It's Andre from the High Performance Academy.
We're here at World Time Attack with
Mark Jacobson from Godzilla Motor Sport.
We're just going to talk a little bit about what makes
Mark's R35 GTR drag car tick.
Currently Mark's tube-frame rear-wheel drive
R35 is the fastest rear-wheel drive GTR
any where in the world
running a best of 6.34 at 224 mile an hour.
Mark, that's a fairly decent accomplishment.
What we really want to focus on here
is what you've done to that engine,
the VR38, in order to get the power
that you need to run those times.
All right, Mark, let's start by talking
about what sort of power levels you're seeing
out of this VR38 engine.
What's it making?
- We recon about 2200 plus.
- In stock form, these Are what, around about
a 500 horse power engine?
- Probably about 400 horse power.
The wheels, yes, about 500 horse power at the crank yeah.
- On the face of it that's a massive increase in power.
What sort of modifications have you needed to make
to that block to support 2200 plus horse power?
- Well, the block itself is pretty well
a standard block.
We use like a hard block, like grout in the bores.
Yeah, around the bores.
- Now that's, what we're talking about there
is removing the water from the engine so the block,
all the water jackets are filled with a grout
to strengthen the block.
- Yes, and then we use a dry, like a cast iron sleeve,
which is about five mil thick.
- Now, a lot of these changes that you've made,
particularly the solid filling in the block,
that's something that really is only
suitable for drag racing,
and really only suitable with methanol fuel?
- Yes, mate, that's correct.
It's purely only for drag racing
and just to give the bores a little bit
of extra strength from the pressures,
the boost pressures and that sort of stuff.
- A lot of people in the VR38 or GTR turning market
are now turning to billet blocks.
Before we came on camera, I know
you talked about you having one made as well.
Can you talk about the requirements for that billet block
and where those proved to be an advantage
over a stock cast alloy block?
- I think the billet block is gonna really
open up a whole new world of strength for the VR38.
The engine itself is great with a girdle
and it's got all the strength with things there.
But to have a solid billet block
where you can put a dry sleeve in.
We can put on some bolt on water plates.
We can run water how we want it, oil how we want it.
Bigger head studs.
The deck will be stronger.
There's heaps of advantages.
It's like a top fuel block.
- You just touched on something that's
of interest to me from my own drag car tuning experiences.
Which was the head studs you mentioned
or sealing the head onto the block.
Now what a lot of people are probably aren’t aware of
is when you're starting to run 50, 60, 70 or 80 pounds
of boost or more, really one of the limiting factors
with any of these engines is sealing the cylinder head
to the block and particularly when
you're talking about a production block
that can in some instances be incredibly difficult.
How are you going about that now with the current block?
- The standard block we just run a permaseal
just like a normal MLSR.
It's about 1.1 mil thick.
Then we run a stainless steel wire ring
on the sleeve, and that's been fine up to
50, 60 pound of boost.
- Now that stainless steel ring that you're running,
or a wire O-ring, so that protrudes from the sleeve
and the block and actually presses into the head gasket?
- Yes, correct.
It just puts extra pressure just sort of
right on the stopper part of the head gasket.
- With the move to a billet block,
and I know you're changing to a different
specification of turbo charger,
that coupled with the fact you're currently
2200 plus horse power.
We've seen the results that these R35 GTRs are making
more in a street drag race trim.
Where do you actually see the limiting
power level on the GTR platform?
- Probably the turbo size you're using, really.
I mean, the guys over in the states,
they're probably making 2500 horse power now easily.
They normally run 80 millimetre turbos on them.
Possibility 82 mil turbos on them.
They run about 65 or 70 pound of boost.
They're sort of at their limit now.
It'd probably just be turbo size
and engine RPM they're running.
- In terms of the rest of the rotating assembly,
what challenges have you faced with getting
reliability with the crank shaft and con rods and pistons?
- The crank shaft is just a standard one at the moment.
It's been fine.
It's been racing for two years.
We've broken one crank shaft, but that's probably
from more to do with maybe,
maybe tyre shake.
But we've got some other cranks,
some Bryant cranks there that we're probably
going to put in the billet blocks.
- Right up to even 2200 horse power,
that stock crank shaft has proven to be reliable that
in itself is quite amazing that a factory part
will handle that sort of abuse.
Look, Mark it's been really interesting
getting some insight into your engine.
You're already the fastest in the world.
Soon we look forward to seeing what
you can do with the billet block
bigger turbos and a bit more boost.
Thanks for chatting to us.
- Thanks, Andre. Cheers.