Thread: D2a TD5 - more mods?

Fellas, just because a tyre is marked as, say, 235/70-16 doesn't mean it will measure exactly those dimensions and the equivalent rolling diameter.
Comprehensive tyre spec charts are your friend.

They can vary quite widely, even from the same manufacturer but different batches (although some manufacturers are more consistent than others )

Several lifetimes ago when racing the Dunlop blokes would run the stagger tape around fronts and rears so we had a roughly even diameter for circuit racing, they varied that much!

You could get over 1/2" difference in height easily and these were the same tyre out of the same mould, so go figure.

Yer stmaxx 245 75 16 are supposed to be 779mm. Rechecked my speeds with another gps, I did have an error.
GPS 100 = speedo and ultra gauge 106 = 2200rpm. I've been warned off changing ratio to defender ratios, would apparently gain 800rpm when I'm chasing maybe 2-300 for towing.
Going for the Ashcroft torque converter , I'll get the hybrid core in and also look at a towing tune as the current one is not right.
I'll hold on the lock up kit till I've given this a good try.
Also booked in for a re foam and trim on the front seats plus a lumbar instal on the passenger, bit of dynamat while the seats are out..... OCT is going to be an expensive month!!

Now I've just had the head done up on my Disco, everything back together but blowing white smoke on start up.

I was using a three hole head gasket rather than the correct two hole, the performance was not what it should, I upped the boost to 1.28 bar but it still wasn't great.

Then I cheated, I advanced the valve timing just in case of a little chain stretch could have retarded the valve timing.

Whalla, a big increase in turbo pressure, it has peaked at 1.36 bar with no other changes, now the only reason that could happen is better combustion creating more and faster exhaust gasses.

The white smoke on start up is gone, just a puff of black, instant start, it works for me.

Just had the trans o/hauled because I wanted to fit a lower stall, larger lockup clutch torque converter and Torque Converter Technologies in Melbourne have supplied mine and it has made a huge difference. I believe 'Buy Australian' when there is a viable source here.

Where the vehicle doesn't have enough power to get up a steep hill it doesn't make a lot of difference but where it used to struggle on a constant slope down change and rev it now it just keeps going, I would recommend a lower stall speed TC even without a power upgrade.

Anyhow that's two points I have found.

Now I just want to find someone that can tweak my ECU.

Cheers

Mike

Hey Mike, how did you modify the timing? Is it involved? I could be interested in giving a tentative tweak to see if it makes any difference. I still have lag, just nothing that drives me too crazy now, but my fuel economy has never been as good as I'd like, you make me wonder if timing could be the issue.

Td5 's really don't run well without the cam timing being spot on , that's what the locking pins are for , there really is only one spot , if you retard it by a degree or two you will have a little better down low in the rev range , but not much high in the range, if a couple of degrees advanced , a little more lag , but a bit better up top, bang on the mark really works best,

Adam,, just a quick pick or two about ratio's
this Ashcroft's calc thing is a godsend,,
ratios 1.jpgratios 2.jpg

I quite like the idea of defender TC gears, solves a few problems actually.

I would have to do a lot of NVH work to be happy to cruise at those RPMs Pedro . Towing the van it would be pretty good though. I'll get the hybrid and torque converter done first before we crack open the transfer case.

Originally Posted by Pedro_The_Swift

I quite like the idea of defender TC gears, solves a few problems actually.

Has anyone done this?

I've got my car in at transmissions R us in Perth for a cooler. They are looking at getting me a quote to swap out the T Case for a defender one. that and a rebuild and sleeve. Solves my problems of leaking front or is it intermediate.

Since I went the bigger 265/75s I've noticed a good 10+ degree increase in trans temp and an increase in engine temps. Hit a few hills and the trans really heats up. Although dropping the gears does help manage it a bit. But I had been hitting 100c on the hills out of perth (with me driving sensibly). That is an external temp too(Sensor bolted to side of trans on an engine watchdog)

I thought getting me back to close to a standard ratio would help with that by reducing the strain on the drivetrain a bit.