High load timing with alchy

[Jeff_Jeske]

When you fellas are hitting 260-280 load levels what kind of timing are you aiming for? I am attaching my alchy timing map. I normally see 7* at peak and 16* at redline. I've been increasing my boost and now I'm starting to see loads nearing 280. I'm curious if the timing in my 260 cells are to aggressive to simply rename that load cell to 280.

[Ralph]

Redo that link, cant see the pic .... just thumbnail

[Jeff_Jeske]

The following is not my alchy map but another members. I'm wondering which map more closely matches what other folks are doing.

[TTP Engineering]

Your timing needs to be rescaled.

There is likely a little too much timing at peak tq depending on boost level.

You should not be tuning without knocksums data.

[Jeff_Jeske]

I'm tuning with a wideband and evo scan. I see no knock at all. I was thinking my timing is to tame. I have rescaled my maps to 300 load (jumps from 260 to 300). When logging with 2 byte load I am seeing 285 falling to 260 loads. For the most part I see 7* through most of the midrange then it rapidly climbs to 16*.

From what I hear alot of people run 10* at peak and 20-22* at readline.

[dudical26]

I dont know how much boost your running or what your AFR might be but its possible that your timing is a little conservative. But rather then setting your timing based on what others have done you can just try increaseing it slowly untill you develop some knock, then back it off a degree or two. If you really have no knock as you said and assuming your boost and fuel are where they should be I would try bumping up the timing a bit.

[Jeff_Jeske]

Boost is at 26psi then if falls to where it falls. Its different in every gear. Afr's are 11.5:1 because this is primarily an open track car.

[dudical26]

I am no expert but that seems fairly conservative to me. However, is you are tunning this for road racing then the margin of saftey you want to have is up to you. You could almost certainly make mroe power by leaning it out a bit more and upping the timing, but then you will have a smaller margin of saftey. As it is now, it seems your tune is pretty safe and would probably be great for road racing, if you are willing to have a smaller margin of saftey then lean it out a bit and up the timing.

[Jeff_Jeske]

I guess the reason I ask is.... to me it seems fairly aggressive when compared to the stock map. I know I am adding octane with the alchy but still, on average for 100 octane, most people say add 2-3* timing and lean out the mixture to 12:1.

If you compare the stock 260 load cells to my 260 load cells the thing is MUCH more aggressive. Take a look at the attached JPG.

My peak timing is +8* +10* from the stock map. I am carrying that time through to a 300 load.

I wonder what the bigger turbos tune for timing wise at 320-340 load cells. Are we to simply stick with the 6* at peak 16* at redline train of thought regardless of load?

[HmanEVO]

IMO, I wouldn't worry about comparing to the stock 260 load cell timing values. It almost looks as if Mitsu set it ultra conservative in the event of an overboost situation, e.g., boost hose coming off the wastegate or someone with no clue cranking up their mbc.

[mad_VIII]

Well man, best way to tell is on the dyno, baring that, find a single stretch of road to test on and do timed accel runs. It is possible that you can run more than the optimum timing without the knock sensor getting upset. Best way to tell is on a good dyno so you can keep adding timing till you see no return in power or a decrease in power then back it off a degree or two.

[gunzo]

Originally Posted by Jeff_Jeske

I guess the reason I ask is.... to me it seems fairly aggressive when compared to the stock map. I know I am adding octane with the alchy but still, on average for 100 octane, most people say add 2-3* timing and lean out the mixture to 12:1.

If you compare the stock 260 load cells to my 260 load cells the thing is MUCH more aggressive. Take a look at the attached JPG.

My peak timing is +8* +10* from the stock map. I am carrying that time through to a 300 load.

I wonder what the bigger turbos tune for timing wise at 320-340 load cells. Are we to simply stick with the 6* at peak 16* at redline train of thought regardless of load?

Really it depends on which school you belong to

Use alky as fuel substitute and lean out the fuel while running lower timing ..
OR
Use alky as knock suppressant and run as high timing as possible ..

Had a friend with whom I helped tune on the dyno with alky ..his timings had to be +6-9* above stock before it recovered some of the lost power .. ended up with almost +12-15* across to be about 30whp on top of his original hp.. .. yes .. at the 240-260 load site I've 25-26* scary **** ..