Scca STX autocross build

[Cligedy]

Sorry for the radio silence, been crazy busy lately. Anyway, weekend before last was the first local event. We usually have great turnout for our first autox of the season, and this year was no exception, with almost 220 drivers. Pretty impressive, plus there were 5 FiST drivers.

Here are some takeaways -
I can't tell if it's a result of the cool temperatures (high 40s) or the narrow tires, but I was getting a lot of wheel spin, even when going relatively straight. Wider tires are definitely working their way up the to-do list. I've come to terms with my wheel options and will probably settle for a set of heavy 15?9 wheels. That would be later this season, or maybe next depending on $$$.

I was pretty surprised at how high I had set the front shock compression at the test and tune. Even though that didn't seem like an especially smooth surface, everything was stable and quiet. At this event, I made it to the second corner before I decided it was set too high. The front end was really skittering around mid-corner and pushing wide. I'll bring it down a few clicks before the next event.

The camber bolts seem to be nearly enough to use the full tread, not just the edge. Compared to the test and tune, even with longer, faster runs the tire temperature difference was only about 10? inside to out. Good to see. Still would like to see it be even, but I'll address that soon.

The e-diff still doesn't act like a diff, but I am a fan of how it pulls the car into sweepers. This is murder on the brakes. Just as an indicator of how active this is, after my first run, my right front wheel measured at 125?. After the second run, up to 165? and vy the third run the wheel was up to 185?. This is the wheel, not the brake rotor or caliper, because I was worried that my IR temp gun may not be able to read extremely high temperatures the brakes could reach. I've noticed before how much heat this puts into the system and I'm really hoping the LSD will minimize this.

When the dust settled, I picked up 3rd place in open STX behind a Mini S and a FRS. I put in a run that was fast enough for first, only to blow it by hitting the last cone on course. Grrrr.
https://youtu.be/BDHzqhXCWEE

Next comes the lsd install. While I'm in there I've got a catted 2JR downpipe. I bought it slightly used. It already had a fair bit of surface oxidation, even though it's supposed to be stainless. I've primed and given it a couple coats of VHT header paint. Hopefully this keeps it in good shape for the long term.

Should have more updates soon, trying to get the diff put in soon.

 

[M-Sport fan]

^^^That 2JR pipe might be 409 instead of 304 stainless.

(Do the 'magnet test' to tell.)

 

[Kazz]

How are we supposed to consider a review on autocross from a guy who still uses training wheels??

Seriously, great review! Keep us posted, please.

Nice run! Love the way you look in the side view at the finish and whisper, "dammit."

 

[M-Sport fan]

Next comes the lsd install. Should have more updates soon, trying to get the diff put in soon.

I WISH I could do this sooner than later

 

[Cligedy]

How are we supposed to consider a review on autocross from a guy who still uses training wheels??

Seriously, great review! Keep us posted, please.

Nice run! Love the way you look in the side view at the finish and whisper, "dammit."

I was pretty mad at myself after clipping that last cone. To make matters worse, on my next, final run I really tried to get right mentally and attack the course. I immediately overdid it and dead-center hit a cone in the first slalom.

Also, those aren't training wheels, those are for extra extreme stuntz you probably haven't even heard about.

Just in the name of prepping for the diff install, I went ahead and put the bearings on.

I have heard of the trick about putting the diff in the freezer and using a heat gun on the bearings, so I gave it a shot. The first bearing went on, no problem. I got it started with a rubber mallet and aluminum plate, then used the hydraulic press to finish up. For the second bearing, I put the diff back in the freezer and was a bit more efficient with heating and placing everything together. The bearing literally fell into place. It was so easy I was worried that the tolerances were off, but once temperatures equalized, it was seated securely. Things never go that easily for me, so a pretty good way to start work on the diff.

 

[Kazz]

That would make me worried about deep cold in the winter... perhaps not in NC, but...

 

[Cligedy]

Naah, there would never be a natural circumstance where the bearings are 150? and the diff is 20?, plus the whole thing is captured by the transaxle housing.

 

[Kazz]

True. Amazing what happens when I type without thinking!

 

[Cligedy]

Over the weekend I was able to install the M-Factory LSD, and a catted 2JR downpipe.

I spent about 3 hours prepping the car Friday night, jack up car, remove battery, intake, shifter cables etc. Got started again Saturday morning. By 1:30 the transmission was out of the car. By 4:45 the diff was in and the transmission was back together. By 8:30 the car was done, wheels down. A big job for sure but it went smoothly for the most part. Others have done a better job of install threads than I would do, but I'll add what caught me by surprise or were a headache.

I had a friend helping who is a Mercedes tech and brought some of his tools. Between the snap-on impact and the cordless ratchet, we probably saved a couple of hours. That impact was impressive, zipping off the axle nut without breaking a sweat. I've added a Milwaukee cordless ratchet to my toolbox and I can't say enough good about it. If you wrench regularly, it's a huge time saver.

Installing the downpipe was a huge pain, mostly because of the heat shields. The header heat shield was tucked in behind the turbo coolant lines. I broke one trying to get the thing out. Arrgh. That the replacement isn't made of shitty plastic tells me the original was not a great design. I got tired of pulling on the downpipe heat shield and eventually cut it off with a dremel. Penetrating oil was enough to get the downpipe bolts off without drama.

The transaxle isn't overly heavy, probably 65lbs, but it isn't balanced so handling it is difficult. The magnet had very little metal shavings on it, which is encouraging after 50k miles.

Even with a seal puller tool, the seals are very difficult to remove. Same for the bearing races. I reused the original shim as others have done.

One thing I did do differently than Rodmoe's build is that after removing the transaxle case bolts, we flipped it over. When we pulled the case off, the diff was on top and pulled right out. That way we didn't have to remove and replace the gearset. Easy peasy.

When bleeding the clutch, the bleed valve opens 180?. If you try to bleed the system with the valve open 170?, you'll get nowhere. Make sure to open it fully.

2 hose clamps and 4" of hose patched the coolant line, with the replacement arriving early Monday morning. A bent brake heat shield made for some terrifying metal-on-metal scraping sounds that you don't want to hear after opening the transmission. After crawling under the car, the shield was bent back in place by hand. Phew.

Having better tools and a professional on hand made the job move quicker than it probably would have, but there were no major hiccups. Being done in 1 full day of work is satisfying, and I'm glad this is behind me.

Next autocross is Saturday. Very much looking forward to putting the diff to the test.

 

[awwwww_shift]

Not sure if you followed the latest Fastrack, but there's a new STH class proposal... very interesting....

 

[M-Sport fan]

THANKS for that review!

I WISH that I could have a real tech with power tools helping me out, but since I do not, and would be working in a dusty, TINY garage (barely bigger than the FiST itself!), DIY for this necessary to me item is out of the question.

 

[AnimalMother]

Over the weekend I was able to install the M-Factory LSD... Very much looking forward to putting the diff to the test.

have you had a chance to drive it yet?

 

[Cligedy]

have you had a chance to drive it yet?

Yes I have, but only on the street. You can certainly tell that it's in there working. Tooling around town, no difference. Full throttle around a corner turn-in is much improved. Autocross this weekend will be the first real test. I'll give a longer write-up afterwards.

I will add on to what I mentioned in my last post. First thing Saturday morning I broke the coolant return line from the turbo. A light tugging broke the plastic in half. A short length of hose kept me on the road until the replacement came in.

The line starts as metal, off a banjo fitting on the turbo. The line then runs into a rubber hose, which then runs into plastic tubing before plugging into the expansion tank. 1 line, 3 different materials over a 3' overall length.
The replacement does away with the plastic length.

Much better design. Good to know that Ford makes improvements instead of just leaving well enough alone. If I ever need to get the heatshield off again, I'll just disconnect both coolant lines from the turbo. A little dripping coolant has to be better than the frustration I had getting the damn thing off.

Also I want to sing praises again for the cordless ratchet I was using. While not exactly cheap, if you wrench on cars regularly this should be a seriously considered addition to your toolbox. Such a great time saver.

I used one once and was sold completely.

 

[Cligedy]

Well, the first autox with the diff is in the books. There is no doubt this is a huge, worthwhile addition to the car. I overdrove the car on every run and still managed to take 1st in STX, but not by much. I was very impressed.

You have to really drive like a jackass to get the car out of shape, which I did. However instead of just plowing forward, the car still turned and only pushed a bit wide. There was none of the one-wheel-peel out of tight corners which will be a big help.

After my first run the wheel temperature was up to 114? this went up by about 10? per run, with a wheel temperature of 145? after my 4th and final run. Compare that to 185? after 3 runs at the last event without the diff. That tells me that the e-diff is much less active with the mechanical diff, which is expected. This makes me pretty comfortable that the rumors that the two don't play together are wrong. We can put to bed any nonsense that you have to disable the airbags (!) to have a mechanical differential in the FiST.

I was driving during the 1st run group in 50? weather and I still wasn't able to get much heat in the tires. I picked up only a few lbs of pressure across all of my runs. I still don't assume that I know the strengths/ weaknesses of the new Rival 1.5.

One thing that did stand out to me happened well after I was done driving. I was instructing a novice driver in a mk7 Gti. For a novice, he was a very good driver,and I got a good feeling for the balance of the Gti. It was very good. The lift throttle rotation he was getting felt fantastic. I'm trying to think back to before I started making changes to the car, and I'm pretty sure I've given up a meaningful amount of rotation in my car. I'll be looking into options to improve the liveliness of the rear end. I was already considering adding more rear rebound, but maybe rear air pressures will be enough. We'll have a plan in place by the next event.

I'll post video later when I'm not on mobile. Thanks for reading!

 

[Nightcrew13]

Yes I have, but only on the street. You can certainly tell that it's in there working. Tooling around town, no difference. Full throttle around a corner turn-in is much improved. Autocross this weekend will be the first real test. I'll give a longer write-up afterwards.

I will add on to what I mentioned in my last post. First thing Saturday morning I broke the coolant return line from the turbo. A light tugging broke the plastic in half. A short length of hose kept me on the road until the replacement came in.

The line starts as metal, off a banjo fitting on the turbo. The line then runs into a rubber hose, which then runs into plastic tubing before plugging into the expansion tank. 1 line, 3 different materials over a 3' overall length.
The replacement does away with the plastic length.

Much better design. Good to know that Ford makes improvements instead of just leaving well enough alone. If I ever need to get the heatshield off again, I'll just disconnect both coolant lines from the turbo. A little dripping coolant has to be better than the frustration I had getting the damn thing off.

Also I want to sing praises again for the cordless ratchet I was using. While not exactly cheap, if you wrench on cars regularly this should be a seriously considered addition to your toolbox. Such a great time saver.

I used one once and was sold completely.

How much for the replacement coolant line and part number? Might be smart to buy one for when I put in my x47....And also is that the M12 or M18 Milwaukee?

 

[Cligedy]

How much for the replacement coolant line and part number? Might be smart to buy one for when I put in my x47....And also is that the M12 or M18 Milwaukee?

I think the coolant line was only $12. The dealership said there were variants of the coolant line and needed my VIN to order it. It's labeled as an expansion tank line.

The ratchet is an M12.

 

[Nightcrew13]

I think the coolant line was only $12. The dealership said there were variants of the coolant line and needed my VIN to order it. It's labeled as an expansion tank line.

The ratchet is an M12.

Nice!
And cool to see the ratchet in M12; since I have a full set already. Burnt out my regular drill few years ago but I abused the crap out of it. And the impact drill only fits in so many spaces, so new ratchet it will be!

 

[Cligedy]

Nice!
And cool to see the ratchet in M12; since I have a full set already. Burnt out my regular drill few years ago but I abused the crap out of it. And the impact drill only fits in so many spaces, so new ratchet it will be!

It will only turn about 35 lb/ft so it won't break loose hard bolts, but you can use it like a regular ratchet to break it loose, then ziiip, it's off.

 

[M-Sport fan]

It will only turn about 35 lb/ft so it won't break loose hard bolts, but you can use it like a regular ratchet to break it loose, then ziiip, it's off.

I'd like a CORDED electric one with more reverse torque, since I cannot work on the car outside of the garage anyway (HOA rules ).

 

[Kazz]

Greatly appreciate the content and quality of these posts!