[Snowblind]

Originally Posted by rotis

Is swapping the diff really as easy as it looks? Unbolt the axles and driveshaft without removing them, and then just pull the (3?) diff bolts? Don't even drop the exhaust?

How do you remove the cooler lines? (I assume the A8 has the same diff cooler as the 6MT?)

Yup, it's that easy.

Cooler lines are retained with a C clips, pull the clips and they slide right out.

[TEEZYSS]

When are you hitting up the track?

[brdornon]

following

[Snowblind]

Long post;

I've been to the track twice since the swap, the first trip was down to Cecil MD on 9/20. E85 passes, 1800 DA and track prep was not optimal (or so I thought,
more on that in a bit) and no tune changes from earlier passes other than the differential input and the tire size change. Now, I was a little time crunched and could not get the shift rpm and mph to line up the day before track day (trans would not shift on time in ANY gear) ...so I was paddle shifting each pass. I banged the limiter on just about every pass (different gears/different passes) trying to achieve optimal shifts manually, they come up very fast (especially the 2-3) and sometimes it needed a lead on the shifts..other times it shifted instantly. Extremely traction limited, the car would not hook on any pass and I tried all variances too (off idle, 1k launch, 1.5k, roll-out etc on 20 psi) but spun each time without fail, I am surprised a little that the 60's are as good as they are considering it felt like I blew the tires off the car...ohh and the 1-2 shift, fuhgetaboutit, violently jerked the car almost out of the groove on multiple occasions. I left there feeling deflated but not defeated.

Most of my previous passes have been in the 1.68-1.7 range with a PB of 1.674 in negative DA (7.39 1/8- 11.46 1/4) so anything close in the shakedown passes was acceptable in my mind.


These passes below are from Atco on 9/26 with the exact same setup. Differences; I made two passes (unrecorded here) and again, no traction. Fraxum's buds were there ( the mid 10 sec Mustang gents) and recommended taking tire pressure down to 15...Jackpot...car hooked good and the 1-2 chirped, but planted. I still had the misfortune of not having enough time to mess with the shift points and I was paddle shifting each pass again at Atco. Difference #2 is that these are 93 pump gas passes with a mix of e (e54) also the DA was just a hair under 2k when I arrived.

Summary; My focus both times I went racing was on my 60' and only run it out if it felt good...I had a half dozen aborted runs each trip just trying different launches out and not concerning myself with a full pass.

I will line out the shift tables tomm and head back Tuesday so I dont have to manually shift the car. I have a full tank of e now also and not pump gas. My 2nd recorded pass here looks good until you see the 116 trap speed, I tried to run the car out in 5th gear but I tripped WELL before the line like a 'tard and stumbled the last 30 feet or so. So these are my results of what is going on so far, Tuesday's runs will tell me if I should continue this route or go back to the 2.77 and get a smaller tire.

I did not data log either of these events but I will this week. I believe 5th gear can run out to 120mph so ideally raising the rev limit to 6700 should give me more head room to go 123ish ?

[LibertyHill]

Originally Posted by Snowblind

I tried to run the car out in 5th gear but I tripped WELL before the line

Could a taller tire get you there?

[laynlo15]

I think a 28" tall tire with those gears would be just right

[Snowblind]

Originally Posted by LibertyHill

Could a taller tire get you there?

Good question

I forgot to mention that I have the 305/35/20 MT ET street, they are 28.7 inches tall.

[laynlo15]

your there

[KingLT1]

Raise the rev limiter?

[PRAY]

You will get it figured out man.

[Snowblind]

Originally Posted by laynlo15

your there

Thanks. I will be soon I hope. Like you, Boost may be calling my name instead of diving into the NA rabbit hole...it's wayy sexier, but is the most expensive.

Originally Posted by cooper1965

Dial in that trans tuning, that thing's going to run with that tire and gear, no doubt about it!!
What does the math equate too, 353's ?

Not sure what the ratio is but if you did the math then I'm good with that.

Originally Posted by KingLT1

Raise the rev limiter?

That is on deck brother.

Originally Posted by PRAY

You will get it figured out man.

I think I may have, heading back tonight with a closer to e85 content too. I think if the car shifts the way it should and the track prep is good, I feel optimistic that I may do well considering the limited mods I've done so far.

[PRAY]

Originally Posted by Snowblind

Thanks. I will be soon I hope. Like you, Boost may be calling my name instead of diving into the NA rabbit hole...it's wayy sexier, but is the most expensive.



Not sure what the ratio is but if you did the math then I'm good with that.



That is on deck brother.



I think I may have, heading back tonight with a closer to e85 content too. I think if the car shifts the way it should and the track prep is good, I feel optimistic that I may do well considering the limited mods I've done so far.

I still think you just need to get the shift mph reduced till you meet the desired rpm.

[KingLT1]

Originally Posted by PRAY

I still think you just need to get the shift mph reduced till you meet the desired rpm.

Agreed... I use a gear vs mph vs trans ratio calculator and figure out what mph I will be @ X rpm then set the shift mph so its 2-300 rpm lower then the commanded shift rpm. Also I always make sure that my part throttle shift mph is the same as the wot shift mph in the last 2 cells. This has eliminated any flare shifting or tagging the limiter in my stalled 60e.

[Snowblind]

I have some data logging to look over but I'm finally moving in the right direction.