9444Alexis

Great pix and explanations...Ilike the fuel cell slosh solution..makes sense. I doubt my car will go fast enough to need a lot of mods. I do realize, in so saying, that I will be bitten by the mod bug and have to figure a way to support my habit!

^'o'^ (OK, I am resorting to ascii art, need coffee.......)

Brian 944

Kewl, I do think that the Goal is very high and every bit helps. I have alot of options to make the car faster and that is a great suggestion.

Reducing Drag under the car is another...

Brian 944

I experienced the fuel problem in Turbo Mazda. We have several traffic Circles here in N.B. and some just beg for 3 or 4 laps..

Luis de Prat

Thanks for sharing this amazing project with us, and welcome to Rennlist!

M758

Ok.. you are getting close then. However the door glass adds extra weight and I amsure you will need a lexan hatch & rear side windows to get to weight. You probably will need to strip the rubber undercoating too. Also get a fiberglass rear bumper. That will save you 15 or so lbs.

How much weight does the supper charger add? BTW... replacing the stock tank with a fuel cell is VERY hard and not worth the effort.

There is guy here who goes by "RedlineMan" he did that in his track car. Said it was the biggest pain in the rear every. And for a living he does race car fab. So that tells you something.

As for fuel starvation... I have run my race car down and fuel starvation is NOT a problem even on stick race tires and a track suspension. The way the 944 tank is designed it has a seperate reservior for the fuel pump. I once ran out of fuel on track during long enduro. I had fuel startvation issues only when I had something like less than 1 gallon of fuel left. Typically I can run the tank well below when the reserve light comes on and still keep full power.

Keep the stock tank.


BTW.. 210-220 rwhp will get you to 160 mph not the 186 you want inspite of the light weight. My stock 944 Turbo S put out 230 rwhp at dyno day and it maxes out at 160 or so. Although I have not feel the need to test that.

My 944 race car maxes out at about 132 mph on the race track. Given a long straight road I might be able to make it see 140 mph, but would probably need to move to a taller 5th as with my 924S 5th gear and shorter tires I hit 132 mph at about 5800 rpm. However it is the perfect gear for racing as 132 is about the max speed I can achieve given the lenght of track I go to. This is with 134 rwhp on a stock motor.

Brian 944

Thanks for such an informative post. Unfortunately the Gas Tank is already out and sold. I decided to do it when the 968 Six Speed went in.

There is alot of extra "Fat" that can be shaved off but none of it will help me break the 180 Mark. Now it's all about Power and Drag.

I'm going to assemble it and run it to see what my terminal velocity is and if it's close try some tweaks to slip the drag down. If it's off by like 10 MPH a 25 or 50 shot will be added. If it blows, then I'll just have a reason to drop the compression to 8.0 and Boost 15 Psi with an intercooler and interesting Fuel Delivery...

Brian 944

Ok, Today I made a cool discovery...

I have seen thousands of 165 Mph Porsche Speedometers, but when I researched it, there was a 180 Mph Speedo available for one or two years on certain models. I waited on E-Bay for two months for one to show up and won it.

Here is the Cool thing.

My car came with a 275 Km/H Speedo (Canada)

It was broken. I replaced it with a Rare 180 Mph Speedo but it was in bad shape.

I Won a second Broken Speedo with Indoglow that had a good case and glass to fix the 180 Mph Speedo that I won.

When I removed the indiglo off the second Speedo to sell it, The Speedometer had a 165 Mph “IndoGay” cover was covering a 180 Mph Speedometer.

Thus I have One that is for my car in mint condition and a second one that I do not need.

They are $300.00 on E-Bay..

Keithr726

I've seen your page on cardomain before. Nice Work!!

86 951 Driver

How are you going to control fuel? I am wanting to supercharge my motor, but I can't figure out how you would tune the fuel with the stock AFM?

95Juan

holy crap that is f*cking nice.

that's what would have happened to old blue if i had the time, money and knowledge to do all of that.

also love the DDR avatar. ever seen a 6'7" 400-lb mexican dancing on a video game?

Brian 944

http://www.sdsefi.com/eic.html



Right now the plan is a FMU, Rising Rate Regulator. It's fairly limited.

The name explains it all. The car runs completely stock untill boost is applied. This device replaces the stock puel pressure regulator and has a vac hose from the intake manifold hooked to it. When the boost crosses over 1 Vac, the fuel pressure starts to increase in the fuel rail.

Much like a toy supersoaker watergun. The more pressure you have in the tank, the more liquid comes out.

It is a reliable and inexpensive solution that many people use but should be limited to lower boost below 9 PSI.

My Mazda has a pair of extra injectors that are controlled by an EIC-2. It's going to probably be added to the FMU on the 944...

"Adding fuel" based on RPM and Pressure. It is a far cry from a proper system such aStandalone, but it is reliable and very capable of running increases well over 300HP as long as the injectors used can deliver the volume of fuel required.

The Idea is this, on a non turbo charged car, the ECU and injectors were designed to maintain balance during the normal use of the car. If forced induction is present on the car, but it never goes into boost, The car will drive normally and not require any additional fuel. The EIC is usually set to come on at the boost threshold, Neutral Vac or 0.5 PSI Boost. When you need the fuel due to boost, the EIC will start adding metered amounts of fuel based on the setting that the driver inputs. The EIC requires different injectors than normal, so rather than just being pulsed by a timed duty cycle. They can be pulsed and metered. It’s rather sweet.

RPM: The EIC has to know how fast the engine is turning. The reason is this. An Engine running 6000 RPM at 5 Psi of boost requires double the extra fuel that an engine at 3000 RPM at 5 Psi of Boost. The Tachometer signal is transformed into a “Duty Pulse”. There will be twice as many pulses at 6000 RPM than 3000 RPM, so that solves the requirement for the variable fuel requirements based on RPM.

Pressure: The EIC has to know how much boost is being put on the motor. The reason is this. An engine running wide open throttle at 10 Psi requires a lot more fuel than an engine at 2 Psi. The pressure is what determines how much the injectors open for the duty cycle that the RPM sets.

These two “Fuel Ramps” are set by the driver with the aid of an A/F or Wideband A/F.

Threshold and Gain are the usual adjustments.

Threshold: Where in PSI will the unit turn on.
Gain: How much it will turn on based on PSI.

Setting the unit is rather easy.

86 951 Driver

My problem is I have heard that the car will not allow that since the AFM can't handle boost. It can only handle seeing vacuum. My understanding is that once boost is seen by the afm the computer will try and return the car to idle settings and cause it to go lean. If all I need is a rising rate fuel regulator and a supercharger mounted then what costs so much. Please if you could explain to how this could work. I would only want to run about 5-6 lbs of boost. At the most 7.

SamGrant951

Welcome - I looked through your project once on a Mazda forum. Impressive work - good luck and keep us up to date.

Brian 944

Does the Car have a MAP or MAF?

86 951 Driver

It has a AFM. It is a flap design. It is at the end of the j boot connected to the intake manifold.