Subpage of MembersPage/MarcellGal/PowerAndTraction
K26-6/27 turbo, the K27 compressor looks like (cm scale):
Exhaust and turbo
We use the factory exhaust manifold, but custom 70 mm diameter exhaust (at least the exhaust is ALS compatible ;-)
A friend purchased [187 USD RS2 exhaust manifold] from [ebay]
- it's actually 187 + 100 USD with shipping to Eastern EU
- as you might expect, the weldings look good outside, not so perfect inside. But not very bad either
- friend will try to stick (bigger than K26/27) turbo on his manifold, without extra strengthening (for street use). I think that is a bad idea, the exhaust manifold will crack (sooner than later) due to heat and vibration.
- I would definitely strengthen: connecting to near engine-mountpoint (seems best: turbo is very close to engine mountpoint in the audi, 8..10cm: only watch some clearance for securing screws). Connecting to head is another option
Turbo (compressor side) upgraded
to K26/27 (appr 6xx EUR). Good for max appr 400HP. Minor compromise is that it is now an oil-only turbo (=> no watercooling: if I understand right, keeping watercooling would require some overpriced factory parts that just aint worth it).
The K26 turbo was upgraded by http://www.ahturbo.hu/ with instructions:
- to upgrade compressor side to K27 with rotor sizes 53mm/76mm
- turbine wheel dia=56mm, compressor dia=53mm (would be useless with turbine smaller than compressor).
- turbine outlet is 56mm diameter (the 6 in KKK numbering scheme). It's the clone of a proven setup (that worked well in an engine built by them earlier). Perfect for the street.
- turbine renewed (but housing kept)
- oil-only accepted (no water-cooling)
K26-6 turbine housing (cm scale):
- Kalske says: Remember that RS2 turbo is 48/54 which is good for about 360, you are getting 53/55 which will do 400++
- Nanassy said exactly the same !
- Kalske and jhwh say: the same turbine wheel goes into 3 different A/R housing, marked (in KKK numbering) 6,8 and 10. Higher nr gives more power (appr 45 HP each step), but boosts later (3000, 3500 and 4000 RPM, respectively).
- so turbine housing="8" is the best choice for this turbo. Stay away from 10. 6 is not optimal, but works. (and 6 might match the restricted exhaust manifold and factory charge-cooler and street-operation better than the other turbine housings)
- you should look for a cheap #8 house. On [ http://forums.rennlist.com/rennforums/forumdisplay.php?s=&forumid=72 rennlist] you can probably get a 8 housing next to free as many people upgrade. I contacted the guy (back than) but he did not reply.
- if you come over a good deal on one it should only be a minor mod, remove turbo, remove housing, bolt back on
- AFAIK KKK uses cm2 rating on turbines instead of A/R (on Garretts, and so on...). I guesstimate the 8cm2 turbine will provide a quick spool-up (maybe in the 2200-2800 rpm range on a 2.2l engine), which means big fun on street, and some restriction in the top-end power. -GergelyLezsak-
Wastegate - to be replaced ?
- after we fixed a small leak
- did a no-airfilter test
- with full (precooler) boost applied to wastegate top
- nothing (athmosphere) on wastegate bottom
max MAP was still only 199..205 kPa => Most likely the wastegate is broken (the diaphragm/membrane is broken?) and the spring is too weak to hold against the exhaust pressure (the area is quite big on this wastegate). If the wastegate membrane is broken, the 1 bar boost is about right (based on other's experience) for this audi factory wastegate.
- What should we do with the wastegate ?
- How can we make sure that is the problem ?
- apply some pressure (with compressor) on top and see if it leaks >
- should we use some mechanical stop (or much stiffer spring) as further test ?
- Does wastegate have to be pulled completely ?
- Or guts can be replaced without pulling the whole thing ?
The quattro car is fun with 200kPa, but we would like 270 .. 280 kPa MAP. otherwise the engine was a bit too expensive (for factory power).