mark kibort

I always had a vision (maybe a little blurred ill admit ) of 8 ITBs, but really tiny, attached at the intake ports of each cylinder port of the stock intake. at WOT, they would open and provide additional air and fuel beyond what the stock intake would provide. only a WOT event, kind of like NOS, but without the bottle.

Strosek Ultra

Go for it!!!
Åke

mark kibort

maybe the easy solution is to just bolt on the NOS system again. there is 50-100hp and the only inconvenience is filling the bottle before each race.
Now, if I could just get it legalized in SCCA/NASA/ PCA competition.

dr bob

Simple hydraulics. There's a pressure drop due to the length of, diameter of, and flow rate through the return line. Obviously the pressure drop isn't constant as engine load changes, so finding the right setting for every engine load would be impossible. There's a reason the FPR is close-coupled with the pressure-regulated zone.

And definitely you don't want a rising-rate regulator. Sharktuning takes that out of the picture, such that "field adjustments" of any pressure regulator would be , um, counterproductive.

Start shopping now for the pieces of wiring harness you'll need for Sharktuning. Mark A is currently or has recently parted a 1989 car so the later bits might be available for that upgrade. I had my "spare" LH controller upgraded to 1989 diagnostic smarts so it could be a drop-in for my car. You'll likely need to have your early controllers similarly upgraded for full functionality. Jim C can tell you what will be needed. You'll also be upgrading to Alpha N so your MAF will be removed. There are some sensors needed for that upgrade too. MAP and inlet air temp would be my guess, but Jim will tell you. They will also tell you what injectors to buy. You'll probably want an air cleaner too. The list goes on!

V2Rocket

You mean like Ford/Yamaha did 25 years ago

dr bob

You mean like a separate Y-shape pipe over each port, one side of the Y with a separate throttle and injector and an air cleaner on it, the other from the more conventional longer-runner intake and its own throttle and injectors? Maybe a different-length stack over the "full-throttle" throttles.

Yep, that would simplify things a lot! Maybe the logical extension of that would be a version of Daniel's multi-section mailbox manifold illustrated in post 408 above, each with its own throttle plate and injector. Just pick the calliope pipe that sounds the best.

James Bailey

It all comes back to the Salsbury 4850 D....the perfect plenum design !!

MjRocket

This sounds something along the lines of the Kenny Bell "Boost a pump" intresting indeed.

V2Rocket

Just looked that up, interesting.
Boost-a-pump makes the voltage to pump higher than stock, looks like from 14v to 17-18V to "overdrive" it, rather than cutting voltage until full power needed like the Japanese.

I was wondering about something like that to drive an electric radiator fan...

Lizard928

There is risk with dropping voltage on a pump.
Far better to PWM it with on/off 12V to achieve say 50% output.

V2Rocket

thinking about it some more, wouldn't a resistor/relay setup leave voltage constant but only knock down current?

V = I/R...but if powered/grounded by the battery it's 12-14V no matter what...say at 10 amps to run the pump.

V = I/R
VR = I
R = I/V

add a 1.5 ohm (high watt) resistor, would make it 6 amps @ 12V?

GregBBRD

Lots of different ways to solve this problem.

The simple way, for me, is to match the return capacity of the FPR (or two FPRs) to the fuel pump.

Keeps the pump from struggling and keeps the fuel cooler without changing somethng else.

mark kibort

that depends on the motor being used. the switching losses of a high frequency chopper drive, will cause heat , but certainly would be more efficient that using a dropping resistor. (as 50 % of the power would be coming out of the resistor and the other out of the motor). only some motors will have risk associated with running half current at lower voltages.

you can have 10amps to run the pump, but if you have a 1.5ohm resistor added to the pump in series , you have a voltage drop across that resistor that will limit current through the motor
if you were running 10amps to start at full voltage, that means the effective resistance of the motor is 1.2ohms and 10amps flow. (120watts) add the 1.5ohm resistance, and suddenly the motor is only seeing 4.4 amps
both the motor and the resistor are producing I^2R or 29 or 23 watts.
you have just quartered the power of the pump with the 1.5ohm resistor.

mark kibort

someone already sole my invention!!!! grrrrr
yes, i think thats the idea! let me research it a little!

mark kibort

yeah.. just like the mailbox but with out the flag ..... and with a few other things.