jamesjedi

Hi,

Is it still believed that the 964 injector will be good for 305hp?

I have the parts to use 993 injectors and ECU, just having second thoughts on there use.

Thanks for any help.

Sire

I thought Geoffrey and nine meister said; that the standerd injectors is the bottleneck if you want to gain more then 300 HP.

jamesjedi

If it will do 300hp, that will work for me.

NineMeister

308hp is the absolute max that we have seen on our dyno on a stock 964RS, Cup or other with stock 964 injectors with most 964 Cup cars making at best 305hp.

jamesjedi

Thanks for the replies.

That is good news. I have been a little off track with buying some 993 parts (ecu, plastic intake, throttle body, injectors). I need to re-configure my plans. Hopefully I can still use the plastic intake.

ALEX P

So if the stock injectors are maxxed out at 305 - 308bhp, what would you recommend swapping them for after that?

Obviously different injectors means a remap but interesting to know as there must be quite a lot of folks running injectors on or near the upper limits of their capacity/flow rate.

robt964

>Obviously different injectors means a remap

You won't necessarily need to remap, just rescale the map.

jamesjedi

Here is what I started;

M64-01 964 long block. Engine is not running at the moment. After doing more research, and talking to Steve Wong, I am starting to think that I should just use the 964 ECU, wiring harness, injectors, intake - unless my 993 plastic intake runners will work 964 injectors, manifolds, throttle body etc.


I was planning on using;

-993 ECU
- 993 plastic intake (with throttle body)
- 993 wiring harness
- engine Group B Super Cup (964.246.071.2) cams installed w/0.57 overlap
- 993 headers w/flipped flange
-Steve Wong chip

Thoughts would greatly appreciated. Thanks.

-nick

Strictly academic-

Are the injectors just at the top of an okay duty-cycle at the 300hp level? Or are they truly maxed out and going lean? In other words, is it still safe to run them at those power levels, or is that the edge of catastrophy?

Is there any margin to increase fuel pressure?

Maybe someday I'll approach these numbers and will need to know. And say goodbye to any competitive event classes!

jamesjedi

I am not sure if being lean is an issue at 300hp, it seams that many are running that and a little more. I am not the one with answers in this field.

jamesjedi

This is very confusing to me. I just read this;

Jeff, didn't I read a thread where you were asking about rebuilding your engine? The bottom line is that a fresh rebuild with a face skim & proper valve job on the heads will easily make more power than changing the intake manifolds.

As for fitting the 993 exhaust onto a 964, the problem that you have is with the opposite hand exhaust flange alignment of the RHS 993 heat exchanger to the 964 head, so without cutting and re-welding the flanges in the 964 position they will not fit. Furthermore, even if you do get them to fit I doubt that they will yield any more power than stock even with a live remap because your fuel injectors will be running flat out to keep up with the demand....

Hope this helps.

__________________
Colin Belton B.Eng.

ALEX P

Jamesjedi, I forgot about this thread and in answer to what injectors you can replace the stock 964 items for: Bosch 803 (944 turbo injectors)

https://rennlist.com/forums/964-foru...injectors.html

I'm currently flipping the flanges on a set of 993 heat exchangers and it isn't a bad job. There's a good write up on how to do it here:

http://forums.pelicanparts.com/porsc...tml?perpage=20

jamesjedi

Thanks Alex. Looking at injector post.

I already have the flipped flanges, they are the engine.

jamesjedi

I hope Steve Wong does not mind my showing what he sent me. I would like to think it could help others.

I believe Porsche underrated the 964 power ratings so they had an upsell when the 993 came out. In many dyno tests performed on 964s and 993s, one chip tuned for optimal power, both engines generally test out making almost the same hp at the wheels, around the 252-256 rwhp range. Injectors have never been a limiting factor on a street 3.6 964, regardless of what you read on the internet.

NineMeister

You cannot replace the stock 964 injectors with the low impedance Bosch 803, the stock is a high impedance injector and needs the same specification to run with the stock Motronic ecu.