The Project Pad

Awsome Marc, :woowoo: That car is going to be SICK I cant wait to see it done.....If you ever want/need my help just LMK

The KW's have turned in arm's right?
What is the wheel width and off set that looks pretty tight to the tie rod end.

Toxcheap wrote:

The KW's have turned in arm's right?
What is the wheel width and off set that looks pretty tight to the tie rod end.

yes, thats what allowed me to run the 255s. The tie arm hit the tire before. The rotation is slight, didn't need to move very much.

The wheels are ET35, 8" wide.

the ball joint doesn't even come close, plenty of room there.

Looks great Marc! If you wanted, you could add a 3mm spacer and be totally safe, depending how much room you have on the fender side.

That picture is deceiving, the line of sight of the camera is not right on the edge of the tire. There's lots of room there.

Sam

just out of curiousity... how much clearance do you have b/n the tire and TRE, Marc?

I am running into the same issue w/ my wheel/tire setup on my 4000 and the tire is just barely clearing the TRE... probably around 1/4". Pretty sure I'm going to need/want a little bit more clearance on that considering tire deflection on the track... thoughts?

Jretal wrote:just out of curiousity... how much clearance do you have b/n the tire and TRE, Marc?

I am running into the same issue w/ my wheel/tire setup on my 4000 and the tire is just barely clearing the TRE... probably around 1/4". Pretty sure I'm going to need/want a little bit more clearance on that considering tire deflection on the track... thoughts?

Mine comes very close, the closest point is the rubber on the tie rod end that bulges out, probably 1/16" from the tire sidewall.

On a tire with a very stiff sidewall you can get away with very little clearance. The other option if you have enough fender clearance is to put in a small spacer, pushing the rear face of the rim away from the suspension.

I am running into the same issue w/ my wheel/tire setup on my 4000 and the tire is just barely clearing the TRE... probably around 1/4". Pretty sure I'm going to need/want a little bit more clearance on that considering tire deflection on the track... thoughts?

Don't mean to jack here but as long as you can slide 2-3 sheets of paper between your tire and TRE you will be fine. That relationship stays fixed during driving. Any defelction you get on the tire will happen at the bottom, where rubber meets the road...as some commercial that just popped in my head says :-D

A small tip as well, on 2 piece struts, you have some adjustability in that area due to 2 bolts on the hub knuckle/carrier. I recently did some work on my suspension and after putting it all together my right side tire was rubbing on TRE and left was ok. Before this both were ok. I just loosened the 2 bolts and pulled the hub carrier out a bit - note that this will take away some of your negative camber so if you can run a spacer do that before giving yourself positive camber.

Tire rack sells 3mm spacers for like $12, but you have to call them, not on the website, I think.

The tie arm hit the tire before

Marc, how tall are those tires then??

Also, that tie rod end looks different. Double nut system as opposed to collar and one nut?? The reason I ask is just trying to judge how much were the arms moved in. Right now, from that picture, it looks like the TRE is almost maxed out....well, moved in all the way is what I mean.

a_CQ wrote:Don't mean to jack here but as long as you can slide 2-3 sheets of paper between your tire and TRE you will be fine. That relationship stays fixed during driving. Any defelction you get on the tire will happen at the bottom, where rubber meets the road...as some commercial that just popped in my head says :-D

:bullshits: :bullshits: :bullshits:

BS on what???

The top of the tire will not deflect anywhere near the amount of the bottom deflects.

a_CQ wrote:BS on what???

Everything you posted was bullshit.
I've had it happen to me. There was an 1/8th inch of clearance to the TRE.
With the car on the ground and wheel fully loaded. With just a few laps at the local off ramps the TRE cut into the tire enough I felt they were no longer safe. There are plenty of open wheel cock pit videos out there that show how much the tire moves in the tire during hard cornering.
And this isn't even getting into how much the rims them self deflect.

The bearings move the most (no really) and hence the whole wheel etc...

Thats why you have to ride the brakes a bit after a corner, or early in the next one. rotor moves so much teh brake pads get a big clearance pushed into them.

H

I've had it happen to me. There was an 1/8th inch of clearance to the TRE.
With the car on the ground and wheel fully loaded. With just a few laps at the local off ramps the TRE cut into the tire enough I felt they were no longer safe. There are plenty of open wheel cock pit videos out there that show how much the tire moves in the tire during hard cornering.
And this isn't even getting into how much the rims them self deflect.

Myke, if you had it happen doesn't mean it's a fact. Perhaps something was lose?

Find me a video showing top 180* section of the tire deflecting, please. yes, tires deflect a lot at the bottom, as I said, but not the top.

If wheels are to deflect then we really have a problem.

I run with 1/8" or less of gap on the track all the time, never had an issue.

But hey, everybody can do whatever they want. Your car, your call.

This was the first example in a quick search, you can see pretty clearly both the top and bottom coming back to there resting place after the turn.
In any case I never suggest to someone something that could potential cause a fatal accident.

http://www.youtube.com/watch?v=FUSZPMl5JsI

As this photo shows, it's clearly possible for the whole tire sidewall to deform, even if the only contact patch with sideforce going into it as at the bottom.


Sam

This was the first example in a quick search, you can see pretty clearly both the top and bottom coming back to there resting place after the turn.
In any case I never suggest to someone something that could potential cause a fatal accident.

http://www.youtube.com/watch?v=FUSZPMl5JsI

Myke, all I see here is bottom portion of tire deflecting. I don't know how/what do you see up top?? I do appreciate your reasoning though.

Sam, can you pin-point to what you are referring to?? Let's even forget that F1 cars are nothing like any street or even race cars out there....and especially their tires.

Either way, i won't beat this to death. All I know is if I can drive around without it rubbing I can do it anywhere, any time. Marc, continue on with your project :cheers:

Check out the left front tire on the car, it's pretty easy to see that deformation from the contact patch is not relieved around the entire circumference of the tire. You may be able to see the same thing here--it's just not enormous like the F1 pic :


Sam

I feel stupid cause I can't see it :bashtard:

SeStone wrote:Check out the left front tire on the car, it's pretty easy to see that deformation from the contact patch is not relieved around the entire circumference of the tire. You may be able to see the same thing here--it's just not enormous like the F1 pic :


Sam

i can not see what it looks like on the inside of the tire. that is what everyone was talking about, right? :wink:

well my solution was to take approx 1/4" wedge out of the steering arm and angle it in so it is COMPLETELY clear of the TRE.

I had about the same clearance as you, Marc, w/ a 12mm spacer and the steering arm at the original position. So I just did some trimming to give me a little 'comfort room'. I have seen how my tires deflect at the track under some extreme cornering, so I'd rather make sure that I have the space vs potentially rubbing through the tire and getting a blow out at track speeds

oh and sam, that pic of the F1 big enough? can't quite see it

Big thanks to Rob for helping me out (read: machined the whole damn thing ) with the CFM sleeve today, at this point I'm ready to bring the heads onto the flow bench and get some baseline numbers.

After I got home I started working on rebuilding the driveshaft. PSA for people who use the 034 bearing, DO NOT install the two curved washers, they will bind when the bearing is pressed all the way on.

I forgot how much of a PITA it is to put together u-joints. :-P

Hi marc

I ripped out ABS on my coupe quattro and cut the wires and then realized that the rear diff wiring is within the ABS harness. If I install the v8 combo rear diff inside my coupe quattro diff I will not need the wiring and the vacuum setup anymore correct?

Thanks
Josh

The tread surface can and does shift everywhere on the tire, not just at the bottom.

The whole point of radial tires is that the circumferential tread plies stay round instead of warping all over.

Plus, think about how much HEAT it would put into the tire if the tire was bending side to side a dozens of times per second. (Well, roughly a dozen times per second at highwayesque speeds) Speed rated tires get their speed ratings by having really stiff tread plies (amongst other things) to combat this squirming - so the whole thread surface will shift on the tire.

Rubbing is common enough on 1st gen RX-7s where the spring perch is at the height of the tire bulge. Even running 3/8" of clearance will result in the tire grinding a groove in its sidewall against the lowest coil on the spring, with nice grippy tires.

(of course if you run rims that are on the wide side of acceptable for your tire size, the tire will deflect a whole hell of a lot less!)