What mfi pump modifications are optimal for racing?

[BReyes]

What mfi pump modifications are optimal for racing?

Who sells mfi goodies?

Happy holidays,

[Steve@Rennsport]

Hi Bernard:

The pump's output must match the cams, displacement, and compression ratio of your engine.

I've had excellent success by sending MFI pumps to Gus @ Pacific FI and telling him all the specs of the engine. When we get it back, all it usually takes is some minor tweaking when the engine is on our dyno.

[Henry Schmidt]

There are a great deal of MFI modifications that can and should be performed for race applications.
The pump should be isolated from the engine oil.
The decel solenoid should be removed.
The heat raiser enrichment should be replaced by a Supertec hand operated enrichment devise.
the altitude compensatory should be remove.
At that point the pump can be tuned with the least number of compromises.
If you are running an engine larger than a 2.0 the throttle housings and stacks should be enlarged to offer the proper amount of air flow that race engine require.
Supertec is the premier shop for these modifications.
As a matter of fact, Supertec is the only shop offering all these services.

[Steve@Rennsport]

Originally posted by Henry Schmidt
[As a matter of fact, Supertec is the only shop offering all these services.

With all due respect to you,......not really,....

[Henry Schmidt]

Originally posted by Steve@Rennsport
With all due respect to you,......not really,....

Really, who else offers a hand opperated enrichment devise?
Who else rebuilds pumps and throttle housings in house.
Who else is making and modifying intake stacks.
Who else is manufacturing fuel lines.

While it is true that many shops can due this work I don't know any who do everything.

Did I miss something? Is Rennsport offering these services now?

[racing97]

Steve Weiner offers perfect advice with out solicitation and displays class

From all of us

[Henry Schmidt]

Steve is a great asset to this board.
His advise is top quality.

That said, if someone challenges my integrity, I will respond.

In this case
"With all due respect to you,......not really,.... "
calls into question the truth of my statement. What I stated was True, not a little bit True. As far as I know we are the only shop that offers all these services in house.

I understand that people enjoy attacking personalities and mine is an unusually easy target. I always find that to be amusing and generally find that people who do it, rarely sign their name.

As for my solicitation on this board, I am busy, I have something of value to offer and a little self promotion seems like a reasonable trade off.

If a majority of the board feels this is an unreasonable trade off, I'll quit posting.

[cgarr]

Originally posted by Henry Schmidt


If a majority of the board feels this is an unreasonable trade off, I'll quit posting.

But then you would be on your phone all day, I have your number

[davidppp]

I'm interested to learn more please..

Why do we need to ditch the baro cell, in particular?

This seems like a realatively reliable bit of kit which saves me having to twiddle the mixture when the baro drops....

Thanks
David

[304065]

Henry, what is that silver cylinder at the top of the pump where the baro cell ordinarily is?

I have seen a red knob on some of the racing pumps, mounted in the same spot. What is that knob for?

I see you fabricated a blanking plate for the overrun solenoid that leaves the main rack adjustment open. Nice.

Finally, what oil do you use in the pump once it is isolated from the engine oil supply? How often do you recommend the pump oil be changed?

[BURN-BROS]

Hi guys, I have an inline pump that has the red knob...which simply is the oil fill cap for pumps originally isolated from engine oil. I'm still trying to figure what car it came off of...

[304065]

Aaron, that's pretty cool. It must be a "PES 6KL" for Pumpe Einspritzung Single-Reihen or something like that. 906E?

[BURN-BROS]

It is a PES6KL but I think its off of a Mercedes from the early 60s. I got it off of evil bay. Maybe a 250 or 280 sl? The governor housing is identical to the one that Porsche used on the MFI production cars. I can't find any info on them....maybe a call to Gus is in order.

[Henry Schmidt]

Originally posted by davidppp
I'm interested to learn more please..

Why do we need to ditch the baro cell, in particular?

This seems like a realatively reliable bit of kit which saves me having to twiddle the mixture when the baro drops....

Thanks
David

When racing it is always preferred to eliminate all or at least most of the things that compromise performance.
Alt. compensates give faulty information and fail.
Most people race at a track that has little or no noticeable altitude change.
If you have played with carburetors you have found that they offer no altitude compensation and yet function very well given they are jetted for altitude.
Another benefit from removing the AC is that stock K&N air filters will fit without modification.

[davidppp]

Thanks, Henry.

I had not appreciated their unreliability..

And it leaves a nice hole for the oil filler I guess?

Kind regards
David

[Henry Schmidt]

Originally posted by john_cramer
.... what is that silver cylinder at the top of the pump where the baro cell ordinarily is?

I have seen a red knob on some of the racing pumps, mounted in the same spot. What is that knob for?

I see you fabricated a blanking plate for the overrun solenoid that leaves the main rack adjustment open. Nice.

Finally, what oil do you use in the pump once it is isolated from the engine oil supply? How often do you recommend the pump oil be changed?

The knob is actually a breather. When the pump is sealed pressure builds up and the pump leaks oil.
The breather allows the pressure to escape.
When we seal the pump we use high grade synthetic oil.

When the altitude compensator is removed it must be replaced with an adjustable plug that sets the pump at a constant mixture until an adjustment is needed.
The breather acts as a filler hole.
The return fitting on the side of the pump acts as a level indicator so if you open the plug and oil comes out then you know the oil is contaminated. Until that happens there is no need to change the oil.

[Porschekid962]

Very interesting Henry. Without getting into some of the "fun" that happens on this board, I am sure it happens elsewhere as well I have always been a fun of your work. Clean, factory look, big performance, pay to play but wont break the bank.

Steve, your stuff is awesome as well, fits a different crowd which is why you two can stay in business without direct competition.

I love mfi for its rawness, I love efi for what it can do. I dont have a dyno or want to spend money to run my motor on a dyno and tune it until my hearts content. That being said both of your systems (no pun intended) and ways of going about things offer huge benefits to individuals seeking different means to an end.

If I had my way I would piggy back and mfi pump to an efi system with itb's, twin turbos and call it a day. Anywhat there is something for everyone and each time I read through anything I take something away as to the ways of Porsche performance. Be it old school or new school I love them both.

Please keep up the awesome work and these little "altercations" only lead to further clarification.

Happy new years to all and may we all live in porschedom happily!

[philippeF]

they even both gave advices to a (far away) french guy ...(me)

philippe

[Porschekid962]

my godfather is french. random i know