Anti-lag /Two step theory using Hondata

[chadington1]

I have been reading threads from various websites all the way back to 2004 (HT) on how to properly configure my launch control and build boost off the line. I have read people suggest everything from +400 fuel and -80 timing to -5 timing and +10 fuel.

My question is how do you go about determining a starting point, I am currently running +20 fuel and -30 timing and only making +4psi after a few seconds @ 5000 rpm. Vtec is set at 4500.
Is the Idea to dump a shitload of fuel into the turbine and ignite it with super late ignition or to have a lean mixture with higher velocity spool the turbine?

My setup is d16a6/ported y8 head with small cam and t3/t3 .63/.70 57 trim garret turbo, stock bore and vitara pistons with 137 mm rods, 9:1 compression. Wastegate spring is 15psi.

Since KCIR is closed and its winter, all I'm really looking for is simulated gunfire and terrified pedestrians, but I would still like to understand what I am doing.

Please don't ask me to go ask my tuner because that's me, and we (Me and I) cannot seem to figure this out, besides that bastard just wants to drink beer and look at porn.

So to summarize, I understand that there is a certain mechanical advantage to having peak cylinder pressure by a certain crank angle after TDC (Like 20ATDC or something) but does the same rule apply with the 2-step? Do we want to just dump fuel out the exhaust (I.E Pull timing, and if soe how to determine a starting point?) or add a bunch of fuel and gradually pull timing?

Also I'm wondering what the values are actually coming from, like if you are engaging the launch control at 5000rpm and I'm at say 10hg of vacuum and that is at 30btc, am I pulling timing from that value, and the fuel is adding onto whatever is also in that Cell location by percentage?

P.S I'm currently unemployed so if someone helps me with this I'm willing to come over to your house and dig holes or carry shit around, or whatever. Teach me your tuning tricks and I'll weed your garden or whatever you need done.

[snm95ls]

Originally Posted by chadington1

I have been reading threads from various websites all the way back to 2004 (HT) on how to properly configure my launch control and build boost off the line. I have read people suggest everything from +400 fuel and -80 timing to -5 timing and +10 fuel.

My question is how do you go about determining a starting point, I am currently running +20 fuel and -30 timing and only making +4psi after a few seconds @ 5000 rpm. Vtec is set at 4500.
Is the Idea to dump a shitload of fuel into the turbine and ignite it with super late ignition or to have a lean mixture with higher velocity spool the turbine?

And how does the compare to what you get without using the anti-lag routine? How is your boost control set up?

My setup is d16a6/ported y8 head with small cam and t3/t3 .63/.70 57 trim garret turbo, stock bore and vitara pistons with 137 mm rods, 9:1 compression. Wastegate spring is 15psi.

Since KCIR is closed and its winter, all I'm really looking for is simulated gunfire and terrified pedestrians, but I would still like to understand what I am doing.

Please don't ask me to go ask my tuner because that's me, and we (Me and I) cannot seem to figure this out, besides that bastard just wants to drink beer and look at porn.

So to summarize, I understand that there is a certain mechanical advantage to having peak cylinder pressure by a certain crank angle after TDC (Like 20ATDC or something) but does the same rule apply with the 2-step? Do we want to just dump fuel out the exhaust (I.E Pull timing, and if soe how to determine a starting point?) or add a bunch of fuel and gradually pull timing?

The same rule does not apply with anti-lag as the point is to create a late burn.

Also I'm wondering what the values are actually coming from, like if you are engaging the launch control at 5000rpm and I'm at say 10hg of vacuum and that is at 30btc, am I pulling timing from that value, and the fuel is adding onto whatever is also in that Cell location by percentage?

P.S I'm currently unemployed so if someone helps me with this I'm willing to come over to your house and dig holes or carry shit around, or whatever. Teach me your tuning tricks and I'll weed your garden or whatever you need done.

This isn't something I have had a chance to mess with, so probably not going to be much help based on actual first hand experience.

We could possibly discuss some rudimentary thermodynamic concepts about how to generate more power across a turbine which is essentially what you are trying to do with ant-lag though.

The following system properties all have an affect on the system:
-pressure drop across the turbine
-temperature of the working fluid.
-the velocity of the working fluid

Whatever combination maximizes these properties will generate the most boost with anti-lag.

[chadington1]

yea, so I was sort of under the impression that the concept is to retard timing in order to open the exhaust late in the stroek so that the fuel/air mix is still burning when it leaves the cylinder and is still expanding as it goes through the turbine.

So, Leaner is meaner, right?

If you dump a shit ton of fuel wouldn;t it have like a quench effect and reduce the spool? Or would running less timing let the valves open at a higher cumbustion chamber temp thereby increasing velocity of the exhaust? It seems contradictory either way. I would enjoy a discussion on thermodynamics and engineering shit

Aren't you Nick?

[chadington1]

I'm uploading a video of currently running settings, nothing, and super rich -40 timing. exactly the same results, also someone called the cops lol.

[chadington1]

Here, notice how it makes less boost when I dump fuel and timing? wtf?

https://youtu.be/HNGmhj6DGXE

[chadington1]

Attempt #2

https://www.youtube.com/watch?v=HJB7PcYI05o

[snm95ls]

Originally Posted by chadington1

yea, so I was sort of under the impression that the concept is to retard timing in order to open the exhaust late in the stroek so that the fuel/air mix is still burning when it leaves the cylinder and is still expanding as it goes through the turbine.

So, Leaner is meaner, right?

If you dump a shit ton of fuel wouldn;t it have like a quench effect and reduce the spool? Or would running less timing let the valves open at a higher cumbustion chamber temp thereby increasing velocity of the exhaust? It seems contradictory either way. I would enjoy a discussion on thermodynamics and engineering shit

Aren't you Nick?

Leaner is meaner up to a certain point.

Correct, if you reach a point where the fuel introduced is no longer being burnt. Adding additional fuel beyond max power is typically done to enhance cylinder cooling for prolonged high output situations.

We can get into some of the thermo discussion later on when time permits.

And how did you know my name?

Originally Posted by chadington1

Attempt #2

https://www.youtube.com/watch?v=HJB7PcYI05o

It looks like you are heading in the right direction.



Also, you didn't mention how your boost control is set up. Are you using EBC, or just running off of the WG spring?

[chadington1]

I know your name from driftkids way back when, I was Signorelli21.

I came over to Williams house a few times while you were there in a red crx and we took your transmission to Ming's shop and that dude rebuilt it wearing sandals lol.


Anyway my boost is running off the wastegate spring, I have the PWM solenoid and all that set up from Hondata but I couldn't get it to work so I just tossed in both wastegate springs I had laying around lol. It makes 14psi and creeps to 15.

With the way my tac bounces around I wonder if I have an issue with my distributor?

Oh well, last night I was talking to these dudes from pakistan and one of them is like the only guy in the country that tunes cars (apparently they have one dyno in the entire country, costs 150 bucks for a tune which also is apparently super expensive lol) and he was giving me various settings to try, then I got pretty drunk and just started throwing random settings at it.
It built 10 psi once but I couldn't reproduce it no matter how long I stood on the damn thing, 6 is fine for the street I just want to understand what I'm doing better.

Lol.

Chad

[chadington1]

3rd attempt lol, was getting a bit flustered.

https://www.youtube.com/watch?v=AdDzW0wQbRg

[DSMspick]

Later the timing, the more aggressive the antilag is but the more it will stress everything after the exhaust valves. The earlier the timing, the more it will stress everything before the exhaust valves, and the less effectively it will spool the turbo. Fuel enrichment is used to*cool*the exhaust, but gives you a more mild pop. Like how running too lean can melt stuff, but running too rich kills power. It's about finding a happy balance.

Sent from my Nexus 6 using Tapatalk

[snm95ls]

Originally Posted by chadington1

I know your name from driftkids way back when, I was Signorelli21.

I came over to Williams house a few times while you were there in a red crx and we took your transmission to Ming's shop and that dude rebuilt it wearing sandals lol.


Anyway my boost is running off the wastegate spring, I have the PWM solenoid and all that set up from Hondata but I couldn't get it to work so I just tossed in both wastegate springs I had laying around lol. It makes 14psi and creeps to 15.

With the way my tac bounces around I wonder if I have an issue with my distributor?

Oh well, last night I was talking to these dudes from pakistan and one of them is like the only guy in the country that tunes cars (apparently they have one dyno in the entire country, costs 150 bucks for a tune which also is apparently super expensive lol) and he was giving me various settings to try, then I got pretty drunk and just started throwing random settings at it.
It built 10 psi once but I couldn't reproduce it no matter how long I stood on the damn thing, 6 is fine for the street I just want to understand what I'm doing better.

Lol.

Chad

None of that rings a bell, so perhaps you are thinking of someone else.

I would think that you get your EBC working , it is more likely that you will be able to build boost with anti-lag set up as you won't have boost pressure trying to open the WG as it should be set up to 100% block manifold pressure to the opening side of the WG diaphragm until you begin to approach your set boost target.

Originally Posted by DSMspick

Later the timing, the more aggressive the antilag is but the more it will stress everything after the exhaust valves. The earlier the timing, the more it will stress everything before the exhaust valves, and the less effectively it will spool the turbo. Fuel enrichment is used to*cool*the exhaust, but gives you a more mild pop. Like how running too lean can melt stuff, but running too rich kills power. It's about finding a happy balance.

Sent from my Nexus 6 using Tapatalk

Agreed.

Either scenario will induce a lot a heat into the exhaust valves.

[chadington1]

Pretty sure this is the culprit, the flange @ cylinder one is warped pretty good, blew the gasket out and I'm assuming thats why it won't spool much and was kind of all over the place when it did. It made 10lbs on one attempt and I couldn;t repeat it so I'm assuming thats when the gasket blew out.

Also I wonder if putting an actual load on the motor matters as well? like guys slip the clutch a big to put a load on the transmission when launching with big slicks right?

[chadington1]

Originally Posted by snm95ls

None of that rings a bell, so perhaps you are thinking of someone else.

I would think that you get your EBC working , it is more likely that you will be able to build boost with anti-lag set up as you won't have boost pressure trying to open the WG as it should be set up to 100% block manifold pressure to the opening side of the WG diaphragm until you begin to approach your set boost target.

Probably so, Maybe you were on a different forum like the original HMT, or I'm a really good guesser lol.

I'm going to rebuild my manifold and try and get the EBC working again, I don't think it could be opening early because it has 14lbs of spring pressure, but fuck I dunno lol. Anyways thanks for the help you guys, I appreciate the feedback very much.

[snm95ls]

Originally Posted by chadington1

Probably so, Maybe you were on a different forum like the original HMT, or I'm a really good guesser lol.

I'm going to rebuild my manifold and try and get the EBC working again, I don't think it could be opening early because it has 14lbs of spring pressure, but fuck I dunno lol. Anyways thanks for the help you guys, I appreciate the feedback very much.

I bet that's where you recognize the screen name. Spent lots of time on there before the big migration.

It may not be opening early, but even an external WG will begin to open before the set spring pressure.

Also, correct about adding load. The preload helps to keep from shock loading the drivetrain and aids in building boost at the line.

[Dester223]

Hondata 2 step will never be "gun shot" popping violent. If you want that. The msd 2 steps will offer you that.

[Dester223]

And no. You dont slip the clutch to "build load" you slip it to preload thr drivetrain to help keep it from breaking stuff.

[chadington1]

Yea that is what I figured after considering it a bit (and testing it lol).

Its alright the current Hondata setup seems loud enough and after replacing the gasket builds boost pretty well, I probably shouldn't use the launch control on the street anyway lol.

Any of you guys used Virtualdyno? the guy who develops it is in Kansas City and I have read some pretty interesting reviews from Innovative tuning and other people showing it close to actual Chassis Dyno numbers.

[Dester223]

I have a chassis dyno. No need to use virtual dyno.

The #s that people tell me have bee so inflated vs what I see on my dyno. It's laughable.

BTW, you using a cheap ebay manifold or a cheap gasket? I've never had a oem honda gasket blow out. Either your flanges are warped or you are using junk.

[chadington1]

Originally Posted by Dester223

I have a chassis dyno. No need to use virtual dyno.

The #s that people tell me have bee so inflated vs what I see on my dyno. It's laughable.

BTW, you using a cheap ebay manifold or a cheap gasket? I've never had a oem honda gasket blow out. Either your flanges are warped or you are using junk.

both actually, the manifold is warped a bit, the ends are kind of pulled inwards just enough so the gasket doesn't quite clamp down all the way.

AND I was running a shit ebay gasket that didn;t have the metal reinforcement around the manifold outlet, I replaced it with a felpro one and seals better, I tried to machine the flange flat but all I have is a palm sander and that was a hilarious no-go, it did however clean the black shit off really well lol.

I have no chassis Dyno, Jeff from Revline says Jesus can tune my crap box but they are not usually open on weekends, so I'll have to make an appointment. I was mostly just wanting to use the Virtualdyno software to make small adjustments to my timing and see if there was any actual change, I think the latest version of that software only logs AFR/RPM and not timing though.

I guess I'll make a pair of det cans and hope for the best till I get a job lol, got a second interview monday