dkcaims

A couple questions for those with TPC SC equipped 964's.
Just trying to be better informed...

1) Mine was installed by a prior owner back in '02. I think that makes it the 1st generation (no intercooler). Here is a pic of the original wiring diagram for the black box included with all my service records. Is the sole purpose of the black box to control the 7th injector?


2) What is the purpose of the 7th injector? Is it simply to enrich the mixture under boost?

3) If so, just out of curiosity... would this item http://www.splitsec.com/products/Enricher.htm be a better solution? Taking the 7th injector out of the loop altogether.
As I understand it and in simple terms, the O2 sensor signal and boost pressure is sent to the SplitSec Enricher, is modified by it and sent to the DME. The DME then pulses the injectors to enrich the mixture under boost according to ideal levels determined while testing on the dyno and fine tuning/adjustments made to the SplitSec Enricher


4) Am I missing something? Seems like a much better solution than using a single 7th injector. Unless there is far more to what the TPC black box and 7th injector does than merely enriching the mixture under boost.

5) If this seems like a better solution than the 7th injector, are the stock injectors up to the task?



Any thoughts?
Thanks!

PNine64

I remember a company in the miata world that added injectors to cool the charge and provide additional fuel to supplement the injectors. Take a look at the "E-cool" section HERE.

dkcaims

Hmmmm...
I would think a meth/water injection system would be better to cool the charge.

PNine64

There were lengthy discussions on that topic IIRC. Personally, I would give the TPC folks a call to see what they recommend. I seem to remember they've had good feedback. I'm sure they've evolved things over time (spent money and lots of trial and error). You could leverage off their R&D while avoiding potential damage. Then again...I'm a wuss when it comes to these kinds of things.

EDIT: I just read your other post and see that you have been working with TPC.

dkcaims

Tried the TPC route, they don't really support the 1st gen SC anymore and did not get a whole lot of information from them. My tech called them too...he wanted details about the black box, but was told that they don't have any specs on it. What do they do, throw away details about early product development?
Sounds crazy to me.

Yeah...still working on getting that running problem solved. Over 35hrs labor so far troubleshooting it.

dkcaims

Discovered that TPC uses the SplitSec FTP1 to control the additional injector and ignition timing on its 993 supercharger kit.
http://www.splitsec.com/products/fue...calibrator.htm
Don't know if that's old information or current.
Still unsure if the original TPC black box on my car controls just the 7th injector or also the timing.
I'll call Split Second on Monday and chat for a bit.
Perhaps they made the black box used on the 1st generation also...

evoderby

1st: 964 injectors don't have sufficient capacity to support more than 300HP,when running a supercharger without 7th injector this requires 6 uprated injectors and complete new mapping.

2nd: when supercharging you not only need fuel enrichment but also need boost sensitive ignition retard, otherwise holes appear in your pistons quicker than you can say detonation.

3rd: running without an intercooler / high inlet temps makes the engine even more prone to detonation, the position of the 7th injector helps cool the charge.

If it ain't broke don't try to fix it?!

dkcaims

Thanks....
My tech is trying to determine if it is broke, hence the query.

PNine64

FWIW...an old thread I thought of this morning HERE. Not sure if it will be helpful. Hopefully you either have a Login or don't need one for that area of the forum.

Oh...have you looked into Megasquirt? I believe a couple of people around here have made it work on 964s. That is supposed to be able to control everything you'd ever want. There was a guy on Pelican who sold a 964 motor with ITBs that was using it. I remember him being very impressed. It is not a band aide and is not as costly as other engine management options.

evoderby

Ah ok, just saw your other thread and the problems you are experiencing.....makes sense now.

dkcaims

Thanks Travis...I'll give it a read

dkcaims

I'll look through all my receipts and see if the injectors were upgraded at some point. Doubt it though...Luckily I have extensive records.
TPC says they never offered an intercooler for the 1st gen SC since it was such a low boost system.
Wish someone could tell me the exact specs.... such as boost levels at various rpm's and max boost for this system.
I'd like to have a baseline to ensure it's working as it was designed. It has the stock pulley.

...and let me say that my goal is not create a fire breathing monster, I just want everything to work properly and efficiently.
If the 7th injector and current piggybacked ecu when working properly is the best solution, I'll leave things alone.
However, if there is a "better way" then I'll consider it.

PNine64

For the heck of it I searched "TPC" and went back to the oldest posts I could find. Some of these old posts are liable to have some of the details you are looking for. I also saw a comment about a "Sept '01 Excellence article".

dkcaims

I have that article in my service records, I'll look it over again.
I'll check the 993 boards also... I think there are more 993 owners with this system than 964 owners.

Marc Shaw

Wouldn't be too hard to figure out for yourself with something like this.

Marc