Bandimere 4/20

[SSpeed]

Legend, a DSM'er in Longmont that's also on this board (not sure how active) has a Dwyer magnehelic pressure gauge....

[Legend]

Here is the log from the 30mph-120mph dyno plot above. (Ack, look how much less air I was moving in the dyno shop 80F w/ little air ciculating vs. the dragstrip 45F... 291g/s vs. 311g/s)

 

log

[LittleBlueGT]

Here is the log from the 30mph-120mph dyno plot above. (Ack, look how much less air I was moving in the dyno shop 80F w/ little air ciculating vs. the dragstrip 45F... 291g/s vs. 311g/s)

 

log

 

That sounds about right. Of course you are pushing about the same amount of air in 3rd as in 4th.

[Legend]

I went into the tune today and made some changes. The two problems in my runs were a) less timing than tuned in 1st-3rd gears due to shift-knock phenomenon, and b) 4th gear collapse around 109mph.

 

Revisiting the logged run, there were shift-knock issues in the following places:

 

• 
  2nd gear (just after 1-2 shift) b/w 2600-3100rpms and b/w 1.91-1.75 g/rev, double knock sum increment 1.9s into run

 

• 3rd gear (just after 2-3 shift) b/w 4100-4700rpms and b/w 1.61-2.08 g/rev, double knock sum increment 5.2s into run
  

 

That's it, 2 places, both immediately following shifts under 2g/rev. The first instance caused my time in 2nd gear to be run with 2 degrees less timing and the second instance cause my 3rd gear to be run with 4 degrees less timing (since no-knock delay from first instance had not cleared).

 

To mitigate the impact of shift-knock events, which I really believe are just drivetrain noise, I have changed the following:

 

• Feedback Correction Minimum Load - changed to disable below 2.0g/rev (was stock value of 0.55g/rev in prior map)
  

• Feedback Correction Retard Value - changed to 1.0 (was stock value of 2.0 in prior map)
  

• Feedback Correction Negative Advance Delay - changed to 150 (was 200 and stock is 250)
  

 

The first of those 3 changes would have eliminated the reduction in timing observed for the 2nd and 3rd gear portions of the run. The other 2 changes seem reasonable based upon the fact that I run E85 and I monitor my tune.

 

To mitigate the 4th gear power loss phenomenon around 109mph, I believe it is predominantly due to heatsoak and can't be tuned out. But I did want to make the tune a little more friendly past 5700rpms at high loads anyways. I honestly don't think it will make much difference but who knows. I richened fuel by ~0.01 lambda, reduced timing by 1 degree, and reduced boost by 0.5psi. None of those changes is all that significant as I am not willing to give up too much top end in gears and speeds that I actually drive on a daily basis. All I need to do is prolong this phenomenon by 0.5s to get across the finish, so a small difference could be enough. I may look into an IC sprayer as well.

[mwiener2]

Turn off knock control with E85. It's not like any of it is real knock anyways.

 

If you have the stock engine cover I have a really good setup for a sleek IC sprayer

[rao]

If you use an IC sprayer, make sure it is on the INSIDE of the IC pipe If you spray anything under you hood at the track you should be thrown out and asked not to return.

 

Besides WI would absolutely, without question reduce the temperature of the charge, but of course, it couldn't possibly work .

[Legend]

Turn off knock control with E85. It's not like any of it is real knock anyways.

 

If you have the stock engine cover I have a really good setup for a sleek IC sprayer

 

:lol: I think I'll keep my knock control enabled, thanks. Just trying to reduce the nuisance aspect of it.

 

Details on your IC sprayer? Yes, I run the engine cover.. have to with a TMIC.

[mwiener2]

We'll have to find my old posts about it... circa 2005-2006

 

found the beta version - http://legacygt.com/forums/attachment.php?attachmentid=6790&d=1115616872

[SSpeed]

I have this sprayer if you want to see it sometime, they have DIY electronic kits to be cheaper...

 

http://autospeed.com/cms/title_Intelligent-Intercooler-Water-Spray-Part-1/A_0527/article.html

 

It's not a manual system, it sprays when two parameters are met, a set delta between ambient and back of intercooler temp, and a set injector voltage.

 

Whether it does the job cooling I don't know, I no longer have my temp probe in the post-IC plumbing... Off stoplights it sprays almost right away, on hot days it will spray after 2-3 seconds of boost, on the highway it often won't come on at all, and in the winter it almost never comes on.... Want me to find a "closed course", get up to 110, and see if it turns on?

[Legend]

Well, since I'd only need a sprayer for the dragstrip I don't think I really ought to bother... since water on the dragstrip could cause big problems for the next guy to race behind me if he has big power. So the only kind of sprayer I'd be interested in would be the cryo2 IC systems... but expensive and probably not worth the hassle for me. But hell.. I think it would work!

 

[ame=http://www.youtube.com/watch?v=m9ZQoZp-du8]YouTube - DEI CryO2 Intercooler Sprayer[/ame]

[mwiener2]

Found pics!

 

http://i13.photobucket.com/albums/a257/mwiener2/IMG_1895.jpg

 

http://i13.photobucket.com/albums/a257/mwiener2/IMG_1896.jpg

 

It's two OEM washer nozzles from our cars set into the corners of the IC opening. It worked very well and wetted the IC perfectly.

 

 

 

I got over the whole it gets water on the track thing. I used washer fluid with a bit of rubbing alcohol added in to help with evaporation. Most of the idiots who drive their AWD cars through the water box track way more water onto the track than my sprayer ever would. Plus, once you got moving, the water gets all misted up and drifts away in the air.

[rao]

Well, since I'd only need a sprayer for the dragstrip I don't think I really ought to bother... since water on the dragstrip could cause big problems for the next guy to race behind me if he has big power. So the only kind of sprayer I'd be interested in would be the cryo2 IC systems... but expensive and probably not worth the hassle for me. But hell.. I think it would work!

 

 

That stuff, if it even works, is way too slow. If heat in the air charge is the problem WI is the answer, accept it

[SSpeed]

Cool, here's mine...

 

http://legacygt.com/forums/showthread.php/need-help-wagon-owners-intelligent-intercooler-sprayer-99906.html

 

I got a second washer pump and dremelled a spot in the washer tank where the wagons have a second pump to add it, because I was too cheap to buy a wagon reservoir... Then I used the connector that's already there in sedans to wire it up.

[mwiener2]

^^ No way. CO2 or nitrous spray is the best way to go. You can use it to pre-cool the IC and it's spraying liquid onto the IC which boils instantly, sucking tons of heat out as fast as possible. I'm always worried about thermal stress cracks with those sprayers.

[SSpeed]

Ideally I would agree that water/meth injection is the way to go for better power. I would do water injection if it could be tied in to the ECU safeguards, but for the most part it's a standalone system, and as it stands if you don't tune for water/meth injection you actually lose power, and if you do tune for it and your nozzle clogs, BOOM!

[mwiener2]

Meth/WI doesn't do squat when you are already on E85.

[rao]

Fascinating, so injecting water will not cause ANY cooling of the air charge?

 

Must be some interesting physics you folks in Colorado have

 

It is the ideal solution for this "problem."

[Legend]

It's all interesting, but I won't actually be doing any of these things, other than the minor tune tweaks (which I think have only a 1% chance of making a difference). Too much energy for me to deal with a problem only happens at the dragstrip in the final 0.4-0.5s. And I already stated that I am finished with the dragstrip for this year anyhow.

[rao]

WIMP!!!!!!!

 

Smart move.

[SSpeed]

Did you say why you're done with the dragstrip this year?

[LittleBlueGT]

1) I do believe that is real knock. Our TMIC are not all that big, don't get a ton of airflow, and the 68HTA wheel is not all that efficient IMO. Why else would the car pull timing up there? If you don't believe that rig up some det-cans. I do believe it is real knock.

 

2) WI would absolutely help with pulling heat, but if only for the odd drag-strip use seems like a waste to me.

[Legend]

Did you say why you're done with the dragstrip this year?

 

I don't enjoy it as much as I used to. I don't think I can improve much on my times as I've already gone 3 times with the exact same setup. I feel like there is a certain magical number of runs that I'll get before something bad happens. 4th gear collapse is REALLY aggravating... it leaves me putting mental asterisks on my timeslips, making excuses, etc. The only way I go again this year is if I need to replace my motor. Then I'm getting a slightly built 9:1 CR motor, changing turbos, and since my car would be already torn apart and I've exhausted all the TMIC turbos in which I have interest, maybe going FMIC. But somehow my entire damn car seems bulletproof so I don't anticipate that happening.

[Legend]

1) I do believe that is real knock. Our TMIC are not all that big, don't get a ton of airflow, and the 68HTA wheel is not all that efficient IMO. Why else would the car pull timing up there? If you don't believe that rig up some det-cans. I do believe it is real knock.

 

Agreed that is real knock. That's why I am not doing much to weaken the role of FBKC in protection of the motor under those conditions and that is also why I made slight adjustments to timing, boost, and fueling in the affected spot.

 

The shift-knock probably isn't.. and even if it is it is only due to very transient conditions created during or just after the shift... I feel that the motor can resume it's demonstrated safe full-timing jaunt through 2nd-3rd gears and shouldn't have timing penalized for that kind of knock, whether real or not.

[SSpeed]

You and I have talked about this, I've always gotten fairly bad shift knock, or more accurately "mash knock", on every tune I've had, even stock....

 

Do you think this change is safe for all situations?

 

Feedback Correction Minimum Load - changed to disable below 2.0g/rev (was stock value of 0.55g/rev in prior map)

 

Looking at some of my logs, setting it to that number would basically disable knock correction on throttle up until I hit about 12psi...

[mwiener2]

E85 just does not knock. Can't make it do it on the dyno either. People that have had issues that would normally cause knock and destroy a motor end up with melted internals instead.

 

I have heard a few people say E85 will rich knock... even had a guy self tuning on the dyno getting "rich knock" on an evo at 40+psi at higher revs. It wasn't rich knock, but that's what he was calling it.

 

Meth/WI on E85 gets maybe 10-15 more hp out of it. Since the E85 itself is netting a 60ftlb and 40hp gain over gasoline, the extra 15 aren't worth the expense and headache of dealing with it.

 

 

The heat energy in the charge air is used to evaporate the water/meth. That's why the air gets colder when you spray. E85 is mostly alcohol and it evaporates really easily. If you use Meth/WI to cool the air charge before the e85 is injected, there isn't enough heat energy in the air to fully evaporate the E85 as it enters the combustion chamber. That's partly why Meth/WI isn't as effective with E85 as it is with gasoline. Meth/WI also raise the effective octane of the E85 mixture so high that it burns slower.