Mongo

You know when I think about it, you can completely redo your intake track to where the intake sucks in from the front... thinking like a RamJet 502 motor.

Now that gives me a good idea for another Eaton supercharger setup!

dprantl

Something like this, maybe?

http://www.mtiracing.com/Video-Gallery-30.html

I don't think that would work though because the 928 has the water bridge in the way.

Dan
'91 928GT S/C 475hp/460lb.ft

AO

I don't have a Murph car myself, but I have access to two here locally. And of course, I have my own TS car as well.

John Speake

OK, thanks Andrew..... watch this space...

DR

Hi John,

Thanks again for another great SharkTuner product for our 928s!! Kudos to you, Jim and all the team that made this happen!!

A HUGE THANKS to Jim for his presentation and sharing his knowledge with everyone at SITM!

I am also once again flattered that SITM is yet again the Event to debut another ST innovation, as it has in the past with the ST and ST2 products!!

Concerning the above mentioned BOV (blow off valve), we do not use that type of setup.

On a Twin Screw system you use a BYPASS Valve. This equalizes the pressure before and after the SC unit to eliminate drag on the engine when not on boost..but also eliminates or reduces cavitation GREATLY...AND installing an OPCON/AutoRotor Twin Screw without a bypass valve also voids the Factory Warranty.

A quick quote from Magnuson about the use of Bypass Valves, more so concerning fuel economy and parasitic power loss, etc.

"Why do you need a bypass valve? The best kept secret in forced induction is the little known bypass valve. This small valve, when properly installed between the supercharger and the air throttle body, allows the supercharger to become extremely efficient in terms of economy and parasitic power loss. Our M90 supercharger uses less than 1/3 of 1 HP at 60 MPH cruising. The bypass is operated by a vacuum actuator control unit that is normally closed. When vacuum is high (idle-cruising) the actuator opens the bypass valve, equalizing the vacuum pressure throughout the system. When boost is required (accelerating) the vacuum is decreased and the bypass valve instantly closes, causing pressure to increase into the cylinders. This equalized vacuum condition virtually eliminates the normal parasitic power loss of a forced induction system."

http://www.magnusonproducts.com/bypass.htm

Thanks again for everything, will call you next week when fully recovered from SITM to catch up!

Cheers,

Dave

John Speake

Thanks Dave for that explanation. So it's a bypass valve, not a BOV. Does your system also use a BOV or does the bypass valve also cope with the situation where the throttle is suddenly snapped shut from high rpm/boost ?

So, clearly with your system we need the MAP version of ST2.

Many thanks for hosting a ST debut again - it's getting to be a tradition :-)

Look forward to having a chat with you again....

928mac

I removed my MAF and replaced it with the 95mm tube that comes with the Tec-GT kit. She is a big honkin hole and needs to be just as long as the MAF sensor if you are using the same air box



It comes with the air temp sensor and also the MAP sensor which I installed here right beside this K&N filter which I installed for ****s and giggles




Sorry I like to post the pics as it saves typing a 1000 words

John Speake

Thanks Brad. Is the MAP sensor a GM one ?

928mac

I am not sure John, Ill see if I can find the #s on it and post them. give me a couple hours to get off my azz.
Just got home, drink in hand, surf-in the web

FLYVMO

For my Tec3r it used the following MAP sensor. I believe it is nearly identical to the GM ones and is what Electromotive ships with their kit.

http://www.distributorless.com/products/sensors.php

Cheers!
Carl

928mac

John the numbers are behind the bracket and not visible unless I completely remove it. From the photo in my computer it dose say GM but I can't make out the number

top left corner

John Speake

Thanks Carl and Brad. The Electromotive does look like the GM. Do you know the price of the 2 bar ?

dprantl

For a vacuum/boost readout to my ST2, I use the MegaSquirt 2.5 Bar MAP sensor:

http://www.newark.com/freescale-semi...?Ntt=MPX4250AP

It's very small and cheap, but requires 5V input instead of 12V.

Dan
'91 928GT S/C 475hp/460lb.ft

John Speake

Hi Dan,
That's interesting. We use exactly that series of sensors for the atmo sensor in the ST-Alpha box. A 1 bar version. MPX4100. .. hmmm...

DR

Since our system is an actual intergrated intake system vs an add-on SC before an existing stock intake system.... the Air Metering and Throttle Bodies are pre-boost, not after boost as with the other systems... in other words, we don't need no stink'n BOV.... LOL

Yes, I long forward to continuing a LONG tradition of hosting ST unveilings!

Definitely look forward to chatting with you too, it has been way too long for me, sorry I have been out of pocket for so long.

Cheers,

Dave