Kevin Doe

iTrader: (1)

No I wasn't there. I don't think my skill level is where it needs to be to compete in XP (nor is my car there yet either). I may do a national tour event next year at Grissam AFB to see where I stand and decide if its worthwhile to continue national tour evnents, or go back to regionals and keep practicing my skills.

This is my car on an old front tire setup before I put the 285s up front on 18s. I think that picture I still have 275/40/17s up front. I don't have any recent pics.





Actually just found a recent pic:
http://www.jlofoto.net/#/gallery/201...20100829-0681/

KKMpunkrock2011

iTrader: (5)

ok, why xp instead of ssm? I know it's slightly off topic.

Kevin Doe

iTrader: (1)

SoloII///M

iTrader: (13)

That's Mark Mauro's car. He's out of Colorado.

KKMpunkrock2011

iTrader: (5)

ooo... that explains it then.

cone_crushr

iTrader: (18)

You mean Mazda didn't make the LSx V8? I'm surprised since i see so many of them.

One advantage of Solo is nobody really cares if you suck, since you're not really endangering them during the race. You might eventually get tired of getting annihilated though.

SBrian2

Kevin,

I'll answer for Dan since I'm his co-driver. We run 3 degrees because that is what works and we get very even tire wear. It also does pull the top of the wheels in and allow a larger tire to fit. We ran 275s before the control arms and they were closer to the fenders than we are now with the 295s.

Brian Johns

KKMpunkrock2011

iTrader: (5)

Wilson, where did you guys find the control arms? I know dan said they weren't cheap but I've been looking for them and can't find them.

jkstill

iTrader: (11)

http://www.rhdjapan.com/nagisa-auto-...d3s-rx-7-53519

Kevin Doe

iTrader: (1)

Thanks for the reply, I appreciate it.

Can you comment if you think it would be a good idea to build in a bit more caster into the upper control arm. If I move the ball joint point rearward a bit in the design, that will move the amount of caster adjust ability, from say 2-6 deg, to maybe 5-10 deg depending on how much I put into the design of the arms. That way you wouldn't have to sacrifice static caster to get the camber you want. Do you think that would be a beneficial feature?

SBrian2

We run 4.5-5.0 caster, and it seems to be plenty. With the adjustable rod ends on the upper control arms it is no problem getting enough caster or camber. It is a little more cumbersome to adjust since you have to remove the upper control arm bolts as opposed to just adjusting a cam-bolt on the lowers. When we first installed the upper control arms we had over 5 degrees of camber if that gives you any indication of how much adjustment you will gain.

Brian Johns

Kman Art

iTrader: (1)

I just got my 6ULR rims and wrapped em in 275/40/17. Just wanted to say a quick thanks to those guys who helped me with the rim info. No rubbing with the 17x10 with the 52 offset!

The car will be a DD and also see autocross events every month. How would the camber/caster/... settings compare to road racing?

s1mpsons

iTrader: (5)

Pics please

Kman Art

iTrader: (1)

Sorry for taking so long, but I was scrambling to get my car sorted out for the autocross event over the weekend.

I ended up going with 2* camber in the front and 1* in the rear. Toe was 1/16" in the front and 0 in the rear. Or at least that's what I asked for.

KKMpunkrock2011

iTrader: (5)

how'd she do?

Kman Art

iTrader: (1)

Aside from the boost playing peek-a-boo with me the entire night, I got 1st for 2wd class during the normal course and 3rd overal in the battle round.

3 Classes - 2wd (fwd, rwd), awd, unlimited (have to use Toyo R888). 2wd and awd can't use any tire softer than 140 treadwear.

I have a feeling my actuator has aids, or just had a flu that night.

s1mpsons

iTrader: (5)

Just revisited this thread because I am planning to jack up my tire sizes from 285/30/18 X 4 (ie F&R) to 315/30/18 X 4.

The plan...

Front: Cut the inside lip out of the front fenders. Same 18x10 7.5bs with 3mm Spacer. new 900lbs/in front springs. ~3.3* camber.

Rear: Roll/Pull rear fender. Same 18x10 7.5bs. New 15mm studded spacer. New aftermarket pillowball trailing arms (not necessarily offset, still awaiting arrival of ebay order to see), new 850lbs/in rear springs. ~2.2* camber.

Any suggestions from the experienced wide tire drivers?

Brent Dalton

iTrader: (31)

Jake, I'm running 315F and 335 R. I will have pyrometer data on my set up after this weekend at Road Atlanta. Currently running -2.5 all around. I suspect I will end up around -1.8 to 2.2 in the rear and -2.8 and 3.2 in the front. I won't have my Penske's on the car this weekend, but their spring rates are going to be 900F/750R starting out.

s1mpsons

iTrader: (5)

Could you please describe your fender work and wheel offset? Front and rear? How did you get those to fit?

Kevin Doe

iTrader: (1)

I'm running 315 A6s in the rear. To get them to fit, here is what I did.

1. My wheels are widened RPF1s. They were 18x10 +38. I cut the back half off with a parting tool (removed 1/4" material), and added in a 1" strip. The wheels now have 3/4" more backspacing than they did originally. I measured the backspacing to be 7 21/32", and I also run a 1/8" spacer.

2. I had to make a set of trailing arms that had a completely offset front bushing.


3. I had to modify my rear coilovers. The lower jamnut was touching the tire are full compression. I removed the jamnut and cut a slit down the bracket and used T-bolts to hold it in place. Been this way for two seasons now.

4. I had to hammer/air hammer/sledge hammer the area of the wheel well area. If you're looking at the drivers side of the car, look at the 9 to 10 o'clock position on the wheel/tire. Thats where it rubs. I had to flatten that area out and beat it inward pretty good.

5. I rolled my fender lip completely flat.

6. I relocated my lower shock mount inboard by 5/8". This was to avoid rubbing the tire on the shock tube lower bracket.

7. After all the aforementioned modifications I was still getting some rubbing in the wheel well area right at the 12 o'clock position, near the outside edge of the tire. If you look in your wheel well you'll notice that the inner metal liner does not follow the body line. It curves inward at a much quicker path. The problem is that the curve there is of a larger more gradual radius than the shoulder of the tire. the shoulder of the tire will rub there at max compression. I took an air hammer and slowly stretched that area to give it a profile that more closely matches the shoulder of the tire. Be careful doing this, for some reason massaging that area caused my quarter panel on only one side to suck in and made a dent. It must have stressed the outer body panel.


So here are the results. Tire rubbing depends on alignment settings. The wheel has never touched anything. Over the last few years I've tried a lot of different alignment settings. Here are my findings.

1. Trailing arm rub: Tire will rub with any toe in setting. Zero toe results in no rub. Usually its a light rub where I just get a bit of rubber transfered to the arm.

2. Coilover rub: No rubbing.

3. Fender lip rub: Slight rub with low camber alignment. I get an area on the tire sidewall where it looks to have melted slightly if I run an alignment with less than 2 degrees of camber. I have went down to 1.5 degrees and the rub is still only minor.

4. Inner liner rubs at the 9 to 10 o'clock position (looking at drivers side rear): I do rub there, with a zero toe alignment. If I toe in, the rub gets slightly harder. It has rubbed through the underbody coating in a few spots, to shiny metal.

5. Fender liner rubs at the 12 o'clock position: No rubs in the shoulder region of the tire. Some rubbing on top of the middle of the tire. To remedy this I set my shock bump stops such that it will completely flatten the bump stop and still not touch the tire to the metal liner. I gave 1/16" clearance there. Then I kept upping my spring rate till I was not hitting the bump stops. I ended up with a 14k spring in the rear (keep in mind though, my relocated lower mount, so effectively a 13k spring if you compare to the stock geometry).

For a more detailed explanation of my modifications, and some clearance shots, see this thread:
https://www.rx7club.com/suspension-wheels-tires-brakes-20/fitting-315s-stock-body-fd-904367/

I hope that helps.

Brent Dalton

iTrader: (31)

Front: Ronin front fenders. I had to trim the front fenders and front bumper a little to get the tires to clear. Once that's done, you need to cut the headlight bracket to get it to clear lock to lock(tire will hit on sway bar(but anything over 275 will and you'll never turn the wheel that much at speed). If you don't want to cut the headlight bracket, I think you get 1.5 or 2 turns of the wheel before it hits(once again, you'll never turn that far on track most likely but I'd still cut the bracket just in case you need that during a correction).

Front wheels are 18x11 CCW Classics with the standard backspacing of 7.5. When I converted these from 18x10 to 18x11 all I had to do was call John(owner and operator of CCW) and order new outer barrels, Changing out the outer barrels is super simple to do and much cheaper than buying a completely new set of wheels. We aren't all fabrication ninja's like Kevin (really cool stuff btw Kevin). I'm also looking into putting 335's on the front possibly, but I think it will be overkill.

Rear: Pettit flares, CCW Classics 18x12(converted from 18x10) with a 7.5 backspacing. With the petit flares, you have plenty of room to take the wheel outbound(take inner barrel to an 8 backspacing) some and get it away from all the usual suspects that may rub and still fit a 335 underneath there. Currently I don't have any rubbing issues but you can see I could fit more rubber underneath the rear if I so chose.

Once again, currently way undersprung with the big tires waiting on my new coilovers to come in but this will give you an idea if you decided to go this route:



Current alignment specs(same as when I ran my 275's until I get the pyrometer out this weekend).

KKMpunkrock2011

iTrader: (5)

damnit I want a purpose built track FD with the JKL SS1 front

s1mpsons

iTrader: (5)

Brent, your front fenders look like they have an aggressive pull. Also, no liners up there, right?

Thanks for the breakdown of your fitment everyone! This information is priceless.

Kevin Doe

iTrader: (1)

s1mpsons, Brents fenders are Ronin Speedworks fiberglass fenders, in case you over-read that part.

Brent Dalton

iTrader: (31)

Yep, no fender liners and Ronin wide front fenders(had to trim them up a little to get the 315's to clear, but nothing to worry about for us racer types... If you were a waxer, you might worry that you have to cut your fenders. Carter and Jim are running 315's in the front as well with the stock front bumper and fenders. I'm pretty sure you were at Nationals last year so you prob. saw his car.