Launching and Timing with TT alky chip

[murphster]

Nothing to worry about. All TurboTweak alcohol chips operate that way, for the last 8 years. Murphster is not describing a problem, just something he found may have helped his car 60' better, but is more aggressive and likely to cause knock on the street for most cars.

Eric

Yes, by all means this is a feature that almost all people benefit from and most people are probably safer using the normal alky chip. Without the timing delay, I was getting a good bit of transitional knock on the street until I changed some of my alky settings in the alkycontrol box. Because of the extra timing combined with the extra alky, the street performance suffers and I still need to be a little careful.

However, for those that race at the track on alky the conditions are a little different and we might be able to benefit from this knowledge. Maybe Eric will be able to do some tricks to distinguish between launching at the track and going WOT from a roll on the street on a future chip. For now, some people may benefit from having a different alky chip to use just for racing without the timing delay.

I wouldn't recommend using a chip without the timing delay on the street, especially for those who don't want to get into tuning their alky to adjust for this and are not good at watching their knock gauges all the time on the street (which is probably almost everyone ).

 

[Razor]

Wonder if making an alky race chip whereas no timing is pulled until 20-25 MPH. Use the vss input and do that. Eric has made these patches in the past, I remember my old ME-r we could set 0-45 MPH knock ignore. For reasons like this and becuase there is a lot of stuff moving around the engine when you launch.

To bad we cant get a graph showing boost to match up the MAF. be cool to see this on a power logger. Another cool thing would be to see WB AFR, and alky pressure as this bottom end knock is visible.

I agree with street cars its best to curb the timing initially to reduce any sporadic knock activity.

 

[Mr.Spool]

murpster,the knock counts are 2 to 3 with the timing delay and without they are 10 as soon as timing rises to 25 if i am reading that right.how soon did you have to bring in alky to curb that knock?

 

[pacecarta]

you're confusing a knock count with knock retard
if you look closer youll see rtd thats knock retard in degrees and both before and after shows RTD 0.0
knock counts is a running tally of kr events that have occured
knock retard is what is occuring as an immediate result of knock counts that are either loud or successive in nature to warrant retarding the timing , erics chips wont pull or show kr during launch , only a knock detector or audible that reads off the raw knock meter will show if there is knock on launch

every time you turn the key you get knock counts recorded and added to the previous knock count and launching hard can cause knock counts on its own unrelated to internal engine tune

 

[Mr.Spool]

ahh thanks

 

[murphster]

As an FYI........

On a chip that doesn't pull any timing, there are a couple things you can do to reduce the transitional knock on the street. The easiest way is to pull the 1/2 (first and second gear) timing down to 21 while increasing the alky output at low boost. If you leave the 1/2 timing at something like 25, its very hard to get rid of the transitional knock and you'll have to dump tons of alky in early and under partial throttle you'll be rich though because you'll have too much alky coming in. If you just avoid going WOT quickly on the street and just ease into the throttle early and then go WOT after the boost and alky pressure come up, you'll avoid a lot of the transitional knock on the street.

Depending on the combo, you'll just have to play with the alky settings until the transitional knock goes away. I'd move the turn on point a little sooner and move the initial gain just a little (like from 11:30 to 12:30 position on the dial) as turning the initial gain knob makes large changes. After you bump up the initial gain, you might have to turn down your alky main knob a little compared to where you were before. With a recent alkycontrol system, you can verify that the light goes from red to green a lot sooner.

For those who wish to play with the alky settings, review the "Tuning the Alkycontrol kit" sticky in this forum.

 

[murphster]

Here's what my new chip did for me (taken last Saturday).

Of course, the HRparts rear swaybar just installed last week probably didn't hurt either . Just a little TE44. I'll be putting a stock turbo back on soon to try to beat the run I made in the GN last year thats in my sig. All on pump gas and alky, of course.

 

[aminga]

As an FYI........

On a chip that doesn't pull any timing, there are a couple things you can do to reduce the transitional knock on the street. The easiest way is to pull the 1/2 (first and second gear) timing down to 21 while increasing the alky output at low boost. If you leave the 1/2 timing at something like 25, its very hard to get rid of the transitional knock and you'll have to dump tons of alky in early and under partial throttle you'll be rich though because you'll have too much alky coming in. If you just avoid going WOT quickly on the street and just ease into the throttle early and then go WOT after the boost and alky pressure come up, you'll avoid a lot of the transitional knock on the street.

Depending on the combo, you'll just have to play with the alky settings until the transitional knock goes away. I'd move the turn on point a little sooner and move the initial gain just a little (like from 11:30 to 12:30 position on the dial) as turning the initial gain knob makes large changes. After you bump up the initial gain, you might have to turn down your alky main knob a little compared to where you were before. With a recent alkycontrol system, you can verify that the light goes from red to green a lot sooner.

For those who wish to play with the alky settings, review the "Tuning the Alkycontrol kit" sticky in this forum.

What if you could trim the ALky based on RPM?

 

[Razor]

What if you could trim the ALky based on RPM?

Look at a FAST VE table, the injector duty cycle between what is lets say 5k and 6.5k is not that much varied. And the alcohol being lets say 10-15% of your overall fueling equation is much less the issue.

Your thinking someone races from 2k to 8k. These cars and most drag cars operate on a very narrow window. As you keep the car where its making power all the way down the track. If your getting out of the motors sweet spot.. you slow down.

Load is the way alcohol is shot in. I'd even venture to say that possibly having a MAF that could read the airflow like from an 07 Vette maybe a neat thing to try. In the end.. if you think the alky is hurting performance, easy test.. drop in good gas and drop the amount of alky. If the power comes back on.. then your spraying too much.

 

[murphster]

Just a little update.......

I upped the timing to 25/21 for the track and also tried it on the street. Definitely some transitional knock on the street with that timing even with my alky coming on sooner. No knock whatsoever at the track though. (This is all with an alky chip that doesn't pull any timing, of course). I've actually never had a problem at the track with chips that don't pull timing at the track when on alky, even with the timing set pretty high.

I changed over to a stock turbo this past weekend and put the timing at 22/21. There's a little transitional knock with the stocker on the street, even with the 1/2 timing a little lower. From what I remember with a past street chip on a stock turbo, I put the 1/2 timing down to 21 to help with the transitional knock on the street.

The boost builds faster with the stocker compared to the TE44, and one might think that means the alky is coming in sooner since its based on boost. But there must still be a delay before the alky hits full pressure. Probably need to set the turn on point even sooner.

I might have to do what Julio suggested and log everything to see whats happening with the alky pressure on the street so I can get the ramps dialed in. I have a Powerlogger with WB, EGT, boost, and alky pressure inputs, but haven't used it yet.

 

[bison]

Just out of curiosity what kind of MAF are you guys running? I never noticed this with a stock one probably because they max out before the car starts the timers.

 

[murphster]

I'm using both a 3" MAF and a 3.5" MAF currently on my cars with a translator. Just out of curiosity I pulled up some logs I had from early 2006 with a stock MAF on a GT6152 turbo. The MAF max out seemed to come sooner and the timing came in at about 8mph or so but on some runs the timing didn't come on until 16mph or so. These were mid 11 sec runs with high 1.5/low 1.6 60fts. So the effect is still there with a stock MAF and would be worse on softer launches than I was doing.

 

[Bigjack7440]

The alky I just got installed on my 87GN works good, but my car runs alot better with the tt full race chip and 110oct. It's idle is alot better runs cooler stays at 160deg and when you hit the gas it just pulls way harder. Now as far as everyday st. Driving yes alky work good at 23lb . But that full race tt chip with the 110oct is the fastest my car has ever went . I guess more timing and I run 25lbs with that chip. Also my car runs better with the st. 93 tt chip on alky than the tt alky chip. I still need more tunning time , also I need to take some fuel out 1/2 wot with the alky tt chip (to fat) . Anyway you guys have better tunning brains than I do.

 

[Razor]

The alky I just got installed on my 87GN works good, but my car runs alot better with the tt full race chip and 110oct. It's idle is alot better runs cooler stays at 160deg and when you hit the gas it just pulls way harder. Now as far as everyday st. Driving yes alky work good at 23lb . But that full race tt chip with the 110oct is the fastest my car has ever went . I guess more timing and I run 25lbs with that chip. Also my car runs better with the st. 93 tt chip on alky than the tt alky chip. I still need more tunning time , also I need to take some fuel out 1/2 wot with the alky tt chip (to fat) . Anyway you guys have better tunning brains than I do.

This is the point if tuning. Technically should run and drive the same no matter what chip you use. At WOT is where it needs to get figured out. Figured out=tuning.

You will make the same power on your car on race gas or pump and alky. Its just tuning to get things sorted out.

Think your alky chip needs to be tweaked a little. As the street chip if anything should run the worse out of the three.

HTH

 

[ryan george]

Excellent thread.

Question, maybe stupid, what is different in the conditions that causes the need for reduced timing on a street vs race chip? Thanks!

 

[Razor]

Excellent thread.

Question, maybe stupid, what is different in the conditions that causes the need for reduced timing on a street vs race chip? Thanks!

Octane afforded. Race gas has higher octane and can tolerate higher timing.