intercooling 1ggte on gas carb

[love ke70]

i wonder if i call racq and tell them im outta fuel theyll bring me 10 bucks worth of lpg lol

[love ke70]

ok, dragging up an old thread of mine.
i was talking to a gas installer yesterday and he told me the vac advance is only for when you off the throttle and tops unburnt fuel going thru the exhaust and burbling backfiring etc.
im inclined to believe him. he also did not see the reason why i would need a boost retard, can you explain to me why i do as im unclear on the matter.
he said all i should need is a mechanical advance in the distributor to advance the timing when i put my foot down the weights throw out by centrifugal force and advance the timing.

is he talking crap or does he know what he is talking about?
cheers guys, andrew

[mrshin]

I'm tipping your installer has got no idea about boost... Leave him with his XE Falcons and talk to someone else!

[love ke70]

will do
he said he doesnt do alot with turbo cars. even tho the advert says theyre a specialist lol

[stradlater]

You DO most DEFINATELY need boost retard..

Example:

My car, at idle, has 20 degrees advance

THEN

it ranges up to 38 degress advance when under load, but not under boost (big arse turbo).

BUT, when the boost starts to kick in, the timing is retarded back to 20 degrees pretty quickly (and up to full boost).

The guy is half right in what he says, but he's very wrong with the boost retard bit.

I know of a guy who has built an XF 250 crossflow turbo, on LPG, with only a mechanical dizzy
But, what he did was, mechanical ADVANCE, and boost RETARD.. THe boost retard being the exact reverse of vacuum advance..

Vacuum advance on a turbo charged car won't really work that well, given you won't HAVE that much vacuum.

[love ke70]

if i have no mechanical advance. which i dont think i do could i be safe running no boost retard?
i know i wont get the best off boost performance, but its probably gonna be alot easier than trying to find a workshop that will do it properly.

so heres the way im seeing it.
vacuum advance...not needed
mechanical advance...not essential, only required to improve off boost performance
boost retard...only needed if mech advance is present

have i got this right?
thanks a bazillion stradlater

[thechuckster]

you'd be better off going to a shop that specialises in(re)building dizzis for race/rally cars and talk to them.

fwiw, even the cordia turbos (of whichi have the vacuum advance/boost retard unit from) had vacuum & machanical advance, as well as boost retard.

So your shopping list should be:
vacuum advance... needed unless the car is 100% dragcar always on boost
mechanical advance... needed as you need a sensible advnace curve across engine rpm range
boost retard...needed, expecially if running high levels of boost

personally, you should just get an ECU to run your spark, but if you are persisting in running old-school hardware for ignition control, go talk to:
-Bob Romano (Lytto Rd, Morningside)
-Brisbane Tuning & Turbo (Woolloongabba)
-Saffordtune (Stafford)
as they list their services as a including distributor repairs/rebuilding

btw: your gas man is talking thru his arse - if that's the standard of advice he provides, then i'd be very uncertain about the safety of his installations.

[stradlater]

I'd go with an ECU to run the spark, but in the absence of any ignition only computers (Thanks Haltech) - Getting a customer built Vacuum & mechanic Advance + boost retard dizzy would be a good idea..

As I think I've said before, your are well served ringing Jerry at Ignition Torque in Bayswater Vic. I know it'd be an std call, but he's built exactly what I"m referring to atleast a few times before. He knows what it is your after.

[love ke70]

http://www.racetechdev.co.uk/em34_spec.php

i think thats what we would need. not sure tho
im really not a fan of ecus, just coz i dont understand them and its easy for things to go wrong, and its hard to know when an electronic sensor or whatever isnt working proper

stradlater, i may ring him, its probably a good idea to do so and the std call isnt an issue. its just when your not definate on what your talking about u sound like a total pratt.

if you have msn would you mind adding me, i hvae a few small questions which im sure you would know the answers to say_it_to_my_face [at] hotmail.com

chuckster thankyou very much for the info. i will call those places soon and see what i come up with

anyone know if a 5m-e distributor has mechanical advance?
cheers guys

[stradlater]

Couldn't tell you about the 5m-e dizzy, BUT, my experience is (and is about to become moreso) don't fuck with dizzies. THey can cause so much grief. Do it ONCE do it RIGHT.

[mrshin]

Another possibility is to look around and see if you can get a pre-loved aftermarket ECU to run the ignition. If you strike it lucky, for similiar money to what you spend on a dizzy, you can have something that is much more adjustable and likely able to support multiple coils.

[love ke70]

so your saying get a full ecu and just use it for ignition?
or try and find something similar to the igntition only haltech one which was discontinued coz motorolla stopped making the chip for them?

[Forcefed6]

I am sure if you wanted to, you could find a second hand Haltech IG5 unit for cheap.. Or you could use the megasquirt to control ignition only (if it does that is). Either option is gonna be better than no timing control at all which you get when you lock a dizzy.

[love ke70]

yeah i may look into sourcing something to do the trick
atm ive been side tracked tho. my harmonic balancer has been seriously abused

u just have to turn your head on the side lol
apparently the furthermost back ring is meant to be as high as those timing marks, same height as the front one. something or someone has done some serious damage tho

[Forcefed6]

Does it still have a timing mark on it.. Like has someone remarked it on there again.

That looks like it's been machined or something, or it just the picture making it look that way.

You can find where the timing mark is supposed to be. It is normally inline with the keyway on the crank. Failing that, you will have to find anoher one... or you could just leave it. If you get stuck i think i got one here that you could probably have.