MSP - Reducing Understeer

[Nextruss]

I am trying to find parts to help me reduce Auto-X understeer at the track. Currently i only have a set of ground control coilovers on the car and am runnig 215-45-17 potenza reo-40's. I am considering a thicker upper strut bar and getting as lower tie brace bar. also i want to get new sway bar bushings and motor mounts to help stiffen overall. any advice is appreciated. thanks!

[JCell]

thicker rear sway bar will make the car oversteer more

[Nextruss]

i was thinking of stiffening the rear more to change the car that way. whats the widest tire we can put under the protege? i read in the past i think on the stockers, widest is 225 without rubbing. what about trying to get 235 or 245 under the car? prolly need a 8in wide rim, with the right offset, would those sizes fit and not cause issues?

[ForceFed]

an 8'' with a 235 will not fit unless you really want to get into modding your fenders hardcore.
225 is pushing it already....not to mention 8'' is pushing it as well.

[Nextruss]

so maybe ill stick to the stockers with 225's. so 225-35-17 what will work or a different profile?

[ForceFed]

I don't think you can get a 35 series on a 17" rim size.
you would have to do 225/40/17's.

EDIT..After peeking around..it looks like a 225/35/17 is avaialble in a few different tires....But the selection is limited.

[jmv]

i know one of the local guys has 10" front wheels (with i think a 285 tire?) on his protege ES with AWR coilovers, at least thats his autox setup.

I'd say a good upgrade would be the AWR rear sway, lots of people say its great for getting the car more tail happy.

[ForceFed]

They must be like 15x10's then.

And would look RIDICULOUS on a street car.

[autoxes]

i know one of the local guys has 10" front wheels (with i think a 285 tire?) on his protege ES with AWR coilovers, at least thats his autox setup.

I'd say a good upgrade would be the AWR rear sway, lots of people say its great for getting the car more tail happy.

Is he on here? Is it Jas00x? He has an FSP protege with 10" wide wheels on it

[Nextruss]

im looking at potenza re050a pole positions or the re01r. anyone have any input? this is a 225-45-17

http://www.bridgestonetire.com/tireselector/SearchBySize_BS_EN.aspx?Size=225%2f45ZR17

http://www.tirerack.com/tires/Compare1.jsp?width=225%2F&ratio=45&diameter=17&manufacturer=Bridgestone&startIndex=0&search=true&pagelen=20&pagenum=1&pagemark=1&x=14&y=15

[autoxes]

For autocross the general rule for street tires is either the Falken Azenis 615, or the Bridgestone RA-01's

[HondaNoMore]

i remember seeing someone with 235/40's on here somewhere.... i can't remember if it was stock wheels or not though. the only problem with this tire size and stock wheels, is the tire itself is designed to fit optimally on a 8-9.5 inch wheel. the size difference between the stock 215/45 and the 235/40 however, is minimal.... about .2" shorter (diameter), and about .8" wider. well, i just read that back to myself and .8" is a lot wider, but for diameter's sake it's not much....

[Tom03es]

One way to decrease understeer is to increase your traction at the front. How much camber are you running? 1st gen Protege Cusco camber plates will fit a 3rd gen Protege.

[yellowmsp035]

run somewhere around a -1 to -1.5 in the front and -0.75 in the rear with lower psi upfront and higher tire pressure in rear. get a beefier rear sway bar and if you have damper adjustment try putting the rear as stiff as it will go and the front around medium and adjust to your liking from there... this is just a starting platform that will get your turn in a lot quicker with less understeer. adjust it from there

[Gobbracing]

If it can help, here's my set-up that I'm running in STX:
- Bridgestone RE-01R 225/45-17 all-around, was running Falken RT-615.
- O toe all-around
- -2.5° of camber in front, -1° in the back
- Clunk-Fix kit (from Evolv) installed in the back (rear sway bar becomes stiffer and more effective).
- Front sway bar stiffened by adding a hole (done by previous owner). Tried regular and stiffer and stayed with stiffer.
- My suspension is original.
With this set-up I can get lift-throttle oversteer.

- Planning to to go to 245/40-17 tires in the front (RE-01R). Only rubs at full steering lock.
Why 245s in the front. A lot more traction and better braking. The previous owner used to run Hoosier 245 in the front and 225 in the back in D-stock. Car even trophied at the Solo Nationals in 2005.

[Nextruss]

245's up front would be nice. i just ordered some awr camber plates for up front so im gonna follow your setup with something pretty aggressive around -2 to -2.5. what width rim would the 245's ride on? 8in? and do you think we would have to look into wheel spacers?

[Gobbracing]

Yes 8inch wide wheels will be better. The tire will be squarer so it will perform better than when it's ballooning on a thinner wheel. I'm running 7.5" wide wheels this year with a 45mm offset and it works.

The previous owner was running 245 A6 Hoosiers on the front on 7" wide wheels with a 50mm offset without any problems.

Here's what Jeff@Tri-point posted when he was setting his MSP for STX:
235/40/17 with a 17x8 47+ Offset fit easily in the front.

Hope this helps!

[122 Vega]

A 245/40/16 on an 8" w 48mm offset fits.

A 235/40/17 on a 7" w 50mm fits

A 245/35/17 on an 8" 45mm fits

Britt

[MX5RACER]

If it can help, here's my set-up that I'm running in STX:
- Bridgestone RE-01R 225/45-17 all-around, was running Falken RT-615.
- O toe all-around
- -2.5° of camber in front, -1° in the back
- Clunk-Fix kit (from Evolv) installed in the back (rear sway bar becomes stiffer and more effective).
- Front sway bar stiffened by adding a hole (done by previous owner). Tried regular and stiffer and stayed with stiffer.
- My suspension is original.
With this set-up I can get lift-throttle oversteer.

- Planning to to go to 245/40-17 tires in the front (RE-01R). Only rubs at full steering lock.
Why 245s in the front. A lot more traction and better braking. The previous owner used to run Hoosier 245 in the front and 225 in the back in D-stock. Car even trophied at the Solo Nationals in 2005.

What do you have done to the suspension to get that much camber? Crash bolts? Camber plates? I am starting to set up my MSP for DS, previously a CS guy.

[Gobbracing]

I run in STX locally and the club is using SCCA solo2 rules.
So I'm allowed to use crash/cam bolts on the front because it is legal in STX.
I also rotated the front top plates to have the green dots aiming toward the outer front. I'll have to reverify to confirm the green dots position but do a search in this section or the Motorsport one because it has been discussed before.

And I was having the dreaded MSP ABS problem before. I was using very aggressive front brake pads (GranSport GS3). Fixed it by going to a 1 step milder pad (GranSport GS5). Kept the KVRs in the back.

Everything seems to have worked pretty well (so was my driving) during the 1st CADL Solo2 event last week-end. Got 2nd in ST (indexed STS, STS2, STX, STU). I've been working on my driving a lot more since autocrossing my MSP and it's paying now.

Note that I changed the sides and front engine mounts with AWR inserts and mount. My OE mounts were gone. Now I get a better traction and feel. But this is illegal in DS.

[MX5RACER]

Thanks for the info. I knew about the green dots, I was just curious if you had done anything else. I will have to look at the service manual, if the crash bolts are listed to bring the camber back to spec, then they are DS legal. Also, on the front bar, what is the spacing between the bolt holes (i.e. original hole and the new drilled hole)?

Thanks.

[Gobbracing]

Good question. I'll look when switching my tires.

[122 Vega]

Crash bolts are not in the Mazda service manual. they are not DS leagal. I talked to a couple of guys from Mazda that were up here a few days ago setting up for the Mazda GranPrix, and I made a joke about that if they'd just throw those in the book there'd be a lot of happy Protege owners. They looked at me and basically said it didn't matter cause they were on to the 3.

Britt

[Gobbracing]

If they'd only do it. If they'd only do it.

[Gobbracing]

Also, on the front bar, what is the spacing between the bolt holes (i.e. original hole and the new drilled hole)?

Thanks.

The edge of the hole is just before the first bend, still on the flat part. There is about 1/4 inch space between the edge of the OE hole and the one done by the previous owner.

Don't ask for photos because I don't have a camera.

[MX5RACER]

Thanks, that should be enough info.

[vinnie mack]

excellent info guys, are most of the cars here street as well? i don't think -2.5 camber would be good for the street or do you guys set it just for track days.

i'm surprised no one has done any body stiffening like trunk braces or anything or are they useless?.

[MX5RACER]

Hey Gobb, you wouldn't happen to know the starting tire pressures they were using on the car in DS would you?

[122 Vega]

excellent info guys, are most of the cars here street as well? i don't think -2.5 camber would be good for the street or do you guys set it just for track days.

i'm surprised no one has done any body stiffening like trunk braces or anything or are they useless?.

I was running that much on the street, but now I run less with my current setup. -2.5 limits the amount of power you can put down anyways.

As far as stiffening, it looks like this thread is mostly STX guys, so most of that "JDM" bling is not legal. I refer to it as bling because I seriously do dont think it has been researched and documented well enough as beneficial. The Protege chassis is already north of 14k lbs for torsional rigidity. You can actually jack up one corner and get three tires off the ground if you want to. front STB is really the only effective stiffening part that is legal in STX.

Britt

[Gobbracing]

Hey Gobb, you wouldn't happen to know the starting tire pressures they were using on the car in DS would you?

Good question and I don't have the answer.

[chuck b]

IAnd I was having the dreaded MSP ABS problem before. I was using very aggressive front brake pads (GranSport GS3). Fixed it by going to a 1 step milder pad (GranSport GS5). Kept the KVRs in the back.

What is this dreaded ABS problem you mention? Is it simply premature/overly aggressive ABS that was entering "ice-mode"? or something else?

my autox experience w/ oem pads on both street and R tires has been pretty good; just a little ABS when I overcook a corner or do too much trail braking.
One Exception however- perhaps it's due to the brakes getting hot by the end of the run (left foot braking so I may drag it a bit) but the final stop at the end of the run the car seems to enter this ice-mode very easily. then again, it just might be adrenaline screwing things up. but that ice mode is enough to get my attention in a hurry as the braking power in ice-mode is crap.

anyway, I want to hear more about the dreaded problem.

thx

out

[chuck b]

Hey Gobb, you wouldn't happen to know the starting tire pressures they were using on the car in DS would you?

depends on what tire you'd run, but with 225 45 kumho's, i used 44F/48R which gave excellent results on a chilly weekend (5th PAX on Sat [silly coned away 2nd] and 1st on Sun; first weekend w/ R's on this car).

good luck

out

[Gobbracing]

What is this dreaded ABS problem you mention? Is it simply premature/overly aggressive ABS that was entering "ice-mode"? or something else?

out

Yes. That's what I was referring to.