1641cc twin scroll turbo

[Wally]

Torque is huge!
But I agree, it drops off fairly fast and hard.
Could be a number of things you mentioned. What was your cam again?
Pity you don;t have a boost line. If it would have shown the boost drops, its says something about the limit somewhere on your turbo, but now we don't know for sure. 'The turbo is good for xxx hp' doesn't work for me anymore either

[my_medusa]

the cam is just a cb cheater cam cb2280 ist something between stock and w100 to compare.
and i also think the turbo is good for xxx hp...i belive in aircooled its allways a 20-30 % less than that readings of flowcharts that is possible.
but the mini cooper people had with this turbo up to 220 hp on the wheels.
i will give it more rpm with the tcs-20 cam and we will see. i bet there is more in it and i belive in the 200hp and hope to come close to it. more rpm, less boost and torque.
the dyno was at a porsche dealer+service and time was close...i should had done a 1 bar pull instead the ~1,3 bar.
and damn no dataloging.
also first time the policeman stop me on the way to the dyno...what an a**h*l*...checked everything twice after i told him i have a dynoday. grrr

so the cam has just 222@ 0.05"
with less boost it would be more flat around 270nm but also would fall after 4000 rpm same in dred's build.

maybe its time for the second turbo

[Wally]

Its probably a bit of everything: small cam, small turbo and small-ish intake.
Look at Kalle's set-up: huge cam, huge turbo and good intake (and E85 LOL). Together it makes all the difference..

[my_medusa]

i will change step by step.
cam is first. than boost control, than E85...than intake.
than two twin scrolls but sec. turbo not that fast.end of 2013....befor it should give a gearbox upgrade. so first find out what the single turbo can do.
in the mini crowd the turbo hold 270nm in a good setup up to 5000 rpm

i will find out.

i mean right now torque peaks at 320nm with 1,1-1,2 bar for sure it does not hold that it also don't do that in the mini with chiptuning and co. dont forgett, i bought that turbo to build a 1192cc engine that should have 150 hp and torque down below...also that torque now could explaine the brocken conrod...in the 1641cc it has 335nm at 1,3 bar the same boost i had on the 1192cc that hp wise didn't felt less
haha 320nm/150hp at 3400 rpm....thats funny when i look at the graph.
in the sec. plot it had 335nm +154hp to the wheels at 3400rpm.

if i can get it close to 200 hp and hold 250nm at 5000rpm than goal is reached and i am happy.

[volksbugly]

I think your hitting the wall due to the nature of the twin croll. Your not putting enough exhaust gas into your high rpm range side of the exhaust housing. There are two things you could try, build your header so 3 cylinders go to the high rpm side, and one cylinder goes to the quick spool side, or buy a quick spool valve. I know I could be way off on that, its just a guess.

Hmm what size exhaust valves do you have?

btw if I did the math right thats 234 ft/lbs of torque ! awesome!

[my_medusa]

quick spool valve du just work on single scroll turboheaders

and i had one pull with 247 lb ft at about 1,3 bar and goal was to use about 1,5 bar. but thats too much torque...i want it more flat and longer. hopefully the cam + less boost can do this. but it's alot room to play with.


exhaust valve is 35mm

[Munchhausen]

exhaust valve is 35mm

I thought you are running stock size (35,5/32)

BTW: Comes to mind the other day, that if the EDIS coil is making 40KV, two sparkplug-gaps has to share it cause of its kind of wasted spark configuration. Means at worstcase just 20KV for each sparkplug. Thats not much. In reality the compressing cylinder will see more KVs cause of its higher resistans at the gap, but you never know what you really get. But that also would mean, that taking two EDIS coilpacks and connecting one sparkout of each coil to ground should lead to a very powerfull ignition then. ( think i will try that in the near future)

Still cant believe the 318nm@3430rpm

munch

[my_medusa]

exhaust valve is 35mm

I thought you are running stock size (35,5/32)

BTW: Comes to mind the other day, that if the EDIS coil is making 40KV, two sparkplug-gaps has to share it cause of its kind of wasted spark configuration. Means at worstcase just 20KV for each sparkplug. Thats not much. In reality the compressing cylinder will see more KVs cause of its higher resistans at the gap, but you never know what you really get. But that also would mean, that taking two EDIS coilpacks and connecting one sparkout of each coil to ground should lead to a very powerfull ignition then. ( think i will try that in the near future)

Still cant believe the 318nm@3430rpm

munch

than better read next time
34,6x33 was the 1192cc from that all the stuff is.
i only have new:
pistons/liners, case, conrods, pushrods, heads 041 (39/35) and lifters...all the rest is the former 1192cc engine. thats why the cam is also that small.

and the edis modul do all the dwell so the xxKV is just a bett. i will go direct coil +++ how i told next.
but more boost is not possible in this setup will not now how much it would do with the 1,5 bar i wanted to go. it makes to much peak torque für my gearbox...i want a little more hp and rpm.

[DRED]

hello,

great result ..massive torque, sure that close setting give close results ..you killed me yet..

according to wally, i think the intake design is really a problem on our setting...

this turbo is really a good turbo for hot-street, spool since low rpm and could blow up to 200hp..but.. the small 30mm (around 28/30mm inside from memory) mexi long-plenum and end-casting diameter would not allow to lower boost if you want to keep torque at high rpm in my point of view...i wouldn't be surprise that this torque curve appearance (high peak at 3000 and impressive decrease after) is closely linked to the intake design...despite i design my own plenum with more volume i kept the 30mm diameter for the 4 long tubbing and stock end casting...give a surprisingly similar torque curve design..)

a bigger cam can help, but not as far as a new intake design would, to my mind..

[madman4]

An easy way to improve the intake design, could be the new CB end casting.
Expensive but ready to bolt on.

http://www.cbperformance.com/catalog.asp?ProductID=1886

[MarioVelotta]

I have a set if you are interested, they are just sitting on my bench. I'm sure I could save you a bunch instead of buying form CB.

[my_medusa]

thanks mario i saw your pics and don't really like them.... i also have only 39mm valves and don't know if that small port that i need is to get in a good shape with that ones.
i will use idf ones when the time is come. and make plenums on them so i am also open to use air/air intercooler one day.


wishes
chris

[Passatman]

An easy way to improve the intake design, could be the new CB end casting.
Expensive but ready to bolt on.

http://www.cbperformance.com/catalog.asp?ProductID=1886

Is there any truth to the story that these end casting can put you in the 400HP range.

[my_medusa]

long time no see, but the restoration of my nsu prinz 4 take all my time. but right now it is still to cold to start finisching the body and paint it so i could start minimum the intake system...as long stage 2 will wait till end of the year.

i will still use the water air intercooler system but also add two air air intercooler and manifilds with plenums made of 44 idf ones + 660cc denso pico injectors and a fiat bravo 1.6 throttlebody... the intake should be good for the stage two that hopefully will get 250+ hp out of the 1641-1756cc with alot of low end torque.

here are the first pics.

[Poloeins]

Dynoday in Doesburg????