Dastrups Track Goblin #243 - 08 SS TC

[dastrups]

Yep. Plenty of close calls. Somehow it just isn’t enough to make you not want to ride. Can’t beat that feeling of a motorcycle.

Wow! 11psi. I’ll have to try that. Is that set cold?

I’ll have to try the R888 eventually.

 

[Rttoys]

We will call it cold and cold hot, basically hot. If that makes any sense. It’s hard to get heat in the tires because we are so light. When I do autocross, I start at 11f/15r. I usually have to dump air out of the rears to keep it at 15, but fronts don’t really move. After a few runs, I can dump some air and it stays the rest of the day. So basically, it’s my hot pressure.

 

[dastrups]

We will call it cold and cold hot, basically hot. If that makes any sense. It’s hard to get heat in the tires because we are so light. When I do autocross, I start at 11f/15r. I usually have to dump air out of the rears to keep it at 15, but fronts don’t really move. After a few runs, I can dump some air and it stays the rest of the day. So basically, it’s my hot pressure.

I see. That makes sense.

Are you running a different alignment setup than what is recommended by DF? Sorry, too many questions.

 

[JBINTX]

Russell was close to what I ran with the Toyo R1R. 12R/10F.
But every tire is different. My slicks now are at 20R/15F.

Most of us of decreased the camber to only about 0.5-0.7 or so. Especially with wide tires.
Justin Reed confirmed 1/8” toe in F/R is pretty good. I checked mine today and am sitting right there.

 

[Rttoys]

Ya. Way off from DF specs.

but…..there a lot of “setup” on the suspension to get where we are.

basically front camber is -.5ish
rear camber is -1.3 or so.
1/8 to 1/4 toe in.

there’s a ton more.

 

[OptimizePrime]

I second everything @Rttoys has said about the r888r's. It sounds weird but the tires have a stiff sidewall so you can run them down to 15psi without any issues. Once they are warm.... incredible

 

[Ross]

I have 400’s on the rear but have it on full soft (fully clicked out). I’m running a base sway bar. Would you change that?

When you say tuck in do you mean increase negative camber or buy wheels with less offset?

1. Well if your car is running well, I wouldn't change it, but since you have wheel hop when you panic brake, something needs to change. I am not sure of the exact diagnosis for your issue, but we are trying to problem solve here. I brought up the rear suspension as a possibility as I think it did play into my issue with hopping front wheels. My car was swaying (weight transferring) from the left to right side, causing my front wheels to take turns lifting off the road. The rear shocks weren't working properly, and replacing them helped stablize my vehicle.

Do you have issues keeping the rear connected to the road? Does your car want to fish tail when applying throttle? I know I struggled with these issues. I sprung my rear with light (300 lb/inch) springs, didn't use a rear sway bar, added a LSD differential, and got 100TW tires. Finally got the rear to connect to the road, and go.

2. I mean buy wheels with more offset, so the wheel goes over top of the king pin.
Get the king pin to point to the middle of your front wheel's contact patch on the road.
The green arrow in this picture is a line that goes thru the middle of the pivots for the front upright. That is your king pin. Ideally, you want the tire to rotate around the king pin. You want the same amount of tire road contact on both sides of the where king pin would contact the road when you extend the green arrow all the way down to the road.

I could be wrong, but your car looks like the contact patch is too wide for the king pins, like this go kart has:

Ideally the bolt (king pin) in this go kart should be in the middle of the white wheel, not sitting outside the wheel.

 

[dastrups]

The rear feels super planted actually. I almost don’t want to mess with it because it feels solid. The front is definitely in need of some help. I really do think just 1 inch more backspace on the same 10 in wheel should make a big difference. That will move the tire center in 1 inch and shorten that lever arm. Then I can try a 400 or even a 300 spring on the front and play with front alignment.

I turned my top a-arm heim joints out three full turns to reduce camber and it made the steering feel more sluggish. The ride quality felt a little more harsh too. Does reducing negative camber change the king pin axis and increase positive scrub radius?

 

[Ross]

Camber can change the contact patch of the tire, so that change should help you a little.
Maybe this article will help.

 

[Rttoys]

I turned my top a-arm heim joints out three full turns to reduce camber and it made the steering feel more sluggish. The ride quality felt a little more harsh too. Does reducing negative camber change the king pin axis and increase positive scrub radius?

Ya. You’ll have more contact area on the tire with less camber. I run -.5 on my front camber and like it, but I don’t have as wide of a tire as you do either.

I would also recommend turning the heims in whenever possible, to reduce leverage and stress. Instead of turning the top out, turn the bottom in.

 

[ATMironov]

The rear feels super planted actually. I almost don’t want to mess with it because it feels solid. The front is definitely in need of some help. I really do think just 1 inch more backspace on the same 10 in wheel should make a big difference. That will move the tire center in 1 inch and shorten that lever arm. Then I can try a 400 or even a 300 spring on the front and play with front alignment.

I turned my top a-arm heim joints out three full turns to reduce camber and it made the steering feel more sluggish. The ride quality felt a little more harsh too. Does reducing negative camber change the king pin axis and increase positive scrub radius?

I have a set of 17x9 22ET (5.9" Back Space?) wheels you are more than welcome to borrow to try it out.
I don't have tires on them yet and the bolt pattern is 5x110.
I would need them back in January or maybe February.

 

[dastrups]

I have a set of 17x9 22ET (5.9" Back Space?) wheels you are more than welcome to borrow to try it out.
I don't have tires on them yet and the bolt pattern is 5x110.
I would need them back in January or maybe February.

I appreciate that. I’m going to just order two for the front with less offset. They aren’t too pricey.

 

[dastrups]

Got my towing package in. Tows nicely. Probably a bit more than the towing capacity of the car but seems to do fine. We’ll have to test it at highway speeds.

 

[dastrups]

Finally made it out to the track for the goblins first little shakedown. The car was a blast to drive and handled well. A few things I need to sort out like my front end chatter under hard braking and installing this new shifter so that I can find 5th gear confidently. Also need to come up with a better catch can solution. Here is a video and some photos.

 

[OptimizePrime]

There's A LOT of debate about catch-cans and the best way to set it up on the TC. What's up with yours?

Great pictures, looks like you had a lot of fun!

 

[dastrups]

There's A LOT of debate about catch-cans and the best way to set it up on the TC. What's up with yours?

Great pictures, looks like you had a lot of fun!

So I was talking to Andrew here on the forum and he said there is a setup by powell motorsports that will drain the oil back into your oil pan. I don't know anything about that setup but I wanted to look into it. I would have a completely full catch can after just two sessions on my current setup.

 

[OptimizePrime]

So I was talking to Andrew here on the forum and he said there is a setup by powell motorsports that will drain the oil back into your oil pan. I don't know anything about that setup but I wanted to look into it. I would have a completely full catch can after just two sessions on my current setup.

Oooo have you completed a leakdown or compression test recently? Before you spend money on a powell setup (it's expensive for what it is) I'd recommend just confirming the engine is okay as that sounds like a lot of oil. If you're pressurizing the crankcase such that it's pushing a lot of oil through, there may be some underlying issue to overcome first (piston rings or ringlands causing blow-by).

Ideally you take the pcv in the intake manifold, bring it external and put a catch-can post pcv. flow would be intake manifold > PCV > catch-can > back into intake manifold. Powell's setup and the catch-cans are really a band-aid to try and lessen the coking on the valves but we can't really get away from it completely.

Did you feel comfortable at speed out there (+100mph) with the wing / diffuser ?

 

[Rauq]

Could you post that video without music? I'd love to play the whole thing in the background while I'm at work.

 

[dastrups]

Oooo have you completed a leakdown or compression test recently? Before you spend money on a powell setup (it's expensive for what it is) I'd recommend just confirming the engine is okay as that sounds like a lot of oil. If you're pressurizing the crankcase such that it's pushing a lot of oil through, there may be some underlying issue to overcome first (piston rings or ringlands causing blow-by).

Ideally you take the pcv in the intake manifold, bring it external and put a catch-can post pcv. flow would be intake manifold > PCV > catch-can > back into intake manifold. Powell's setup and the catch-cans are really a band-aid to try and lessen the coking on the valves but we can't really get away from it completely.

Did you feel comfortable at speed out there (+100mph) with the wing / diffuser ?

Man I sure hope the compression is okay. Its a brand new motor and I really followed the break-in recommendations closely. I wonder if my catch can is set up improperly. I will check.

 

[dastrups]

Could you post that video without music? I'd love to play the whole thing in the background while I'm at work.

I will try and do this sometime this week.