- Jay from Real Street should be no stranger if you've been anywhere on Youtube
and you're a car fanatic.
Jay's Tech Tips is a Youtube channel that we follow regularly and we love what
he's doing, educating the enthusiasts out there in the industry.
Now we're here at TX2K with Jay to find out a little bit about what makes this white
Supra behind me go so fast.
It's running in the 2JZ class here at TX2K.
First of all, this 2JZ class is pretty competitive but you are no stranger
to 2JZs and 2JZ performance.
Can we start by talking about the engine that you've got in there.
We've seen a lot of people now swapping over to billet blocks.
And there's a lot of debate about when you need to go from a cast iron block
to billet so can you give us your thoughts on that?
- I think that the exact when is depending on what kind of failures you're experiencing.
There are guys that can tear up a stock block way earlier than others.
So we were getting some deformation in the deck after six or seven runs with
the power that it took to go into the sixes.
So the goal for us was to get in the sixes on the stock block and then
move to a wet billet block.
- Now just coming back to that as well, this car's gone as quick as a 6.91,
199 mile an hour and change.
So it's definitely no slouch.
And we were just talking off camera before about that change from
running in the 7.0s, 7.1s, to the six second bracket.
And while to the average viewer that might sound like a small change,
we get exponentially more difficult to go faster.
So can you talk to us about the reliability when you were in that low seven bracket
versus the sixes.
- Well when we went 7.03, we had a combination that had gone anywhere
from the 7.0s, down to 7.03 and it had better than 30 runs on it when
we took it apart to look at it and that same block, we went to drag week with,
and raced the car more but it just seemed once we went to the 88 millimetre turbo,
and running more nitrous, the deck would not hold straight between the cylinders.
So as you looked from cylinders one to cylinders two, you'd have a little bit of
a gap and it was hard to make coolant pressure.
So we have a copper gasket and an o ring and it never torched but once
it starts making coolant pressure you just have a matter of time.
That's your warning sign.
- So for those who aren't really familiar with what we're talking about here,
it's really all down to head gasket integrity and as soon as you start
getting a little bit of leakage there, it makes its way into the cooling system,
and that's why we start seeing the coolant pressure so you can catch it quicker
and avoid some more expensive damage where it's actually torching the head
and the the block.
And what's one of the things where there is an advantage with the alloy billet blocks
is that they run a thicker deck surface so that's really where you're seeing one
of the advantages?
- Well this engine block is similar to what you'd see if you were sleeving your Honda.
So you'd cut all the factory stuff out and then drop in like a Darton MID.
So that's how this block is done so it has water around the top three inches
or so of each sleeve.
- So in terms of the power you're at now, where is it running and what sort of boost
pressure are you using to get that?
- Well the Motec suggests this abnormally large power number that I can't
really believe, it's just their fuel MAF and maybe it's right or maybe it's wrong
or maybe it's good for the internet, but it thinks it's making over 2500.
And I would say that it has to be probably 22 or 2300 horsepower.
- Possibly sounds a little bit optimistic.
- In Australian that's probably about 1600.
- I'll just point out here, we're Kiwis so that's like calling an American a Canadian
so just to clear that up.
- Oh shit sorry.
- No problem, alright so we've talked about the engine block there.
Can you just tell us what the internals are to support that sort of power?
- So it's Brian Crower 90 millimetre billet crank.
It's a R&R rod, stock length rod.
It's a CP piston with a trend pin.
Conventional ring set, King bearings.
- So nothing particularly unique there, what's the capacity end up there with that
90 mil stroke?
- It's 3.2 and it's 9.6:1 compression so it's got a little bit less than flat top in it.
- And in terms of the cylinder head to flow the air in and out of that,
what's been done there.
- It's a CNC ported head from Mazworx, the same place that supplied us
with the block.
It's a factory casting that has Supertech valve train and a GSCR 1 cam.
- Now in terms of drag racing, making the power is one thing and 2200, 2500,
we're not arguing it's a hell of a lot of power but getting that to the track
is the next challenge and I also noticed you're running on a 275 radial tire there.
You've gone away from the independent rear suspension though so it looks like
a proper four link in the back of it.
But what I'm interested in there is you're running an automatic transmission.
So that's a fair shift away from the manual transmission that we often see in the Supras.
What's the aim behind that or the reasining behind that?
- Less work, so if you had a race grade style Liberty or something, you have
to work on the clutch quite a bit.
And the torque converter set up with the TH400, it's been pretty reliable and
we just run it.
And it does a very good job so when you let go of the trans brake
it's 5400 RPM, the engine speed surges up to 8500 or so and then it pulls the car
into motion.
In about 1.5 seconds in it rises up to red line and you make the gear change
and it's around a 8500 RPM stall speed.
But at the end of the track it's only slipping 3% or 4%.
So it's a nice beast for sure, it's from Pro-Torque and then the transmission's
from M&M.
- So that's one of the things I just wanted to talk about there.
There's pros and cons with the automatic transmission and one of them,
particularly when you've got a reasonably small capacity engine where you really
want all of the power getting to the rear wheels, the torque converter slip is
a bit of an issue.
But 3% to 4%, that sounds like it's pretty tight, is that normal to what you'd
expect to see?
- Well at the start of the run there's quite a bit of slipping, so it's coupling all
the way down the track.
It doesn't get to 3% or 4% until probably 1200 feet.
But yeah that's what it takes to get it moving.
- But there is actually also some advantage from that slip initially off
the line as you're also explaining.
One of the downsides of course when you've got a relatively small capacity
engine, a big turbo and an automatic transmission is getting the car
up onto the torque converter, up onto the two step limiter at the start line
so how are you going about that?
- Well there's normally, between the five and seven second time out,
before the time you turn the first bulb on to the time you have to race.
So right now I'm using a series of transmission dumps to dump charge
pressure out of the converter and then I have one nitrous kit on at 2800 RPM,
another nitrous kit on at 3700 RPM, and then the first nitrous kit shuts off
at 200 kPa and the second nitrous kit stays on, they're dry nitrous kits
and the Motec does the enrichment.
- OK so a bunch of stuff you've just mentioned there and those dump
valves, for those who aren't aware, you're basically dumping fluid pressure
out of the torque converter so that allows the engine to come up and basically putting
less load temporarily on the engine?
- Yeah so it basically takes the torque converter less energy leaving the engine
make it in with less fluid, just a fluid drive.
- And then you've obviously got the nitrous there just to explain on top
of that and you've said that second stage stays on, now are you running that
second stage the whole way down the strip or is it just for the staging?
- So the way that Motec did the nitrous system, it's pretty cool.
I use the overrides to stage the car and then when you let go of the
trans brake, the nitrous shuts off, and they're on timers so one comes on
at 100th, so right back on, and then the other one comes back on depending on
how the track is.
So as soon as 2/10ths, as late as 6/10ths.
And then I run one nitrous kit for three seconds, the other nitrous kit on
for five seconds and I go through on boost.
- And what sort of power are those nitrous kits adding?
- 250, so they're, it's a reasonable amount of nitrous.
- Yeah you're not messing around there.
Now in terms of getting a car with what is still a relatively small tire,
although we talked off camera and you feel the 275 really isn't a disadvantage.
But still getting a two wheel drive with a 275 wide radial tire down that
drag strip, I'm gonna guess that at some points you've got more power than you
can put to the track, so is that an issue and how are you managing that if so?
- It depends on track prep so right here, I can't get enough, I can't manage
all the power available.
So I have to, it's not a traction limited thing.
So we'll be at the starting line at 25 pounds of boost and as soon as we
leave the starting line, we're asking for 60 pounds of boost.
So as fast as that turbo will get up and the nitrous helps get that
online as fast as possible.
- Now in the ECU you've mentioned you're running Motec there,
we'll dive into that a little bit, are you using any traction control
strategies through the Motec?
Not necessary?
- Well you, not necessary on a proper surface but you'd have to do it off of
driveshaft speed because the front tires aren't guaranteed to be on the ground.
- Yeah a little challenging, normally in a road race application we'd look at
undriven wheel speed versus drive speed of course when the front
wheels are in the air which we've noticed this car's quite prone to do,
that's a little bit useless.
So that's the other way of doing the traction control essentially is profiling
the driveshaft speed versus RPM.
Now as a tuner, when you're tuning a car like this, and you're trying to improve
it run after run, when the car comes back into the pits and you
download the data, what are you actually looking for in that data?
- The first thing I look for is engine health.
So if you look at the crank case pressure, is the crank case staying under vacuum?
Is the oil pressure healthy, is the coolant pressure reasonable, are the EGTs
staying in line?
Once you get through all that stuff, then you can nitpick things like lambda.
- So in terms of that there, you've just mentioned the crank case pressure,
so you're running a dry sump in this and that crank case pressure,
we're using that to sort of analyse the quality of the ring seal because if the
ring seal starts to go away or you hit a piston then you're gonna end
up with a lot of blow by making its way into the sump and hence you see
that crank case pressure increase.
Beyond making sure that the basic engine health is OK and you're able
to go and do another pass, what are you then looking for to try and improve
the performance on the next pass?
- Well you can make the judgement call on whether or not you wanna leave the
nitrous on longer.
So if you leave the nitrous on longer, obviously the car's quicker.
So I try to just balance that based off the competitor and the day and what
we have going on.
- You also mentioned the exhaust gas temperatures there, are you using these
sort of as a individual cylinder tuning device to adjust the fuelling from one
cylinder to the next or is it more along the lines of you've got a safe limit
that you wanna stay under and you're tuning for that?
- Well I just had put EGTs on the car so I had been tuning it off of reading plugs,
which is pretty archaic but effective because I haven't changed any cylinder trims,
the EGTs are pretty good.
So I'll pull the plugs out of it and look at the plugs on a regular basis and make
sure that they're in line.
- Now in terms of what we just sort of alluded to before, the car's having
a little bit of trouble keeping the front wheels on the ground.
And particularly when you're in a class where, I believe you can't run wheely bars
or you're at least not running wheely bars?
- Yeah we're not running wheely bars.
So we'd run the car quite a few times at a lower launch power and yesterday
I was greedy and I put a couple of pounds in it and it drove up into a wheely.
And then today the boost control solenoid actually stopped flowing air to the bottom
of the wastegate.
So the second time we ran, we were 15 or 16 pounds above launching.
- OK well that's definitely not gonna help but probably impressive that it
actually hooked up anyway.
- There's your 275 tire answer, it took 38 pounds of boost on the starting line.
- Yeah that's probably the tires not holding you back too much there.
Look Jay it's been great to get some insight into the car, there's still a lot
of racing left to go here at TX2K, so we wish you all the best.
Look forward to seeing it put down a full pass.
- Yes thank you.
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