Anyone using TWM Throttle Bodies?
09-10-2009, 03:30 PM
#17
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The engine rpm is limited to 7000rpm max by the stock rods, pistons & valve springs. Unlike the standard engine, when you drive this car it does accelerate up to the rev limit incredibly quickly and you are well aware that the engine is still pulling strong when it gets there. Because of my experience driving and mapping race engines that you can comfortably drive past the peak power & hence use the additional area under the curve, I really missed the 1000rpm capability past the peak power rpm.
09-24-2009, 01:37 PM
#18
Rennlist Member
Reading the manual for the Motec knock module, I note that they give an example of a car's knock programming being changed simply by adding a roll cage and changing the resonant frequency of the chassis.
If the knock sensor tuning is this sensitive then the only way it can be tuned is driving the car, right?
If the knock sensor tuning is this sensitive then the only way it can be tuned is driving the car, right?
09-24-2009, 02:00 PM
#19
Nordschleife Master
Knock tuning can be done on an engine or chassis dyno, but it needs to be validated on the track for the reason you mention. Engine mounts too are an issue. This issue is in finding a frequency where knock can be identified from general noise like might be transmitted through a roll cage or through a solid engine mount.
I've seen an issue with a solid engine mount in a Corvette causing the engine to lose performance due to the computer removing timing due to its inability to distinguish knock from noise.
I've seen an issue with a solid engine mount in a Corvette causing the engine to lose performance due to the computer removing timing due to its inability to distinguish knock from noise.
09-24-2009, 03:00 PM
#20
Rennlist Member
Geoffrey- Would it be easy to integrate the Motec knock sensor to the Porsche piezo sensors and bridge or do you have to use other sources for sensing hardware.
09-24-2009, 05:05 PM
#22
Rennlist Member
I am an old carburetor & mech. FI guy, but I have been intrigued with a Motec ECU FI engine for some time, but have not been there yet so I need to learn.
I have inherited an '04 GT3 long block sans intake and exhaust with a hole in the crankcase from the wreck it was in.
I am debating what to do with it, my plan is to rebuild it with a new case, eliminating the Variocam using Cup GT3 intake cams, then I need to figure what to do for exhaust and intake.
What I am reading here is that it should be easy to add an individual throttle body kit if I machine up some adapters for the GT3's 4 bolt intake ports, add some headers and a Motec for the ECU using all the GT3's Bosch ignition coils, hall cam and crank position sensors, knock sensors, temp sensors, etc. then put it on the engine dyno for tuning then into a chassis for final knock sensor touch up on the road (to run on our 91 octane horse pee here in CA).
Correct? Or am I missing something?
I have inherited an '04 GT3 long block sans intake and exhaust with a hole in the crankcase from the wreck it was in.
I am debating what to do with it, my plan is to rebuild it with a new case, eliminating the Variocam using Cup GT3 intake cams, then I need to figure what to do for exhaust and intake.
What I am reading here is that it should be easy to add an individual throttle body kit if I machine up some adapters for the GT3's 4 bolt intake ports, add some headers and a Motec for the ECU using all the GT3's Bosch ignition coils, hall cam and crank position sensors, knock sensors, temp sensors, etc. then put it on the engine dyno for tuning then into a chassis for final knock sensor touch up on the road (to run on our 91 octane horse pee here in CA).
Correct? Or am I missing something?
09-24-2009, 10:50 PM
#23
Nordschleife Master
No need to remove the variocam as MoTeC can (and I have) control it. I have a better option for coils (plug and play) than the stock ignition coils which simplifies the wiring and eliminates the need to purchase two three channel ignitiors. Cases were about $1500 last time I checked. Depending on what you want to do with the engine, you could get a stock intake with resonance flap, or ITBs. Or even better a DBW throttle body from a Turbo with the turbo intake system.
But, yes, basically what you say is true.
But, yes, basically what you say is true.
09-25-2009, 01:02 AM
#24
Rennlist Member
The GT3 engine has 6 individual coils, 1 atop each plug, why does one need the three channel igniters- are you thinking air cooled?
09-25-2009, 07:59 AM
#25
Nordschleife Master
The inductive ignition on a GT3 requires an ignition driver. The Bosch ECUs (3.1MS and 5.2 or 7.x street) have them built into the ECU. The MoTeC ECUs do not have any type of ignition driver built in and will require an external one. The reason for this is that the MoTeC can drive both inductive and CDI ignition systems with the same output. Further, the drivers run very hot, so separating them from the ECU allows the ECU to run cooler. The ignition coils I'm referring to have an ignition driver built in, are a direct bolt on for the stock coils, and are FAR, FAR better in performance and reliability.
So no, I'm not thinking air cooled.
So no, I'm not thinking air cooled.
11-19-2009, 02:05 PM
#27
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Is it possible to do ITBs without giving up the midrange torque? Maybe gaining midrange?
Bob
Bob
In my experience there are possibilities to gain power with ITB's on a standard engine provided they are complemented by a suitable equal length header package and engine management system, however I can understand others being sceptical about the results because the degree of gain caught me by surprise.
My customer came in with stock 911 Carrera 3.2, we dyno it then remove the engine. In goes a 993 Varioram engine on 9m throttle bodies with 9m equal length headers and (of course) Motec engine management (on stock ignition system). The dyno results show the stock 3.2 engine in green (234hp), the 993 ITB engine in red & a similar motec equipped 993NVR engine for comparison. As can clearly be seen, the ITB & header package makes significantly more power at the top end at the sacrifice of a small amount of torque in the mid range, however the fun is cut short by the self-imposed 7000rpm rev limit.
The complete 9m ITB package including twin cable linkages, insulators, annodised CNC billet manifolds, throttle bodies, fuel rails, carbon air horns & air cleaners costs £2590 excluding shipping & taxes.
My customer came in with stock 911 Carrera 3.2, we dyno it then remove the engine. In goes a 993 Varioram engine on 9m throttle bodies with 9m equal length headers and (of course) Motec engine management (on stock ignition system). The dyno results show the stock 3.2 engine in green (234hp), the 993 ITB engine in red & a similar motec equipped 993NVR engine for comparison. As can clearly be seen, the ITB & header package makes significantly more power at the top end at the sacrifice of a small amount of torque in the mid range, however the fun is cut short by the self-imposed 7000rpm rev limit.
The complete 9m ITB package including twin cable linkages, insulators, annodised CNC billet manifolds, throttle bodies, fuel rails, carbon air horns & air cleaners costs £2590 excluding shipping & taxes.
11-20-2009, 04:19 AM
#29
RL Technical Advisor
11-20-2009, 11:31 AM
#30
Rennlist Member
Has anyone tried these from Hargett Precision Products? They can be made in any diameter a buyer calls out for throttle body and port and have thread in velocity stacks of your choice of length. Sealed ball bearings throughout. All CNC machined with cable throttle linkage.
http://www.hargettprecision.com/prod...roducts_id=133
http://www.hargettprecision.com/prod...roducts_id=133