how many degrees retard per pound of boost?

[love ke70]

hello good people of toymods,
well am gradually making progress with my ke70 with 1ggte on lpg GRA carby.
got my ignition control thingy magigy today (mallory hyfire VI series of electronic ignition controls) and am reading through the installation instructions as i will save myself the 88 bucks an hour and install it myself.
just wondering how many degrees should i be retarding pound pound of boost. just as a base figure before i take it for the tune.
cheers guys, andrew

[30psi 4agte]

Its a hard question to answer as all engines will respond differently to the amount of ignition timing being used.Things like the compression ratio and the fuel being used will allow some engines to permit more timing to be used without detonation.

AS A ROUGH GUIDE
On a stock comp engine for every 10 psi retard 5deg BUT in saying this i would not retard timing at all untill about 7-8 psi (on stock engine) then start to retard it from there.



So for example at 8psi if you have 25deg timing then at 12psi run about 20deg

[myne]

There is no rule of thumb.
But, it probably wont matter anyhow since it's on gas. Gas has excellent detonation resistance. I hope you didnt reduce the compression. High compression + boost + gas = great.
If you're uncertain, just set the idle to 15* and max it out at about 25*

[thechuckster]

discussion on msefi.com suggests the following rules-of-thumb:

subtract 0.3 degrees of advance for every kPa above 100kPa

... that works out to about 2 degrees per pound of boost.

and the maximum amount timing 'taken out' should be 50% your maximum advance at 100kPa. e.g., if your advance at 100kPa is 30 degrees, the most retard you want to apply is 15 degrees.

note: kPa is absolute pressure - so atmospheric-level pressure is around 100kPa.

Taken from here.

[stradlater]

Ey Love KE30.. I have my Haltech Map that shows exactly what gets retarded where and how much, if that would be of use to you, that way you can guage how to setup yours, considering we've got the same setup bascially.

Good to see you got yourself an electronic igntion setup finally too.

[BrianRA23]

1ggte on lpg GRA carby.

Have you had it running on the LPG yet?

Is this a simple or complex mixer you are using and is it before or after the turbo?

I ran (past tense - sold it) my Cressida 1JZGTE on dual fuel so I am interested in your setup in case I can glean or give any info. I hope to do a similar setup on a 3SGTE on LPG in the future.

The results from the dyno tuning session will be interesting.

[love ke70]

myne: no, compression is still stock as far as im aware, i most certainly did no mess with it anyway.
strad: that would be great if you can email it to me, or ill try catch you on msn sometime!
and yes, im very glad, even if i am eating 2 minute noodles for the rest of the month stoopid unemployment haha

brian: yes it was running, apparently, amazingly if you will, it was even running before i got it. he was running it draw thru and couldnt work out why he kept destroying turbo seals

but, ive bolted the carb to the manifold now running blowthru, it goes, its running uber rich and stalls when you attempt to give it some go but that will all be dealt with.
i too am clean for some dyno results but that may be a couple of weeks away still, and they will be quite poor im feeling until i strip it down and rebuild as she is burning a serious amount of smoke. (note to self: redo that compression test)

i believe its a simple mixer, looks pretty bloody simple to me anyway haha

cheers guys, hopefully ill have this installed by tomorrow and then ill just have to make her presentable and trailer to the shop.
but as always, many things will come up, things will need fixing and all in all it will take much longer than anticiapted
so anywho, cheers again for the help and ill stop rambling now

[chris davey]

Looking forward to seeing the results.

I met the previous owner of your car about 1.5years ago down the gold coast and was very intrigued at the time

[love ke70]

you poor poor soul
haha nah, hes an alright bloke, shame about the dodgy setup he had running tho.
all to be fully sorted very soon

[stradlater]

Ey Chris, what's wrong with my setup? Doesn't that interest you enough? ;-)
:-(

[BrianRA23]

I assume you have connected the balance line from the converter to the pressure side of the turbo (somewhere near the mixer). If it stalled when the boost comes on then this might be your issue and if so your diaphram might now be blown.

Maybe requires a new thread - LPG and Forced Induction.

[love ke70]

i have the flange, and i just need to weld it on and hook it up.
thats not the problem tho as this is from idle and i have a huuggeee intercooler so its not gonna get boost that quick

[BrianRA23]

The diaphragm is very very sensitive and if you suck or blow (just a little bit) on the low pressure gas feed line you will hear it hit the full movement limit. I think the small pressure differences across your intercooler and piping plus the time delay in the pressure delivery will give you enough variation in the mixtures to cause you grief.

Normally a vacumn is required to make it go full movement and this is meant to be vacumn generated by air flow, not the vacumn from a semi blocked air cleaner. For a suck through or NA setup the balance line should be connected to the to the inlet after the air cleaner to take this out of the equation. The diaphragm cannot handle any boost without the balance line connected and seeing the same pressure otherwise the diaphragm will burst. You also need it there for proper mixture control.

The balance line will be a 1/2" hose that comes off the back of the converter.

Maybe you have it covered, but if not, I hope this helps

[oldcorollas]

chuckster and 30Psi, is that specifically for LPG, or for petrol, or you are saying it doesn't matter which?

[love ke70]

brian: am installing the balance line tomorrow.
just wondering why you need a 13mm hose when the hole for the barb to go in is only yonder 8 mm?