Cars look great and Thill is a great track for a turbo. Can't believe I have been driving it for near 25 years. I remember when it was only 1.9 miles and a few strips of asphalt and gravel for the pit

Motha F###a!!!

So the best laid plans with this car and its turbo have failed miserably twice. Turbo arrives the day before Emory Campout, goes in, albeit a really tight fit and...no one told us that the new K29 cold side compressor is larger than the original K27. For perspective, the original k27-7006 compressor has a 2" outlet. The new compressor is 2.5". Regardless, the existing uppipe solution was a no-go. Not to mention the interference of the outlet and the shroud will require some judicious persuading for clearance.

So frustrated.

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The joys of bolt on mods.

I've decided to sell this turbo. Would work great with a car that is more modded than mine. Wanting to keep the stock up pipe and bypass just make it too challenging.

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Sold the turbo. The new one is en route from Evergreen. Having some concerns that I'll be able to feed it enough fuel to keep the AFRs under 12. [emoji33]

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What did you order?

Custom 965 K27 7200 with a huge billet compressor wheel and #11 hot housing. Same setup as Chris Nielsen's which hits .8 BAR at 2000 RPM and blew 591 crank HP at the same pressure. Admittedly that car is an insane EFI build.

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Kenik la' Freak, I figured you were just going to run a hose from yer big ol' maw straight to the throttle body!

Man I just read the whole damn thread. Awesome story kenikh. And big ups for your persistence.
Hope it all comes good for you soon. The problem, as most of us have found, is you never stop fiddlin. And each time you do, you get a rats nest of new problems to solve. Knowing when to quit is a fine art I have not yet mastered.
Regards
Alan

Ha! So true.
I swore I was going to leave this car stock. The pile of performance parts I have been collecting says otherwise.

This was more of a while-you're-in-there deal. Same difference.

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OK everyone, finally time for a real update.

Got the new turbo installed without drama this AM. It's a 965 vintage K27-7200 with a big billet compressor wheel on a #11 hot housing. First some impressions, then a question for those in the know on CIS tuning.

IMPRESSIONS: the turbo is more responsive and linear than the old 7006. Spools about 500 RPM sooner, as well. For better or worse, the turbo "hit" is much less dramatic. The 7006 sent my mind into an altered state. This is much more predictable, but is less exciting and less likely to induce psychotropic hallucinations from excessive acceleration. Not sure how I feel about that...

MY QUESTION has to do with AFRs. This sucker is definitely blowing more air and much earlier. My AFRs from 2000 RPM until fuel dump at 4500 are lean, as in 13.5:1 lean. That's a full point higher than the old turbo.

As a reminder, I have a Leask WUR and delay solenoid set to 4500 RPM.

Once the fuel dump hits, the pendulum swings the other way: I'm pegged at 10:1 AFR from 4500, all the way to redline. The car as a result feels sluggish at fuel dump, where it should feel like it is taking off like a rocket ship.

So, my best guess is that I need to lean out the warm control pressure, fatten the idle mixture a few clicks to get it back up to 12.5 and perhaps move the dump RPM up a couple hundred RPM.

Thoughts?

Obligatory pics below.https://uploads.tapatalk-cdn.com/201...c6af70db69.jpg
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You need to raise the boost enrichment CP to lean out the AFR on boost. Push in the disk on the bottom of the wur a couple mm and check it again.

Excellent. Will do.

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You are lean before the Leask WUR dumps and too rich after. The way to control the too rich is raise the WP in the WUR. You may need to go as much as 0.5bar. This will make it even leaner before the dump. Two options, drop the rpm on the leask switch, or initially, by pass it completely and let the WUR run as per factory. This will tell you when you get too much fuel, and set the rpm switch to the point where it is just enough - eg AFR12.0
Before you lean the WUR off you probably need to sort the pre-dump leaness first. Then harden the WUR pressure up. May be a little bit of to-ing and fro-ing. You prob won't get it completely right first time.
Regards
Alan

This makes sense. Will hook up the gauges tomorrow and will adjust while running shooting for .5bar.

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Or use AIC-1 to control fuel without WUR boost/vacuum line. With AIC you could also control the boost (second map like thierry did) with a boost solenoid.

Ah, that old problem of pumping losses. It takes more energy to drive a larger compressor. With that same old tech turbine your exhaust backpressure has to rise to get that extra airflow.
Do you have a baseline of pressure differential across your engine?
HP = positive pressure differential over engine at a fixed manifold pressure.

Or switch to a FrankenCIS and eliminate all of this contraption. :D

^^^ STEEP SLOPE AHEAD!... Proceed with Caution :D