26 replies to this topic

[jack be nimble]

Looks like you know way more than me, but that was what i was going to say. bmt is before knock on e85.
I dunno how you could tune it without a dyno other than the electronic dyno on your ecu.
maybe bmt correlates to a egt ?

Interesting topic too

[bazeng]

Egt tuning with e85 didn't work for me.

Had to be done on the dyno.
Temps simply identified bad plugs and balanced fuel trims.
I had a hot cylinder and pulled the plus. The hot cylinder had a damaged spark plug. Saved us time and possible disaster.

[JETGSR]

yep great for diagnostics.

I've been still seeing hi-ish temps but i'm slowly adding more timing which is decreasing the temps.

I have a question regarding timing maps, I checked out my old pulp 98 map from Mark Jacobson (Godzilla Motorsport)
I noticed in the old map the same timing is used all the way thru each load bar. eg: 3000rpm to 7500rpm @ 10 psi = say 13deg
and 3000rpm to 7500rpm @ 15 psi = 11 deg and say at 20 psi it would be 8 degs

where on my current map I've stayed with the low ign timing at low rpm and ramping it up to the desired timing at max rpm
obviously this changes each load 5psi 10 psi etc ..
so it is the nice smooth 3D map we all know (not to dissimular to the factory style map)

From what I can see there is merit in what he has done as if you look at the tracing of the log (run) watch the different cells the trace passes through
on it's way to redline. and in each gear you are in a slightly different line on the trace so a different group of cells are used.
I've seen the ign timing go up and down from 17 - 15 - 16 - 15 - 17 - 18 and then up to redline
this can be felt as surging as it makes it's way to redline.

where on marks map it doesn't matter where in the rpm range you are you have the same timing it just varies accross the load say from 0kpa @ 24deg to 18psi @ 9deg

The car was fast and responsive on his map! ... but now i'm on e85 it's a different kettle of fish (I think ther are blue ones now .. the fish)

I done 2 maps with the different ign timing just to see what effect it has and the power delivery, I've kept timing under 18 deg at the high load end

any expierence in this area? care to show your ign maps?

[caged]

Ill try dig up some maps for you. for every 1000 rpm you need 2deg (from memory) more ignition timing just for it to keep up to the delay due to rpm increasing. Iv seen a few places do maps like that, way quicker and still has the big top end but isnt ideal.

[JETGSR]

heres a copy of my experimental ign map and what I was talking about with regards to the 0kpa to max boost ign being the same across each rpm site.

Attached Thumbnails

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[Advanced Jap]

Another update!

950 = bad
820 - 830 = normal

currently pushing hi 800's sometimes so i keep adding timing and temps are dropping
i'm up to 17deg at 24psi at 7500 (on e85)
it is getting more on the scary holy shit, my knuckles are going white! way of things now.
seriously I think it needs to get onto the dyno

unfortunatly without a reliable knock detection setup I'm not sure where the "go bang" mark is. bloody thing will probably put a leg out of bed before I find knock anyway.
thats the only problem with e85 - if there was one. Bang B 4 Knock

As baz mentioned it's a great tool for diagnostics and tuning to a point , if your map is really retarded then you can work your way closer to the edge using egt's, but the temp reading you see is delayed

 

You cant really sit on the dyno watching the egt's with one finger on the page up key , 2  strokes to far (with pump fuel) and someone might lose an eye as the result of an  airborne dipstick. 

 

egt's are really for tuning diesel engines  

 

The knock monitors aren't that reliable, I reckon a good tuner with a passion for tuning and 20-30 years under his belt is more reliable 

 

 The Gizzmo kmon uses a bandpass filter to block out  noise but  engine  bay rattles  inter cooler piping etc... can replicate the same frequency (85mm = 6.5khz 4G63).   

 

I have seen the transducer type knock detection units that has a pressure or load sensor built into a spark plug and they measure cylinder pressure  , they are expensive and from what I've read they can catch knock just as the cylinder pressure starts to rise ( or a little knock   ), I'm not sure I like that idea although a great tool to have as a precaution  but inducing knock to stay away from knock is just plain old silly.

 

We have tuned a few cars they had previously been tuned using a knock monitor as a guide and we made 60 kws more because we knew it could take another 6-7 degrees just by looking at the map.

 

Even though the power fc hand controller was showing high knock we didn't pay it any attention , 10 degress on 21psi 7000 rpm with  the turbo that was fitted is just way to retarded even for pump fuel  , and when an engine responds by giving you 60kws  in return it means  it needed that 7 degrees of timing.

 

the knock on the pfc hand controller ended up being a cooler pipe rubbing on the body,  the customer isolated the noise later on and  the knock count on pfc disappeared .

 

that is old school tuners like con are great at what they do along with 100's of other tuners around Australia that have 20-25 years experience.

 

 They take in to account all the variables , fuel , comp ratio, turbo size , mods etc..etc.. and they already have a picture of an ignition map inside their head .  

 

I'm not going to tell you to running more timing , (disclaimer) I would have run more  on E85  , the burn rate is different and much slower  and more stable

 

That burn rate has made your timing retarded hence the hi egt's ( listen to George )  

 

 

What George said ----> I don't think you will break the engine with e85, 

 

you can run  more timing as the engine revs and torque drops off,

 

The peak torque loads sites areas of the map is where you would need to be careful (with pump  fuel especially) E85 is a very forgiving fuel 

 

 

i've only got like 16Deg at 7500 @ 20psi     (is less than what we have run on 98 pump fuel on some decent power  set ups being 4g63 rb25 rb26)

 

If you makming big power Don't forget to change heat ranges on the plugs coz preignition  can bite you in the ass real quick and  the best fuel in the world won't save your engine .

 

check this site out  http://www.efi101.com  it has to best the best sites on the internet next to 4gtuner of course. 

 

 

and get the intake manifold tested if your haven't done it already 

[Advanced Jap]

heres a copy of my experimental ign map and what I was talking about with regards to the 0kpa to max boost ign being the same across each rpm site.

looks  a bit like one of cons maps , it would need massaging of course  but makes the world of difference when you have somehwere to start and that looks like a good place. 

 

I believe if you have enough passion for something it's just a matter of time before you are really good at it 

 

break a few engines along the way, it's the only way to learn

Edited by Advanced Jap, 19 October 2013 - 01:59 AM.