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Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Thu Aug 23, 2012 1:50 am
by volksbugly
the td04 turbo you used does it have water and oil cooling? If so what did you do with the water side?

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Thu Aug 23, 2012 2:27 am
by Wally
volksbugly wrote:the td04 turbo you used does it have water and oil cooling? If so what did you do with the water side?
Yes, it does.
And no, I didn't connect the water side: I am very strict with regard to my car being air-cooled! :mrgreen: :lol:

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 1:14 am
by Wally
In 2013 the 'annual 1200 dyno-Challenge' continues, so I pulled the engine from under the workbench and will start preparing it some some upgrades 8)
Besides the plan to compound charge it (two turbos in line), the charge will blow through a pair of these just released bad boys :mrgreen:
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Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 1:17 am
by Kalle
Funny.. same bad boys are going on my little 1641ccm engine.

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 1:39 am
by Wally
Well, you know what they say about certain minds... :-))

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Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 1:45 am
by MarioVelotta
My god!

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 1:48 am
by Kalle
:D

They would of course flow better with a bellmouth/trumpet intake but I guess that will be up to the customer:

http://www.nsxprime.com/w/images/9/9e/% ... ._2006.pdf

-BB-

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 3:04 am
by AirSick
Where can i get a set of those intakes?

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 3:09 am
by Wally
Kalle, for N/A I think so too, but for turbo not sure. Good article btw, tnx!
AirSick wrote:Where can i get a set of those intakes?
I think Paul should have them ready shortly:
http://www.vwspeedshop.com/home.php

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 8:41 am
by volksbugly
crazy intake manifold! but I'm confused, is it a split manifold inside or just one big tube? is it 6 injectors or 3 injectors? ...I understand 1 injector for methanol, 1 for fuel, but what would the 3rd be for? If more fuel then why not just the appropriate fuel injector?

If its not a split manifold I don't think its optimal because you won't be able to run a true sequential setup.

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 9:32 am
by Wally
For all of those who are easily confused :lol:

viewtopic.php?f=65&t=141332&p=1139831#p1139831

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Nov 21, 2012 2:17 pm
by andy198712
poop the bed!!

and can you explain the turbo design?

have you thought about de stroking a CW 69mm crank?

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Thu Nov 22, 2012 5:27 am
by Wally
andy198712 wrote:poop the bed!!

and can you explain the turbo design?

have you thought about de stroking a CW 69mm crank?
Yes, having DPR destroke and CW a nice german stock crank is best. By far.
However, costs are always an issue and the stock (and relatively weak) 1200 64mm crank and stock rods have hold up to last years abuse, so an immediate action was not deemed neccesary.
Of course the (surface)treatment we gave them and the ARP bolts might have helped there too. You never can exactly tell untill something finally breaks.

The compund turbo design.
Well, basically its a small ('secondairy') turbo thats directly connected to the headers that spools fast and 'feeds' the big ('primairy') turbo.
It works like this: Once the small turbo hits wastegate pressure, the big turbo then is driven by both the exhaust of the small turbo AND more and more by the wastegate flow of the small turbo.

The benefit is that a small turbo on these very small (1200cc) engines is usually designed in such a way that they get inefficient after bigger boost figures then about 18-22 psi or pressure ratios (PR) of 2.1-2.5 .
In order to overcome this, you can feed the small turbo with an overpressure to begin with after they have reached that area and just set an efficient pressure ratio of say 2.0 while you vary the incoming air with the (amount of boost of the) big turbo. After all, a turbo is just a pressure ratio device. For instance, if you feed the small turbo (that makes a PR of 2.0) with say 0.5 bar of boost (PR of that is 1.5), the resulting boost the engine sees is 2x 1,5 = 3 bar PR, so the engine sees an efficient 2.0 bar of boost at an atmosferic pressure of 1 bar.

Therefore its two turbos in-line. One feeding the other. Lots of misconceptions exist with this set-up, but I think it has the right amount of simplicity combined with actual performance benefits to try out on a really small engine and see if we can get a nice torque curve coupled to really good top-end power.
I hope I explained it somewhat understandable?

My old Challenge engine from last year seemed the ideal candidate for this to try out this concept. The idea is nothing new in the turbo-world, but I think it has never been tried on an VW aircooled engine, so lets find out and pray the stock crank, rods and cast pistons survive all this. :roll:

Oh, I also got finally hold of MarioT and he is sending me a new Pauter cam! (I get easily bored :lol:)

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Thu Nov 22, 2012 12:03 pm
by andy198712
I'm with you, thanks wally! Don't modern vw's use this on some engines? Reduces turbo lag also doesn't it? Never heard of it on a ACVW, that's cool!!

Coating pistons? If you got a mate with a sandblasted and spray gun it an be quite cheap, same for DFL ...?
I'm waiting on a spray gun to do my bearings, I could do you a set if you wanted?

With the crank you don't know it's limits till you reach it I guess, I hope it goes well for you, breaking 200bhp would be crazy!!

Re: 1200 Turbo EFI build 'Challenger motor'

Posted: Wed Dec 12, 2012 8:22 am
by Wally
Just received the manifolds with throttles linkage and neat Pico Siemens injectors (thanks Paul!) and one of DonP's cams: its a K8E8, but now on a 106LC intake and a 114LC exhaust ("K8E0") 8)
Very curieus how well or wild this cam is or isn't.
According to my idea, this should be ~perfect, but I'll have to check that firstly of course :twisted:
Case is now split and parts scattered all over the place. You know how that works..