Carl Fausett

We have two SC kits in production for the 16v 928. Our first development was in CIS, and more recently, L-Jetronic.

Taking the 219 crank HP M28/01 or M28/03 CIS motors to 340 HP at the crank has been worked out now to where it is not too difficult. It WAS difficult the first time, but the trial-and-error research has now all been done in that area.

Being these are kits meant for bolt-on HP by Average Joe, we tend to stay away from tweaky systems to eek out the last HP available - we leave that to our Stage 3 kit or our own cars.

I can tell you a few things that we have learned....

... to get the fuel delivery neccesary to support 400 HP with CIS, you need to drop the control pressure significantly. Dropping the control pressure on the CIS system has the effect of increasing the fuel pressure to the injectors. Dropping the control pressure in CIS is achieved by dumping control-side fuel back to the gas tank.

... by the time you have dropped the control pressure enough, you are returning so much fuel to your tank that you actually have reduced available fuel volume. Its a paradox.

... we use a little piece of piggy back electronics on our Stage 3 system that we co-developed with Andial Racing - when the boost comes in it starts reducing control pressure on the CIS system, thereby increasing system pressure to the injectors. We have a dash-mounted switch that actually allows the driver to dial up or down his air-fuel ratio under boost with this system. Its pretty slick.
But it too, has a ceiling.

... another obstacle to 450 HP with CIS 16v cars is that there are no "hi-volume" fuel injectors for the CIS 928. The injectors we have cannot be modified, and nothing else fits. L-Jet is easier - you can swap out the injectors with high-volume ones and keep tuning.

... the next obstacle is the Control Regulator - commonly referred to as the WUR (Warm Up Regulator). It's job is to add or reduce fuel pressure, and all of our adjustments need to apply to it or thru it. There are many models, and a few places that modify them for hi-output CIS systems that we know of.

The crank is not a problem - in fact there is a belief out there by some that the 78/79 cranks are the strongest of all - and they are starting to get in shorter supply because of later-model motor owners who want to back-date their cranks to 78/79.

I think that, with auxiliary injectors electronically controlled - the 4.5L motor is certainly capable of 450 HP. With CIS? I'm not so sure. Mercedes-Benz built a 420HP CIS V8 with Bosch systems...

We learned too, that it was a mistake to go thru the expense and time to upgrade the US version CIS 928 to Euro intake runners and Euro throttle body and Euro cams and Euro heads and Euro WUR (this gets EXPENSIVE) - BTDT - only to supercharge that motor later.

The superchargers perform better with all the OEM US-spec parts than they do after all the Euro upgrades. This is not unusual - many SC books will show the same results on other motors.

It is because - although opening up all the intake passageways is a very good idea on a naturally aspirated motor - on a SC motor it has the effect of reducing the velocity of air thru those passageways. Poorer throttle response and poorer bottom-to-mid-range is the result.

So if you KNOW you are going to Supercharge in the future - save your money and don't hunt down Euro-everything and install it as a pre-project. You do not need it or want it.

I am building a 5.0 liter CIS motor right now with Arias pistons, steel sleeves, 8.5:1 CR, Supercharged, and 450 HP is my goal.

sublimate

Carl, is your 16v kit going to get a cold air intake like the 32v Murf kits you sell? Also, what is the efficiency of your intercooler vs the Murf cooler?

Carl Fausett

Yes, we have a cold-air intake for our systems in R&D right now. It was always planned.

As to efficiency of an intercooler system - there are so many factors: the GPM of the coolant pump, the restrictions (number of bends) in the cooling lines, the sizes of all the fittings and hoses, the temperature of the air flow thru the heat exchanger (location), the size and effieciency of the heat exchanger itself, the size and efficiency of the intercooler, the location of the intercooler.

Tim and my kits do not compete - his kits are meant for 32v and mine for 16v systems - so the comparison is somewhat moot. But I believe - for the reasons listed in the paragraph above, our 16v air/water intercooler SYSTEM is more efficient, but I also believe his Intercooler is more efficient than ours.

Reason - the 32v cars have more room for a larger intercooler than we do. So, we 16v kit guys have the largest intercooler that will possibly fit, and make up for any shortfall by improving the rest of the system (larger heat exchanger, pump, lines, etc.

They both work very well.

TeufelHei

Carl--
Since you and John are the only ones who seem to be seriously developing forced induction systems for the CIS and L-Jet cars, I'll ask you.

What about 78/79 camshafts incorporated into a '81 L-Jet and then Supercharged? If I recall, there is a bit more duration and lift to the older camshafts. Also, which injectors are cross compatible? I know that the later 914 (74-76 I believe) was an L-Jet car, were these bigger?

Would you recommend the standard efficiency gainers (port matching, extrude hone, etc.) as good use of your performance dollar for a car who will likely be SC'd later?

928ntslow

Just to give an idea of what bolt on's can do, I took my stock 1982 to the dyno last year and recorded a baseline to see what the car had. After that, I bolted on Euro Intakes and Euro throttle body, added a RRFPR, MSDS headers, custom Y in place of the cat and Borla 2.5" exhaust. Though I moved the power band around a little bit, it made some very pleasing improvements for not getting "into" the engine. I just had the 82 dynoed this past weekend, so here are the before and after dyno charts.

DYNORUN.002 Max POWER= 170.3 Max TORQUE= 222.4
DYNORUN.001 Max POWER= 163.6 Max TORQUE= 197.7



DYNORUN.002 Max POWER= 184.8 Max TORQUE= 220.2
DYNORUN.004 Max POWER= 185.9 Max TORQUE= 230.0 (leaned out A/F mixture)
DYNORUN.006 Max POWER= 182.1 Max TORQUE= 214.7 (richened A/F mixture)

BC

Thats pretty good for a 4.5L with the auto Keith.

I'm hoping for a bit more then that. I have rebuilt the engine and have done what I mentioned above in my earlier post.

I think the key will be all the changes put together with the megasquirt.

Here's hoping.

SharkSkin

Keith,

What was wrong with the later runs? Tire out of balance?

hacker-pschorr

Keith,
Your making me feel better for pulling 160rwhp with my 81 5-speed while running very rich. Many have speculated my engine had internal damange, rings, something causing the low power. Compression test came out good so I was confused.

928ntslow

Yea, I thought so too Brendan, but driving the car, now feels like more than what the numbers show. Having recently installed a KD by-pass, the car launches much better now. Definitely a blast to drive for a daily driver. I think larger injectors would get me a few more ponies, but I think I will leave well enough alone.

Erik, get yourself a RRFPR and do some tweeking, but you will need a "balancer" on the other fuel rail.

I am sure Carl's kit will make way better performance with out getting into the engine. I would like to know myself though, what other numbers are being produced with out cracking open the engine and not SC'ing.

Oh, and Dave...tires out of balance??? LOL, no...too rich of an adjustment to the RRFPR.

hacker-pschorr

I'm already running too rich on WOT. From the time I installed the A/R gauge to my last (ok, first ever) track event there was not really any time to try and lean it out. I didn't want to risk breaking anything just before the track event. I'm still not 100% sure how to tackle this problem, I'll worry about that once the head gaskets are replaced.

SharkSkin

Ah, OK... just looked pretty jumpy. I thought your 82 sounded a lot smoother than that!

rixter

hadn't heard this... I have 2 early cranks if anyone needs one

928ntslow

It's interesting to look at where the power band moved from the mods. It "feels" like the lower end lost power and now makes it at 3200rpm and above, but it may be that I just gained the above amount that makes the "feel" much different. If we take comparisons from 3Krpm to 5Krpm, you can see the changes.

ESTIMATED
Before 3Krpm @ 105hp, 185 ft lbs 4Krpm @ 152hp, 205 ft lbs 5Krpm @ 165hp, 180 ft lbs
After 3Krpm @ 110hp ,158 ft lbs 4Krpm @ 164hp, 214 ft lbs 5Krpm @ 178hp, 190 ft lbs

Before- hp flattens out after 5Krpm, torque takes a dive from 5500rpm at 160 ft lbs
After - hp rises a bit more to 5500rpm , torque takes a dive from 5500rpm at 170 ft lbs

Anyway, wasn't trying to change the subject, just noting what bolt on's can do with out breaking the bank.

mark kibort

with the 82 from Scot Graham, we got up to 218 rear wheel hp with only MSDS headers, RRFR , and complete euro intake (no heads though)

My 84 went from 178 to 188 to 200 to 230 to 242 with only bolt ons. headers, exhaust, better ypipe, euro intake and cams, rrfr. all in that order. (and thats the 4.7)

the 5 liter added to the above 2 valve engine, went from the 240 rear wheel to 292rear wheel with also the euro heads. (no porting or valve work). Keep in mind, all from the Ljetronic fuel system.

mk

928ntslow

Mark, cams would make a nice differnce, but did you change out the injectors on the 84? I think once you crack open the block and heads, you have a few different ways to go to get more bark out of the 16v's. Bolt on's are easy, quick, less wallet shock and produce instant gratification.

The top end of my 82 is from your old car...nice