High Butterfly for the street

[Jimmy18E]

I have the opportunity to purchase a High Butterfly injection system off an early Franz Blam built 2.5SS that the current owner had in his 911 Hotrod for weekend use. He switched to PMO’s and is willing to part with the injection system.
He stated that he switched to PMO’s because the car was very hard to drive on the street, was great at full throttle but he said that it was a bitch at lights/hills and in traffic. He is very pleased with how his car drives now with the PMO’s
I love the look of the High Butterfly and am considering switching out the 46 PMOs on my current 2.5SS in my car (71 Hotrod). My question is: Can the High Butterfly injection be made “streetable”, user friendly for a weekend hot rod or was the issue the owner had the norm. He states that the car was sent out twice to a shop that specializes on early Porsche/Injection and was told these systems are really for race and not great for street use.

I have never driven a High Butterfly injected car, can it be made/massaged to be user friendly on the strret or was the above issues the norm?

Thanks,

Jimmy

[kentf14]

Sub'd

Kent

[mrg3.6]

Sub'd Kent

Ditto

Martin

[912-2.8]

Im not an expert by any stretch of the imagination, but the tuning is in the pump, not the throttle plate placement.

Get the pump dialed in for the engine and all should be good. The TBs are just valves passing air.

MFI is sensitve to the whole package. An exhaust change typically needs a white/black screw fiddle assuming you had it perfect before the change.

t

[Mr9146]

High butterfly works fine on the street when tuned properly, it's the lack of air cleaners and noise from the stacks that are more a concern than anything else.

Sounds to me like the donor motor needed some tuning work and that carbs were used as a shortcut. Is it 1980 again?

[targa74]

Marco's right - it's really a factor of having the pump setup right for the engine. I've found mine to be great for the street or track and making good tractable power across a broad rev range. But, I'm running them on a 3.0, twin plug with 10.5 compression and GE60 Cams. A 2.5 short stroke is a different animal - and cam choice would seem to be a huge factor. I solved the air filter issue with some Weber Carb Foam socks and zip ties. But without cold start enrichment - have to squirt fuel down the stacks on cold days for starting. Makes a beautiful sound :-)

[Longballa]

HB is cool but you need to think about filtration for your street car. I don't like the thought of all that dirt getting in the motor. Porsche rebuilt these race engines often so they had less concern. I have also heard that HB likes to run best at full throttle but I have no experience with it. Just what I heard from guys who have it. It sure looks cool though. If you're getting a good price on it then you have to buy it regardless, right?

[Longballa]

Marco's right - it's really a factor of having the pump setup right for the engine. I've found mine to be great for the street or track and making good tractable power across a broad rev range. But, I'm running them on a 3.0, twin plug with 10.5 compression and GE60 Cams. A 2.5 short stroke is a different animal - and cam choice would seem to be a huge factor. I solved the air filter issue with some Weber Carb Foam socks and zip ties. But without cold start enrichment - have to squirt fuel down the stacks on cold days for starting. Makes a beautiful sound :-)

That's one sweet looking engine!

[gled49]

The bigger the motor the smaller the throttles. Same for cams. A 3.0 or in my case 3.4 drives great with HB. A 2.5 will need more care in tuning and driving. gled

[Jimmy18E]

Great looking motor...... Love that MFI.

My little 2.5 is pretty much maxed out, DC-62 cams, extreme heads, GT3 Oil Pump ,Pauter modded crank,etc,etc. I would love to get the High Butterfly on there If I could make it work.

If I pick up the system, who should it be sent off to, to have properly set up?

Thanks for the info guys.

Jimmy