Paul's R32 Gtr Track Build

[Russman]

What power steering coolers are you running? I had big problems with boiling power steering until I used a silvia auto trans cooler. Worked wonders.

[Roy]

Yes mine get heavy for no apparant reason. Some times it is like u have to wrestle the car at PI.

I am definately going to do something funky. At the very least an mr2 electric hydraulic pump plumbed into the system.

Maybe a full electric servo system like epas. This looks to require a whole new manual rack though.

LOL, $10 your belts are a tad loose Why complicate a simple thing:)

[355GTS]

Roy,

you mean to say that I put mega dollars into a racepace built car and it goes to the track with loose belts? Loose belts are usually obvious with noise. I am confident that is not the issue having pulled the motor my self I would have noticed as well.

Roy, is your car always light on the steering no what how hard the 4wd system is working? Interested to know this.

[Roy]

LOL,, mine is a GTSt Never had a problem...other than that one time when the belts were a bit loose and the steering go heavy and slipped. Didnt make noise, not a big deal, just tighted the pulley a turn or two. As a GTSt owner i only change belts when they snap

Seriously, a fair wack of load goes into the belts on the track and belts do wear. Not the sort of thing that you would pick up test driving a car.....and forgetting all that is an easy thing to check. Though with the car being repaired ... I have ony driven a few GTRs in anger and have never noticed it. Not sure the othet Targa cars have the problem?!?!?!

[paulR32gtr]

What power steering coolers are you running? I had big problems with boiling power steering until I used a silvia auto trans cooler. Worked wonders.

I have a little PWR core plumbed into the rear stage of the p/s pump and I think the temps are under control, I don't get any out the top of the reservoir like all the other GTR's I see.

I think Troy might be on to something there. I did get a bit of squealing on start up before one of the sessions. It's not really obvious the change, sometimes you are not sure if it is just in your head lol - will see if the belt needs a nip up.

[RBN1]

I have a little PWR core plumbed into the rear stage of the p/s pump and I think the temps are under control, I don't get any out the top of the reservoir like all the other GTR's I see.

I think Troy might be on to something there. I did get a bit of squealing on start up before one of the sessions. It's not really obvious the change, sometimes you are not sure if it is just in your head lol - will see if the belt needs a nip up.

Interesting that two people have a similar issue.

RPM took the HICAS completely out of my car, including all lines etc. A long hose to give it a bit more fluid capacity was added initially but it had to be taken out as it would pull itself off the clamps on load.

Admittedly i've only done one Deca and one Hill Climb so far but I haven't noticed anything weird with the steering becoming harder under load. (Standard diffs so far)

[paulR32gtr]

Interesting that two people have a similar issue.

RPM took the HICAS completely out of my car, including all lines etc. A long hose to give it a bit more fluid capacity was added initially but it had to be taken out as it would pull itself off the clamps on load.

Admittedly i've only done one Deca and one Hill Climb so far but I haven't noticed anything weird with the steering becoming harder under load. (Standard diffs so far)

Yeah I have done the same, completely taken all the rear HICAS gear, pump lines etc out, so I only have the front rack, lines pump and reservoir with my cooler plumbed into the rear (low pressure) stage of the pump.

That extra hose you had on was that on the high pressure stage of the pump? I think that gets up to some crazy pressure - I had to use the full on high pressure speedflow gear to replace a section of the high pressure line.

[Dale FZ1]

Double post

Edited August 18, 2014 by Dale FZ1

[Dale FZ1]

Short run events like a skidpan/slalom or hillclimb is over in a couple of minutes at best. You wouldn't expect to see problems there provided belts are tight. I have found the belts need to be tighter than expected to keep things happy. Look at the belt, 3 grooves in the case of a GTSt doesn't give as much drive as the wider alternator/fan belt.

Track runs lasting 10-15 minutes,or tarmac rally special stages will more likely show weaknesses in steering systems with heat soak/high pressures.

GTR is not a race car out of the box, and the power steering pump is geared to provide effective assistance at parking speeds. Prolonged high rpm is likely to be running it outside efficiency zone, and pushing a lot of heat into the fluid. Much the same as overspeeding a turbo.

Running a proper heat exchanger for the power steer is a good idea, and effective without changing pulley size on the pump or going to the expense/difficulty of engineering an electric power steer system.

[RBN1]

That extra hose you had on was that on the high pressure stage of the pump? I think that gets up to some crazy pressure - I had to use the full on high pressure speedflow gear to replace a section of the high pressure line.

Yeah, I believe it was. Apparently made a nice proper mess in the workshop when it popped too.

Short run events like a skidpan/slalom or hillclimb is over in a couple of minutes at best. You wouldn't expect to see problems there provided belts are tight. I have found the belts need to be tighter than expected to keep things happy. Look at the belt, 3 grooves in the case of a GTSt doesn't give as much drive as the wider alternator/fan belt.

Track runs lasting 10-15 minutes,or tarmac rally special stages will more likely show weaknesses in steering systems with heat soak/high pressures.

GTR is not a race car out of the box, and the power steering pump is geared to provide effective assistance at parking speeds. Prolonged high rpm is likely to be running it outside efficiency zone, and pushing a lot of heat into the fluid. Much the same as overspeeding a turbo.

Running a proper heat exchanger for the power steer is a good idea, and effective without changing pulley size on the pump or going to the expense/difficulty of engineering an electric power steer system.

Yeah I thought as much. I'll keep an eye on it, come time.

[355GTS]

Great feedback guys. After consideration my way forward is:

1. Upgrade pump to reconditioned R33 pump. Lighter I am told.

2. Install PS cooler. What size do u recommend? Similar to RPM oil cooler size?

3. Recondition PS rack. Just because it hasnt been touched since I owned it.

4. Tight belts. Monitor on first shakedown at PI. Adjust if necessary.

5. Consider installing a temperature transmitter in PS system to monitor track day temps.

Have I missed anything?

[355GTS]

Great feedback guys. After consideration my way forward is:

1. Upgrade pump to reconditioned R33 pump. Lighter I am told.

2. Install PS cooler. What size do u recommend? Similar to RPM oil cooler size?

3. Recondition PS rack. Just because it hasnt been touched since I owned it.

4. Tight belts. Monitor on first shakedown at PI. Adjust if necessary.

5. Consider installing a temperature transmitter in PS system to monitor track day temps.

Have I missed anything?

[paulR32gtr]

Sounds like a good plan of attack Evan, see mine here:

http://www.sau.com.au/forums/topic/328473-pauls-r32-gtr-tarmac-build/page-9#entry6808285

[LotusGTR]

I had all the HICAS stuff removed (lines pump etc) and a lock bar fitted and my steering has been heavy ever since. Nizpro said there was nothing that could be done about it....

The heavy steering is not great (in fact I hate it), but removal of the HICAS system is. So much more predictable.

Before that I never noticed heavy steering on track days. Never needed anything but light hands on the wheel.

[paulR32gtr]

I know standard the 32's increase pressure at low speed so you get a lighter wheel. 80kmh I believe the pressure is dropped to give firmer steering.

Was speaking with a guy at Sandown and he said there is a wire that can be cut to the HICAS ecu that will trick it into thinking the rear pump has pressure.

I just have the bulb removed at the moment but the HICAS computer would be going into limp at start up. Wondering if that would give us our higher pressure at low speed back...

[355GTS]

Got some time to spend on the car on Saturday.The filthy power steering pump has been bothering me, and the factory high pressure line looks like it would interfere with the oil cooler line once the engine is moving.So pulled it off and gave it a clean.Also cut down the retaining bracket and gave it a bit of paint.I then ripped all this gear out including the front factory cooling loop.And set about replacing it with this. Seeing the entire rear HICAS has been removed including all lines, and then this stuff I figured I better put a cooling core in.The rear stage of the pump will be used to pump the low pressure fluid through the core and back to the reservoir, this will hopefully stop the fluid from boiling out the top of the reservoir.Started making up the lines.And back on.Made up a mount for the core with some right angle alloy strips, need to hit it with some black paint.

Got some time to spend on the car on Saturday.The filthy power steering pump has been bothering me, and the factory high pressure line looks like it would interfere with the oil cooler line once the engine is moving.So pulled it off and gave it a clean.Also cut down the retaining bracket and gave it a bit of paint.I then ripped all this gear out including the front factory cooling loop.And set about replacing it with this. Seeing the entire rear HICAS has been removed including all lines, and then this stuff I figured I better put a cooling core in.The rear stage of the pump will be used to pump the low pressure fluid through the core and back to the reservoir, this will hopefully stop the fluid from boiling out the top of the reservoir.Started making up the lines.And back on.Made up a mount for the core with some right angle alloy strips, need to hit it with some black paint.

Is that cooler mounted front passanger side in front of oil cooler? Or is it in front of radiator?

I will follow this setup I think Paul.

[355GTS]

Mine has the hicas locked out as well. I wonder what the system is really trying to do under heavy load with 4wd engaged.......

I am definately going to install temp and pressure sensors to this system and give it proper monitoring under track loads. This will tell us the answer I am sure.

Probably going to need something for datalogging now....ff$$$$$sake. LOL.

[LotusGTR]

Just sold my Motec dash / data logger!

[paulR32gtr]

Is that cooler mounted front passanger side in front of oil cooler? Or is it in front of radiator?

I will follow this setup I think Paul.

Yeah just mounted there passenger side in front of the radiator.

My oil cooler setup is a bit different in that it sits inside my radiator end tank (water to oil), so the radiator coolant takes on the heat from the oil and dissipates through the radiator core. You can see the fittings on the back of the end tank in one of the shots. Bit of an experiment, and with some recently added ducting is working very well.

[paulR32gtr]

2. Install PS cooler. What size do u recommend? Similar to RPM oil cooler size?

I meant to say before, you don't need a very big core for the p/s. Something around the size I have should be plenty.