jammapic's XUD 306 DTurbo Track Car

[jammapic]

No replacement for displacement mate.

That remains to be seen dude!

[darrenjlobb]

No replacement for displacement mate.

Lol there is always a replacement for displacement....it goes by the name of, B00ST!!

Certainly a different direction anyway, going for the midrange torque punch by the look of the spec, deffo gunna need that twin plate clutch lol!

[Ed Doe]

No replacement for displacement mate.

What a daft thing to say!

Go buy a Lambo then!

[Dave]

And if your retiring that engine what are the plans for replacement...............

an engine should never be retired if its still got everything inside!!!

[Atterz]

Can not wait .

[jammapic]

So a few of you popped over this weekend and asked how my engine build etc was going. Basically, waiting on a few bits arriving. The head is all done, all gas flowed, big new valves and higher lift cam all set up and ground in. The head has gone off for ceramic coating on the exhaust valves, exhaust ports and precups - that should all be ready in a couple of weeks.

Gearbox is cleaned up, and converted to the XUD style (rather than HDi) clutch mechanism and I'll be popping the Quaife Limited Slip diff in it in the next couple of days. The clutches have been ordered from Helix and just waiting for them to pull their finger out and get them delivered to me ASAP!

My biggest problem is the bottom end - and why the whole build has been delayed much further than I'd hoped.

One of my pistons got damaged (or there was a forging error) so I'm waiting on a new one arriving, sadly because they are coming from the states it could be 4 - 6 weeks.

The rods are done, and are of I beam configuration with custom big ends to suit my custom long throw crank... not QUITE sure what to do about the big end shells yet, as while the forgery supplier some I've been thinking about getting a set of tri-metal ones as used in the GTi-6 with boost etc. Some more thought required there I think.

The block is cleaned, and has been bored out to suit the larger diameter pistons and modified to take the crank all it needs now is painting really (seems the done thing!!) and the bits putting in it.

I've got a VE pump stripped down and ready to rebuild, but I'm hunting around for a 10mm head with not a lot of luck at the moment... I might just have to bite the bullet and join the 11mm crew - I just don't like the smoke so again, a bit more work required around that.

What I do need - and hope someone can help me with, is a set of injectors? I need to send them off to be modified / reconned and at the moment I haven't got any - let me know if you have as I have cash waiting.

Last piece of the puzzle is the turbo.

At the moment I'm running the same GT25 as I have been for 18 months, with the 56mm compressor wheel and titanium internals. I had Brynllwynog2 run a few calcs on how this will perform on the new motor, with it being bigger capacity etc and it looks like it should spool up MUCH earlier... like around 2200rpm which is good - however it getting pretty close to choking at 2.2bar boost at the red line.

This has led me to a bit of a dilemma... do I enjoy the earlier spool or do I get the turbo taken out to a 59mm comp wheel, have some exhaust turbine mods done and go back to 2600rpm spool but so it will rev out much better at 2.2bar and upwards???

I'm thinking at least for running the engine in, leave the turbo as is (as I will only be running a 9mm pump anyway for the moment) and then make a call as I start to turn up the wick.

That's me up to date!

Cheers,

JP

[Dum-Dum]

I reckon if your pistons are gonna be 4-6 weeks then youve got plenty of time to get things right so keep hunting for a 10mm head and in 4-6 weeks Dan! might be well enough to help you with injectors.


As for the turbo the bottom end isn't gonna want to be quite so happy revving now its got the longer throw so you need to consider that Im you might have you reign where you rev to in a little so actually having the quicker spool on the smaller could help you keep the same rev range.


Maybe go 1mm bigger on the comp as with the ceramic coated exhaust bits your gonna have hotter exhaust gas so a faster spool (as long as you dont melt anything).


Personally I reckon your gonna be aiming for much more boost so it might be worth you looking into a twin scroll exhaust housing and a quick spool valve (basically a valve that is shut at low boost so you only use one scroll of the twin scroll housing to get a fast spool) they cost big £££ for what they are but it reckon you could make one for sub £50.

Im seriously considering a twin scroll housing for my car.

[jammapic]

MMM.. Good points there.

I think 32/34psi will be enough for what I want to do really... This stock motor made over 200hp at 30psi so I'd like to think bigger capacity, better head design etc etc will give me the same sort of power at LESS boost. I'm not aiming for much more than 200hp anyway really, just want to get it reliable round there, so I'm not worried about tanking it for long periods of time.

Hopefully Dan! can help me out... he's than man that can... it's Dan!

JP

[Dum-Dum]

But your car has been reliable at that power?????????



Oh why not use a pre turbo water methanol jet for a quicker spool?

[jammapic]

I've never run it at 200+hp for very long.. I always drop it back from 2.0bar to 1.75bar and turn the fuelling down... guess I'm just a fag It's run 180hp for 18 months, and *touch wood* never missed a beat, including some track sessions, road rally's etc.

I've been thinking about water methanol actually... but I have things you have to "fill up" all the time.

[Dum-Dum]

Depends what size nossel(s) and tank you use really.

I was using a 1gph and 4gph set up and i could drain the small tank in less than 30 miles however I had the boost levels on the progressive controller set REALLY low so it was spraying on the motorway.

I know you want full driveability full time but Id rig it with a switch so you only use it when you need.

Also Id get the big tank (iirc about a gallon) and only use a single pre turbo nossle as my post turbo one made f*ck all difference. (i did a bit of testing with it on the dyno). Youd only need to fill it up once a week or less with the small single nossle and big tank as your using a 1/5th of the water and have 4 times the capacity.

[jammapic]

Finally got round the sticking the battery in the boot.

Should help weight distribution a little:









Also gives me a little bit more room under the bonnet.

JP

[Matt]

Just seen this on fb, looks goo mate I've thought about doing this too but as I'm proper skint right now it's going to have to go to the bottom of the list for a while for a while

[jammapic]

It's about £10 worth of wire to do it!

[Matt]

Really? Schweet!!!!! Might look into it a little more

[Jonny81191]

Car looked great at FCS,

There's a few sets of injectors in the local scrappy I'd be happy to pick up for you next time I'm there. But probably only worth it if you're stuck for a set.

[Poodle]

It's about £10 worth of wire to do it!

Any chance of a link? That's a lot cheaper than i've seen any decent thick core, want to get on that!

[jammapic]

It's about £10 worth of wire to do it!

Any chance of a link? That's a lot cheaper than i've seen any decent thick core, want to get on that!

Fraid not mate - I'm using the wire from Bryn's HDI - just had to chop and change a few bits to get it to fit.

Starter spins over *slightly* slower than it used to, but still fires up fine...

[cully]

whats the lower cross brace for ? as there are no struts and your belts are on the rear cage

you might wont to up the CSA cable size if the car turns over slower
also it might help if you increase the CSA of the earth strap from battery to chassis and on the gearbox to chassis

[darrenjlobb]

Did they let you off with the battery in MOT, think its meant to be in a sealed container and if your being really anal meant to have a vent to outside... Think its so if you roll it / battery explodes etc you dont get showered in acid / run down inside the car on you etc lol

[jammapic]

whats the lower cross brace for ? as there are no struts and your belts are on the rear cage

It's there to add some lateral rigidity in case of an accident basically.

you might wont to up the CSA cable size if the car turns over slower
also it might help if you increase the CSA of the earth strap from battery to chassis and on the gearbox to chassis

It's not enough for me to worry about but I'll bear it in mind...

Did they let you off with the battery in MOT, think its meant to be in a sealed container and if your being really anal meant to have a vent to outside... Think its so if you roll it / battery explodes etc you dont get showered in acid / run down inside the car on you etc lol

Did it after the MOT to be honest, but yeah I'm looking around for the box top, if I can't find one I will get one of those sealed container things.

Also, there is a nipple on the battery to vent it to atmosphere, so I just need to hook up some pipe to that and whack it through the boot floor... battery acid all over me doesn't sound fun!

JP

[Matt]

Where did you get the rear brace? Quiete interested in one just for looks

[Atterz]

Haha i remember when that battery exploded down in the Shed Darren.

You can get them battery boxes for caravans James, dont think they are too much! And then vent it through a hole into the wheel arch. I think its somthing to do with getting rid of the hydrogen produced. Be careful and rust proof around the battery, as i think the gases are corrosive to metal, ive seen a few cars that have had batteries relocated rot in that area after a few years.

---

@Matt, the rear brace was a custom made jobbie for when James didnt have the cage in place but still wanted to run the harness, in theory it wont do anything bracing wise as the rear beam is torsionally stiff anyway which is what made these cars so great handling as standard!

[jammapic]

Correct and correct....

Maybe I should whack a breather on and put it in a sealed box... don't want the back end rusting away!

[Dum-Dum]

My starter actually span faster when I moved the battery. I was using proper battery cable that was about £8 a meter (ebay ill give you a link if you want) and rated to 250amp (ish)

[darrenjlobb]

I used to have cranking amps issues before, but recently upgraded to chronic cable and no issues anymore..

Tbh it WILL cost alot more than 10 quid to do it, even the cheap crap cable is more than 10 quid new, unless you find a load of second hand welder cable or something...but then time you account for new battery clamps / crimps etc to do it properly your well over £10.00.

Much easier to do it right in the first place than be fookin around all winter with bad starting etc

[jammapic]

I'll do a video and show it starting. It's not bad at all!

[darrenjlobb]

If ur gunan video it starting do it cold without plugs so it dosnt acaully start, otherwise you wont even hear how slow its motoring as XUD's normally fire up instantly anyway

[jammapic]

OK. Will do it now.

[jammapic]