Mythbuster: continuing project thread of my 1303 '75

[NO_H2O]

Nice work. Love the "wheels up" shot.

[Fast65]

having seen wallys car last weekend, i can say its an awesome car every run seamed easy, no fuss, no effort a very well put together car with a nice guy driving it

cheers andy

[Wally]

Thanks for that Andy! It was definately great finally meeting up with you guys. The photoshoot with all of us on the track at once was real fun too!
Definately hope your car is there next time. It sure sounds very promising what you've build so far.

The clutch I run now is not as effortlessly to operate with drag starts mind you. The wheelie was actually a real big bog, but the other way around, but don't tell anybody I said that

and welcome to the german car board

[Luismj]

Wally,

This really beautiful picture!
One question ... the clutch is noisy or works smoothly? What are you thinking now about the double kennedy clutch?
Thank you.

[Wally]

Originally Posted by Luismj

Wally,

One question ... the clutch is noisy or works smoothly? What are you thinking now about the double kennedy clutch?

That are two questions
Actually both: its noisy when depressing the pedal, but smooth on all other moments.
So far, only this kennedy double clutch holds the power and gives me a light (=street friendly in my book) pedal.

More surprising is the stock cast flywheel still holds. I would rather have a steel ('forged') flywheel, but only 200mm and 215 seems to be available (the 215 only very recently and is not in stock afaik).

[Wally]

Received this photo from Santa Pod's official track-side photographer. I really like this one.

[NO_H2O]

That is a nice one.

[vdubzack]

I think i found my new screen saver

[70Turbobug]

Originally Posted by vdubzack

I think i found my new screen saver

Hehe,yeah he does post some nice pics,doesn´t he? I have a dedicated folder aswell The updates and events that are posted are really great reading and inspiring - keep up the good work Wally!

[wrenchnride247]

Very nice pic!!

[Wally]

Tnx guys!

I seem to have reached some sort of goal already with the latest dyno run. A goal I had planned only after some major engine updates for the next year(s), but this one already took me there

This is corrected engine hp at the crank. Power at the wheels was 342.4 at 6150 rpm. BTW 500 Nm ~ 370 lbs.ft (also at the crank)


The remaining goal is a '10 second' car...As I am only an '11-second driver', that goal may take some more time and/or even more power...

[Humble]

Damn, those are some good numbers. What turbo are you using now? I'd like to clear 300whp with the addition of an intercooler.

[70Turbobug]

Congrats Wally! That is really awesome! That curve is amazing - actually it´s not much of a curve,more like a rocket start.. If I read the log correct,your max boost was 1,46 bar? What springs are you running now? Do you think that your valves were beginning to float? Richard sent me an interesting link on springs they use in drag bikes. http://www.psisprings.com/index.php?...ask=view&id=20.

[Sandeep]

Thanks for the detailed information and posting the log.

I have 370lb springs in the twin plug heads, but they will lose some pressure as they are run, estimating 10% so should end up at 330lbs. I told Len that I would not be boosting past 20psi though, or revving past 6500 rpm.

I based my turbine selection (Garret GT3076R, 0.63 hot side) on information provided mostly through Subaru boards, as the STI engine is 2457cc vs my 2413cc, and I had no aircooled data at the time. It is 4v vs 2v though as far as valves per cylinder is concerned, but I think the 2v per head should have better intake velocity.

The .63 is supposed to provide better spool but not as much top end as the .82, which is the next step up for the Garret GT3076R.

I was looking at an honest 300 FWHP motor, not stressed but living a comfortable life, but it looks like 350-375 FWHP should be more realistinc.

Thanks for all of the information, your motor build has been very educational and inspirational and I hope to be able to join your ranks in the coming months.

Sandeep

[Wally]

Originally Posted by 70Turbobug

If I read the log correct,your max boost was 1,46 bar?

Not really: that point was just where the cursor was at that moment. More random therefore. Boost was about 1.0 bar at 4K, then climbing further to just over 1.7 bar at around 5K, then tapering to 1,5 at 6K and further down to 1,4 bar at 7K.
On the road, in 4th, 1 bar is reached at 3600 rpm if its not too hot outside.
Just follow the horizontal lines on the y-axis at the right. The scale is there. If you can read plots, it shouldn't be too hard to see what is reached when

What springs are you running now? Do you think that your valves were beginning to float?

Originally Posted by Wally;

The ripple after 6200 rpm is valve starting to bounce of the seat imo...

I use the Berg dual springs with Ti retainers. I will try to install my CB650's over winter. That will sort that out.

@Sandeep: I think every motor is different and maybe I have restrictions elsewhere, but boost is tapering despite my EBC set at closed-loop... so I suspect my 8cm² turbine (~0,63-ish I think) is just too small for these kind of hp. My back pressure readings kinda confimed this imo.
For an even bigger engine like your comming 2413cc, I would surely get the 0,82 A/R if you had free choice. You may loose some spool as opposed to the 0,63, but you already got that covered by the 200cc's more you have over mine...
I also looked heavily at what Subaru owners use (hence my DOM3 I got off a us Suby owner) and this combined with my current experience, I would surely get the 82 for your 2413cc. Our engines are just more responsive by themselves somehow I think.
You don't want to know what my next turbo/turbine size will be...