DIY (no Prins) 65hp/cylinder LPG, ~380hp straight-six.

[carl0s]

What would you suggest for a 65hp/cylinder straight-six, semi-budget DIY kit (something like AEB)?

I say no Prins because they are both expensive, and authorised-dealer only.

Car would be a MKIV Supra turbo, straight six 2jz-gte.

[Tubbs]

Ive done a few on the Emer system. 360 bhp is knocking 60hp a cylinder. A lot of injectors out there are not really capable over 50. Two issues you encounter, firstly injcetor times 'topping out' duty cycle of the injectors are around 24 ms. But if you are starting high then you will hit the duty cycle quicker than the petrol times. So you need to get a set of injectors that not only work below or just above the petrol timings at tick over.
Next problem is gas stability. If the reducer drops the pressure then you are in the mire. So you need a really stable reducer, and running more than 1 bar.
So either you ask TT niceley if they would sell you a kit. Or your other route may be Hana injectors, King ecu and an Emer Palladio reducer. You may get away with a zeta s ? But im not sure.

[hardcorepit80]

...or Hana2000(green) and stag300+ and 2x zavoli for 380bhp.

[carl0s]

Thanks guys.

Those Hana injectors obviously come quite highly recommended. I understand they are Korean licensed clones of the whachamacallit Jap ones used by Prins, but, they do need some sort of fuel rail fabricating and what not. They look like they're designed for OEM use. Still, I like the look of them, so any more thougts on them would be appreciated (what LPG ECUs work best with them?) I know Mr Autogas-LPG has them, and some sort of fuel rail for them too. Is Stag stuff worth a look?

I'm slightly put off the idea of LPGing this engine due to the need for valve lube, but, it seems everything else is telling me to buy another Supra this weekend, so I might start this project after all.

[carl0s]

I have had my eye on those Hana injectors a lot lately. It's good to hear the Stag 300+ likes them.

Is the Stag 300+ the same as the 300-Premium ? That is the closest I can see at autogas-lpg.co.uk.

According to the chart here ( http://autogas-lpg.co.uk/injector-seque ... denso.html ) I would need the A+ blue ones (KM = Polish for metric horsepower, like PS), so even those are very close.

What's the score with the page name there - it says "hana-h2000-1cyl-type-a-green-entry-into-nippon-denso" - why does it say "entry into nippon denso"? Are they a drop-in replacement for Denso petrol injectors? (if you were planning a car to run on LPG without petrol at all ?)

[hardcorepit80]

Is the Stag 300+ the same as the 300-Premium

Premium has OBDII connection but I think it's not worth it.

What's the score with the page name there - it says "hana-h2000-1cyl-type-a-green-entry-into-nippon-denso" - why does it say "entry into nippon denso"

It's got denso connection so You'll need adaptor cable to connect to Stag or anything else.

[Gilbertd]

What's the score with the page name there - it says "hana-h2000-1cyl-type-a-green-entry-into-nippon-denso" - why does it say "entry into nippon denso"

Because that is what whoever wrote that web page called it, they could have called it anything they liked. Why it says that in the heading above the picture though I've no idea. You could try asking them but I doubt they'd reply, most people have found they don't usually. Unless they mean the injectors use a Nippon Denso connector.

[hardcorepit80]

And it would be Hana2000 "Blue" for your car.

[Tubbs]

The king ecu also supports hana injectors by the way.

[markocosic]

You can buy HANA injectors on a rail:

http://translate.googleusercontent.com/ ... OsKNchLNQw

They use the "standard" super-seal connections that come with the Stag wiring harnesses. The site above sells the 1.9 ohm flavour ones (slower 3 ohm HANA injectors are also available) and I can confirm that they work well with the Stag ECU. Incidentally I rate this vendor. If you call (48) 41/25-28-040 ask for Margaret her English is good. Else emails to megapol@drypa.pl in English are turned around in a day or two.


When sizing your injectors, remember that supercharged/turbocharged engines have higher manifold pressures than naturally aspirated engines. The gas rail pressure is X bar higher than manifold pressure, so as you boost goes up your gas density goes up and the flowrate of the gas injectors is increased. 125 litres/minute naturally aspirated is the same as 90 litres/minute at 0.8 bar boost. At 1.2 bar it's only 80 litres/minute. There's a spreadsheet here that you can play with if you like: (bear in mind that boosted engines will run a lower air/fuel ratio on boost/need more fuel for the same power)

http://www.cosic.org.uk/MarkoStuff/lpg/LPG-calc.xls

Shorter less accurate answer: The power that you can support with a given injector nozzle on a boosted engine will be 20-30% higher than with a naturally aspirated engine.



One of these kits for 370 euro inc VAT, plus a second Zavioli S for 50 euro inc VAT?

http://translate.googleusercontent.com/ ... _CVu2v6QXQ

http://translate.googleusercontent.com/ ... nsC-ygpFjA


An AEB King based system is essentially the same price and has the OBD support, but I wouldn't rate them after my experience with King & MagicJet injectors. (MagicJet are officially supported by King, but the setup of the injectors in the firmware was completely wrong)

http://translate.googleusercontent.com/ ... Z9jZ1QP8pA

[Dualtech]

You can buy the Hanna and king ECU here
http://www.tinleytech.co.uk/acatalog/Sp ... ories.html
Nice n easy does it.

[carl0s]

Thanks guys. All very interesting stuff. Great info regarding the boost/manifold/gas pressure too.

I didn't buy the particular Supra this weekend anyway. It was looking a bit tatty.

Common sense says I should sell the V8 RX7 before buying a third car anyway. I still intend to do it though. I've had two Supras before and I like them. They make a great daily driver in auto form, just thirsty..

[carl0s]

You can buy HANA injectors on a rail:b

One of these kits for 370 euro inc VAT, plus a second Zavioli S for 50 euro inc VAT?

http://translate.googleusercontent.com/ ... _CVu2v6QXQ

http://translate.googleusercontent.com/ ... nsC-ygpFjA


An AEB King based system is essentially the same price and has the OBD support, but I wouldn't rate them after my experience with King & MagicJet injectors. (MagicJet are officially supported by King, but the setup of the injectors in the firmware was completely wrong)

http://translate.googleusercontent.com/ ... Z9jZ1QP8pA

Thanks. I have an AEB ECU on my BMW (Zavoli), and while it works well (finally), I find the software rather basic, with just a simple map and a couple of enrichment sliders. For example, I can't alter anything depending on temperature. When cold, the enrichment in acceleration slider could do with being a bit to the left, else the car hesitates a bit until it's warmer. But when warmed up, the car works better with the slider in the middle. I can of course raise the switch-to-gas temperature from 20c to 35c (or whatever it is - it's at the minimum), but I don't want to. I like that it goes to gas very early. Ideally I would be able to map the enrichment dependant on temperature.

Also, it runs on petrol for something like 30 seconds *every* time the engine is started. If I've just popped in and out the car, I don't want to wait that long. You would be surprised how often I have to put £20 of petrol in the car (every 3 - 4 weeks at a guess). I gather some ECUs will allow a faster switch to gas on repeat starts, but not my Zavoli, not with the consumer-level software/cable anyway.

So, I am a bit interested in looking at something different next time around, and Stag it might be.

That one you linked to though is a "Stag 300 ISA2". Is this more basic than a 300+ ?

[hardcorepit80]

That one you linked to though is a "Stag 300 ISA2". Is this more basic than a 300+ ?

After upgrade 300+ become 300 ISA2.

[carl0s]

That one you linked to though is a "Stag 300 ISA2". Is this more basic than a 300+ ?

After upgrade 300+ become 300 ISA2.

Thanks!

[markocosic]

You can fiddle with all of the above annoyances to your heart's content on the 300+/ISA2 ECU. The "Premium" option with OBD is £20 or so more, if you want yet more things to look at and the Supra supports it. Some screenshots in the Daimler Super V8 thread in the "tell us your story" section.

For the BMW you might want to take a look at the "bodge" I did on the Rover 820 in the "tell us your story" section. When the gas flicks on, a relay shorts a resistor across the CTS to force the car ECU into "fully hot" map. No mucking about trying to lean out the LPG map based on temperature this way, and mpg on short cold town runs is improved.

There's also the adding "0" to the map for full control over what is and isn't a micro-injection to be cut. I've used it to be more aggressive than OE on the over-run fuel shutoff.

If you want the car to change over below 20C water temperature, you can kludge the vapouriser temperature sensor with a resistor too. (reduce the resistance and the ECU will think that it is hotter than it really is) We've set this up on the 820 too, but will wait until winter comes to see if it'll handle really low temps on gas before deciding whether sub 20C water temp is a good idea.

The 25 seconds can't be changed though, even if 5 is likely plenty. You probably don't want hot start on gas anyway mind, as weird things can happen when cranking.

[carl0s]

You can fiddle with all of the above annoyances to your heart's content on the 300+/ISA2 ECU. The "Premium" option with OBD is £20 or so more, if you want yet more things to look at and the Supra supports it. Some screenshots in the Daimler Super V8 thread in the "tell us your story" section.

For the BMW you might want to take a look at the "bodge" I did on the Rover 820 in the "tell us your story" section. When the gas flicks on, a relay shorts a resistor across the CTS to force the car ECU into "fully hot" map. No mucking about trying to lean out the LPG map based on temperature this way, and mpg on short cold town runs is improved.

There's also the adding "0" to the map for full control over what is and isn't a micro-injection to be cut. I've used it to be more aggressive than OE on the over-run fuel shutoff.

If you want the car to change over below 20C water temperature, you can kludge the vapouriser temperature sensor with a resistor too. (reduce the resistance and the ECU will think that it is hotter than it really is) We've set this up on the 820 too, but will wait until winter comes to see if it'll handle really low temps on gas before deciding whether sub 20C water temp is a good idea.

The 25 seconds can't be changed though, even if 5 is likely plenty. You probably don't want hot start on gas anyway mind, as weird things can happen when cranking.

A lot to go at there - thanks! The switch-over temperature is great in the current ambient temps. I get about 1/4 mile away and it switches. As short as only 150 yds on a properly warm day.