy with it. I upgraded the front end as above. I won't buy those pads again though as there was only a small increase in stopping power.


Weight Reduction

Nill. The class I race in doesnt allow any weight reduction.





I think that is all I can think of to put in at the moment.
If anyone else with racing experience thinks this sort of thread will help, post your set up.
 

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First a comment or two one Daevilone's setup.

Think hard about going with a shorter sidewall. In AutoX and similar low speed sports with rapid transitions the reduced compliance of a shorter sidewall can cause the tires to break loose easier than a similar tire with a taller sidewall.

Check out the competitive racers at these events, typicaly they will be running taller sidewalls than people who run larger road courses.

If you want improved acceleration try smaller wheels. With 15,s you can run taller tires and still be quite a bit shorter in overall height. If you have them in Aus. Mazda Millenia 9 spoke wheels are a great option if 205 tread width is enough for you. They are very light for stock alloys and are usualy cheap to come by.




Now for my own "setup in progress"

Car 96 MX-6 LS (USDM)

Events: Auto X and non competative open track events for now.

Power: DE with headers, exhaust and a K&N stock style replacement filter.

Suspension, wheels, tires:

3rd gem Protege strut conversion (illumina) Includes Protege style upper mounts and stock MX6 springs.

14mm rear bar, stock front bar (soon to be smaller Protege bar)

Stock Probe GT wheels with very bad tires. But I have a lead on Mustang Cobra wheels with good tires.


Comments:

I need tires bad before I can go racing at all. If the Cobras prove to be a direct bolt on with out spacers or clearance issues I'll run them if not I have a friend with stock Probe SE 15,s with all season tires I can possibly borrow.

I liked the handeling of the car when I put the 14mm bar on and I'm looking for a larger bar for the track. I had the front bar disconnected for a while and didnt like it so i'm replacing it with a smaller bar to promote over steer with out getting to loose. Hopefully lol.

Brakes:

Upgraded to mazda 626 brakes as per my sig. Using Duralast pads on street (sub standard even compared to stock Mazda pads) But will use a hopefully better set for the track. I havent decided yet but am thinking EBC and of experimenting with different compounds front and rear to tune ballance.

These brakes are a great improvement over what was on the car for feel and initial bite but the cheap pads fall short even on the street, I wouldnt think of using them on a course.

Weight reduction:

Removed ruined A/C system and front of car now rides noticably higher than stock :( I need springs.
 

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http://www.mx6.com/forums/1g-mx6-ot...6-gavins-1st-gen-mx6-dsp-autocross-build.html

Pretty much whats been done to the car(1991 MX6GT) for autocross.

Think hard about going with a shorter sidewall. In AutoX and similar low speed sports with rapid transitions the reduced compliance of a shorter sidewall can cause the tires to break loose easier than a similar tire with a taller sidewall.

Check out the competitive racers at these events, typicaly they will be running taller sidewalls than people who run larger road courses.

If you want improved acceleration try smaller wheels. With 15,s you can run taller tires and still be quite a bit shorter in overall height. If you have them in Aus. Mazda Millenia 9 spoke wheels are a great option if 205 tread width is enough for you. They are very light for stock alloys and are usualy cheap to come by.
Are you sure about this, because this tire/wheel recommendation seems more suited for drag racing than autocross or road racing.

It is exactly in motorsports where there are transitions (and even more so in autocross) where you would want a shorter sidewall to aid in steering response and feel. A taller sidewall would be more slow/sluggish to react from turning inputs and feel more vague, less crisp and reactive.

There are a few specific instances where you may want a taller sidewall, but those would be high power RWD vehicles that add a bit of sidewall height to the reartires to aid in getting a bit more traction off the corners.

daevilone....those V700s must have been old or heat cycled out(or both). A new V700 is in another league compared to a new Federal(which is a VERY good street tire, just not anything close to a V700).

Gavin
 

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Discussion Starter · #4 ·
daevilone....those V700s must have been old or heat cycled out(or both). A new V700 is in another league compared to a new Federal(which is a VERY good street tire, just not anything close to a V700).

Gavin
They v700's were used. But only for one race by a lotus series. I think 1 maybe 2 cycles and about 60% tread.

The Federals now have about 60% tread and get daily driven. They still grip better than the v700's ever did. So no idea about that one then.
My next tyre is probably going to be an R888, as I've a lead for about the the same price as the Federals....
 

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Old.

The V700 isnt a new tire so unless you saw them fresh out of the tire truck...they are old......and used. I have a set of V700 victoracers that I got new......in 2004. And they were secondhand at that point. They have been sealed in black trash bags with as much of the air removed and in a cool and dark place. Even with those precautions, they are still slowly aging. At a certain point, they simply harden to rocks.

the Toyos will be "ok". Im not sure how Toyo managed this but theres a lot of club racing here in the states that have the Toyo as their spec tire. The old RA-1 was "ok", but fairly well known. The new 888 is, er.....not as good (and mind you, the RA-1 was just bearable). People here who have them specced in their series are not happy.

For the average "hobbyist" they should be pretty decent. They are (again) much better than street tires. They do have their curiosities though.

Gavin
 

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Discussion Starter · #6 ·
oh!

I just realised one thing for confusion.
looking on the Kumho website I infact had V70A's, which are of course different to v700's


and interesting comments on the 888's.

I've heard nothing but good things about them from other hillclimbers.

I guess its a slightly different style of motorsport so tyres will act differently.
 

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Are you sure about this, because this tire/wheel recommendation seems more suited for drag racing than autocross or road racing.

It is exactly in motorsports where there are transitions (and even more so in autocross) where you would want a shorter sidewall to aid in steering response and feel. A taller sidewall would be more slow/sluggish to react from turning inputs and feel more vague, less crisp and reactive.

There are a few specific instances where you may want a taller sidewall, but those would be high power RWD vehicles that add a bit of sidewall height to the reartires to aid in getting a bit more traction off the corners.



Gavin


I stand by what I said although I should qualify it by saying the best side wall height is going to be largely relative.

The problem with super lo-pro tires like the 35's mentioned above is that during the multiple sharp transitions encountered on an autox course the tread at the road surface would be experiencing much higher lateral loads for fractions of a second that even at low autox speeds can be enough to break the tires loose.

And as you would know once a tire is sliding sideways it dosnt take nearly as much load to keep it sliding and usualy takes a significant transper of load to regain traction. In an autox any sliding can cost you dearly as there isnt any extra pavement to recover with before you wipe out a cone.

With a taller sidewall the tire has an added damping mechanisim to reduce the peak loads seen at the road.

Also a taller sidewall deforms more under a given load at a given psi and thats important since body movement is much more severe in autox than in open road racing and the extra contact patch can help a lot when the inside front or rear tire is being unloaded.

All this dose come at the expense of feel and sharp turn-in but that simply requires an adjustment to the drivers technique.
 

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In the states, the V70A is called the ecsta V700 and the V700 is called the ecsta V700 victoracer (somewhat confusing). Same compound but different tread patterns for the two tires. They have since been replaced as kumhos top tier race tire with the V710. Kumho is phasing out the V70/v700 and keeping the V700 victoracer as its still a great club racing/lapping day 2nd tier race tire.

Its true that road racing and hill climbs in general have different needs, but depending on how long the hillclimbs are there may be much difference in the usage of the tire. There is a big difference in terms of philosophy and politics of the groups though. But thats another story ;)

Gavin
 

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The problem with super lo-pro tires like the 35's mentioned above is that during the multiple sharp transitions encountered on an autox course the tread at the road surface would be experiencing much higher lateral loads for fractions of a second that even at low autox speeds can be enough to break the tires loose.

And as you would know once a tire is sliding sideways it dosnt take nearly as much load to keep it sliding and usualy takes a significant transper of load to regain traction. In an autox any sliding can cost you dearly as there isnt any extra pavement to recover with before you wipe out a cone.

With a taller sidewall the tire has an added damping mechanisim to reduce the peak loads seen at the road.

Also a taller sidewall deforms more under a given load at a given psi and thats important since body movement is much more severe in autox than in open road racing and the extra contact patch can help a lot when the inside front or rear tire is being unloaded.
Maybe it would help to quantify what tire(s) you are talking about, because in the years that I have been autocrossing and and being crew for road racers, what you have suggested is completely opposite to whats done.

The "problem" with lower profile tires you mention largely doesnt exist because....

that simply requires an adjustment to the drivers technique
In other words..... dont overdrive the tires. But thats a given no matter what tires/sidewalls you have. So all things being equal, why would you give up the feel, responsiveness and lateral grip offered by a lower profile tire?

Dont get me wrong, I like to hear alternate ways of doing things, Im just not seeing the ends to the means as described here.

Gavin (who is running 35series profile tires currently)
 

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Discussion Starter · #10 ·
In the states, the V70A is called the ecsta V700 and the V700 is called the ecsta V700 victoracer (somewhat confusing). Same compound but different tread patterns for the two tires. They have since been replaced as kumhos top tier race tire with the V710. Kumho is phasing out the V70/v700 and keeping the V700 victoracer as its still a great club racing/lapping day 2nd tier race tire.

Its true that road racing and hill climbs in general have different needs, but depending on how long the hillclimbs are there may be much difference in the usage of the tire. There is a big difference in terms of philosophy and politics of the groups though. But thats another story ;)

Gavin
is the V710 road legal? It looks almost like a slick apart from those 2 lines... but the blurb for it mentions dot approved... I just cant imagine it being road legal.
Mentioning this because the tyres I use have to be road legal.

the hill climb i regularly compete at is a 1km track - around 53 sec.
 

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is the V710 road legal? It looks almost like a slick apart from those 2 lines... but the blurb for it mentions dot approved... I just cant imagine it being road legal.
Mentioning this because the tyres I use have to be road legal.

the hill climb i regularly compete at is a 1km track - around 53 sec.
It dosnt take much at all to get a tire DOT aproved. As long as it has a certain minimum tread wear rating (I forget what that is just now) and something that you can call tread with a straight face, it dosnt seem to matter.


Gavin: I defer to your greater experience for now but I have seen all the quickest street driven cars at the local autox running taller sidewalls than many low profile street tires.

I still say you can go too low but without experience to back it up there's no point in insisting.
 

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is the V710 road legal? It looks almost like a slick apart from those 2 lines... but the blurb for it mentions dot approved... I just cant imagine it being road legal.
Mentioning this because the tyres I use have to be road legal.
And this is where local law comes into play. Our DOT(department of transportation) laws are fairly comprehensive. They go through the usual like burst strength, load ratings, wear/abrasion ratings, tire construction, etc. Two things that are a little "loose" are the standards on measurements(this is kind of a universal one not limited to the states) and "measurable tread depth". The DOT says to be a road tire there has to be a certain amount of measurable tread around the tire....but they dont say how much. I think Japans laws say that there has to be something like 15% (or more) of the tire has to be tread pattern to be a "road tire". Naturally manufacturers will exploit this and you have something like the Kumho V710.

It meets the *letter* of the law here for what constitutes a road worthy tire, but..well, you know.

Think of it this way. Its an evolution of the summer tire. An extremmmmmme summer tire with limited application. Just like high performance summer tires are so-so in the rain and never to be used on snow, these tires (called DOT R-compound race tires here) are absolutely limited to dry weather and never to be used in the rain.

PS: Most of the manufacturers that make these tires have literature with words to the effect of "not for highway use", so yeah.


Gavin: I defer to your greater experience for now but I have seen all the quickest street driven cars at the local autox running taller sidewalls than many low profile street tires.
Im not trying to shut you down. While I do think you are a bit off base in this, I am curious to what it is that you have seen. I have a feeling theres a disconnect with what is being used, why and the results thereof.

Heres a picture link to last weeks autocross for me. This is what I see every other week. Zenfolio | Pozzi Photography | AAS, 3-09 Nothing there that I would consider high profile tires. [shameless plug]theres a picture of my car in there too[/shameless plug]

Gavin
 

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Just to my eye it looks like some of the late model Vetts could use more sidewall with a smaller wheel if it'll fit over the ZO6 brakes.

That early vette is proabably on the upper limit of sidewall height.

http://nrscca.com/ :: View Forum - Solo Photos

The last 4 threads starting with "first NO POINTS event of 09" contain pics of the first event I attended this year.

The 2nd gen Camaro has a healthy sidewall and is a quick car.

I think I was reminded of this piece of advice this time because of the weather. It was cold and proabably exagerated the effect I described above as many people had trouble early on with traction, especialy people running slicks but I saw a definite difference between very low pro tires and tires with a taller sidewall.

The taller sidewall equipped cars looked looser because of some extra body movement but didnt seem to suffer traction loss as badly as the other cars and they ran decent times right away where the low-pros performed much better
 

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The 2nd gen Camaro has a healthy sidewall and is a quick car.

I think I was reminded of this piece of advice this time because of the weather. It was cold and proabably exagerated the effect I described above as many people had trouble early on with traction, especialy people running slicks but I saw a definite difference between very low pro tires and tires with a taller sidewall.

The taller sidewall equipped cars looked looser because of some extra body movement but didnt seem to suffer traction loss as badly as the other cars and they ran decent times right away where the low-pros performed much better

Tires have a profile/series/height, this is what decides the sidewall stiffness of the tire.
With that in mind, a 205/35r17 will have a sidewall of 2.8" and a 275/35r17 will have a sidewall of 3.8". Both are 35 series tires and despite the fact the 275 is 2" taller then the 205 both will offer the same performance characteristics and tire stiffness.
A higher sidewall tire will just bow in turns, then after the turn the tire and rim will want to line up, if the tire keeps traction then the car shifts, resulting in a jerk after every corner.
The wider the tire the more "sidewall" it can have without flexing in corners.
 

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Tires have a profile/series/height, this is what decides the sidewall stiffness of the tire.
With that in mind, a 205/35r17 will have a sidewall of 2.8" and a 275/35r17 will have a sidewall of 3.8". Both are 35 series tires and despite the fact the 275 is 2" taller then the 205 both will offer the same performance characteristics and tire stiffness.
A higher sidewall tire will just bow in turns, then after the turn the tire and rim will want to line up, if the tire keeps traction then the car shifts, resulting in a jerk after every corner.
The wider the tire the more "sidewall" it can have without flexing in corners.
Yes I'm aware that the sidewall # is a percentage of the tread width and so is gavin so neither one of us pointed that out.

I'm trying to avoid speaking in absolute terms because I'm discussing a small sapect amid hundreds of variables but I'm trying to point out that while there is definitely such a thing as a "to-tall" sidewall there is also such a thing as a "to-short" sidewall. A point where there is so little compliance that traction may be compromised.

Assuming you need tha stiffest sidewall is no different than asuming you need tha stiffest struts and springs.


There are more aspects of tire design than sidewall height that effect sidewall stiffness and overall performance.
 

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That early vette is proabably on the upper limit of sidewall height.


The 2nd gen Camaro has a healthy sidewall and is a quick car.

especialy people running slicks but I saw a definite difference between very low pro tires and tires with a taller sidewall.

The taller sidewall equipped cars looked looser because of some extra body movement but didnt seem to suffer traction loss as badly as the other cars and they ran decent times right away where the low-pros performed much better
You didn't seem to understand the reason for my last post (to explain why wide tires can have a higher sidewall and be low profile) so I will try this another way.

Upper limit of sidewall height, healthy sidewall, taller sidewall...
I checked the pics and vids you posted in the link, all the cars you are referring to a rear wheel drives, they run wide tires, because of the width of the tire even low profile tires of the same series (as the FWD) will have a taller sidewall.

You need to go read what size/profile tires are on these cars at you next event and stop thinking just because the sidewall looks taller on the very wide tires that they are different profile then the rest.
 

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You didn't seem to understand the reason for my last post (to explain why wide tires can have a higher sidewall and be low profile) so I will try this another way.

Upper limit of sidewall height, healthy sidewall, taller sidewall...
I checked the pics and vids you posted in the link, all the cars you are referring to a rear wheel drives, they run wide tires, because of the width of the tire even low profile tires of the same series (as the FWD) will have a taller sidewall.

You need to go read what size/profile tires are on these cars at you next event and stop thinking just because the sidewall looks taller on the very wide tires that they are different profile then the rest.


What are you going on about? Most of the wide tires are the ones with to_low sidewalls in my opinion not the other way around.

And you seem to be mistaken. Like I said there are more factors than tread width and aspect ratio to the stiffness of a sidewall.
 
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