Mach 1 as a dual purpose street-track car (DE)

[VictorH]

Dana Pants, I think the torque spec issue is a really good point. I have long standing habit of torquing and then paint marking my critical nuts and bolts. Just did that on all the big parts two weeks ago when I had the subframe out and bushing replacement. Still a good idea to check torque here and there and on the Z-06 guys at least one, was whatever eccentric that held his alignment it was NOT to proper torque spec, so point well taken.

To the fuel starvation issue. It's been discussed in the forums here but basically the passenger side of our cars has a vacuum fuel pick up, which when the tank gets (at least for me) below 3/8 or so, I would get starvation on longer sweeping left hand turns (you'd think that the fuel would be sloshing to the passenger side but for some reason it doesn't). For me it was turn 11 (pretty sure) at Barber which is a sweeping 80+ mph left turn. Symptoms were sudden engine miss. First you wonder, what's going on, but when it repeats on the next lap you know something with the fuel system is up. KPM which uses another fuel pump to pick up from that side was a complete fix for me. However, this was NEVER a problem on the street.

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[VictorH]

This was my subframe 2-3 weeks ago.

 

[RTR077]

Thanks @VictorH I am trying to understand if heat soak (Roush SC) and fuel starvation may feel the same - sudden loss of power. I've always assumed heat soak, but I do run banked tracks (Charlotte) so perhaps it fuel

 

[VictorH]

I've run Charlotte, it's fun, and even pre-KPM fuel module didn't have an trouble there. I would say the fuel starvation is really a complete engine cut for just a fraction of a second. Might have one or two of those in a row. It's not subtle at all and feels like it can't be good for the motor.

 

[derklink]

Great write-up, VictorH, and thank you for sharing your insights and experience with the community!

 

[VictorH]

Thanks for the compliment.
Back from alignment today. Lots of tire shops don't want to do non-stock spec alignments. Then booked with a local, private shop, and they were nice but said my car was too low and wouldn't make it up on their alignment rack, so recommended the Ford dealer and said their alignment guy was good and they they had a flush mount alignment rack, so that's where I ended up.

First alignment is from race shop at local track where I run. Worked nice and I liked the handling on track.

Second alignment is from the Ford dealer, who I provided the prior set up specifications. First one is metric (from the race shop) and Ford dealer is in degrees. Had to get another because of removal of rear subframe for some parts installation and lower rear control arm bearing. They looks to be fairly equivalent but I'm not sure if the front toe is OUT or IN. If it's really OUT by 0.05 degree (which seems like nothing) it seems that, that would not be within Ford spec, i.e. that box should be RED. Anyway, it feels fine on the road, we'll see how it is on the track. I would do this at home if I could but, there's just no way, with the tools I have, to reach this level of precision.

 

[RobZ71LM7]

I would want the rear toe redone. I would want 0.12-0.15 in each side or 0.24-0.30 total toe in. Having one near zero and other toe’d out is a no no on a rear wheel drive car.

 

[VictorH]

Well, I measured my total toe, front and back with a set of toe plates I have.
Remember, I wanted TOE out up front, what I got was 1/32" toe IN (wanted around 1/16" OUT). Not the end of the world but if you're "the alignment guy" and you need to keep my car "all day to get it right." Why can't I get what I asked for?
Rear toe, again, it's total, is 1/16" IN, which is probably just fine even though the read-out shows a few hundredths of a degree toe OUT on the right rear, I don't think it's going to be material.
Anyway, that's just the saga of having things done now-a-days. When you find a true craftsman, mechanic or person who really knows what he or she is doing, be happy, send them your business and whatever you can do to support them. Those people are getting more and more rare.

 

[Dana Pants]

Measure the car cold and measure the car as hot as you can make it. The alignment moves around. Also measure repeatedly over a few days. The real tolerances and repeatability are rarely discussed.

 

[murick]

Well, I measured my total toe, front and back with a set of toe plates I have.
Remember, I wanted TOE out up front, what I got was 1/32" toe IN (wanted around 1/16" OUT). Not the end of the world but if you're "the alignment guy" and you need to keep my car "all day to get it right." Why can't I get what I asked for?
Rear toe, again, it's total, is 1/16" IN, which is probably just fine even though the read-out shows a few hundredths of a degree toe OUT on the right rear, I don't think it's going to be material.
Anyway, that's just the saga of having things done now-a-days. When you find a true craftsman, mechanic or person who really knows what he or she is doing, be happy, send them your business and whatever you can do to support them. Those people are getting more and more rare.

The way I read your second report (from the Ford shop), your front toe is out (-0.04° and -0.02°). I do not know what should be the corresponding inch measurement, but if you measured toe-in instead, I guess there is something fishy.

In general, I believe the precision and reproducibility(!) of these measurement is overrated. The fact that they give you values to hundredth of degree does not mean it is a reproducible value. Few years ago, I have three consequent alignment measurements done (to resolve a dispute about an out of alignment front wheel) at three different Ford dealerships, and they differed in tenth of degree, not hundredth.

 

[VictorH]

Totally agree, the accuracy and precision of these alignment systems is probably greatly overstated.
Probably yes, 0.1 degree plus-minus is the level of accuracy, NOT 0.01 degree which is absolutely tiny.

Just got my replacement PFC rotors today, from Spain! No sets in the US, had to order from PCF Europe. These parts then sat in the Barcelona airport for 11 days before being loaded onto the airplane, crazy.
Anyway, they are here now and they're so nice it's almost a shame to install them.

 

[VictorH]

From my prior post, I can't get any rear rotors for the PFC hats that I have and it sounds like they are not likely to produce them again. Went searching for some options as I like the hat and spring retainer system, which has been reliable for me.
I was directed to a company called Pro-System which is a brake manufacturer and includes Alcon and their own brake calipers. I had a tour of the company and left one of my rear rotors with them.
They will custom machine a new pair of rotors to match your hat, balance and then bed them in with their own pad material on their brake dyno. The brake pads I use are evidently compatible with their bed-in process.
Was pretty cool to see the whole process. I'm going to put a new thread and more detail under the track section since it seems to be a better fit there.

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