TPC Supercharger and a 993
10-25-2007, 01:43 PM
#31
Race Director
Instead of the somewhat "hokey" 7th injector, why have people not used larger fuel injectors? Im not sure what the standard size is on the 993 (id imagine it to be around 26lb/hr or so), but if the connectors are the same, there are a bunch of bosch pintle style injectors that would provide more than sufficient fuel flow (42lb/hr for instance).
10-25-2007, 02:05 PM
#32
Weathergirl
Rennlist Member
Rennlist Member
Agree totally--that just sets off warning bells. If they can't figure out how to remap the ECU for longer duty cycles or for bigger injectors, just how competent are they in general? If they use one hack, they probably use others...
10-25-2007, 02:39 PM
#34
I think that sums up what many of us think... it seems like a very hokey solution, not befitting a car like this.
10-25-2007, 04:06 PM
#35
Rennlist Member
This hokey 7th (and now 8th) injector is what's kept many of us from pulling the trigger.
10-25-2007, 04:08 PM
#36
Drifting
I'm guessing here, but it's probably because they didn't want to bother reprogramming the ECU. Most of us believe they should have just bit the bullet and done it right. Other reasons may include (1) cost of new injectors, (2) cost of a new $1800 DME for all 1996 owners since they can't be chipped, (3) lack of adjustability in a one-size-fits-all chip (as opposed to this black box that I assume you can tweak in situ).
This hokey 7th (and now 8th) injector is what's kept many of us from pulling the trigger.
This hokey 7th (and now 8th) injector is what's kept many of us from pulling the trigger.
10-25-2007, 04:18 PM
#37
Burning Brakes
What about the 9m billet head package? it delivers similar power and is still NA with no messing about. I have just had mine installed and am just waiting for the live re-map, but what an upgrade, and what a difference! I looked at both options and have to say I was much more comfortable with the clean and simple package of the 9m heads.
10-25-2007, 04:34 PM
#38
Weathergirl
Rennlist Member
Rennlist Member
It is inconceivable that heads would deliver the midrange torque boost of forced induction. With our absurdly tall gearing, an extra 100 ft-lbs of torque between 2500 and 5000 rpm will make the 993 far faster and more fun on real world roads than more hp up top.
10-25-2007, 04:52 PM
#39
Addict
Rennlist Member
Rennlist Member
I understand Todd at Protomotive has done at least one reprogrammed Motronic ECU that does away with the 7th injector and the TPC piggyback ECU. My mechanic installed and did the testing on his dyno. I don't know if there have been any others, if this is a regular product or a one-off. My mechanic says it works great.
Greg H.
Greg H.
10-25-2007, 05:05 PM
#40
Burning Brakes
It is inconceivable that heads would deliver the midrange torque boost of forced induction. With our absurdly tall gearing, an extra 100 ft-lbs of torque between 2500 and 5000 rpm will make the 993 far faster and more fun on real world roads than more hp up top.
10-25-2007, 05:12 PM
#41
Three Wheelin'
Why not a purpose built (lower compression) 4.0 liter motor with both the 9M heads and and the TPC package along with larger injectors and a chipped/reworked DME. Go crazy! . . . J/K 
10-25-2007, 05:38 PM
#42
Race Director
I'm guessing here, but it's probably because they didn't want to bother reprogramming the ECU. Most of us believe they should have just bit the bullet and done it right. Other reasons may include (1) cost of new injectors, (2) cost of a new $1800 DME for all 1996 owners since they can't be chipped, (3) lack of adjustability in a one-size-fits-all chip (as opposed to this black box that I assume you can tweak in situ).
This hokey 7th (and now 8th) injector is what's kept many of us from pulling the trigger.
This hokey 7th (and now 8th) injector is what's kept many of us from pulling the trigger.
10-25-2007, 06:46 PM
#43
Drifting
10-25-2007, 07:19 PM
#44
Addict
Rennlist Member
Rennlist Member
You need programming to tell the injectors when to deliver additional fuel. It isn't going to be the same as an N/A engine. TPC includes a piggyback ECU that works with your stock ECU to tell the additional injectors when to deliver fuel and how much. I don't think the TPC ECU changes the stock programming, it just adds fuel as needed. If you want to eliminate the additional injectors, you need to reprogram the stock ECU.
Greg H.
Greg H.
10-25-2007, 07:27 PM
#45
Race Director
Does the "7th" injector come on line only during certain boost conditions or what? Or: if 42lb injectors were used would they only deliver "additional" fuel when needed? If the 42# injectors would work - why not use them??? Maybe we could invite a guest speaker from TPC to come in and brief the system for us.
With larger injectors, a tuner would have to reduce injector pulsewidth for vaccum conditions along with messing with the maf x-fer functions in order to deliver an a/f at cruise that is as close to 14.7. Then when you stomp on it, the larger injectors open the flood gates so to speak.