timing vs boost vs comp vs ron??

[JustCallMeOrlando]

Which bit did you want explaining? Basically, a richer mixture generally is cooler than a leaner one. If you're running lots of boost, it's nice to have a safety margin because temps will already be hotter due to the bulk charged air being pumped in.

[mic*]

Yeah, that makes sense to me.

I was just reading something backwards i think...

more boost = hotter -therefore need- lower AFR = richer
(very generally)

[kingmick]

AFR? ... just keep it FAT up top or it'l overheat the piston and damage it ideally 11.5:1 or lower on anything over 20psi

12.5 sooty is what i use

[1jzracing]

sorry buddy was going to send a reply im just a slack-ass!

cant say i recognise the car in the pic looks a bit like the ones who run with us they all pretty much follow a similar theme ... steve vigors has claimed to have built quite a few chassis including jackos calebra how do you know that car so well? ... its fast but so nervious and twitchy!

i definatly hear what your saying about intercooling, ive had quite a few goes at getting it right from medium FMic ... was ok bit of pressure loss....to a big water air... totally sucked!! ... just heat soaked and temps hit 65+ degrees..... buy buy to no6 piston.. now using a biger FMic seems to be ok with intakes down around 45degrees at 23psi

i seem to be on the right track picked up a forth a third and second in the feature last weekend and we punched out 354rwkw not bad for a dead stock $900 short block in a full floorpan car, std firewall! ..... but still theres always room for more!! ....

hehe think that puts me ahead of jackson in the points now

pm you some tech stuff

[kingmick]

that chassis is totally difffrent from the steve vigors one. it had the whole front cut off and redone properly and i add 10 or so piece of cage to try and fix it! all the alloy inside is new!
the rear set is redone! had to spen $75k to make it a half decent car. even wiht all that the chassis was that bad it still bends! have a look and the height of the bottom of the drivers side firewall and then the other side! the drivers side is slowly bending up!

[Pimpin_1JZ]

With my setup I am running 16 degrees with ~19psi of boost and BP 98 ron. (Can't get shell where I live). This was the old tune but am to go back for another tune with some more fuel and boost very shortly, will post up the results aswell. Timing looked about perfect for the setup according to the line on the plugs. So we didn't push it any further. We left timing until the end and managed to pick up 40rwhp from it.

[pilot]

Basically, a richer mixture generally is cooler than a leaner one.

I´m sorry but this is wrong. Leaner mixtures burn slower, that´s why they seem hotter. The opposite is true too: rich mixtures burn faster and that´s why they seem cooler.

When a mixture burns slower, there is "fire" for more time when the piston moves downwards and thus there is fire in contact with cylinders for more time. That rises engine temperature. Similar thing happens when you retard your timing.

[18rc turbo]

as my signature suggests i'm running an 18r-c turbo, 14 psi (has been as high as 20 psi), with 24 degrees ignition timing. And as far as i could work out when i had the head off, i'm running 12.4:1 comp ratio. And i'm running straight LPG (which i have been told vary's in between 100 and 110 RON. don't know if this is true or not though...?)

[PHOBIA]

A totally different engine than the ones referenced here, but for the point of this thread my 22R-E is tuned with the following.............

12 degrees of timing advance with 25psi of boost on 100LL Avgas. Air/fuel ratios of about 11.5:1 with a compression ratio of 8.5:1.