Ninemeister 4.0 litre 911 Engine Test

This is the 4.0 litre engine in Colin's 993RS CS being tested on the 9m Racing chassis dyno, the purpose of the test was to see if there is a benefit from running the fuel injectors overhead of the intake tract. We did this to help work experience student Jack with his final year University project who made the temporary adjustable height fuel rail support just for the purposes of the test.

Category:

Autos & Vehicles

Tags:

• 9m Racing
• Ninemeister
• Colin Belton
• Jack Davy
• 993RS
• RSR
• Clubsport
• Porsche
• engine
• dyno

[job1bf]

Cool, do you plan to exp. with different length trumpets? What EFI system are you using. Again, great video. Looking forward to more.

[9mRacing]

We previously tested the engine to determine the optimum intake tract length, the trumpets fitted gave the best top end power without sacrificing a lot of mid range torque.

We're a Motec distributor so we used a Motec M600 ecu with twin lambda and datalogging. I would not use anything else on a project like this, it gives us incredible flexibility to test any combination of injectors and intake with ease.

Thanks for the thumbs up.

[job1bf]

great video of standoff injectors. You can get a really good idea of intake reversion from this video..showing the fuel mist above the intake trumpets at certain RPMs. Great job. What was the conclusion?

[9mRacing]

The overhead injectors made 5hp more (456hp peak) than when located under the throttle plate, but more interestingly after the engine was tuned for highs it then ran lean in places with the injectors back in their side location.

[shogunballa14]

wouldn't the reason for this be that, when the injector is in the side location, its spraying on a different plane other than the direction of air. So, the fuel goes out of suspension thus making it run lean in certain spots. whereas the stand off injectors are squirting fuel in the same direction as the air entering the engine, making the fuel stay in suspension longer than in the side position. I always wondered the difference between conventional placement as opposed to stand offs.

[9mRacing]

@shogunballa14 Yes, the conclusion is that the fuel and air mixes better with high injectors. Hence either less fuel ends up on the walls of the intake port, or the droplet size/atomisation is better such that less fuel lands on the wall of the combustion chamber.

[silversmoke06]

Running a motec you should be able to run twin injectors no problem. Especially for what that system costs.

[welshpug]

ever consider twin injectors? sometimes run as smaller pairs rather than switching, so both run at high revs, finer degree of control of fuelling with the small items, cheaper too!

[daveinamini]

MY MATE DID ONE JUST LIKE THAT