New Build - GTM Rescue

[Apexspeedtech]

Hello all!

A friend rescued this incomplete GTM project, now I'm helping bring it back from the brink, and look forward to sharing our experiences and hearing your ideas.

The last pic with that catalytic converter pretty much sums it up - exactly how many ways can you kill a car within minutes of starting it? I think that the previous shop had a Golden Retriever that took a liking to the car - I am a dog person myself but have never seen that much hair in a vehicle, let alone one that never drove!

Still, the bits are all there and we have some great motorsports gear going in: MOTEC engine management system/MOTEC C1212 LCD dash display/Bosch motorsports ABS. It will have integrated traction control, launch control, and speed-adjusted ride height. There's a lot to do and I look forward to sharing!

View of the top
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525hp Turn-Key LS2
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View from the front
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Oh boy.....
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[Shoeless]

That sounds like a heck of build plan, can't wait to see more!!

[Apexspeedtech]

That sounds like a heck of build plan, can't wait to see more!!

Thanks! This is going to be a cool projects for all of us. I'm a "retired" motorsports engineer, working with another "retired" motorsports engineer, and our buddy Lou's car was just too cool to let rot like it has been. I've been working on high-performance custom streetcar projects for the last 8 years or so on the side since I stopped going on the road, but never had a chance to work on anything from FFR.

The first question I had what I posted in another thread about front shocks - does anyone have drawings/specs/part number for the KONIs so I can get KW equivalents?

Thanks,
Neel

[Shoeless]

Its always awesome to have more GTM builders around. I guess I started mine (about 3 years ago) after the main peak of GTM builders a while back.

I ended up going with Bilstein coil overs from Quick Racing Products, so I won't be much help on that question.

[crash]

Ping RR46 as he is my driving partner in the endurance races with the FFR PDG GTM race car and he just "restored" a GTM bought on Copart. I know he just ordered some shocks from White Brother or KW or some such for the street GTM and so he should have those specs. You might want to also check out his re-build threads.

[Apexspeedtech]

Ping RR46 as he is my driving partner in the endurance races with the FFR PDG GTM race car and he just "restored" a GTM bought on Copart. I know he just ordered some shocks from White Brother or KW or some such for the street GTM and so he should have those specs. You might want to also check out his re-build threads.

Thanks, I just read his posts on the car, are you guys based in California? By the way, I think the speed-sensitive steering module you built is really interesting; I'd like to control this with the MOTEC. Can I output a square-wave signal from to your unit, which I can then connect to the MR2 steering pump to get the feel that I am looking for, or - if you're willing to share - does the MR2 power steering pump simply take a PWM input for a speed signal?

We're designing this car with multiple drive modes: Track, Street, Wet, Valet. Each one will have unique settings for ABS, Traction Control, ride height & (potentially) steering effort, so I'll be looking for a good way to do the latter.

Cheers,
Neel

[crash]

The controller is really a bridge between the wheel speed sensor and the onboard PWM controller of the MR2 pump. If your ECU has the counter and PWM outputs that are required then you don't need the stand alone unit that I sell. That is the beauty of using the MR2 pump in that all the high power side is taken care of and variable right from Toyota. All you need is the low power signal controller.

[Apexspeedtech]

The controller is really a bridge between the wheel speed sensor and the onboard PWM controller of the MR2 pump. If your ECU has the counter and PWM outputs that are required then you don't need the stand alone unit that I sell. That is the beauty of using the MR2 pump in that all the high power side is taken care of and variable right from Toyota. All you need is the low power signal controller.

I'm finding all sorts of references online on how to do it, but not some simple info I'd need to use a PDM output to control it. The MOTEC C121 has PWM outputs where I can vary the duty cycle based on a table such as drive move switch position versus ground speed. Might you know what its look for at max and min assist so I can program the table?

Thanks,
Neel

[crash]

I don't know if you read the instructions that I posted here http://myraceshop.com/Power_Steering_Controller/controller%20MJS.pdf but while a specific voltage and/or pulse width is not listed it does tell you what it does in percentages.

Please note that in order to reduce the pump pressure down to where the feedback is really good at high speed the pump Hz can get down to where some pulsing is felt in the steering wheel. In order to mitigate this a different torsion bar needs to be used in the Mustang rack. If you are using a different rack setup, then this is likely another factor you will need to address.

[KGTM]

I don't know if you read the instructions that I posted here http://myraceshop.com/Power_Steering_Controller/controller%20MJS.pdf but while a specific voltage and/or pulse width is not listed it does tell you what it does in percentages.

Please note that in order to reduce the pump pressure down to where the feedback is really good at high speed the pump Hz can get down to where some pulsing is felt in the steering wheel. In order to mitigate this a different torsion bar needs to be used in the Mustang rack. If you are using a different rack setup, then this is likely another factor you will need to address.

Hi Crash,

what do you mean by Pump Hz? I do not see this or at least have not felt it, the frequency goes up with speed and it only goes down so much from assist point of view.

My general frequency for controlling this pump is about 20 Hz at low speed and 2200 Hz at high speed, above this is all the same. at speeds above 60 I have it set to almost max speed, so least assists

Mostafa

[crash]

That is good if you have not experienced the "pulse issue". Some folks do and some do not. It is not talked about in the instructions so I like to mention it to head off any potential problems.

[KGTM]

Thanks for the update.

Mostafa