Homer's 1990 240 redblock exorcism

Can't this year, maybe there will be room for a road trip in a year.

May have to make an excuse to go to KC then. Something about baseball and BBQ should convince my wife.

Homer said:

707 pressure plate and a new 850R disc. Based on the conservative sachs rating and the reduced area on the 850R disc it should be good for ~420 lb/ft

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What clutch did you run in the original build, the standard 850R? Did it slip on you?

It is my understanding the Sachs RACE clutch won't slip..... are you planning to target 400 lb-ft of torque?

Harlard said:

May have to make an excuse to go to KC then. Something about baseball and BBQ should convince my wife.

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Deal

DET17 said:

What clutch did you run in the original build, the standard 850R? Did it slip on you?

Understand the Sachs RACE clutch won't slip..... are you planning to target 400 lb-ft of torque?

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Yes I've been running the 850R PP and disc. After 25k miles the clutch started to slip at roughly 360 ft/lbs crank. The first slip happened when it was 10F out, I assume the extra torque sent it over the edge. I had to keep turning the boost down just below the slip threshold.

Understand what? I don't want to keep the boost turned down. That's why I bought the pressure plate and new disc.

What was the deal with the Sachs 707 Audi pressure plate? The dowel pin holes are in the same location as they are on the 850R pressure plate, but bolt holes are not? Or the other way around?

What about the disc thickness? Works as it is with the Volvo disc?

Wagner said:

What was the deal with the Sachs 707 Audi pressure plate? The dowel pin holes are in the same location as they are on the 850R pressure plate, but bolt holes are not? Or the other way around?

What about the disc thickness? Works as it is with the Volvo disc?

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None of the above, dowels are in a different spot and the bolt holes are slightly off too.
Disc thickness is the same, no shimming needed. I think that's the big thing (besides the extra clamping force)

Homer said:

Deal

Understand what? I don't want to keep the boost turned down. That's why I bought the pressure plate and new disc.

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That the race clutch doesn't slip..... with sane torque levels. Pardon the sloppy English, now fixed.

Actually 360 lb.ft for the slip point of the R is better than what I'd read of other users.... pretty good bite for a factory clutch.

Got the 707 clutch setup in this past weekend. Quite a bit firmer but the feedback is nice.

Since GCP now sells the previously NLA parts I took the opportunity to replace every bushing in the shift mechanism while I had the trans out.


20 years of oil exposure does hilarious things to rubber.


Cleaned out the trans tunnel. Previous steering rack made a mess of it.


Put a new trans mount in too.


Next weekend it's TURBO TYME

It's HAPPENING

What is going on with that transmission cross member? Is that an OEM piece?

mopar318 said:

What is going on with that transmission cross member? Is that an OEM piece?

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Just a modified M47 crossmember

Bump.

Karl Buchka said:

Bump.

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I heard he put a 15G on it.

propav8r said:

I heard he put a 15G on it.

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confirm.

Karl Buchka said:

Bump.

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a dump

propav8r said:

I heard he put a 15G on it.

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True

Quin said:

confirm.

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Confirmed.
Busy weekend. Swapped a 15g in saturday/sunday.


Never gave me any troubles but that's where you belong now.


So much more room for activities








Solution for the coolant feed. A 7/16-24 banjo bolt fits in where the block coolant drain petcock goes.


Had some dumb luck with the downpipe alignment. I was expecting to shorten the downpipe height. Nope!




Haven't done much stainless in a while so this ended up being my warmup. Bought some 0.045 filler rod, much easier to control compared to 1/16". Tried to not hurry through this project.


I had thought about cleaning up the entire top section of the downpipe out of vanity but that thought quickly disappeared after how long it took just to clean up the section around the weld.


IC piping didn't have to change much at all. Just had to add a boost reference port for the wastegate on the underside of the hot side IC pipe. I didn't want to drill my new compressor housing.


The coolant hard lines are from a Mazdaspeed 3. They do a nice job of clearing the oil feed and return and they're bent for the correct clocking on the CHRA.


I purchased an oil return tube for the last gen eclipse turbo from the mistu dealer. I wasn't sure what I would need to do for the return and those cars have a nice stainless corrugated flexy return. The return flanges are the same as well. I just ended up using the flange and welding it to my old return hard line. I finished Saturday thinking all was well but when i snugged all the bolts down Sunday morning my return tube ran in to an exhaust runner. Took a few hours of rework to fix that.


Changed the heat shield sleeving on the flex portion of the return tube and added some to the hard line.


After a bit of cussing and sweat, I got it all buttoned up.


First impressions and notes:

1. It's fantastically smooth in torque delivery
2. The car is much more enjoyable, it's not like the 2.0T in my A4 that spools at 1800 rpm but it has no issue making at least 13 psi before 3k rpm.
3. I turned the TPS vs boost DC ref scaling off this morning. Full boost at part throttle is weird and it reminded me why I turned it on in the first place. Turned it back on before I left work. I like treating the throttle pedal as a torque request device
4. The boost control (specifically the open loop DC curve) needs some work. It overshoots and oscillates by 5 psi in certain conditions and eventually damps out. No worries there, just laptop time.
5. I don't have to downshift on the highway. Lean on the throttle and full boost is there almost immediately. So is 95.
6. It's quiet, that holset was absurdly loud. The exhaust is a bit quieter too.
7. Prob could use some fueling adjustments in load sites vems has never seen!
8. No detonation
9. It transformed the car, no doubt about it.

It's a GTX3067R with a T3 .63 a/r hotside. Running it at 18-19 psi

Sounds like more or less the difference between 57 trim and GTX2860R to me as well: slightly weird/touchy closed loop control, 15 psi at 3000 RPM, and excellent efficiency at different pressure ratios...I have my boost targets scaled to throttle position.

Apparently the photos aren't working. I'll fix them shortly

Been playing with the idea of a new turbo for my car next year, it all sounds really good!

Yay, thanks for posting details. I'm excited to check it out in person, whenever the next opportunity presents itself. Boost vs. TPS sounds like a good thing in this case. Reducing effective throttle modulation range does not sound ideal for a street car.



I'm also really curious to see how much of the midrange torque curve is filled in. I'll dig up my old match simulation and see how close it was.

Fix your pics!

Harlard said:

Sounds like more or less the difference between 57 trim and GTX2860R to me as well: slightly weird/touchy closed loop control, 15 psi at 3000 RPM, and excellent efficiency at different pressure ratios...I have my boost targets scaled to throttle position.

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Most definitely

Stiggy Pop said:

Been playing with the idea of a new turbo for my car next year, it all sounds really good!

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Do it!

Duder said:

Yay, thanks for posting details. I'm excited to check it out in person, whenever the next opportunity presents itself. Boost vs. TPS sounds like a good thing in this case. Reducing effective throttle modulation range does not sound ideal for a street car.



I'm also really curious to see how much of the midrange torque curve is filled in. I'll dig up my old match simulation and see how close it was.

Fix your pics!

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Pics fixed!
Your help and guidance has been much appreciated.
I'm really curious to get it on a dyno. Not that it matters but for comparison sake and your own validation