V1 Stretch’s ext. track goblin #386 SS/TC

[Stretch2126]

Just a quick checklist.
Adjust prop valve till the rears lock first then back it off a tad so fronts lock first. you get it just right and it’s an almost simultaneous with the front ahead of the rear.
flush is always good, especially if running a lot of track/autocross
alignment could be an issue
at autocross my fronts are 2 clicks from max, but I turn them way down for street and don’t have shake. Weird.

ya. His are the floating rotors. the few of us that have them are having several problems with them because our cars are not modified exactly like his. I got a bad shake, but have corrected it (kind of my fault). They are very aggressive, but tons of stopping power and loss of weight, which is all I was after. Now trying to dial it in better, which is posing a different challenge. Autocross was …….interesting for me yesterday to say the least

I was running 12-14 from soft up front with mine. Any more and it would push too much. This is also running a7s on new asphalt so it was sticky

 

[Rttoys]

Those are the tires I want to switch to when my Toyo’s wear out. Ross and JBinTX are on slicks, so I wouldn’t think they are too sticky.

 

[Stretch2126]

After changing all of the rod ends up front the car still rattles on hard brake and clutch gets weak at high rpm. Just did a fluid flush so it shouldn’t be that. Anybody ever have to replace a rack and pinion? If I lift the front off the ground and grab the front wheel and turn it, there seems to be a slight “numb” spot or loose spot in the center. As for the clutch I wonder if the feed line from the reservoir is collapsing or something past the master cylinder.

 

[Gtstorey]

Weak clutch is rarely on the hydraulic side since pressure releases the clutch. It would have to be holding pressure when off the pedal, which is rare but not impossible.

Racks can wear and can be damaged in crashes also.

 

[Stretch2126]

Weak clutch is rarely on the hydraulic side since pressure releases the clutch. It would have to be holding pressure when off the pedal, which is rare but not impossible.

Racks can wear and can be damaged in crashes also.

Yeah I believe the rack could be done. Still drives straight it’s only under panic/race braking. I meant the clutch pedal is weak my bad lol. The pedal goes to the floor easy and doesn’t like to disengage. The physical clutch is ok, the pedal limps out.

 

[Markm]

Yeah I believe the rack could be done. Still drives straight it’s only under panic/race braking. I meant the clutch pedal is weak my bad lol. The pedal goes to the floor easy and doesn’t like to disengage. The physical clutch is ok, the pedal limps out.

Most of the steering racks I replaced in the cobalts that made noise were loose on the passenger side, you could grab the inner tie rod close to the dust boot and move it up and down roughly 1/8-3/16”. The intermediate steering shafts I replaced a boat load of those for knocking noise too but that you could try to grease then exercise it a couple times and see if it helps before replacing it.

 

[Gtstorey]

O

Yeah I believe the rack could be done. Still drives straight it’s only under panic/race braking. I meant the clutch pedal is weak my bad lol. The pedal goes to the floor easy and doesn’t like to disengage. The physical clutch is ok, the pedal limps out.

How are you bleeding it?

But that is usually a problem with master cylinder or the mechanics of the pedal.

 

[Stretch2126]

I’ll have to check the shafts on the rack. It’s pretty violent shake once it gets the oscillation.
as for the clutch I have someone slowly pump it like 10 times. Then I crack open the bleeder and push it to floor. Tighten bleeder then snap pedal back up. Not sure how the other versions are but the LNF pedal has a spring that helps it stay all the way in or out on a pivot.

 

[Rttoys]

So you are getting the Ross front brake shake?

 

[Stretch2126]

So you are getting the Ross front brake shake?

It’s very similar to that. Thing is I have the full frame already, hubs are tight, and it didn’t always do it. Caster angles are nearly identical and the car drives fine other than in that case. I can post the video clip I have but it might have to be scrubbed down to see the shake.

 

[Stretch2126]

Here’s the video

 

[Gtstorey]

I don't remember Ross ever speculating that his might be a rack issue so it doesn't really sound like the same issue.

 

[KSLunsfo]

Is it a wheel hop you're experiencing under hard-ish braking? What tire pressure are you running?

If it's the same issue, I was experiencing a harsh wheel hop under hard braking until I dropped front tire pressure down to ~15 or so. (Was really only running a higher pressure to keep the dummy light off as I was only doing casual street driving). Discussion of that in the link below.

http://dfkitcar.com/forum/index.php?threads/add-on-brake-proportioning-valve.2498/post-94250

 

[Rttoys]

I know i keep talking about the prop valve, but is it adjust where the fronts just barely lock before rear? I set mine by getting the rears to lock first, then back off just a tad so the it’s almost a simultaneous lock just barely starting with front. With the JR setup this was a huge callange to get right, but when it wasn’t, it did just like your video. I wouldn’t rule out the rack, though. I’m sure mine needs a rebuild here before long. It has a small bump too, just it’s an annoyance, not a problem, at least for now.

 

[Stretch2126]

I know i keep talking about the prop valve, but is it adjust where the fronts just barely lock before rear? I set mine by getting the rears to lock first, then back off just a tad so the it’s almost a simultaneous lock just barely starting with front. With the JR setup this was a huge callange to get right, but when it wasn’t, it did just like your video. I wouldn’t rule out the rack, though. I’m sure mine needs a rebuild here before long. It has a small bump too, just it’s an annoyance, not a problem, at least for now.

Yeah when I have it off balance they just lock up and slide front or back. If it’s biting hard it will wiggle. Rack could have 145x miles on it if it was never replaced before me.

 

[Stretch2126]

Ran the car on the dyno today with the Zfr and a modified version of the zzp goblin intake. I added a piece of straight 3 inch to help give the maf room for better flow. Best run made 350whp but even better the power curve is fantastic compared to what I had tuning the ko4. Still sorting out some maf issues and closing up plug gaps. Either spark blowout and/or coils failing was giving a little bit of missing up top.

 

[Rttoys]

Dang. That’s awesome

 

[Stretch2126]

Valve cleaning time finally. Had another PCV valve go out I think in the engine. The first one was definitely bad cause I could blow air both ways. This time I can’t but it had the same symptoms of pushing oil thru the turbo seals. Compression is still good and plugs look good. No misfires or anything. I think some gunk got in it or the meth injection doesn’t agree with the seals.
Anyways, I’m plugging the intake and routing an external check valve thru a catch can sorta like powells v3 setup and cleaning my valves while I wait. Didn’t realize how gummed up the runners were until it was caking up the brush. I’m using gdi intake valve cleaner and an assortment of brushes and air. The black marks you can see on the clean side isn’t the gummy stuff but leftover dissolved liquidI just couldn’t reach. It splatters when hit with air.

 

[Stretch2126]

Still working on that similar issue that Ross had a while back (hard braking wheel hop). Tried some additional bars to stop what seemed like framed flex but it looks like mine is from elsewhere. Tried different wheels with 22mm offset at 18x9.5 and the problem still persists. Hubs still feel tight and rod ends are fairly new. Going to put new outer tie rods on but the steering all feels tight still. When turning the wheel on the ground you can see the rack move slightly from the holes in the rack and bolt clearance but I don’t think that slight movement would do it. Later on this week I might search for a cracked weld possibly on a lift but I haven’t seen on yet.

 

[Rttoys]

Are you running stock brakes?
edit:
never mind. I looked back in the trad to see you are. Odd it‘s shaking.