LAT

I would like to hear the pros and cons of either from anyone who has personal experience.

In another thread I had someone suggest a hybrid of both.

Any other reason to favor one over the other.

Thanks all.

Kevin

Call Ruf and get there advice..

LAT

Done that, just wanted another perspective.

Kevin

What did they say?

LAT

Christian fronm RUF.DE states that 90% of CTR-2's out there use manual boost control. Manual is faster spooling and more consistant with no spike tendancies. The electronic unit provides an extra level of safety when the engine knocks as it will reduce boost pressure as well as retard the ignition. With the manual control unit we rely on timing change as the only the engine safety system.
The RUF manual unit I have installed, works well. My concern real or imagined is with fuel quality and I was looking for real world experience with the two units on the same car.

Thus my question "I would like to hear the pros and cons of either from anyone who has personal experience".

Hope this answers your question.

L

Woodster

Lat,
As you know this became a huge subject when I was in the midst of my mods.
My software guy, Todd at Protomotive uses manual boost controller most of the time,
it works perfectly on my car with 92 octane pump gas (set at .9 bar). I do not pretend
to know all the ins and outs of why this works, but if you had the luxury of someone custom
programming your car to your exact conditons, it may not require one. To me it makes sense
to limit boost control manually and seems to work great (we will try my car in mid-july when
you are in Minneapolis), and we can talk to Joe Jeppson.
FWIW
mk

K24madness

LAT

I prefer the electronic boost controller. Very flat boost curve and quicker response. Since I only run race fuel (100-103) detonation is not a major concern.

98% of others people I would recommend using the factory solenoid boost control. The diagrams I gave you in the other thread allows you to retain all of the safety features of the factory system and have the abilty to eliminate boost spikes.

You have to ask yourself whats more important to you. Response vs Safety.

Woodster

Just to clarify, K-24: YOU mean that you prefer external boost controller (non factory), like
a Greddy that I have or similar??
thanks,
MK

K24madness

Yes woodster thats what I prefer. I have the Profec A.

Porschefile

An EBC is more responsive and will hold boost better than a MBC. All of my results are from a 951, but the same basic physics apply to pretty much any forced induction setup. I've used both on my 951. I had nothing but problems with MBC's, although I must confess that a couple of them were $10 ebay ones. There are some fairly high quality MBC's available, but these were old technology 10+ yrs ago. Using an MBC on such a top of the line car is kind of like using a Fram oil filter on a 962. Why take the chance? It's just not something you should do. I got some serious boost spikes with the MBC's I used, and I'm talking .3-.5bar spikes. That much of a spike is a SERIOUS problem. On my Biltz EBC with gain turned to 100%, I get a maximum of .03bar spikes, and usually only due to significant temp changes. I wish my scanner was working so I could post up before/after dyno sheets. Switching from the MBC to an EBC I make full boost 700rpm earlier and it holds boost rock solid on the top-end. Before, after ~4.5-5krpm my boost would drop to stock .75bar with all the MBC's I tried. Now I hold 1bar to redline.

On many EBC's, there are safety functions built in. I have a Blitz Dual SBC, and it has a safety/warning mode. If boost goes over my specified limit, it will beep and flash to let you know, as well as cutting the boost back to prevent too serious of an overboost.

You guys crack me up. Owning $70-80k+ 911 Turbo "Supercars", but using $10 worth of valve components you could find at a hardware supply store as a boost controller. Please don't take offense as that's not meant as an insult but, stop being so cheap guys! Technology has progressed quite a bit within the past 10-15yrs.

K24madness

Kinda supprised you get spikes with the Blitz EBC.

On my Profec A Boost goes to preset level (1.1 for now) and never goes any higher reagrdless of gear or temp. It also has the same safety features you mentioned.

IMHO the only application for the MBC is when used with the factory setup to prevent boost spikes.

https://rennlist.com/forums/attachme...id=66192&stc=1

LAT

Porschefile, you make a point and I must profess that my expertise in engine building and tuning, has been with NA motors. This is my first turbo of any kind other than a turbo diesel suburban I had once.

The MBC I installed and I have enclosed a picture is one that RUF provided. It is simple in design, yet so far I find it effective. It has a tapered adjustment screw that goes into the intake distributor line. On my car the boost is 15.7 to 15.9 psi and I have a target of 16.0 psi. I would consider that fairly constant.

I am guessing that the tapered cone allows for a constant flow versus and open port and thus no spike.

I have tried to upload the picture of the unit installed and the set screw, I will have to reformat to a smaller size and post later.

LAT

Porschefile

Actually, a .03bar spike is pretty small, and is something like less than half of 1psi. Even then, this rarely happens and is more a result of temp change or very quick throttle use. It's like this because I have the gain turned to 100% to compensate for the crappy, worn out stock wastegate. I should have put that my boost is consistant 99.9% of the time, and very rarely do I get a spike.

There are high quality MBC's available, of which I'm sure the Ruf version is. Though, my main point was that for the $100+ one of those mbc's might cost, you could spend $100-200+ more, get an ebc with a built in boost gauge, warning/protection mode, more response, etc.

LAT

I would have guessed that the other MBC you speak of have springs and other moving parts, the RUF is a variable venturi style that once set has no moving parts and therefore no room for variance once set. What it cannot do is bleed off boost if detonation occurs which a ECU connected EBC should be able to do, other than this feature the MBC I think could be the prefered method.

LAT

BTW the RUF unit was 108 Euros