911mhawk

Today I finally got to drive my car after sitting since November when my bearing noise turned into a complete rebuild by Brian Copans. He did GT2RS main, Motorsport Cup LSD, steel synchros and all new gears and bearings. The thing already feels wonderful with very easy/smooth downshifting and no noise. No noticeable vibration at all through the shifter when cruising, even with Cup cables and RS engine mounts. Also got a LWFW and new clutch kit that feels great from Kevin at UMW. The most difficult part of this process is now upon me, keeping my foot out of the gas while the clutch and some new UMW ZC turbos break-in!

"02996ttx50

phenomenal list of well matched/sorted parts. break em in and let er rip. enjoy

Scott.

Nice work, I'm jealous of your lift at home and trans build (next on my list)! Any track time coming up? I'll hopefully be at the Ridge on 5/14 for test laps.

z06801

Your patience will be rewarded I was really careful breaking in my mine in and there still pulling hard 65,000 miles later

911mhawk

Never seen rain, mostly highway miles


See you there, I have a credit from last year because I didn't want to get the last mile out of the trans and parked it. I have not been there yet, SIR is only 15 minutes from my office so I make it there for lunch occasionally.

911mhawk

I have been meticulous so far too. Waited till the wife fell asleep last night so I could get another heat cycle on them.
I have only been able to press the throttle about 3/4 inch before boot starts and I need to get out of it. These things start spooling earrrrly.

Was happy I passed emissions with them yesterday too, now I can go 2 more years. Kevin's break-in tune worked fine with 100cel Miltek and like 50 miles on the car since parking it. Maybe the fresh o2 helped.

"02996ttx50

whats the "break in" on these zc's? i have older 16/24's but i swear their spool is nearly instantaneous for real. 1.3 comes on VERY quickly. i;m sure yours will act similarly.

but how long ya gotta wait?

powdrhound

If I recall, 1000 miles is what Kevin recommended before hammering them at the track. It's a combination of heat cycles and mileage to carefully allow the compressor wheels to wear their own pathway into the zero clearance coating on the compressor housing walls (the black coating seen below).

[url=https://flic.kr/p/FJGc1M]

"02996ttx50

wow.. mine have been "heat cycled" so many time its off the charts.. but I've never seen them glow red! HA!

sweet pic. i have a feeling my wheels aren't that sharp

911mhawk

I'm going to err on the safe side, I've already put over 420 miles on them since Monday morning. Has been difficult to stay in my office, or inside the house after dark. Every time they cool down, it's tempting to drive again. There is some track time available this weekend but I'm going to finish up the cooler pump and put in the GT2RS intercoolers before I go.

Kevin

The Zero clearance is a process. Those compressor wheels share nothing to stock K24's in design or efficiency. The compressor housing wheel inlet is 2.75"

mhawk should be able to tell by now how these boost vs K24's...

MonkeyKing

mhawk, what were the symptoms/conditions when you had the bearing noise? I'm trying to diagnose a noise on mine. Also, what are the advantages/disadvantages of the steel synchros? Thanks

911mhawk

Boost is nuts, at 40 in 2nd I go from 0 to 1 bar in 1000 rpm.
Also stays on boost way easier it seems on the freeway, did a couple short shift 3-4-5 pulls this evening and it made me giggle thinking this is just a break in file I'm not even standing on yet.

The difference is night and day with the lack of lag. The K24's with Kevin's tune hit hard, but 1000rpm later. The car feels very snappy for a turbo now. I've done several mods from UMW or at Kevin's recommendation and the car is transformed. GT2 gearing makes 1st gear useful and 2nd a lot better suited to launch from around town speeds. The 100 cel Milltek has no drone, and I passed emissions 40 miles into the new turbos on a break-in tune. Very pleased with the results, thank you Kevin!

I'll certainly be posting a couple more threads after some more miles.

powdrhound

At 4000 rpm I'm at +670 wtq and +500 whp with these turbos. This in on 91 octane. Hp continues to climb to 600 by 7500 rpm. The area under the curve is huge. This is with Cats and a fully emission compliant set up. You really need rods, fueling, and intake so Kevin can unleash these things. I'm pretty sure the basic k16/24s top out shy of 500hp on 91 but Kevin can clarify... I would not run a different set of turbos if they were given to me, unless Kevin built them of course...

911mhawk

You forgot to mention you're also at 5000ft! I remember driving my aunts old 4 door Corolla up Boulder canyon to Nederland and it was anemic to start, pathetic by the top. Your altitude sucks power quick.

I did Kevin's intake and fuel system, we discussed keeping the power below rod bending until I go completely off the edge of the earth here and open the case. This car already makes my big block muscle car feel slow at anything other than launch so I'm thinking I'll be satisfied with the power long enough to let my driving skills catch up.