- With a best ET of 6.86 at 204 mph, and somewhere in excess of 2500
horsepower at approximately 80 psi of boost, Croydon Racing Developments'
Jun II is currently the fastest street legal R32 GTR in the world.
We're here with Con from CRD to find out a little bit more about what makes this car
so fast.
So Con, over here in Australia, particularly the GTR drag racing record market has
become quit heated, there's a lot of tooing and froing, you guys are currently the
fastest of the crop and you've done it in a street legal format in a car that
essentially is also at full weight, making your life incredibly difficult.
I want to go through some of the aspects of what makes this car go.
For a start, I want to actually avoid the engine for the moment, we'll come
back to that, I want to talk about the drivetrain 'cause it's quite interesting,
you're still four wheel drive but you've got rid of a manual gearbox in favour of
an auto, what's running in it?
- It's running, ours race close to about 400, with an upgraded standard
transfer case.
- So it's standard R32 GTR transfer case on the back of the Turbo 400?
- Correct yeah.
- So that's how it's still four wheel drive?
- Yes.
- OK so we've seen a lot of cars, a lot of drag cars going from a manual style
transmission, maybe a Liberty or a Lenco, to an auto, where do you see the advantages
of the auto over a manual gearbox?
- Well one, it's obviously easier on the drivetrain 'cause it preloads everyrthing.
Second of all, you can throw a lot more at it and keep the car more settled with the
converter.
- So it's a case of also not unloading the car on the gearshifts down the track and upsetting
it, upsetting the balance?
- Yeah correct, 100%.
- And that's what we see with a lot of the cars on the gearshift, the car gets unloaded,
it gets unsettled and then the car is basically all over the track after that,
that's sort of a fair assumption?
- Yeah that's fair enough.
- WIth the torque converter though, one of the problems we see with small
capacity engines, particularly small capacity turbo engines is actually having enough
torque to get up onto the converter at the start line.
So how are you overcoming that?
- We're obviously using nitrous to get it up to whatever RPM we need and then set
it up all through the ECU.
- Are you using that nitrous solely to get the engine up on the converter or is it being run
down the strip as well?
- Initially we use it just to get it up on the converter and then we turn it on where
we need to depending on the track.
- Alright so with the four wheel drive system in the GTR, it's pretty unique in that
predominantly the car is rear wheel drive and then through the transfer case by using
hydraulic pressure, more or less torque can be fed to the front axle line so hence the car
can do a rear wheel drive burnout before converting to four wheel drive.
Are there any tricks you're doing with that in terms of how much torque you transfer
forward, are you controlling that as the car goes down the drag strip, what are you
doing there?
- Look we obviously know how much torque we can put in the front before we start
breaking things so we dial it back a bit further, back from there to keep the car
reliable.
And then depending on the track, that's where we'll decide where we need to turn the
four wheel drive off or whether we need to run it the whole way down.
- So if you've got a really good track, can you kind of use the front wheel drive
portion maybe up to half track and then actually reduce the front wheel drive
component in order to go quicker?
- Yeah of course, 100%, plus it'll keep the car a lot straighter as well.
So obviously that much torque going through the front wheels, it's a lot of power to try
pull the car around.
- Let's get into the engine, obviously that's the heart of the whole thing and we sort
of talked before, you're conservatively somewhere around about the 2500
horsepower mark depending on the boost pressure, can you talk us through the engine
combination, what are you running for a block for a start?
- We're running a billet block, we made the switch about a year ago.
Probably, we started about 1.5 years before that 'cause we were reaching the limitations
of the cast block.
We've done a best of 7.20 with the cast but pushing that sort of power through it,
they wouldn't hold that sort of power, they start flexing and twisting
and carrying on so we decided to go to the next level,
we had to make the change to the billet block.
- And with the cast block, before you did swap, what sort of failure modes were
you seeing at that sort of power level, 7.20s?
- Mainly the deck twisting and carrying on.
The tunnel obviously would move a bit as well but it was mainly in the deck where
you'd find the biggest issues.
- Is that resulting in problems with head gasket integrity?
- Yes 100%.
- Alright so you're on that billet, obviously there's a variety of components you can
choose to put in that so can you talk us through the rotating assembly you're using?
- Yeah we're running the Nitto crankshaft, the EN40B one.
And the Carrillo rods as well as CP Pistons as well.
- And what's the bring the capacity to?
- It's still 3.2.
- Is that the limit before the stroke that you'd need to go larger in capacity becomes
a limiting factory for engine RPM?
- Yeah that's where feel the engine's the most happy.
- In terms of the cylinder head, that's sort of one of the key areas for airflow
obviously in and out of the engine so what's been done there?
- We've worked very closely with JHH, Will up at JHH to develop a head
package that can flow 3000 horsepower.
So everything we've been doing is just really a stepping stone to the Pro Mod
which we're building as well.
So although we can't utilise the power in this, we're building for 500, 600, 700
horsepower more than what we're currently running as well.
- Alright we'll come back and we'll definitely talk about that Pro Mod project in a second.
So you've got a head that's basically more airflow than you can currently use
it's fair to say?
- Yeah pretty much.
- More airflow than you need.
OK what's the turbo package you're running on the engine?
- At the moment it's a Pro Mod XPR 98.
- And you've just recently changed to this turbo from a smaller Pro Mod?
- Yes we've done the 6.86 with Pro Mod 94.
Now we've switched over to the XPR series, the latest one and obviously a bigger
turbo as well.
- Alright so newer series of turbo, larger compressor wheel, so the potential
for even more airflow so you're expecting, I'm assuming that the car can go quicker?
- 100%, yeah we've done the 6.86 with just the 94, now with the XPR 98, we're probably making
a solid 300 horsepower more at least, at the moment.
We haven't really tried to push more than that because we're not at the point yet
where the chassis will take it so it's just a balancing act now between power
versus chassis.
- Now that's something I wanted to talk about, you've kind of just addressed it there,
obviously power is only one aspect of it, it's sort of a case of getting the power
to the track that's really important and the chassis here, you're dealing with a production
street car chassis.
So what are you doing for a start in terms of torque management as the car goes
down the track?
Obviously we've talked about the four wheel drive aspect and the ability to vary that,
but what are you doing with the likes of boost control to try and tune the torque delivery
to how much the track can handle?
- We're doing the boost control through CO2 and it's really again just dialling
it in to suit every track.
We're not doing too much with traction control or anything at the moment.
It's mainly all in the boost control.
- So varying the boost as the car leaves the line down to the finish line?
- Yeah.
- We haven't talked so far about the electronics package in the car so what ECU have you
got in there controlling it?
- An M150.
- And is that doing everything, so boost control, your four wheel drive control and everything?
- It's doing that along with obviously the dash and the rest of the MoTeC electronics,
so it's literally running the whole car.
Everything from indicators through to engine management.
- And you're using the MoTeC as a central logging hub as well when the car's out
on the drag strip?
- Yes we've got the, some things obviously we do through the dash and then other
things through the ECU as well.
- Coming back to the engine, fuel system wise, safe to assume you're running on a
methanol fuel there?
- Yeah we're running methanol, we've just made the switch to a Waterman pump as well.
- So that's a mechanical pump as opposed to electric?
- Yeah mechanical fuel pump.
- And that's being run off the front of the exhaust cam there?
- Yeah.
- So where are the advantages or requirements for a mechanical pump like that over electric,
is it just a certain fuel flow that you just can't really reliably get with an electric pump?
- The biggest thing's obviously reliability and to get an electric pump to flow,
the sort of volume that we need, you just want to get info, they've got a massive
current draw which obviously leads to more load on your electronics system which can
lead to failures as well.
- Fair enough.
In terms of the car as it sits now, 6.86 and as you've said, you've got the potential for
another 300 horsepower with that new 98 mm turbo.
Balancing that power delivery versus what the track will take, where do you see the potential
in this car in terms of its ultimate ET and mile an hour?
Looking into your crystal ball here.
- Look on a perfect track, the car's capable of at least the 70.
But obviously you need the right track to do it and all the stars have got to align.
- And you mentioned there before, the Pro Mod car, so you've got a cylinder
head here that's developed to flow a potential for 3000 horsepower, a billet block
that potentially can do the same.
Obviously you're not going to be able to put 3000 horsepower to the track in this
particular chassis so talk us through the Pro Mod and where you see that going.
- Well really we reached the point where the power has just overcome the chassis
and we've put that much development into the car, into the engine, where it's, OK well
what do we do from here.
We've put that much time into it, the only way to do it is really build
something to try tackle the 2Js.
So we're looking to build, we're building an R35 Pro Mod.
Obviously it's Rob's car which he's put a lot of time and effort and money into
and the aim is to really step it up and go fives, well into the fives.
- So another Australian competitor looking to take it to the 2Js and be at the top of that
five second list?
- Oh 100%, that's the aim and anything less than a five second pass is a failure for us.
- Well look, for a start, we look forward to seeing how much faster Jun II can go with
the right track and a little bit more power but also definitely in the future,
looking forward to seeing an 2, RB26, excuse me, competing with those 2Js
in the five second zone, thanks for the chat there Con.
- Not a problem mate, thank you, cheers.
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