Woodster

MY CAR IS READY TO GO AND RUNNING PERFECTLY;
I HAVE NEWLY INSTALLED STAGE 2 Z/C HYBRID TURBOS (KEVIN'S)
PORTED/POLISHED HEADERS, 100 CELL CATS, RSR STAIGHT THRU
MUFFLERS, BILLLET DV VALVES, PROTOMOTIVE ECU AND GREDDY
PROFEC TYPE S BOOST CONTROLLER. THIS HAS (2) SETTINGS,
LOW AND HIGH. WE HAVE 93 OCTANE AVAILABLE AT ANY GAS
STATION AND 100 OCT AND 130 OCT AVIALABLE. 10 MILES FROM
ME. I FIGURE I WILL MOSTLY RUN 93. WHAT SHOULD MY TO
BOOST PRESSURES BE SET AT? EXAMPLE .9 BAR AND 1.0 BAR?
MY SHOP SET THEM AT .8 BAR AND .95 BAR BUT I THOUGHT A
SIGNIFICANT PART OF INCREASING PERFORMANCE IS INCREASING
BOOST PRESSURE (WITHIN REASON). I WANT LONGEVITY AS WELL!
THE CAR RUNS VERY WELL WITH .8 BAR--IT RUNS PERFECTLY
AND NEW VIPER BOB "LIGHTWEIGHT FLYWHEEL/CLUTCH IS NO BIG
DEAL) I WILL TALK ABOUT MY IMPRESSIONS LATER.

viperbob

Hi Marty... Glad your car is going again. On 91 octane, I run 1.0-1.1 BAR with no issues. With 93, 1.1 should be fine. On 100 I run 1.3-1.4 (yes Kevin thinks I am crazy). The 130 octane is probably leaded so you might want to stick with the 100.....

I kind of like the Prefec II Spec B over the S model. It is all digital with an LED display, and can show boost pressure so since you factory gauge is now useless you will know exactly what you are hitting for boost.

ScottMellor

Uh Bob, it's not just Kevin....

seege

I see you have the Protomotive software, what pressures did they recommend?
I have a nearly identical setup, Todd at Protomotive set mine at 1 bar and 1.2.
I turned it down to .95 and 1.1 bar.That's plenty of umph for most of us non ViperBob types.Also make sure to study that boost controllers instructions, and fully understand them BEFORE you try and adjust it. Any mistakes with that unit could cost you big, even more than that round of mods you just made.

viperbob

Thanks Scott... Remember to slow down to drive faster

jrgordonsenior

Funny I was just remembering your adjustment snafu when I started reading this thread. Glad you chimed in CJ with your experience...

Jan and I are at The Lodge this weekend. Cocktails/coffee if you're not out racing. Cal Speedway with POC the following weekend...

Jean

Marty

Congratulations, that is quite a nice setup! I guess the 130 Octane was a typo and you meant 103 Octane? The stress levels on your engine are not linear, components suffer exponentially from the increase in boost and RPMs. I would definitely not go beyond 1Bar if you are in for longevity, unless you can rebuild engines yourself. At 0.95 Bar you will be running very nicely, especially if your ECU was programmed by Todd K. and using Kevin's turbos,.. A LWF will not make a big difference on a 4WD car, your best mod would be to do that and go with Bob's 2WD conversion kit (-100 + lbs). If you need any more hp after that , I would start putting the car on a diet rather than increase boost..again, if you are in for longevity.

Please keep us posted, some 60-130s would be very nice too.
Enjoy it!

seege

Yes the snafu...fortunately I sent the settings downwards and the reset was only a couple hundred bucks as opposed to much worse. Drinks sound great but I'll be in Phoenix at PIR this weekend. You guys enjoy the sunshine and relaxation this weekend, the forecast is perfection - low to mid 80's

Woodster

thanks guys, i think i might set it up for .9 bar for standard boost and 1.0 or 1.1 for 100 octane
(unleaded). (viper bob is right the 130 octane is leaded). It seems like the above 1.0 bar
boost is less "popular" for those of us unable to rebuild the engines ourselves. I have my
shop (AUTO EDGE) do all the boost pressure settings. they put two guys in the car and a
temporary boost gauge and do the adjustments (while trying not to get a ticket). 60-130
will be tested soon (it is raining today), the roads are still fairly sandy. I am very delighted
with the overall nice drivability of this set-up. thanks to viper bob, steve at rennsport and
others who helped me with questions. everyone has been great!!

Kevin

CJ have you rebuilt you engine recently?

Making boost for me is very easy. The hard thing is getting the programming that will utilize the boost. Bob and I had this same conversation about my reservations of >1.2bars of boost on a "stock" engine, a few days ago.. There are many things to consider when dialing the "**** of death" or "dial of death" timing, inlet charge air temps, and fuel grade.. Most street programming does not yeild effective results after 1.1bars. If you are running 91 octane, I would not go over 1.1bars period.. Timing is being pulled to net out little gains over .9bars or 1.0bars.. You can't have it both ways Engine reliability and boost greater than 1.1 bars. Accelerated wear happens..

seege

Kevin
No rebuild needed-my engine is tip top as it was just out for the gearbox R&R and Todd couldn't find anything but a drippy lower valve cover gasket.We did 3 of the gaskets,wires,plugs belts,etc.

But I respect "The Dial" I have not run more than a tank or so of 91 since the mods. I can't remember now if Todd originally set my low boost(91 octane) at 1 or 1.1 bar, but the high boost setting was 1.2(100 Octane) After a previous thread or 2 on the subject I tried to lower my boost settings and mucked it all up where I was getting nearly no boost. I took it back to Todd and had him reset them lower. I now have a better understanding of the unit and can work it if needed.

wini

Why is the 993tt engine limited to approx 1 bar boost? Most high performance turbo engines can run more than this,is it the air cooling which is the limit or heads lifting? Also are 2 valves per cylinder a limiting factor to the amount of air that can be flowed? does the 996tt have an advantage because of 4 valves per cylinder and water cooling?

nman413

Jean, I have a LWF in my car and it does make a difference. Quick revs are good

Kevin

wini, have you ever seen a VW Bug drive by making a loud clanking sound, most people think that it's a bad muffler.. Basically the cylinder heads to piston liner seal has breached. The hot combustion air gases have blown past the sealing surface. This is the what happen to the same air-cooled, similar design engine. Now we add a turbocharger with boost.. The 993TT has a sealing ring cut into the liners to help seal the liner to the head.. However, at boost levels over 1.2bars we start adding stress to the rod and rod bearings. The 993TT rods are the weakest rods that Porsche has used in there turbo engines.. If you have the cash, run the boost.. There is a big difference between a H2O cooled engine and an air-cooled engine.

Jean

Jauder, it is a great mod on 2WD and 4WD, if you like it on your TT you should see what it's like on a 2WD TT!! 2WD benefits much more than 4WD from this modification.