some questions on AAZ conversion

[james 1978]

im nearly there with what i need to do, and the bits i need

has anyone used a g60 inlet manifold??
the little aaz ones dont seam like they would have good flow??
be easy to make an adapter to bolt up where the air flow unit should be with decint size for piping to intercooler!

anyone used a golf 8v cast turbo exhaust manifold?
the turbo mounts in center of manifold, would get better flow to turbo no??

where on the t25 would you say is best for intercooler and what size??

whats best size turbo for extra zoom zoom, but not 3 minute lag??

any thoughts on lightened flywheel??

[HarryMann]

Thoughts?

the little aaz ones dont seam like they would have good flow??

1) Unless you have a flow bench would you really know?
2) Even then simple flow benches don't fully simulate dynamic pulsing conditions.
3) Its a supercharged diesel, and once boosting even a little, everything changes

anyone used a golf 8v cast turbo exhaust manifold?

Not know... not heard, normal is either a JX, original AAz, or fabricated tubular one (a lot of work)

the turbo mounts in center of manifold, would get better flow to turbo no??

Ditto 1), 2), 3) and maybe a 4) as speed of sound much higher in exhaust gases..

Intercooler poition
Most put a small one in the rear quarter behind tailight with or without a fan
Many now use watercooled-intercoolers, and mount the rad in various places, up-front being best
I have a large watercooled-intercooler between the load bed and engine deck (~5" depth of my Doka.)
Currently uses two radiators one with fan psotioend variously at the back, but intend to fit a rad at front sometime
Flat underneath on a 2WD is not a bad position for a rad, if you don't want to run pipes right to front, with a diverter plate,
so air flows into rad face and out the top, with small gap betwen top face and floor, justin front of rear cross-member isn't a bad place

Don't forget the oil-cooler

Sounds as if you would like VWGTD forum..

[james 1978]

thanks
yeah ive been on gtd forum
asked a couple of questions on there and got no reply
so read some more and then some

some crazy and some basic ideas on there, by the time ive read so much, my head is full, and miss or forget little details!

my thinking was the inlet manif looks very small, so not a lot of area for flow, wasnt sure if on here anyone tryed anything like that
i have seen the one baxter and some american chaps have fabbed up to get better flow, was thinking of easyer alternative

also my thinking for zaust manif, was turbos get better results from equal length runs fromzaust outlets, so wondered if the centrally mounting maif would get any better results??

im going to buy a pipe bender, ebay have hydraulic ones which go up to 3" pipe for about 70 quid, then it would be play time

so much to think about

[HarryMann]

also my thinking for zaust manif, was turbos get better results from equal length runs fromzaust outlets, so wondered if the centrally mounting maif would get any better results??

Well, without wishing to pooh pooh ideas, even if it did (and I'm dubious of anything other than rigorous engineering studies, and the one you've chosen is extremely complex (quasi-steady pulsing flow dynamics in very hot gases ), there are so many other things that would make a noticeable difference for sure.

In other words, if 'all' the exhaust gas through the turbine within a reasonable distance of the exhaust ports, that's the main goal to transfer it's energy - and of course it does unless there's a leak (a good area to concentrate on - exhaust-manifold flange mating, and turbo-manifold flange face - both in Wiki)

For a 1.9 in moderate tune, it's generally thought the ideal exhaust pipe diameter is 2.5", so a system using that size with a straight through (absorption) silencer seems the best bet

[james 1978]

ok ill keep it simple then
stop thinking too much
and just go bigger turbo
fat 2.5" zaust
cooler
and thats about as much as practicalaly possible can be done you think??

i have boost pin sorted

what turbo are you running??

have you or anyone took a lateer aaz pump apart to lock out the springs on the fuel limiter thingy?

all the tuning tips for the pump on gtd forum seam to be about early pumps which look a lot different to mine!!

[HarryMann]

I'm running a Garret T2 (K14 equiv) but have a T3 (K24 equiv) that i might put on and have already modified the engine mounting (it's an inch longer with a larger inlet). 2.5" stainless exhaust (flex section just after the big curve round to face backwards)...

I would have thought all the Bosch pumps are the same inside, and think mine came off a Peugeot, with the larger drive shaft (20mm)

Yes, I've had the the top off and shimmed the main governor a bit, and the 'progression' givernor fractionally - not a job for the feint hearted, and essential to scribe up the throttle arm and spindle first! Lose that setting and it's anyone's guess. Getting all back together is a bit of a 'fiddle' to say the least. Can't say I noticed much difference but didn't go mad with the shimming nor add a stiffer main givernor spring. Depending on the main fuel-screw setting, it'll rev round to 4500 ish.

If I were you I'd concentrate in these areas,:

Instrumentation
OIl-cooling
Really effective Intercooling
Waste-gate by-pass + blocking the BOV
Fuelling levels
Maybe a proper Bosch pump, sounds like VW fitted all sorts of things to them

Roughly in that order.
What I am now considering, in the longer term, is a mechanically controlled VNT turbo setup which promises better fuel economy whilst retaining or even enhancing the performance.

It might be worth PM'ing Andy Simpson to see if he has any bits for sale that might save time and trouble (his 3" exhaust!!) or even what he recommends.

Cheers

[james 1978]

IT IS A BOSCH PUMP

funnily enough, andy simpson dropped off a jx manifold for me the other day, i got off ebay,
ill give him a try as he lives only a few miles down the rd from me now!

my car will rev to 5500 but backs off a bit

[HarryMann]

IT IS A BOSCH PUMP

OK, also ask Andy when you see him about Bosch pumps and Bosch pumps...

[andysimpson]

AAZ inlet manifold is fine even for big power increases. AAZ ex manifold does look like it will flow much better and it gets turbo well above oil level but causes problems with engine mount. LIghtened flywheel a good idea but don't bother going to the trouble with a standard JX one, use a passat one. Alot of power can be realeased from the pump with the right mods. AAZ turbo is fine upto 20psi which is a big imporvement over standard. A K24 turbo will get you upto 40psi but be ready for blown head gaskets bent con rods, broken blocks and turbos breaking, clutchs letting go. Just this year i am on 3 engine blows, 3 turbo's, couple of head gaskets. Don't get carried away unless you like fixing things, i know these engines inside out and like playing with them but it costs alot. It will also need lots of oil cooling.

[andysimpson]

IT IS A BOSCH PUMP

funnily enough, andy simpson dropped off a jx manifold for me the other day, i got off ebay,
ill give him a try as he lives only a few miles down the rd from me now!

my car will rev to 5500 but backs off a bit

There are 4 AAZ pump ranging from bad to sh2te.

[james 1978]

best using a jx pump then??

have you any usefull bits i can buy??

i might have to come over to watch you expertly blow the breasticles out of one one day

[HarryMann]

Nope, JX pump has a crap LDA I think...

[james 1978]

he said pug 306/406 pump best

now i need to know why, and how easy a swap it is
or watch him do it

[HarryMann]

Easy swap, it's just finding one... get the Pug sprocket too and nut, just in case, though cannot guaranatee its a match for the VW

from what I've seen in scrappies, might be easier to put your best burglars kit on and wander the streets at night looking for a 306 in a lonely spot

[james 1978]