Proper antilag, thoughts, comments, suggestions?

[fredio54]

posted here because i only want at least semi serious ppl to read it and comment on it. that rules out half or more of the normal 1g community who bought their gt for a grand as a cheap car :-)

when i say proper, i mean air injected into the exhaust manifold while running the engine very rich off throttle and at low pressures such that the fuel ignites as the extra o2 is introduced.

toyota had the makings of this on the celicas (rc versions of the gt4)

here are some pics :





that doesnt appear to use venturis, and thus must somehow rely on pressure to feed the exhaust.

i was hoping that by making venturi tubes and welding them into the runners of my mani i could use check vavles close to the mani and a pwm valve further away to supply air that would not get blown in, but rather sucked in in the same way as evos pcv system (please link that here?)

with a bit of custom ms code, a tps/map/rpm table could be made that supplied the turbo with enough flames to keep it spinning fast enough to boost all the time even if its not as much as when its up and hauling :-)

obviously i have this in mind as an (highly desirable) alternative to downsizing my turbo to a small bb vf34 or something. it would likely be less effort also.

i have read that ppl use controlled bovs to provide the air feed to the valves from a pressurised source (turbo feeds itself bypassing the engine). this could work without the bov being shut once i relocate the bovs to the throttle side of the IC such that there is some back pressure right next to the compressor. but i dunno how effective it would be. it might be that its good at maintaining boost once you have the sucker spooled, and no good at generating it from the get go.

holding pressure in a reservoir is not a goer as it would be consumed far too quickly.

seems like a good way to test the welding on my manifold ;-)

the holset will be up to it i'm sure, and if not, i can get another...

i might have missed some bits n bobs somewhere.

what i want to discuss is the mechanics of getting the air in and the control strategies of making it happen via the ecu.

i might cross post this on hmt and ms forums depending on how poorly i get responses from this one.

fred.

[STW]

I don't think a reasonably sized reservoir feeding from eg. wastegate pressure pipe would run out that fast, as each pulse would replenish it; a delayed jet engine cycle, if you will

I think separate runners to cylinders 1-4 and 2-3 have something to do with it; conserving air os something else. It can't be from a bypass, since those aren't used in rally cars.

But, whatever you do, use antilag very very sparingly... it'll eat your turbo in no time. Mine works simply by feeding a rich mixture into a cylinder and then skips a spark. When the next spark hits the cylinder, it's on the exhaust cycle.

[fredio54]

yeah, thats normal soft mild anti lag, i want full blooded hairy chested MAN antilag :-)

i'm pretty confident that the holset can handle it. its built like a brick [shizzle] house. its also got a pretty large exhaust side, so the explosions will have an easy time escaping.

i'm more worried about the manifold blowing apart :-)

i'm outa town for a few days, so no posts from me (sigh of relief echoes through the world of dohc fes)

fred.

[evo626]

From what I read the most common is to have it run uber rich at low pressures and have it severly redarted and that will get the engine to run on the exhaust cycle. The heat is what would consern me.

evo

[carcenomy]

I was under the impression from articles I read many years ago that the antilag system on Celicas was a fifth injector into the exhaust manifold - it was disabled by default on the road model GT4 RCs, but could be enabled in the ECU? I d'no.

Realistically, the only real antilag system is to scrap the hairdryer and get a supercharger

[moebius]

I have to agree. The best way to remove lag is a super charger.

More info:
Turbo Anti-Lag System - IWSTI.com: Sponsored by www.Subie.tv
and
Anti-Lag System - Wikipedia, the free encyclopedia
and
Turbo Anti-lag systems - A technical description


Seriously, I was thinking that on certain older cars - late 70's in particular, they came with an "Air Pump" - or "smog pump" also called "air injection". The idea was to help burn off un-combusted hydro carbons to help improve smog producing gases.

HOWEVER, in this case, just a little extra air could go a long way. The smog pump kits for holdens/chevys/fords should not be too expensive... In theory, it's like a little super charger. Put an electromagnetic clutch in, so it only engages less than 3000 rpm, and you've much faster spooling on your turbo - - a supercharger for your exhaust gas.... in effect. Of course, the problem is keeping the hot exhaust gases out of the air pump, but you know...

I think it would a lot safer, and longer lasting than the injection skipping trick that STW is using - more work, since you'd need additionaly hardware, and you'd have to do some additonal fabrication (mount it off of the Alternator.... ) but, it ought to work.

Just another point of view. The whole fuel injection into the manifold is rather off putting to me. But then, my bias is towards reliability.

The best overall solution is a turbo feeding a supercharger, ala the Lancia Delta, and the VW TwinCharger... use the Supercharger at low speeds, then switch over to the turbo, and use both if you happen to have 150 octane fuel and want four bar boost.

[infamous_t]

With 'true' antilag apparently the IHI turbos seem to hold up better than there garrett counterparts... possibly the reason standard(ish) WRXs can run antilag systems(with just a upgraded ecu) and get decent life out of them(year plus and counting)...

Im sure Sick has something to say about antilag lol...

A nice alternative that may do the job for the FE3, Bee*R has a kit for the SR20DET(which surely could be easily modified for FE3T) which runs a supercharger with a turbo blowing thru it (or vise versa cant remember)... No lag with that system.

[rodhog]

all I really know of anti-lag is that for drag racing it works well.

YouTube - Turbo S2000 Run 10.7 @ 129miles

that's my mates S2000 on this run he ran antilag setup through his ECU so he had boost off the line. you notice the backfires.

But all other anti-lag is on top pro rally cars. yet under most of there rules conditions - they need it so they have god sort out systems to keep them on boost.
I don't see why you need it in NZ - then again most of your roads are like rallys.

They do put alot of stress on your turbocharger but. I know a few people running group N type production rally cars in both national and smaller loacl compitions and most can use it but they don't because the cost of killling a turbo for that minor bit of performance is not worth it. Most just drive around the lag. but most of the cars are setup for almost no lag right ratios' etc.

That bit on the GT4's it was an option for rally owners. When they bought there GT4's for rally use Toyota had a number of options. They could option the ECU for examples and the hi-spec Denso unit was mapped for more boost and more torque but did not meet emissions etc. This was I think on the St185 or St186 only the first model with air -to air top mount, beofre they went Water to air. But on the later model about 93 they went water to air cooler the whole setup was even stronger again.

Some of you noted early or lates 80's cars
Back then to clean up emissions they used vacuum pumps or air pumps to pump in freash air into the exhuast system so not only did you loose power from bad pre Cat exhuast you lost 1-3hp at the crank driving this pump.
The thing is people have turned them into anti- lag type setups with right retard and extra rich fuel it works well.

but again of course the main issue with anit lag is turbo damage to the turbine - not so much the housing as it can take the sudden change of temperature - well it can take it better then of a turbine.
Don't try it on ceramice wheel RB garrett turbo.

But to give you an Idea you can turn a turbocharger into a Small jet engine.

you plump the compressoe outlet into venturi of small chamber basicly a nossle add a injector for fuel- feed into another smaller outset so air fule mixes behind it add glow plub for ignition or spark plug then plum the out let to the turbine inlet and make small after burner exhuast and mount to device - feed it gas and one quick spark.
Jet enigne now it was comon to do this at Qanats by apprentices to find away to improve it etc and see if you can make it last.

Results we made the injector not melt by pre mixing before spark or igniton area.
that's all we did and it last 2 mins more the early guys. Turbine wheel melted - lost compressor pressure flame caught up to open injector - ONe bit bang.
only good big on turbo was compressor and rest was stuffed. Even the oil feeding the bearings could not keep up.

Anti lag is very similar.

[fredio54]

Originally Posted by evo626

From what I read the most common is to have it run uber rich at low pressures and have it severly redarted and that will get the engine to run on the exhaust cycle. The heat is what would consern me.

evo

yeah, thats why i want proper antilag, not [shizzle]ty retard to all hell, hold open the trottle and run it rich... thats not road usable...

[fredio54]

Originally Posted by carcenomy

I was under the impression from articles I read many years ago that the antilag system on Celicas was a fifth injector into the exhaust manifold - it was disabled by default on the road model GT4 RCs, but could be enabled in the ECU? I d'no.

Realistically, the only real antilag system is to scrap the hairdryer and get a supercharger

the silly car system is an air injection system like what i wanna do. but, i dont know how it actually works, as in, how they get air to go into the exhaust mani. the hardware was there for it, but the mani wasnt drilled below the fittings, and the ecu knew nothing...

also on the silly cars was a water injection system (i forget if it was cooler sprayer, or into the engine) but it was also disabled. the rules state parts must be present, but not necessarily working...

a supercharger is off the menu. i'll go smaller if i cant get anti lag happening.

fred.

[fredio54]

Originally Posted by rodhog

all I really know of anti-lag is that for drag racing it works well.

YouTube - Turbo S2000 Run 10.7 @ 129miles

that's my mates S2000 on this run he ran antilag setup through his ECU so he had boost off the line. you notice the backfires.

can you fix your link, it might be messing up windoze users... i fixed it in the quote.

But all other anti-lag is on top pro rally cars. yet under most of there rules conditions - they need it so they have god sort out systems to keep them on boost.
I don't see why you need it in NZ - then again most of your roads are like rallys.

thats just it, when sideways (and i am sideways a LOT) you NEED good, ney, great response... so i must have a solution for throttle modulation whatever it is...

They do put alot of stress on your turbocharger but. I know a few people running group N type production rally cars in both national and smaller loacl compitions and most can use it but they don't because the cost of killling a turbo for that minor bit of performance is not worth it. Most just drive around the lag. but most of the cars are setup for almost no lag right ratios' etc.

i also want some better ratios for the ute, but that doesnt solve the skid problems, and thats what i love to do most. it also doesnt solve the mid corner modulation proplems either, and i need that to be spot on also for going as fast as possible on a track (or windy road) with maximal safety and control.

That bit on the GT4's it was an option for rally owners. When they bought there GT4's for rally use Toyota had a number of options.

homologation spec cars had it, otherwise silly car purchasers couldnt use it in the rally, and wouldnt have an advantage over other vehicles.

Some of you noted early or lates 80's cars
Back then to clean up emissions they used vacuum pumps or air pumps to pump in freash air into the exhuast system so not only did you loose power from bad pre Cat exhuast you lost 1-3hp at the crank driving this pump.
The thing is people have turned them into anti- lag type setups with right retard and extra rich fuel it works well.

now, this is the good oil, any links etc on these pumps and or ppl that have done it? sounds feasible. i'd still like to know how well a venturi system would work. once there was a bit of spool in the turbo, i reckon it could keep it spinning, but getting it there from idle maybe not so easy.

but again of course the main issue with anit lag is turbo damage to the turbine - not so much the housing as it can take the sudden change of temperature - well it can take it better then of a turbine.
Don't try it on ceramice wheel RB garrett turbo.

yeah, i know those are [shizzle], no one worth their salt uses them for much at all... fine stock, but above stock, you need to ditch them... the holset on the other hand is a brick [shizzle] house, and i'm confident that it can survive intermittent als use for my application.

fred.

[fredio54]

Originally Posted by moebius

I have to agree. The best way to remove lag is a super charger.

More info:
Turbo Anti-Lag System - IWSTI.com: Sponsored by www.Subie.tv
and
Anti-Lag System - Wikipedia, the free encyclopedia
and
Turbo Anti-lag systems - A technical description

read those, the relevant bit is at the bottom of the wiki page. the other two are pretty crap...

Seriously, I was thinking that on certain older cars - late 70's in particular, they came with an "Air Pump" - or "smog pump" also called "air injection". The idea was to help burn off un-combusted hydro carbons to help improve smog producing gases.

tell me more tell me more :-)

HOWEVER, in this case, just a little extra air could go a long way.

yes, yes it could.

The smog pump kits for holdens/chevys/fords should not be too expensive... In theory, it's like a little super charger. Put an electromagnetic clutch in, so it only engages less than 3000 rpm, and you've much faster spooling on your turbo - - a supercharger for your exhaust gas.... in effect. Of course, the problem is keeping the hot exhaust gases out of the air pump, but you know...

4 check valves and some fab is easy stuff for me. i'd have to look into how much volume they could pump out.

I think it would a lot safer, and longer lasting than the injection skipping trick that STW is using - more work, since you'd need additionaly hardware, and you'd have to do some additonal fabrication (mount it off of the Alternator.... ) but, it ought to work.

safer for the engine, but less safe for the manifold and turbo. i think its going to be fine though.

Just another point of view. The whole fuel injection into the manifold is rather off putting to me. But then, my bias is towards reliability.

the fuel goes into the cylinders overly rich, and is still only partially burnt when it exits again. thus you are just burning the leftovers all of a sudden later rather than a whole lot just for antilag thats been all the way through the engine and is burning as it exits. ie, there is no fuel injection into the exhaust. its just running uber rich. and in the case of the half arsed type, the throttle stays open a little too, and you end up needing a vac pump to operate the brakes.

fred.

[rodhog]

look at well hmm NZ didn't get some of the emiison things we got in Aus or the US

I know in Aus there is on the Rx-7 S2 and S3 a air pump.

but THe main thing to look at might be early model Commodores about 83 or so. they had the air pump up untill about 86. All the carby ones.


Oh and it was water sprayer on the early Air to air top mount and then a Water injection set-up. Rules were still being thought out. on the Gt4 that is. Yeah all the homoligated cars mostly the Jap sold ones.

I think from memory the toyota setup was air injection -over rich setup. effectively on every 4th cycle of each cylinder it would fire late or something along that line. It was quite well thought out. It's why the Toyota Rally team hear still uses a full GT4 setup in a Corrolla.

Mitsubishi get around it with Titanium turbine on the turbo and this allows retard - anit-lag.

but I think over all with your ute not weighing that much anyway. Your better off with a more responseive turbo. It really depends how unresponsive your current one is.
With limited weight to move and well obvious lack of traction you should be able to keep it on boost with ease. I know few turbo Hilux utes that can't get on the throttle because the rear just kicks out.

Most of the winding roads don't have long straights in them. So top end would not be a problem.

[RbluEMx6]

Here's a picture of Lancer Evolution IV with an anti-lag system. By the looks of it, it seems to get its source for air right before the throttle body. And it looks to be controlled by some sort of valve that opens/closes based on vacuum or maybe by a solenoid that starts to open it up based on TPS position.


Hope this helps out.

[fredio54]

Originally Posted by RbluEMx6

Here's a picture of Lancer Evolution IV with an anti-lag system. By the looks of it, it seems to get its source for air right before the throttle body. And it looks to be controlled by some sort of valve that opens/closes based on vacuum or maybe by a solenoid that starts to open it up based on TPS position.

Hope this helps out.

where did you source that pic? are you sure its not egr? i thought the toy system was the only one on a road car at the time?

thanks for the pic though :-)