downsizing project

[my_medusa]

hi, i am chris from germany. a short text to understande that project. here in germany we have since 2009 a 1200cc dynochallenge, for that and in fact that fuel isn't cheap + david against goliath is allways fun a friend and i decided winter 2009 to build this 1192cc turbo engine. he become a happy dad in april so i will finish this engine now.
i think wally also will build such an tiny fun eingine

the engine facts:
1192cc
77mm polo g40 oversize pistons machined to 35,85mm compression hight 14,75cc chamber
64mm stock crank + lighter flywheel ballanced together with pulley and pressure plate
stock ballanced conrods with new bushings 470g
stock zylinders shortened
1300 DP heads with 34,5/33mm valves, ported, B-chamber and 21,2cc
1,3:1 rato rockers
outer springs with 104kg at 1" (from scat double springs)
merged changed
garrett gt 1752 turbo (changed a bit)
pop off
water intercooler
maybe waterinjection if needed
E85 fuel
injection AME or MS1Extra HR not set jet because AME is favorit but will get new mass flow sensor at the moment.
porsche cooling because it was here in the garage...haha

stock cam first. infact that a friend of mine has a simmilar engine with lower compression and pushes 1,6 bar aut of a k03 through a 34 pcib carb without any kind of intercooling ans revs over 6000RPM + an 2009 dynoed engine very simmilar to our hat peak at 6800rpm with stock cam and 1,25:1 rocker....we will see.

some pics:


















this all goes next into my rusty 60 bug wich has at the moment my 36 supercharged engine into it.
the new home


if somebody has some improvements in theorie or some ideas to make more and more power out of it let me now.
our goal is 150hp plus.

wishes
chris

[yvre]

Excellent...

if somebody has some improvements in theorie or some ideas to make more and more power out of it let me now.
our goal is 150hp plus.

Nitrous!

[my_medusa]

ok
engine tuning...not chemie tuning hehe. but someday maybe

[Steve Arndt]

I like the tight combustion chambers.

[Steve Arndt]

21cc chambers? Did you check your valve to piston clearance?

[WickedWagens]

I love both of your projects. It is cool to get so much power from those smaller motors.

[my_medusa]

thanks. alot.
with the chamber it is no problem. the stock cam with the 1,3:1 rockers just make around 10mm lift and this mild cam has at TDC (OT) not much lift. i remember we had 4-5mm room between piston and valve as we tested it.
we wanted go as far as possible away from stock head chamber.

for the gt1752 there is no compressormap from garrett directly, but we found this one.

some mini cooper guys spend alot of time into this turbocharger and made this map.
for the turbine we found nothing but it should be like a gt1548 maybe or a bit more?
i will messure it out at the weekend as good as i can

our exhaust is in my mind a bit big. we have 35mm inner diameter and it is made of an 1 1/2" merged with a 32mm innner diameter pipe direct befor the turbine.

i could build a hole new exhaust when this is poop but will test it first...what do the turbo experts think?

[vwgillybilly]

I'm watching this with interest - awesome!

[spoonerdtg]

I will be watching as well, Have seen your supercharged beetle on you tube that thing shifts.

[Wally]

I like it A LOT!

I agree, the exhaust primary seems a little big for a 1200, but thats based on gut-feeling and comparing.
I think that compressor map looks ~perfect for 200 hp goal. I preddict you can/should be able to do that.
The intake mani with tha cooling like that is sweet too. I am not sure I like that heads fly-cut that much because of strength, but who knows what these 77mm cylinders/1300 heads can do/hold?

Did you use 10mm head studs like it was original?

Maybe there is some extra in camchoice?
I would have done some things a bit differently, but so would everybody as we all think to know how to do it best haha!
For the most, powerwise that is, it should be pretty optimal with our current knowledge of turbocharging the 1200 I think.

Well done already mate!

[my_medusa]

I like it A LOT!

I agree, the exhaust primary seems a little big for a 1200, but thats based on gut-feeling and comparing.
I think that compressor map looks ~perfect for 200 hp goal. I preddict you can/should be able to do that.
The intake mani with tha cooling like that is sweet too. I am not sure I like that heads fly-cut that much because of strength, but who knows what these 77mm cylinders/1300 heads can do/hold?

Did you use 10mm head studs like it was original?

Maybe there is some extra in camchoice?
I would have done some things a bit differently, but so would everybody as we all think to know how to do it best haha!
For the most, powerwise that is, it should be pretty optimal with our current knowledge of turbocharging the 1200 I think.

Well done already mate!

thanks!
and well, i had it in my hands today... (the exhaust) and really think it is too big. there is something to do at the moment so i still have some time to think about it. and you are right, the map is very good for 200-230hp but fist we think 150ps goal is more than good but my personal goal was some day go close to the 200hp. but the exhaust, cam+++ we will see.
with the heads you are right, that is a thing that we will see. otherwise all my engines have 77mm bore and much less cooling. my 36er daily driver see up to 17psi all day long and i got the heads maximum 150°C after some 1/8 passes with 25-27° temperatue that day, so it is 50/50 thinking its to much and its on the save side. we test it!
and the heads have all fins on it. just the last fin is only half thick because the cylinder comes close.
head studs are 10mm right.

at the moment there will be no changings in camshaft, we decided it and now we give it a try.
after driving, testing and building on a friends 1200 turbo i have no problem with that cam.the power climbes up to over 6000rmp, he stoped befor peak was reached and he had just stock rockers on it.the small engine + the 35,5/32mm DP heads breath preatty differend than i thought....
tell us your ideas if you want, you have way more experiences it turbocharging with your projeks than we have.

here is a short video of my friends engine
1200cc, 35,5/32mm DP heads. the rest is stock. just a k03 turbo+pcib34 carb and horror just 6,7:1 compression (he forgot that the chamber cc are for 1300 via 69mm stroke) in this video he has no good timing and a rev limiter at 4700RPM. now with saab 9000 turbo vacuum tin he climbes earlier and faster up to 1,6 bar.
http://www.youtube.com/watch#!v=ioefn8N ... re=related

wishes chris

[my_medusa]

exhaust A/R is 0.56.
trim i will measure tomorrow.
seams a little big right?
it is out of a renault (master) 2.8 diesel.
there are also gt1752 with A/R 0.47 out of saab 2.0-2.3 turbo gasoline. better?

[my_medusa]

exhaust wheel= ~(44/37)mm so trim misz be ~72
so the hot side is very bug for our 1200cc right? this must be good for arround 1600cc. but i am fresh in turbosizing.
just to think about it...a gt15 exhaust possible on this charger?

[Wally]

exhaust wheel= ~(44/37)mm so trim misz be ~72
so the hot side is very bug for our 1200cc right? this must be good for arround 1600cc. but i am fresh in turbosizing.
just to think about it...a gt15 exhaust possible on this charger?

Yeah, the 2,8ltr diesel already gave an idea it would be to big on a 1200cc right?
Be carefull with diesel turbo's as they are not thermally intended for gasoline or so I heard

Not much to add as my only experience is larger engines...Myself I would try to make the engine a little stronger as its a type 1 , but that would of course also cost more.
Power wise we already gone through all options, heads, cam and turbo choice being the most important ones imo. There is nothing 'special' about either one of these parameters.
But you already knew that of course
After all is said and done, its still all 'in the combo' and in tuning the engine...can't tell you how to do that as it requires years of carefull planning

[my_medusa]

thought today a bit about it and will rework the exhaust and turbo.
all about the turbo i messured today:

kompressor
wheel: 52/38.5 trim 55 and 0.53 A/R

turbine
wheel: 44/37.5 trim 72 and 0.56 A/R

so it is to much for this one
with the temperatur i don't care we will run E85 and i have the waterinjection in the car so it will also become that. + its in first point a toy
so now the way to think about is:
gt1752 exhaust side from a saab turbo with 0.47 A/R or gt15 exhaust side with 0.35 A/R???
other option is a K03-029 turbo and keep the 150-160hp goal. i messure the exhaust ports next time and will go as low as possible with a new header.

with this exhaust turbine it will be good for a 1641cc-mild 2000cc???