K26 vs K27 size...?

[gerard]

> I think You do not mind, if I put this to the list too.
> No personal things in the mail and maybe someone
> else might find this helpful, or if somebody thinks
> I am bullshitting, one can correct me ;)

Not a problem. I hit the reply, not reply-all.

> You have a 10v MC-1 and want no more than 250Hp.
> That is quite easy. ( not talking how to raise the boost
> etc. there are several ways, easiest is to fool WG and
> ECU with a regulator ). I did it to my MC2 engined
> 100 TQW this way:
>
> http://groups.yahoo.com/group/audifinns/files/10vboost/Drawing10vmc3.jpg
>
> More clever way is to modificate the ECU ( chip )

Have done this to the MAC-13A ECU in the car thanks to help from Scott
Mockry so many years ago when I first joined the list. I managed to find
a ECU that had been breathed upon by some sort of Porsche tuning shop
from upcountry. Copied the chip and still have the code around somewhere
(can't find it on my PC, must be on a backup CD somewhere), but I never
put it in the car at the time as the engine had oiling problems.

> Before I this year started two projects: big BMW Turbo
> and Audi 20v, I played a lot with MC 10Vs and found
> something: K-24 is much faster than K-26, but there is
> lots of backpressure at 17 Psi. K-26 makes heat soak
> after 15 Psi, bad effiency. K-24 has few millimeters bigger
> compressor than K-26, but I remember 6-7mm smaller
> turbine.
>
> What to do with Your setup? IMHO You have two good
> possibilities ( for 250 Hp ):
>
> 1. Buy a K-24, it is just enough for 250, good response,
> but torque decreases at the top.

If I'm looking for a K24 I'd need to get it from a S4 or something
similar over here. That just means money, really. There is a brand new
K26 sitting at the turbo shop. Some type-44 owner ordered it and then
didn't take it once he found a spare unit in a junkyard. Still sitting
there for something like $650 new. That would be the price of a new K24
as well, I guess, but I've already done about $100 in the rebuild of the
turbo which included a brand new turbine shaft.

> 2. Modify Your OE. 55/42 K-26 to a 55/48 one, not bad
> lag and better top end than with K-24

I will talk to the turbo shop folks tomorrow to see what front end they
have with that size or a little larger. Keith, the guy at the turbo
repair shop, has tried to convince me before to take a K27 front end for
my K26. Perhaps it is time I did, but would prefer find a junked K26
first just to see if some costs can be cut.

> If You are going to keep Your CIS and not making major
> modifications, the K-26/27 charger does not give You
> anything but lag. That hybrid is good for 250-320 range,
> or with special EM to +350.

CIS is sitting in a crate in the corner of the garage. Fuel injectors
and head inserts are on the way, fuel regulator already here, just need
to sort out some slog work before I order the LinkPlus ECU and other
bits.

> 2-piece EM is a little better than older, and with 55 turbine
> You will have quite nice ex. flow. 48mm compressor and
> MC´2´s single pass IC will make effiency of intake a lot better.
> With everything else ok. and 17 Psi boost there will be some
> ++230 Hp. ( 100/S4 AAN has ~ 230 Hp and car is heavier
> than Your 5000/200 T-44 :-))))

I already have the single pass IC, it was stock fitment. I was hoping to
improve on that as well, just takes time looking around for some decent
intercooler cores. Once again, they do nail one over here for things
like that, so I try and watch things like eBay.

G.