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-   -   Road Race EP Fuel injection ???'s (https://www.rx7club.com/race-car-tech-103/road-race-ep-fuel-injection-s-188727/)

T_Racer 05-21-03 11:21 AM

Road Race EP Fuel injection ???'s
 
Need help with a question. Right now the car is 1st gen with 13B, side draft Dellorto, fully gutted, stock ignition modified with MSD and direct fire coil setup. I am needing info to go E Prod racing, SCCA of course. For E Prod, I am required to run the original fuel injection components as I understand it. Although now, obviously needing to know if anyone knows of any mods that can be done or has a simialar setup that has some tips. I know that first gen GSL-SE's have some of the largest injectors stock, and I believe there is a pair on the shelf that is being protected by layers of dust. :D I am not sure if this is clear enough, but does anyone have any tips, ideas, contacts to call? Thanks in Advance.

Travis

maxpesce 05-21-03 12:21 PM

My understanding (from discussions w/ Jim a Mariah) is that to run FI on a 13b in E prod. you have to use the STOCK intake manifold BUT the Injectors can be modded/upgraded (iirc). If you run a Carb you also get to run any custom manifold. - They (Mariah) run a carb on the FROG TEAM RX-7 b/k it alows them to run a very efficient short runner manifold for maximum top end power. The stock FI manifold will give slightly more bottom end torque (good on the street) but dosen't flow worth s**t above 6000 rpm, Bad for the TRACK.

buttlips 05-21-03 01:03 PM

The only guy who has had any success with the 1st gen fuel injected 13B motors in EP is Mike VanSteenburg. His company is called ISC racing. His number is (863) 324-4539.

tims 05-21-03 02:05 PM

in EP you can run the stock injection manifold and throttle body or use a weber type carb and manifold. this year there was also an increase in the size of the venturi's for the carbed engines. this has made about a 20hp advantage over most of the FI engines I have seen. the carb setup is much easier to develope and maybe better setup at the present time. I am working on my own EFI EP 13b motor right know and we will see how it works against some of the fast carbed engines.

Bern 05-22-03 08:49 PM

Guys,
I think the dilema comes from running a 13B GSL-SE 1st gen car. The non GSL-SE 12A cars are allowed to run the weber type combo but, if I am not mistaken, the 13B 1st gen cars must run the OEM FI. I'm not sure if I am remembering this correctly or not... obvisously you should check the GCR manual.

The main adavantage of the 2nd gen FI system is that it has the "potential" for a lot more air flow than the IDA carb w/42mm venturi's. The down side is the atrocious OEM FI manifold design for racing purposes. The runner length and design just don't help it much at the top-end. Another drawback, is that one should switch to an aftermarket ECU to control and tune the FI system. That being said, there are a few folks around the country working fevershly to solve and improve this situation, there-by taking advantage of the "potential" air flow and power.

Mariah Motorsports has both carb and FI systems for EP cars. Give Jim a call.

-Bern

Bern 05-22-03 08:51 PM


Originally posted by tims
<snip> I am working on my own EFI EP 13b motor right know and we will see how it works against some of the fast carbed engines.
Tims, who are you working with on this project? What ECU are you running?

Thanks,
-Bern

tims 05-26-03 10:56 PM

I am using the Haltech E6K, but AWR built an EP car which is using Motec. their engine has had alot of developement and they are still down on HP to the weber cars because they can now use a 44mm venturi this year. this has given the carb about a 20hp advantage. until the SCCA allows the FI cars a larger throttle body(or a manifold similair to the weber) or restricts the venturis on the webers it may be tough. my engine is finished and in my shop. it has some unique porting that my engine builder thinks may help, but the tuning and testing should start in a month or so. I hope to race it next at NASA's Hyper fest at California Speedway.

Bern 05-26-03 11:30 PM

I know Mr. Gist car (AWR car). It's a very nice set-up. Although, he's had a very steep development cycle.

BTW, the EP cars are now allowed a 42mm venturi not 44mm, but most of the advantage is still in the intake manifold, with the carb set-up still having an advantage. The OEM TB should still outflow the carb, but the OEM intake manifold is still the biggest challenge. The next year or so should be very interesting, as far as 6-port EP motors go.

Dave at Mazdatrix, is running what I feel are the most powerful EP 6-port motors around. Dave has taken great lengths to dyno test and verify his set-ups.. He's also a great carb set-up guy. Check out his ride at a local race if you have a chance.

Tims, who is your engine guy? Is he local?

BTW, I'm local to you in N. Hollywood.

Oh yea... God willing, I'll see you at the Hyper-Fest. The So-Cal RX Club will be in attendance.

Cheers,

-Bern

tims 05-27-03 08:17 AM

yes, I am very familiar with Dave Lemon's car. it has all the same suspension as Gary Gist's car all from AWR. you are right that Lemon's engine has a big advantage at the moment and it is mainly due to the increase in venturi sizes(Dave is also a more experienced driver than Gary). the AWR car has had several engines and porting configurations, but it is still down to the weber engines. even the FROG car seems to have a bit more than the FI cars. I don't know the particulars of the porting on Lemon's engine, but the FROG engine was built by my engine builder. the porting on my engine is a little different but internally it is the same(rotors, apex seals, etc). yes my engine builder is in Palmdale his name is Pablo Mobius. He has been building rotaries for decades. has built engines for IMSA GTU teams and developed some of his own porting techniques. If you are in need of an engine builder let me know and I'll help you get it done.

maxpesce 05-27-03 10:40 AM

Wayne & Jim (Mariah / Frog team) are now building their own motors and will soon have their own Chasis & Engine Dynos, and Flow Bench up and running. They have used Mobius motors in the past but (I believe) they have blown them all up.
Berny may know better though.


PS this is my 1500th post! :D

Bern 05-27-03 04:42 PM

Yes Jim and Wayne (FROG Team) used a Pablo motor in the past, but that was a while ago (2 or 3 motors ago). Wayne and Mariah have been building, porting and developing their own engines over the last year. In all of the newer FROG Team motors, nothing remains of any of the original Pablo work. All the seals, porting, rotors are different. BTW, I know Pablo, he's a great guy and builds good motors.

Actually Max, Mariah has had the Chassis Dyno up and running for a little while now and the Flow Bench has been in service for a good spell also.

Tims, thanks for the info. Best of wishes and continued success on the project. If you ever dyno it, let us know how you did.

-Bern

maxpesce 05-27-03 07:17 PM

Shoot they worked fast on the Flow bench, they were just unpacking it when I was there a week ago Friday (5/16), I know they had the dyno itself running but it wasn't set up w/ data recording or w/ enough cooling for mutiple runs last time I was there. I will be stopping by there on my way home from work tonight. (in about ten min :d)

tims 05-28-03 10:27 AM

Bern,

I am curious what "different" rotors and seals they are using. not many choices out there. porting is always different even from the same porting hand. I would assume they changed to ceramic apex seals and lighter rotors? I have done this to my motor as well(not using the ceramics though). I have also found a contact that does alot of custom machine work for a few of the big name engine builders and he will do the same work for me if I want. it is good to see people are still trying to develope the rotary engine(by adding flow bench and dyno), but nobody seems to be developing any new parts. we are all still curious if any of the new renesis motor parts will be interchangeable with the old 13b. I may dyno the motor but lap times and durability are what I am looking for so I will let you know how it goes. I don't have any runoffs aspirations, so I am out there to have some fun and race as long as I can on my small budget.

Bern 05-28-03 02:32 PM

tims,
At the risk of getting in hot water.. I can confirm the ceramic seals and light rotors.. nothing really out of this world or secret, but the porting is definitely being developed and honed constantly. What I meant was, "different" from the original Pablo motor. I can say that there are a few of the big names out there, throwing development at the 6-port now and we should start to see some new things in a year or so, I would think and hope!

As far the RENESIS goes, it still a wait and see. Mazda is pushing the SCCA to allow them to run in GT class. The Star Mazda guys have done some development on the motor and feel there is big potential there. Not to sure of what, if anything, will really swap to the older B motors yet.

If you really want to see some of the newer stuff being developed for the B motor, look to Australia. These guys are doing some real nice work with their GT type racing engines. I hear 350-360hp out of custom FI n/a PP motors.


I guess National Level Racing can be serious business, but it's great fun!! :D

Cheers,
-Bern

tims 05-28-03 03:09 PM

I wish the dollar was tronger so I could afford some of the parts the Aussies are developing. there are alot of trick parts available for the rotary platforms that are just not economically feasible right now. I hope you and I can both make the hyper fest race.

Bern 05-30-03 01:53 AM


Originally posted by Bern
Actually Max, Mariah has had the Chassis Dyno up and running for a little while now and the Flow Bench has been in service for a good spell also
Correction here guys, I was at the shop today and the Flow Bench was not operational yet. It will be very soon though. Some of the recent/previous flow bench work was not done in house. Also the engine dyno is very close to be fired up.. both the engine dyno and flow bench are very nice Superflow units. The Chassis Dyno is up and running though.

Sorry for the previous incorrect assumption.


-Bern


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