other options for vacuum...

[fantapants]

so curious and possibly dumb question.

what other options are there for getting vacuum to brake booster? The blacktop quads i have used on my 3s have a big built in vacuum chamber above the fuel rail, alos built in to the bottom manifold.

The manifold adaptor i have has no comunal chamber so to speak. Two of the throttles, 1 and 4, have a vacuum line attchment, but i planned on using those for the map sensor. How big a source does a booster need? like can i run these two small fittings to a laregr chamber that works for map sensor and booster or would that fuck up the map readings?

suggestions welcome :)

[julzy]

what i have done on my 16v quad conversion is,
Using an electric air pump.
There is a map sensor in the booster in which is run off a jaycar adjustable relay box.
When the map reading gets below a set Voltage aka, pressure,
the pump zaps on for a second and provides the lost vaccum.
Been running it for 2-3 months now with no problems,
it has a normal feel in the pedal and its an easy way to get a strong MAP signal while having good brakes.
hope it helps

[Golberg]

what i have done on my 16v quad conversion is,
Using an electric air pump.
There is a map sensor in the booster in which is run off a jaycar adjustable relay box.
When the map reading gets below a set Voltage aka, pressure,
the pump zaps on for a second and provides the lost vaccum.
Been running it for 2-3 months now with no problems,
it has a normal feel in the pedal and its an easy way to get a strong MAP signal while having good brakes.
hope it helps

That's an awesome idea!

[Cerby86]

i'm running a set up where a vacuum port comes off three of the runners into a canister and the booster, fuel pressure and map all run off the cannister. I'm running an adaptronic though so i don't know how a standard ecu would go. Very good pedal feel though!

[Golberg]

You can't run a standard map ECU on a motor which didn't have quads to begin with anyway so it doesn't really matter. Well I guess technically you can, but its dumb idea.

[fantapants]

yeah im runnin adap..... more wandering if it would produce enough vacuum.... i only have two attachments, do you just drill and tap the others ?

[Cerby86]

You can't run a standard map ECU on a motor which didn't have quads to begin with anyway so it doesn't really matter. Well I guess technically you can, but its dumb idea.

I know of a lot of people have. Apparently the only time it isn't massively rich is at WOT.
And i have heard of a few people who run the standard ecu with a air fuel ratio piggyback and they seem to get good results though not as good as an aftermarket ecu obviously!
Oh and the adaptor manifold i bought had four massive ports welded into it but i had to block one off because the fwd water setup interfered with it.
One thing i noticed when i was pulling my motor down was that the vaccuum for the booster appeared to come off one runner!! So if you have two runners i would say you would be fine!!

[skit]

Mine setup is 16v engine, silvertop quads/T3 mount with a haltech.

I just used a series of tee pieces & small dia vac line to supply the fuel reg, MAP sensor & brake booster - the simplest way possible. Not very elegant but it works. Braking power is fine; no noticable change from standard.

I wasn't too concerned if the fuel metering accuracy decreased momentarily when braking (i.e. disrupted MAP signal), as I presume everything comes back into order basically instantly when you release the brake & crack the throttle again. Perhaps in autocross or gymkana events when you often use rapid throttle,brake,throttle applications the advantages of a vacuum manifold would be more warranted.

Vacuum manifolds are nice, but I don't think anyone has actually quantified the benefit they offer over a simple tee setup. Guess you could go for a drive with the laptop plugged in to monitor the MAP input reading when braking with both setups to evaluate the difference.

But just using a T3 style adaptor & quads you are already compromising all the benefits offered on a factory 20v setup (e.g. idle air bypass valve) so I guess it's back to the individual as to how perfectly you wish to replicate the factory setup.

Either way, it'll work.

Electric vacuum pump & signal switch is a great idea, I wondered about that myself.

[julzy]

The only reason i went the way i did,
was because i couldnt get a decent map signal off the manifold.
Now im running the T3 fittings for the map and blocked the others off.

[skit]

The only reason i went the way i did,
was because i couldnt get a decent map signal off the manifold.
Now im running the T3 fittings for the map and blocked the others off.

So you're using an external FPR instead of the factory vacuum one?

[julzy]

Fuel pressure reg?
Standard item, no vac line to it, just blocked it off

[skit]

Yep ok, guess there is no reason why not when using an aftermarket acu.

[Anthony]

AE86 brakes work fine on a 20V with the booster connected to one TB only. So you should be OK. with the one way valve, the booster holds on to enough vac for 2 - 3 applications of the brake pedal anyway, so WOT isnt really a problem.