AUTO-X -Bang for buck setup

[brandon3212]

I have the JBR competition RSB on my car and they do kill the understeer depending on your track layout.

It would be cool to have options to go with a lighter front sway bar to further alter the cars rotation.

[snailD]

OOPS

[skoski17]

Originally Posted by brandon3212 I have the JBR competition RSB on my car and they do kill the understeer depending on your track layout. It would be cool to have options to go with a lighter front sway bar to further alter the cars rotation.

Hhmmm now you have me thinking.

[snailD]

@skoski17; holy signature batman!

[MS3Shadow]

Yeah, his signature is WHOA!

sent from my Nexus 6P

[skoski17]

Ya... I have been meaning to change that lol

[zenit]

Originally Posted by snailD OOPS

Which endlinks are those?

[snailD]

Originally Posted by zenit Which endlinks are those?

@grantmm; got the custom made for the AST suspension i bought off of him

[zenit]

Originally Posted by snailD @grantmm; got the custom made for the AST suspension i bought off of him

Still jealous.

thankfully- that rod end should be replaceable, probably for pretty cheap.

[snailD]

Originally Posted by zenit Still jealous. thankfully- that rod end should be replaceable, probably for pretty cheap.

Yea i just cant find it locally so i need to order one

[phate]

Originally Posted by snailD OOPS

I wouldn't just slap new rod ends in. That link is binding and it is bending due to that. Double check alignment throughout the entire range of motion to make sure the rod ends don't neck out. Binding suspension bits don't allow your suspension to work properly and can introduce some nasty behavior.

[KevinK2]

Originally Posted by snailD Yea i just cant find it locally ... GTX 2867/ JBR OG 3.5 WP/ Snail Ported IM/ ITV-22/ DAMOND RMM EBAY DP wCAT/ HKS BPV/ CP-E FP/ COBB EBCS/ PG FMIC W/ TR8 STOPTECH/ EBC YELLOW/ GOODRIDGE LINES/ MOTUL RBF 600 [443/409]SAE CORRECTED -------------245 DZ102 / 245 NT01

Just a quick note to the OP about the dyno numbers posted. They may well be overstated by the dyno CF.

The latest 2011 version of the SAE Standard for car manufacturers rated Hp & Tq, J1349, finally has a note about engine dyno tests for boosted induction, done at high elevations. The standard is the basis of the chassis dyno's "SAE correction factor", that is supposed to tell what the power would be at sea level and standard ambient pressure and temperature.

This standard was originally written for normally aspirated (no boost) engines. It does not work for boosted engines regarding the ambient pressure variable at high elevations, and Breckenridge Co at 5000 ft has an ambient pressure of only 12.2 psi. The typical SAE CF would be about 1.2 because of this NA basis. The latest version of the standard states that if the boost control system maintains the same absolute pressure at ground level as at high elevation, NO ambient pressure correction is needed. This means for a car with 20 psi of boost at ground level, the compressor would overspeed to maintain the same absolute manifold pressure at 5000 ft, making 22.5 psi boost.

For years people have used a modified version of the SAE formula for boosted engines, when dyno'd at at high elevations, to include difference in absolute manifold pressure. You can Google for more info on this.


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[snailD]

If you are just trying to say my dyno numbers are wrong, then say you think they are wrong lol. Just a few things.... They equal to about the same numbers as those dyno-Ing at sea level. It was dynoed in Utah at 4500ft at 1.16 cf factor and Breckenridge is at 9600ft in elevation.

Originally Posted by KevinK2 Just a quick note to the OP about the dyno numbers posted. They may well be overstated by the dyno CF. The latest 2011 version of the SAE Standard for car manufacturers rated Hp & Tq, J1349, finally has a note about engine dyno tests for boosted induction, done at high elevations. The standard is the basis of the chassis dyno's "SAE correction factor", that is supposed to tell what the power would be at sea level and standard ambient pressure and temperature. This standard was originally written for normally aspirated (no boost) engines. It does not work for boosted engines regarding the ambient pressure variable at high elevations, and Breckenridge Co at 5000 ft has an ambient pressure of only 12.2 psi. The typical SAE CF would be about 1.2 because of this NA basis. The latest version of the standard states that if the boost control system maintains the same absolute pressure at ground level as at high elevation, NO ambient pressure correction is needed. This means for a car with 20 psi of boost at ground level, the compressor would overspeed to maintain the same absolute manifold pressure at 5000 ft, making 22.5 psi boost. For years people have used a modified version of the SAE formula for boosted engines, when dyno'd at at high elevations, to include difference in absolute manifold pressure. You can Google for more info on this. .

[KevinK2]

Originally Posted by snailD If you are just trying to say my dyno numbers are wrong, then say you think they are wrong lol. Just a few things.... They equal to about the same numbers as those dyno-Ing at sea level. It was dynoed in Utah at 4500ft at 1.16 cf factor and Breckenridge is at 9600ft in elevation.

I don't know where I got 5000 ft ... I skied at Park City, close to 6k, and went for a jog and could not catch a breath! Can't imagine 9600 ft. Local air pressure just 10 psi!.

Were the boost pressure gauge numbers the same at 4500 and sea level?


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[snailD]

Originally Posted by KevinK2 Were the boost pressure gauge numbers the same at 4500 and sea level? .

yea and i played soccer up at that altitude this summer lol.

i'm not sure i understand your question, im just comparing my numbers to others running the same if not super similar set ups with the same amount of boost pressure coming very close in numbers.

[KevinK2]

Originally Posted by snailD ... i'm not sure i understand your question, i'm just comparing my numbers to others running the same if not super similar set ups with the same amount of boost pressure coming very close in numbers.

I see that now, you were clear about it, but I still misread it as if you dyno'd your car at sea level too.

This is a good example of why the SAE CF (and some others) are not correct for predicting hp & tq at sea level, when dyno'd at high elevation like 4500 ft.

The trouble with Dyno's at high elevation

And an elevation vs ambient pressure table: engineeringtoolboxair-altitude-pressure-



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[jeffdevo]

here are my mods, I have a few hundred to spen on mods for autocross. any additional braces that may help handling? or motor mounts?? thanks!

Corksport SRI - Corksport Rear Sway Bar - H&R Springs - Koni Yellow Struts - JBR Camber Arms - AP v2 -Autotech internals - Tork Motorsports Tuned - SST brake lines - Stoptech Sport brake and rotors w/ sst Brake lines

[phate]

If you haven't been out autocrossing every couple weekends (or more) up to this point, seat time will be the best investment.

[KevinK2]

Like Phate said, seattime is essential to improvement. If they have extra runs for a few bucks after the competition is over, invest! I did not see a race alignment on your list of mods ... if not already done, research and do it. How long have you been Autoxing?

There are HPDE's held at tracks near Atlanta, like Road Atlanta. Best to find one with more tight turns. You may need to add full race pads up front, and back off the rear bar setting. But when I was competing for a class win in the local autox, I would do HPDEs that improved my braking skills. Every time I did one, I was faster at the next autox, relative to my close rivals.
HPDE, Road Atlanta


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[KevinK2]

Originally Posted by snailD OOPS

It looks like an extra wide tapered spacer was used for extra offset of the rod-end (vs oem offset) on the right side of the pic. This increases the bending load on the joint. If that much offset is needed, make sure you use a 12.9 strength bolt, torqued to the max allowed. Look up on the net metric bolt "torque table" 8.8 10.9 12.9, etc

also make sure you use high strength rod ends, and check for no binding as Phate described.

EDIT: I think Phate is correct about a binding issue. When you lowerd the suspension, you often need shorter end links. And the front ones that came with the C/O system may not have been adjusted right for your car. I think you mentioned the car did not feel right with the new suspension.

I doubt the end links were not up for an oem front bar, if adjusted properly. But for someone looking for heavy duty end links, this place uses oem tie rod ends that are sealed and not designed to get loose with wear: http://www.powergridinc.com/swaybar.asp


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[jeffdevo]

Originally Posted by KevinK2 Like Phate said, seattime is essential to improvement. If they have extra runs for a few bucks after the competition is over, invest! I did not see a race alignment on your list of mods ... if not already done, research and do it. How long have you been Autoxing? There are HPDE's held at tracks near Atlanta, like Road Atlanta. Best to find one with more tight turns. You may need to add full race pads up front, and back off the rear bar setting. But when I was competing for a class win in the local autox, I would do HPDEs that improved my braking skills. Every time I did one, I was faster at the next autox, relative to my close rivals. HPDE, Road Atlanta .

we caught the last SCCA race of the season last fall at bremerton Motorsports park in Washington. Planning on going to a few events this spring and summer. Fortunately got my wife involved too and she had a great time! Its my DD, I will look up a race alignment.

We also bumped up the tire pressure to about 40 psi to minimize sidewall tire compression.

Def want more seat time and will def pay for extra time on the course too!

[blackms3_71]

Originally Posted by jeffdevo we caught the last SCCA race of the season last fall at bremerton Motorsports park in Washington. Planning on going to a few events this spring and summer. Fortunately got my wife involved too and she had a great time! Its my DD, I will look up a race alignment. We also bumped up the tire pressure to about 40 psi to minimize sidewall tire compression. Def want more seat time and will def pay for extra time on the course too!

Hey, ill be moving to washington in the bermerton area and would love to come out for some auto x

[jeffdevo]

check out this link. Autocross Solo Events In Washington - Where2Race

hit me up if you go!

[miata_racer]

Budget driving to me would be what I started with:

Corksport camber plates and a JBR Race rear bar. Then wide wheels and tires. 17x9 and 245/40-17s fit pretty easy up front. Fender lip rolling required. Out back I'd do the same actually.

Whiteline offset upper rear bushings.

Alignment I'd do about -2.5 up front (some can't get over -2.2 or so) and zero toe. Out back do -1.5 and a smidge of toe out.


This should work nice on even stock shocks and springs. For an upgrade and not much more money ($1000 vs nearly $400 for the CS camber plates) get some custom valved BC coilovers. Streetable rates like 10k front and rear will be pretty similar balance. Go up to a 12 or 14k rear to get some good rotation going.

I daily drove my 2008 on their ER series doubles on 10k/14k. The car weighed about 2690-2700 so the 300+ extra lbs on the MS3 should make it smooth. I'll be much stiffer on mine

[Rose City Speed6]

I've had my MS6 for less than two months. It has stock suspension. Wheels are stock. The tires are 225s, but they are mismatched. Yokos on the front, Federals on the rear.

I just competed in a local autocross and was surprised that it is quite tail-happy. Definitely fun to drive, but I want more balance. I'm sure the tires factor heavily into this tendency. Does the stock MS6 tend towards oversteer? What will balance it out?

[KevinK2]

The MS6 tends to understeer in an AutoX. This thread is mostly related to the MS3, look at this MS6 suspension forum that is found at the bottom right of this page, labeled "forum jump".
official-mazdaspeed-6-suspension-Forum
and search it and the many threads in it. This one in particular:
Phate's MS6-suspension-data-diy-bilstein-coilovers. Phate is an expert autoxer, and all tasks are DIY with pics.

And in tight money days, I had hard and softer tire pairs for my old GT6 that I moved front to rear to get more or less oversteer.


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[ViperTGB]

Originally Posted by jeffdevo we caught the last SCCA race of the season last fall at bremerton Motorsports park in Washington. Planning on going to a few events this spring and summer. Fortunately got my wife involved too and she had a great time! Its my DD, I will look up a race alignment. We also bumped up the tire pressure to about 40 psi to minimize sidewall tire compression. Def want more seat time and will def pay for extra time on the course too!

Here's a very simple, yet very effective, alignment that works great for street/AutoX use:

Front: -2.0 camber, 0 toe
Rear: -1.0 camber, 0 toe

This will keep your tires lasting a somewhat reasonable amount of time. If you want more of an autoX setup then you'll want more camber up front, around -3.0.

But just like everyone else is saying: seat time, seat time, seat time. Nothing will improve your times faster than a driver mod.

[the_red_baron]

Originally Posted by ViperTGB Here's a very simple, yet very effective, alignment that works great for street/AutoX use: Front: -2.0 camber, 0 toe Rear: -1.0 camber, 0 toe This will keep your tires lasting a somewhat reasonable amount of time. If you want more of an autoX setup then you'll want more camber up front, around -3.0. But just like everyone else is saying: seat time, seat time, seat time. Nothing will improve your times faster than a driver mod.

Hate to resurrect an old thread but apparently I don't have enough posts yet to send PMs. Guess I need to fix that. Viper, in an older thread you had stated you were running 1/4" toe all around but here you're suggesting 0 toe. I'm assuming that's because here you're saying it would be optimal for street/autox. It's been over a year now since you posted this, do you still feel this would be a good set up? Based on limited information I managed to cram into my head regarding suspension, it sounds good, but I find it interesting that a number of guys on here are running 1/16 toe up front with 0 in the rear. They're willing to wear out their front tires a bit more to reduce understeer when racing I suppose.