NineMeister

Bold statement. With all due respect it is your prerogative to believe what you want to believe. Myself? I prefer to work things out from solid engineering principles.

Back in 2002 I ran the first ever 9m Motec 964RS conversion on stock injectors and achieved 305hp and noted that the injectors were running at 100% duty cycle at full power. We replaced the injectors with the 803's (which is OK on Motec as you can choose the injector current), took the car back to the dyno and achieved 324hp with no other changes. Here is the dyno plot from that final run, showing the crossover of the power curves with the resonance flap fixed open and closed. The second plot from the 9m dyno shows two similar 9m Motec conversions compared to remapped 964s on stock injectors.

jamesjedi

Thanks Colin, I have read a quite a few of your posts. I love it when people like yourself provide input.

I believe Steve was talking about street engines that have been lightly modified. I doubt that my build will be limited by the injectors. A more modified race engine would be. I will not have the parts necessary to yield that kind of power.

It looks like I will not be using the 993 intake, ECU, and injectors. I will try to use my 993 plastic intake.

HiWind

Has anyone got the part numbers and prices for the 993 injectors or the right high impedance Bosch ones?

NineMeister

In relation to the 964 injectors, I firmly believe that they are inadequate for a stock engine and that you only "get away" with using them because the stock ecu runs them practically fully open at full power. In my view if you are not prepared to address this issue first any subsequent modifications you do to your 964 engine would be a waste of money.

In your case using all the parts from the 993 is a great idea. The 55 pin euro 993 ecu package is a much better unit than the 964 and in our experience is good enough for engines up to 360hp with just remapping, hence would support a set of sport cams, ported heads and cat-free exhaust. Don't be tempted to replace the 964 heat exchangers, they are not a performance limitation and will work just as well as the 993 version on this specification.....

jamesjedi

Ok....well I have edited this post due to my selling some things. I sold the 993 ecu a while back. But still have the injectors. Steve Wong said he can use them, but has to scale them. Will they still be worth using with the 964 ecu? From what you are posting...I will try them. I would love your input!


The chip is going to be made by Steve Wong.

So far....

964 long block
993 headers
Patrick Racing air intake
Group B cams
Very mildly ported intake to match the 993 plastic intake
964 ecu w/Steve Wong chip

Thank for any guidance.

jamesjedi

I edited the above post, after rereading the entire post. Thanks.

jamesjedi

At the risk of double posting;

Colin, I am hoping to have the chip made this week. I have been going back and forth between the 964 injector and the 993 injector when used with the 964 ECU and some mild mods to the engine. I would love to hear your thoughts. Should I use the 993 injectors, even though I am using a 964 ECU that is remapped. Thanks for any input.

Here is a thread that I started; https://rennlist.com/forums/964-foru...w-964-ecu.html

NineMeister

I stand by my earlier statements. Since the stock 964RS engine makes +20hp with no more than larger injectors with the same aftermarket ecu, the stock injectors are a definitely a limitation and should be considered to be an essential requirement for any upgrade package.

ThomasC2

Are 964RS injectors really different than stock 964? Never heard that before and there is only one version in the PET program. What is the part number for those injectors? Are they plug&play with the DME or do you have to do a re-map?

NineMeister

No, 964 and 964RS run the same injector. I would guess that the RS would have been fitted with flow matched injectors from new.