Race Tracking Your Supra - Information exchange

[94boosted]

Just throwing it out there. I used to transport mine (had no choice in my dedicated track S2k). Then, in my MX5, I started just changing my tires when I got there, like a lot of other track guys. Monkey see ? monkey do ?. Fast forward to today, since she’s an extra car that I don’t daily, I stopped changing my tires and just drive there on my track tires. Luckily I’m only 90 miles to Sebring and 150 to Homestead.

I usually drive to all of my local events but the 1-2 a year I go to an event that's far away (~600 miles) I prefer to tow.

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[Eyelise]

And sure you already know this, you’ll have to buy camber plates or adjustable control arms to dial in additional camber up front.

So it sounds like the car is maxed out from the dealer. Any increase requires suspension components. I thought there might be a little left on the board.

 

[Eyelise]

Whatever it gives you ?

No adjustment in front. Rear has camber adjustment. Can easily get -2.5+ in the rear.

Ahh this is what I was looking for TY. -2.5 is not that bad.

 

[Eyelise]

Just received my sway bars from Eibach. I was surprised that the included directions did not mention buying new hardware nor were there any torque settings. The Cusco directions clearly stated all bolts and nuts need to be replaced and included the torque specs.

 

[razorlab]

Ahh this is what I was looking for TY. -2.5 is not that bad.

yea but you want more negative camber in front since it’s McPherson.

 

[kaj]

The location of my D-Rings on my trailer doesn't really allow me much of an option for how to strap the rear of car down... had no choice but to cross the rear straps. Worried that it's going to cause the rear alignment to be out tying it down like this, I didn't cinch them down overly tight, it was just a quick test tow to the local scale to set my tongue weight.

Any thoughts?

Having the rears pulling side to side that much doesn't do much to keep the car from rolling forward. They need to go front to back.
It looks like your car is too far back on the trailer. Is that where it's balanced? The trailer doesn't "wag" while going down the freeway?
Also, here's a quote from a rep at Mac's (tie downs) as food for thought:
"McLemore is a firm advocate of a straight pull, and he brings up some valid points. A strap achieves its maximum rating when pulled in as straight a line as possible, and any side-loads introduced reduce the theoretical capacity of the strap. If one strap fails with an X pattern, the remaining strap will have a tendency to pull the vehicle over to one side of the trailer, where it too can become loose due to the shorter distance. He also points out that most X patterns are the result of having improper tie-down locations or straps that are the wrong length. He points out that most of the time you see crossed straps because the anchor is too close to the vehicle or the straps are too long to work for a straight pull. Having the proper anchor placement and straps for the application is best. He also points out that crossed straps can abrade each other, shortening strap life. Still, even he acknowledges that crossing straps isn't wrong, it's just less right than a straight pull. It's also not a good idea to mix and match, i.e., cross one pair of straps and not the other."

 

[Eyelise]

yea but you want more negative camber in front since it’s McPherson.

Definitely I just haven't decided whether I want to do camber plates or LCAs. It's my daily and I have a track car. I might max out the rear go 275 square on OEM wheels and just remount the tires once.

 

[FLtrackdays]

Definitely I just haven't decided whether I want to do camber plates or LCAs. It's my daily and I have a track car. I might max out the rear go 275 square on OEM wheels and just remount the tires once.

I love having the flexibility on any sports car. Camber plates are the most popular way to do this & relatively inexpensive. My MX5 didn’t need it. But this one does. Go for it amigo. Sounds like you have track experience and will appreciate having that option.

 

[Eyelise]

I love having the flexibility on any sports car I might take on a track. If you track your other car, you should at least try this one on track. Camber plates are the most popular way to do this & relatively inexpensive. My .02 cents

I'll check out the camber plates. If it is not a major cost and I can do it I am not opposed. I am tracking the car this summer working on the driver. Back after a long hiatus. 4 track days so far. The dedicated track car is being rebuilt and won't be ready this season. Any plates you recommend?

 

[FLtrackdays]

I'll check out the camber plates. If it is not a major cost and I can do it I am not opposed. I am tracking the car this summer working on the driver. Back after a long hiatus. 4 track days so far. The dedicated track car is being rebuilt and won't be ready this season. Any plates you recommend?

I loved these:

https://1fastsupra.com/products/verus-front-camber-plate-assembly-mk5-toyota-supra

I have adjustable control arms now but these are easier for an alignment shop to adjust & served me well.

 

[razorlab]

Definitely I just haven't decided whether I want to do camber plates or LCAs. It's my daily and I have a track car. I might max out the rear go 275 square on OEM wheels and just remount the tires once.

The car will plow if you max out the rear negative camber and it's more than the front.

 

[94boosted]

Having the rears pulling side to side that much doesn't do much to keep the car from rolling forward. They need to go front to back.
It looks like your car is too far back on the trailer. Is that where it's balanced? The trailer doesn't "wag" while going down the freeway?
Also, here's a quote from a rep at Mac's (tie downs) as food for thought:
"McLemore is a firm advocate of a straight pull, and he brings up some valid points. A strap achieves its maximum rating when pulled in as straight a line as possible, and any side-loads introduced reduce the theoretical capacity of the strap. If one strap fails with an X pattern, the remaining strap will have a tendency to pull the vehicle over to one side of the trailer, where it too can become loose due to the shorter distance. He also points out that most X patterns are the result of having improper tie-down locations or straps that are the wrong length. He points out that most of the time you see crossed straps because the anchor is too close to the vehicle or the straps are too long to work for a straight pull. Having the proper anchor placement and straps for the application is best. He also points out that crossed straps can abrade each other, shortening strap life. Still, even he acknowledges that crossing straps isn't wrong, it's just less right than a straight pull. It's also not a good idea to mix and match, i.e., cross one pair of straps and not the other."

I think I'm going to pop out the jacking pads and use the slots in the frame with T-Hooks, it's how I tied down all my previous autocross/track cars for years. I'm just getting too much conflicting info on the best way to tie down using the wheels (cross vs. don't cross etc.) .

As for the car being too far back on the trailer, it may appear that way but it's dialed right in. I have a max 600lbs of tongue weight on my tow vehicles hitch receiver, which works out to 11.5% tongue weight of my trailer + car and that's exactly where I've got it. She seems to pull fine.

 

[Eyelise]

The car will plow if you max out the rear negative camber and it's more than the front.

Sure but hoping I could rebalance with the adjustable Eibachs. The idea is to max out contact patch/grip (tire wear) and adjust balance with sway bars. I am seriorusly thinking about the verus camber plates for up front though the install looks straight forward and price is not bad.

 

[razorlab]

Sure but hoping I could rebalance with the adjustable Eibachs. The idea is to max out contact patch/grip (tire wear) and adjust balance with sway bars. I am seriorusly thinking about the verus camber plates for up front though the install looks straight forward and price is not bad.

Unless I'm not understanding, you are thinking about it the wrong way.

The reason you want more negative camber in the front is because it is strut based, so as one side loads up and compresses, the negative camber reduces. An extreme example is if you have -2.2 at static height, when the suspension compresses and the arms articulate, you might lose negative camber and be at say, -1.6, now you are losing more of the contact patch, and thus, less grip. So, the more negative camber you have in the front, the less tire contact patch you lose as the suspension compresses in a corner.

Basically, you want the car to roll ONTO the contact patch and you do that with more static negative camber, as the car rolls into the contact patch, the suspension is compressing and you are losing negative camber at the same time.

Here is a great visual to illustrate the car rolling into more contact patch:

The rear on the Supra is a multi-link setup so you actually do not lose negative camber when the suspension articulates, in some instances, you actually get more. So you want to balance negative camber vs straight acceleration grip in the rear. If you have too much negative camber in the rear, and less contact patch, you will have less acceleration traction.

 

[Eyelise]

Unless I'm not understanding, you are thinking about it the wrong way.

The reason you want more negative camber in the front is because it is strut based, so as one side loads up and compresses, the negative camber reduces. An extreme example is if you have -2.2 at static height, when the suspension compresses and the arms articulate, you might lose negative camber and be at say, -1.6, now you are losing more of the contact patch, and thus, less grip. So, the more negative camber you have in the front, the less tire contact patch you lose as the suspension compresses in a corner.

Basically, you want the car to roll ONTO the contact patch and you do that with more static negative camber, as the car rolls into the contact patch, the suspension is compressing and you are losing negative camber at the same time.

Here is a great visual to illustrate the car rolling into more contact patch:

The rear on the Supra is a multi-link setup so you actually do not lose negative camber when the suspension articulates, in some instances, you actually get more. So you want to balance negative camber vs straight acceleration grip in the rear. If you have too much negative camber in the rear, and less contact patch, you will have less acceleration traction.

Nope that is correct you are maxing contact patch, grip and tire wear just as the illustration shows. The only thing missing is the fact that the tire is not a rigid structure as in the illustration suggests. The effect is more of a subtle thing where the downward force on the tire are changed by Camber to max the contact area and forces on it especially in cornering. The contact area is a dynamic thing. Check and you will seldom see a gap in reality like in the pic. Ok for illustration sake though. Depending on your application it is all a tradeoff. For circuit courses with lots of turns you want the camber. Looking at tire wear can tell a lot off the story. Where is the contact patch on the tire most of the time. In the worse case scenario you may only use half the tire and a bit of the sidewall. The sway bars effectively add compression on the weighted side and "lift the inside tire. Unclear if the overall grip is increased or reduced but can have a major effect on balance/handling.

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