200hp 1200DP Turbo 'Challenger motor'

[andy198712]

Looks like a Porsche 356 top pulley.

Well spotted.

a ha! hows that work out? was thinking of going the same way if it would cool ok..... alot cheaper then other options!

is that a cb pump or other? if other what pickup are you running as i see a pipe heading under the engine?

sorry if this has already been covered, must have forgotten in the 11 odd pages

[Wally]

No, its not a CB pump Andy. Its a 'TP' (Thorsten Pieper) dry-sump pump (26mm/38mm gears). Routing is the same as a CB though (internal, stock pick-up location). The AN12 connection you see is the feed line.

The 356 pulley did just give that much more air so head temps were normal again. Stock top pulley doesn't work with a 135mm DS bottom pulley and street driving.

[andy198712]

Sorry when you own a TP pump, someone calling it a cb one is kinda insulting! Did you get it direct from him? I think I'll use his lifters on a build.

Cheers for the info, so the 356 pulley setup is working ok for you on street use?

Your using the flywheel for the crank trigger too right? Might look into that if you don't mind a bit of copying

How do you think the twin turbos will behave compared to the a single?

[Wally]

LOL! No, no insult taken as the CB dry-sump pump works very well too. I had the CB pump on my 914 2.0 engine in the VW412S I used daily and also Sandeep used it on his 2.0 T4 turbo for a quite a while. The small gears in the CB pump (21mm pressure) show us that the VW engine really doesn't need big gears as long as your bearing clearences are in order and oil supply is excellent and thats where dry-sumping stands out.

The 356 pulley made the ('too') small crank pulley (135mm) just 'workable', but borderline. A little more ratio is still better I feel.

No, I use the VWSpeedshop.co.uk pulley triggering set-up (behind the pulley). I modified the dry-sump sized crank pulley you see in the picture for it, as Speedshop themselves don't do this small of a pulley (135mm). They supply two sizes (original size, 171mm iirc and a 'power pulley', 145mm iirc), but not as small as to be used for a protruding dry-sump pump... so I modified my own

I can only hope how the two turbo's will act, namely that they broaden the torque band giving an ever climbing hp line, which will hopefully go over the 200hp mark this time. Maybe this super small engine might not see the full benefits of this turbo combination (small turbo should have been even smaller still for that), but it will be very interesting to see if it works like I hope/engineered it to be.

This is the 'secondary' (small) turbo just tacked in place. Lots of tubes to connect still...

[andy198712]

200bhp would be crazy! i'll pop you a pm on the crank trigger as i dont wanna hijack

[Wally]

200bhp would be crazy! i'll pop you a pm on the crank trigger as i dont wanna hijack

Not that crazy: my 2,2ltr type 4 turbo engine had over 210hp/ltr. I would need over 250hp from the 1200 to get in type 4 territory...

[andy198712]

200bhp would be crazy! i'll pop you a pm on the crank trigger as i dont wanna hijack

Not that crazy: my 2,2ltr type 4 turbo engine had over 210hp/ltr. I would need over 250hp from the 1200 to get in type 4 territory...

but give yourself some credit, given the 1200 is deemed the weak engine of the pack when pushed

250 is next year

[Wally]

Been working on the wastegate and downpipe tubes of the small turbo this weekend and made some progress I thought I'd share:

[andy198712]

it looks great but i still dont have my head around it... so the exhaust feeds the smaller turbo, and the cold side of that goes? and the hot side goes?

[Wally]

it looks great but i still dont have my head around it... so the exhaust feeds the smaller turbo, and the cold side of that goes? and the hot side goes?

The two exhaust pipes ('downpipe' or hot side and wastegate pipe) you see are from the small turbo (you also see that on ein the picture), which is located on the right side of the engine (in the direction of forward movement of the car). Those two both go to the (twinscroll) turbine of the big turbo, located at the other (left) side of the engine.
The big turbo's cold side feeds the small turbo's intake.
Only the big turbo has an air filter and normal downpipe into the free air.

Hope that helps?

[andy198712]

I'm with you, so how do they work together? Once that big turbo spools up won't it push too much air for the smaller turbine to cope with?

[Wally]

Once that big turbo spools up won't it push too much air for the smaller turbine to cope with?

Not really: the very fact the small one gets fed with pressurized air to begin with, makes it able to flow (much) more then it would if it sucked ambiant air.
Turbo's are pressure ratio devices: they mulitply the incoming air pressure. You just need to be able to cool the resulting higher temps which come with more boost, otherwise you could see the set-up as a huge compressor map extension of the small turbo.

[my_medusa]

hey walter, which one is the small turbo is it the one u used last year challenge? with the smaller (fist) exhaust side?
it is at the end a heavy but very interesting setup. 2 intercoolers, two turbos and alot of pipes, wastgates...what do you think round about the extra weight will be?
and how do you control the big wastegate? when is pressure of a adjustetd number between the big and the small turbocharger? do you think that will be seen as a step or hole or spike in the dyno graph when the wastegate opens?

wishes
chris

[Wally]

hey walter, which one is the small turbo is it the one u used last year challenge? with the smaller (fist) exhaust side?
it is at the end a heavy but very interesting setup. 2 intercoolers, two turbos and alot of pipes, wastgates...what do you think round about the extra weight will be?
and how do you control the big wastegate? when is pressure of a adjustetd number between the big and the small turbocharger? do you think that will be seen as a step or hole or spike in the dyno graph when the wastegate opens?

wishes
chris

Last year I finally used a TD05 turbo... The TD04L was used only in test runs and a test dynorun before the Challenge, but I will use the smaller TD04L as the small turbo in the compound set-up.
I think its about 15-20kg heavier with the extra parts.
The big wastegate will be just spring pressure, but this one (Syncronic) doesn't have a diafragm and has 3 openings so you can switch vacuum/pressure lines between ports to set a higher or lower boost pressure.
The big turbo's wastegate will be controlled by my electronic boost control (EBC) device. For that I will only install the smallest spring (6 or 7psi it was I believe) as boost multiplication goes very rapid.
From what I've gathered boost transition should be relatively smooth and turbo size and wastegate control would dictate where its at. Its all new for me too, so we'll just have to see where it goes.
I do know my rods and pistons are gonna hate me!

[andy198712]

blows my mind!
i guess the only way to improve your rods from where they are would be custom rods or maybe cyro treatment and custom pistons... but then its getting seriously big bucks ontop of the build and that seems to not be in keepings with your original plans if i'm right? ceramic coat the pistons & chambers?

i honestly think you'll have the most powerful STREET DRIVEN 1200 ever made surely! thats something very cool!!