AAN into Ur quattro, 400-450 Bhp Target

[diesel des]

Sounds like a 28 turbine of some description.

[DJones]

Interestingly I finally took mine apart today to fit the larger exhaust housing..

This gave me the chance to measure my wheel dimensions:

Compressor wheel - 53.1mm inducer / 71mm exducer.
Turbine wheel - 52mm / 56mm

This conflicts with your earlier post which referred to the dimensions of the MD357, the compressor wheel is identical to your old GT3071 but interestingly the turbine wheel is 3mm and 4mm smaller than what you believed the MD357 and GT3071 was..

This would certainly aid in the crazy low down aggression i have.

To top it all the housing i have is to big, if my measurements were as you previously pointed out it would probably of fitted.

I wonder if mine is an odd ball which is why it has response low down better than many people think it should.

Anyway i will talk to the turbo shop Monday to see what is the best way forward..

[diesel des]

Sounds like a plan.

[URquattroGus]

My plan was to check AFR and disconnect N75. Then not lean on it too much before it's mapped.

I'm hoping that the head work will help keep EGT's down too amongst other things... (not that I know what it runs at currently)

[diesel des]

Afr is one thing, but you could get ping and detonation with the better head. I would stick to low boost till mapped.

[URquattroGus]

Yes I am going to have it remapped eventually, whether I have standard cams or changed cams. I think I will have to wait just over a month or so until a certain someone is free.

In the interim and before mapping with the STD cams the plan was to use my innovate LM2 to log AFR's and check there is no danger with driving the car after just the head work, but no change in cams.

I'm itching to get the car back and enjoy it

[Jamo]

RS2 exhaust cam does not hurt low down like the 7a cam

However the RS2 cam does seem to induce surge especially on garrett turbos, I would stick with stock.

You can confirm this with Doug at MRC

[diesel des]

I think stock cams work best for torque which is what you want I think? Rs2 or 7a exhaust cam helps up top, but hurts down low.

[Jamo]

Are you having it remapped?

[URquattroGus]

One last Jitter before the head is fully back on, how about lobbing in an RS2 exhaust cam??

I have searched on the subject, but still unsure!

I understand that a few other items need to be changed to do this?

[diesel des]

Sexy guage. Will be interesting what delta p you find.

[URquattroGus]

Well, I managed to get a differential pressure guage from ebay, it's a BMF at 6" accross, but looks like a quality item and should be easy to read!

Should allow me to get some easier measurements of the pressure drop between the turbo and inlet.

Surely air velocity come into it too?

[newsh]

Awesome headwork, looks fantastic

[URquattroGus]

Thanks for looking anyway des.

I have bitten the bullet and ordered an Innovate LM2 wideband logger (basic kit version with ODB), inductive rpm pickup lead and one map sensor.

This should allow me to log AFR's, rpm and boost.

If I add a second map sensor this will allow me to measure the pressure drop and actually log it.

something like that anyway

[diesel des]

Good lookin head. Will be interesting so see what difference it makes. But I still think there is a restriction in your inlet or intercooler system. I couldn't find a diff gauge that would be suitable for testing, the ones I had were 3 bar diff.