964RS

When surfing the internet I stumbled by Ninemeisters site and found that by changing the injector stub there is a premium of 15 bhp. Sounds interesting.

Can Colin or anyone else tell some more?

Best regards
Anders


Copied from the eminent Ninemeisters
--------------------------------------
"12.05 9m 964/993 injector stub

Our development work on the road and race engines found that the standard black plastic injector stub restricted engine performance due to its parallel bore profile. Used in conjunction with a suitable modified 993VR lower manifold section, this injector stub added around 15hp to our 993+3 engine conversion. 6 units required per set."
-------------------------------------

Indycam

What are you hoping to find , info wise ?

964RS

Well, some info about the problem and of perhaps the solution. I'm of course not after the secret of how the exact solution is, I'll still have to pay for that.

/Anders

Indycam

A better flowing intake system . Thats what I understand .
The injector stub is swapped out from one type to another and the new stub flows air better so that more HP is made .


"this injector stub added around 15hp to our 993+3 engine conversion."
If you don't have a 993+3 engine , you might not get the same results .

964speed

What is the cost associated with changing out the injector stub?

Thanks -

964RS

Don't know. It wasn't stated on the Ninemeister website. I could of course made a private question to them, but I thought that there would be some others who are interested in the same thing.

/Anders

Sire

I want to know.

springer3

Me too!

In my experience and in the opinion of an engine tuner I trust, cheap extra horsepower on the 3.6 is not going to be possible. The 3.2 liter left some opportunities, but the 3.6 breathing was designed using computational fluid dynamics (CFD) computer programs. Computerized engine controls and the resonance flap leave very little safe horsepower for after-market tuners to find.

That said, technology has advanced in the last 16 years. I keep an open but skeptical mind about simple/cheap performance mods. There have been a number of very informative and at times heated threads on performance chips and MAF conversions. I am willing to pay for a performance upgrade, but so far I am running a stock engine.

Removing weight and taking out the power steering pump are "low hanging fruit" that will noticeably increased both performance and handling.

lapu01

So, if i lose the wife and 20 lbs I'll gain 16 bhp?
(If I lose the wife, the car probably goes too in the settlement)

dfinnegan

There was a pic floating around the internet recently of a Boxter with the license plate "WAS HIS"!

demonfish

you sell it to a trusted friend prior to starting proceedings...

then buy it back

NineMeister

It's always a dangerous game to take items out of context, as is the case with the 9m modified injector stub, so here's the head's up of what we actually found:

At that time we were dyno testing our first 9m +3 conversion (3.8 upgrade with billet heads, sports cams, mechanical followers) on a 993 Varioram, and as a point of exercise when we first built the engine we decided not to bother gas flowing the intake manifold runners and intake manifold stubs. Suffice to say that following the initial mapping session, the peak power achieved disappointed us as it failed to make the same top end power as the previous +2 conversion. Thus, without doing any other modifications, we removed the intake manifold, ported the runners, taper matched the injector stubs to the runners and refitted the intake system. We gained 15hp on the dyno from this modification on its own before the ecu was re-optimised. Suffice to say we now do this modification on all +2 & +3 conversions.

So, would you gain 15hp from the same mod on a standard VR?
No, you would not, because the standard engine does not demand sufficient flow for the intake manifold and runner to be a restriction.

Would you make any gains from this modification on a standard VR?
Probably, but I doubt that it would be enough of a gain to warrant taking the manifold off and doing this work on its own, although I would guess that it would be beneficial if you were fitting a typical RS cams, ecu & cats upgrade whilst you were there.

Here's the copy of the dyno results, just in case anyone thinks we are trying to pull the wool over your eyes:

964RS

Thank's Colin,

So take an example in my car, a 964RS; it's fitted with a 993 MAF, 21 mm throttle body, 100 cells racecat, rear silencer delete, ECU uppgrade done on the dyno.

Would it be any gain on my car?

/Anders

NineMeister

No. Injectors have to be your highest priority.

kos11-12

hi Colin ,
I though the aluminium manifold on a 964 may be better as it could be gas flowed (it if there is enough materiel) ? can you gas flow the plastic one ??!! any gain power anyways ?

Konstantin 964 C4