EA81 supercharger revamp by Tweety

Tweety · Post by **Tweety** » Sun Feb 08, 2015 6:48 pm

We took tweety for a ride today to Yea wetlands park. I owned a home opposite the park in the early 1990's.

Tweety, Deb, me, Rosie and the Waeco CF-18 fridge that I swear by. Best buy I've made ever.
Now with full throttle available I was eager to see how it performed especially up hills without towing. Well much better but the richness of the jets spoiled the event. Certainly an improvement but until I get that tune it cruises very well on the freeway at 110kph and has heaps of spare throttle but open it too quick and you get less acceleration than a light throttle squeeze.

This light throttle is required around slow corners too or it bogs down.

Got a brake master cylinder issue ATM (could be stripped thread on a line end bolt) leaking so that takes priority first then the tune. The MC has recently had a stainless steel sleeve inserted so am dissapppointed I think I stripped one of the threads. (Can I get it fixed?)We are saving at the moment for these.

tambox · Post by **tambox** » Sun Feb 08, 2015 7:44 pm

Still get distracted by how good Tweety looks in the photos.
Sort of makes you forget the problems.
You could try adjusting (dropping?) the float level slightly, costs nothing, within budget

Tweety · Post by **Tweety** » Sun Feb 08, 2015 8:07 pm

I'll think about that float level Greg,

When it idles (so nicely) it is rich also. Timing is at 10 degrees so that isnt the issue. Platinum plugs set at 32 thou. 8mm leads. 98RON.

As Dr Zackary said...."oh the pain"......

For you young guys it was Lost in space 1960's....

tambox · Post by **tambox** » Sun Feb 08, 2015 8:30 pm

Thinking is the first stage Tony.
Action is required to relieve the pain.
Drop the float level 1mm at a time, idle screws out 1/2 turn with each float level drop.
That's "A" theory.
If it gets worse go the other way.
Worst case, put it back to where it was.
Just time (sorry, education), no money.

Tweety · Post by **Tweety** » Sun Feb 08, 2015 9:25 pm

Thanks again Greg.

I've read this PDF http://www.webercarbsdirect.com/v/vspfi ... 0Guide.pdf which states the float level in new webers are often correct. So really dont want to touch them.

It also states that the mixtures screws should be set half way from hesitation inbound to hesitation screwed out. Not quarter of a turn out from hesitation screwed in. might make a difference if I try that. Funny, installed supercharger but dont feel confident even looking a tthe new weber. lol

tambox · Post by **tambox** » Mon Feb 09, 2015 5:22 pm

By dropping the float level slightly you will lean out the progression mixtures.
Raising it richens the progression mixtures.
But WOT is jets, as long as the float level is in the ball park, exact float level makes little difference.
From the motor size vs carbie size, it should be rich.
Even setting the idle, by the book, tells you it should be in the 1-2 turns range, otherwise jets are wrong.
Many many variables.

The suspense will kill us, but a dyno report, previous/post will be satisfying.

steptoe · Post by **steptoe** » Mon Feb 09, 2015 9:00 pm

I think the spfi is bigger inside and the cause of the bog - I get it too, but is so much better since I leaned things about half a ratio - seeing 15.9:1 instead of 15.5 for LPG
Bloody Greg was right of course ...new manifold - new tune !

Subydoug · Post by **Subydoug** » Mon Feb 09, 2015 10:02 pm

The bog will be from a lean condition. If the mixture screw is set correctly you need to look into the accelerator pump. Does your carby actually have a pump jet per barrel? Given the size of the throats I would hazard a guess that your going to need a pump jet on steroids. Do you get a drumming drone out of the airbox or is it chrisp?

I dont think the larger manifold will make the difference Steptoe. The standard one is far less then the displacement of the engine (around 500ml) so the spfi one might be an extra 150-200ml if your lucky, still shy of the whopping 1.2L it actually breaths

.

Regards

Doug

Tweety · Post by **Tweety** » Mon Feb 09, 2015 11:35 pm

Exhauts are black as. No drumming, pretty crisp. Don't know about acc pumps.tis why wanrt to leave it to the experts. One who fiddles with Cray pot can lose fingers. Old tweety proverb

Nubaru · Post by **Nubaru** » Tue Feb 10, 2015 7:10 am

exhausts have not gone light grey nice combustion since the days of leaded super grade petrol. ULP tailpipes are always sooty black with or without cats

tambox · Post by **tambox** » Tue Feb 10, 2015 7:00 pm

The beauty of these carbie's is they have a million (well almost) jets and adjustments.
You can have a simple little play for curiosity (put your fingers near the biting things, not too close), but it needs a dyno and scope and an EG analyser to get serious results.
Oh and someone that knows what they are doing:D