Joe, I'm giving your last post a lot of thought... I'll be tied up a lot with work until next Friday so I probably won't get back to it until then.

Meantime, I've been working on a few things:

• Sealing the intake leaks, there is still a small leak around the LPG pipe but overall much improved.
• Blocking the 3mm hole. Now sealed with an 8g, 12mm self-tapper cut down to 5mm and a liberal dose of #1 hard-setting gasket cement. Both hot & cold idle are now much smoother, hot idle especially is beautiful, as good as it was when the LPG system was brand spanking new..
• Getting a wideband O2 sensor and meter to keep an eye on the LPG AFR and help me set up cold-idle enrichment properly.
• Trying to source a s/h Airod variable mixer
• Booking in a dyno run next Friday to check the petrol AFR's now the leaks are under control, and hopefully get a number!

I'll post more as things develop.

Since my last post, I've sourced a less-restrictive LPG mixer (Airod variable venturi). I fitted it on Sunday, along with a replacement throttle body (the old TB having the restrictive 42mm mixer jammed and sealed inside it). I also had to make some changes to the intake as the "new" mixer moves the last bend a few cm. I'd previously booked a dyno run for Monday and thought the less restrictive mixer would help things along a bit. What could go wrong...?

Plenty, as it turned out. How about 153rwkw (others are getting 190-200 from their Raptors), a bit under 7psi of boost (should be 9-odd) and AFR's in the low 10's? Not to mention some pipe separation (my workmanship BTW, not Raptor's) and some very professional repair work by the guys at Blacktrack. Petrol runs BTW. We ran out of time to do any troubleshooting on the day as I had to get to bed for dogwatch, so that had to wait until today.

A bit of arithmetic shows that boost and AFR are both 20-25% low. The belt's not slipping and there's no indication of any problem with the head unit, so I decided to go looking for air leaks first.

Starting at the head unit I worked towards the TB checking each clamp, eventually finding the last one on the TB was loose and the rubber joiner was folded back on itself at the bottom of the TB... not conducive to a good seal. Here's the general area:


So after remounting the joiner and tightening it down, along with a slight realignment of the other joints, it was time to go for a spin. Oh, I also reflashed the tune and reset the ECU as idle speeds have been 200-300rpm higher since installing the mixer. The intake now looks like this:


The improvement was obvious straight away. It's felt a bit doughy since I rushed the mixer install... now I know why. Now it's responsive right from idle. Anyway I did some gentle warming-up then set up to give it a quick 0-100 (or thereabouts ) full-throttle run. Away she went, chirping the treads in 1st as 4000rpm arrived (and traction is pretty good with the LSD) then PHSSSSHHHHHT! Yet another pipe separation, my fault again for having mistaken where a barb was and putting a hose clamp in the wrong place

So we limped home at dusk for a repair, ready for another go another day. Positives are:

• It went harder than it did before I changed the LPG mixer (that chirp at 4000 was a real surprise)
• Idle is now back to stock, smooth and unfussed on either petrol or LPG
• Having had the tranny serviced this morning along with increasing the line pressures and having a cooler fitted, shifts are now as good as stock without flaring or hesitation. The 3-4 change had got really dodgy at around 3000rpm in 3rd. As the converter unlocked in 3rd before changing up, revs would flare to 3600 or more for a second or two. All that is gone now, replaced by decisive shifts that surprisingly don't feel any harder than before... no banging or jerking. I'm pleasantly surprised.

So for now I'll just drive it for a week or so to be sure it stays all good, then I'll tee up another run at the dyno. I think the figures are going to be a lot better next time...

Where do you go for your Dyno Run's Sly? Would be good to find somebody local so I can get this thing tuned right.
Had enough of the backfires!
Good work in sorting yours BTW
Mick

I had this dyno run done at Blacktrack at Thornton, mainly because they are a Ford Flash Tune dealer and can custom tune. Not much help with tuning an NC unfortunately, and they don't like LPG at all... I only had a petrol run done. To Dyno tune LPG, Gaspower at Cardiff, Gossies at Morisset or Tag Performance at Kurri are the only locals I know of. Sorry, one more, John Collins at Broadmeadow can tune old-school systems with a power valve, but apparently doesn't do computerised systems.

Thanks for that Sly! Gaspower at Cardiff is pretty close to me. I'll drop in and have a chat I think.
Mick

Hope you catch Tony on a good day, he 's legendary for not being warm & fuzzy

Tony sounds like things are working out for you with the new mixer, there are some mods that you can do to the mixer to be better suited for forced set up remember the tension of the spring in the mixer is set up for n/a.... so some play around time is needed...

Joe

Thanks for the tip fella's, can't handle arrogant C**k heads, so I don't think we would get on that well
I'll go for a spin past on the way home from work tommorow and see if I can find this Skaza's. (I only live 2 minutes away in Macquarie Hills)
And I didn't think there were many Dyno guys around in Cardiff

I went looking for Skaza's once and couldn't find him... did he used to be in the back of the BP servo near the rail underpass? Also Ian Benson at Benson's Turbo Centre (now somewhere near Skaza's AFAIK) knows a lot about LPG even though he's not licenced for it. He uses an LPG installer that he speaks highly of. He may be able to give you a recommendation.

I'd wondered about that, the spring seemed quite soft. Am I looking at a change of spring or shimming it with washers?

I also need to get up and running with the wideband O2 sensor (Innovate LC-1) and gauge. Do these work well enough clamped up the tailpipe? I know I have to get a 2nd bung in front of the cat for best results, but I thought a tailpipe setup would flag if the mixture was really rich or lean under load... like 10:1 or 16:1 (for petrol).

What make of convertor are you running ?? also with the mixure some machining & spring change can improve it but first I'd worry about sorting the a/f now & get it right before starting to worry about the mixure, what are you using to control igntion timing ??? & put the LC-1 near the factory o2 sensor which will give you the best reading also best if you had someone with a 4 gas as at idle using lamba is not always right for LPG you need to look at the other gases to see what the engine wants rather than just saying I want it to have 15:05 for idle & obvisely other factors can change this reading, lamba has no idea what size cam your running how much timming is in & what comp ratio you have, CO.... CO2 & HC dose, there is more to setting up lpg that what people think, a pic of the last job I did...

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Hey its great to see some intelligent fault finding happening. I am sure the results will soon be stacking up and if Sly (and others here) result in the gas going hard and good..... that in itself will be a major plus for the LPG cars.

Going real good I reckon, keep up the good work

beautiful car

I have an OMVL R90/E on it Joe. I've been playing with springs in the mixer and making some progress. It no longer has a midrange stutter, but surges and flatspots a bit coming off idle under load with a light throttle (in traffic, coming uphill to a roundabout). I'm hoping to get some datalogging or monitoring going shortly so I can tell if it's rich or lean... I've found it hard to pick in the past.

I've made some balance line changes too. I had the local exhaust shop make up a piece to replace the Raptor-supplied pipe with the BOV outlet in it. It looks a bit like this:


This seems to have helped driveability a bit, especially around the transition to boost.

BTW Joe I'm just using the Raptor-supplied tune to control spark. So far, so good. I want to keep the factory ECU to help with getting it engineered.

Tony the idle transition problem may be related to the convertor sensitivity adjustement as you have alted the spring tension in the convertor so the sensitivity will change you may need to set it up as a 50/50 balance ?????? how much timming are you pulling out on boost & is the timming comming out in one large hit or gradually....I'm glad the balance line worked....