ALFAGTV6.COM

[kevin]

Garth, maybe I got it wrong but I did not worry about my manifold design on my twin turbo as my GTV had way to much power for the drivetrain in it very inefficient state. I think mats was meaning it was just easier to turn boost up(as its cheaper) because you are limited to what you can put down. I am surprised you managed to keep your gearbox in one piece.. Put your box up front than go mad like the guys do here in there TT. (sub 4 sec o -100km) in legitimate road test. Otherwise you will be like me picking up shrapnel of my gearbox down my road.

[jamal555]

Anyways whats the magic number for transaxles to break under torque/hp?

I've heard of 320-340 hp and ~340tq?

i mean with hard drag launch and hard clutches... anyone had any experience with this?

[Duk]

Well, if we had a gearbox that could take the power a "perfect manifold" is nice, but I guess a log-design and some extra boost works fine for us...

Doesn't this belong to you Mats? http://www.youtube.com/watch?v=0ft7W_2PbYI.
It seams like a lot of effort and fortunate access to the sort of software that most of us only hear about, for someone with who has a 'she'll be right' attitude towards exhaust manifold design

[GarthW]

Well yes i may have been on the limit with the gearbox, but i never really abused it..much. I shifted gears smoothly and never really dumped the clutch, but yes your right, one day i'll be picking up the pieces unless i do something about it.

As for putting the box up front, i'm still not sure i want to do that...how will it handle with the box up front..? I suppose with the extra power it becomes irrelevant..? But would like to beef up the rear transaxel instead and see what i can do with it. Well will see what happens...

Jamal i'm not sure what the limit is, would depend on how the power comes on and who's driving i suppose, i just dont know..I've done afew hard launches... one time she just squatted hard and swallowed the 2 blocks to my driveway before i could say i need bigger brakes lol. But after 10,000kms of hard driving, i think i did notice the box wasnt feeling exactly as it was before..but still good, but yes its on the borderline..

[grant]

What does the 1.8T have that's better for boos than the NA nord engines?

I'm thinking about a low boost 2.0 liter for my Alfetta. Using stock pistons, 9.5:1 compression. Would be happy with 150-170hp if possible.

Any thoughts on this? Would probably have a friend build a log manifold.

So what am I missing with the non-turbo Alfa engine?

[Mats]

Well, if we had a gearbox that could take the power a "perfect manifold" is nice, but I guess a log-design and some extra boost works fine for us...

Doesn't this belong to you Mats? http://www.youtube.com/watch?v=0ft7W_2PbYI.
It seams like a lot of effort and fortunate access to the sort of software that most of us only hear about, for someone with who has a 'she'll be right' attitude towards exhaust manifold design

It is. But that is on the inlet side, you realize that I hope?
On the inlet side it is nice to keep volume down and when you do that you really need to keep your flow balanced between cylinders.
This was one of those "why not" things, The opportunity was there to test my design, how could I resist?
Made some small changes because of the first simulation results actually so it was worth it.

I also have pretty pictures of my projected exhaust manifold in another thread and yes, merge collector and lengths within 5mm. Probably not gonna give me any more power but why not? I'm not looking for an installation that fits the stock engine bay or such and this gave me some nice benefits besides being "theoretically optimized".
On a race engine where you spend 100% of your time over spool/boost threshold and 90% of the time over 5000rpm you need something that can take heat elongation and keep the cyl-cyl balance rather then something that will spool fast and have a low surface area.
A log manifold has a very small volume wich is the primary parameter for building boost quickly and less surface area means less hear radiation. May have issues with cracking though since it's very rigid.

[kevin]

Some pics of Fracos car in our series. I have posted before but its always interesting to see other running projects.

[grant]

I'm thinkin' stock compression, Euro cams, log manifold, t25, and 60mm exhaust piping, with a small intercooler up front... Mount injectors on the stock Spica intake runners if possible and use VEMS.

Anything obvious that I'm missing?

[Greg Gordon]

Grant: your plan seems reasonable to me, although I would probably swap out the head and intake plenum for an L-Jet unit. That will make things a lot easier.

Greg Gordon,
www.hiperformancestore.com

[grant]

Yeah Greg, I was thinking the same...maybe would be easier to drop in a good S3 engine. I'm wondering if I can utilize VVT to help torque down low, but I have no idea how the Alfa sytem works. All I know is, getting VVT to work on my 1.6 4AGE 20V increased torque tremendously from 2000 rpm up to 5000 rpm. Like 15% or more improvement.

All it does is advance the intake cam 30 degrees between 2200 rpm and 6300 rpm.

Is the Alfa system nearly that effective? Anyone know what it's operational modes are?



1 more question:
Are 1.8T log manifold hard to come by? I'm wondering if it would make more sense to import a 1.8t manifold, and change the flange if I have to to use a different turbo. I dunno, I have PLENTY of time before I start any of this.

[jamal555]

Alfa Variator works between 1000 and 3500 rpm... and it boosts torque between 2500 and 3200 rpm...at 3500 it goes back to normal timing...

It advances the valves 10 degrees between those rpm... and thats it...

1.8t engines are not as common in europe as u might think... the whole series was sold on just 3-4 markets and never made it to any significant numbers... u can get some parts for it from time to time but thats pretty rare... as they are highly valued in collectors as well as street racing crowd... and engines are hard to come by themselfs, TS is the common engine in europe u can get TS engine for 100e easy... just LE-Jet ECU for turbo goes for 200+ and the iginiton ECU EZ-201k is also very hard to come by... from time to time u have ppl upgrading their turbo engines and selling original stuff, ecu, wiring, manifolds... but thats rare...

[Jim K]

Rototest results of a 'bad' 1.8T:
One of the guys here in our 1.8T gang, went to map and measure his car on the Rototest dyno here. Particulars: Cosworth management, GT2876 snail, 10548...intake cam, front-mount IC and modified 75TS intake plenum with front-mounted 70mm throttle body, 70mm exhaust. Results in the table are with 1.6bar (23.5psi) boost. Torque is in kgm(ftlbs). I call this 'bad' because the snail is too big for this engine, as indicated by the lack of low end power. This is an example of wrong planning from the outset regarding the most important choice for a turbo engine. Measurement stopped at 6140rpm because of insufficient fuel flow, owing to very low pump voltage...Overall power is not bad, but the car certainly does not feel too 'alive' in the street.

RPM---- TORQUE--- WHEEL HP
3000---- 14.3 (103)---- 60
3500---- 17.8 (129)---- 87
4000---- 24.9 (180)---- 140
4500---- 37.9 (274)---- 238
5000---- 37.7 (272)---- 263
5500---- 36.1 (261)---- 277
6000---- 34 (246) ---- 285
6140---- 33.6 (243)---- 288

[jamal555]

greetings Jim,

Is that with t3 inlet on a log manifold or EL manifold?
And u are right, smaller turbine housing would be better... that 100 hp kick between 4k-4.5k rpm is crazy... you say it doesn't feel alive in the street? yes the power comes in late but it must be fun

[Jim K]

Modified TwinSpark intake manifold with the throttle body moved to the front, coupled to the std turbo manifold. Exhaust manifold is a fabricated short 'octopus' type, obviously much better than the oem one. Compression ratio is std (7.5:1).
Jim K.

[Mats]

Must say that looks promising for my build.

Discarded my block today though.
Good thing ikhad another one under the bench.