1961 VW Beetle - Test Drive with Strong BOV Spring
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- Опубліковано 4 лют 2025
- In this video I put back the harder blow off valve springs and tune it to have 4.5 psi of boost at idle, and then about 10 psi when revving. Then we go for a drive! It is still stumbling a bit, but is definitely more promising. When you catch it not stumbling it is surprisingly strong power. I think this is going to eventually be much faster than the 8.22 seconds 0-60 - but we will see...
That was awesome when you got into the throttle on the second run 👍
It’s getting closer, but there are stumbles - and it is tricky to get the carbs tuned with the pressure hats on…
Hi, slight chatter is ignition missing caused by one of 2 things in my experience. Either too steep timing curve, however with yours set at 20max advance, this is unlikely. Or more likely is the spark is getting blown out on boost. Try a smaller spark plug gap. This was what it was on my draw through sc12 blower set up. I hope this helps. I'm interested in your blow through set up as with mine I have cruise issues being too rich. Do you have the same issue? This type of setup could be my answer if not. Cheers C
Yeah - so I took off the pressure hats and balanced the carbs with natural aspiration. They were way off. Then I did lean best idle on both at natural aspiration. It ran great with no boost. Then I put the pressure hats on and it ran well, but idled slower with the 4 lbs of idle boost. So I barely bumped up the idle speed screws symmetrically, and ran it for a while. But now the Air Fuel ratio is at 9.5 to 9.6. Way too rich. I think it is the turbo emulsion tubes - but I have 2.00 air jets and 1.35 main jets. So my next step is to swap in 2.10 air jets and 1.30 main jets and evaluate how it works. It is annoying that it takes a week for these new jets to arrive, so I am stuck waiting…
I was unable to get my supercharger to work. It showed signs of LOTS of boost power, but then the AMR500 delaminated and all these Teflon flakes got jammed into my dual carbs. This was the second AMR500, because the first one started grinding and was reaching 300 degrees on the pulley. I think my lesson is that I needed a more expensive centrifugal supercharger.
@@LarsonSplitBus- yes they are pretty cool but expensive. Since I last messaged you I tried an amr500 myself but again as a draw though ste up. It delaminated on me as well. I took it apart and the build quality is very poor compared to the sc12. I've gone back to the SC12 even though it means I have to use stand offs in the engine lid again. It gets warm not hot like the amr500 and has lots of miles on it without delaminating. I suppose you get what you pay for. Hoping for more VW adventures from you soon? Cheers
How do I tune this beast?
Yay you did it! Webers can have a flat spot even on a good day. Like I've heard, with dual Webers you will always have something to do on Sunday. Being out of sync can cause it. And then the transition between the idle and main circuits etc... But good job! If you could data log the AFR that would be interesting.
Yeah - it is close - but I don’t know how to proceed yet - I think I want to lean it out just a bit with 2.10 airs and 1.30 mains. Turbo emulsion tubes really do their job richening up on boost. Then a bit of timing experimentation…
By the way it seems to haul ass when all 4 cylinders are firing with no bogging
Yeah I could hear it making happy sounds@@LarsonSplitBus-
G'day,
Your slowly working this out.
It certainly hauls arse when you give it the boot.
Q. How much power do you think you've gained.
So thanks for sharing. I look forward to seeing what happens next.
✌️ Peace from Melbourne Australia.
Impossible to know yet - I need to tune it properly. I think I am figuring out how to do this - first balance and tune with naturally aspirated carbs. Then put carb hats back on - where I needed to slightly bump up the idle speed. Then it ran well, but Air Fuel ratio was 9.5 so I really need to swap in one size bigger air jet and one size smaller main jet and then re-evaluate my setup…
@LarsonSplitBus-
Thankyou for the extra information.
It really is trial and error with dual carburettors and more so with yours.
✌️ Peace.