anti lag launch control?

[cfdeng7]

Hey guys

So my buddy just picked up a 08 rclb xl for cheap cheap. Its going to be strictly a drag truck. One of his mechanics is into hondas and imports etc. And brought up anti lag to help spool a big single. I vaguely remember reading on comp d awhile ago about someone doing it on a cr cummins drag truck. I believe he was using a standalone computer. Do we have the tuning capabilities to add a very retarded injection event to continue combustion into the exhaust to spool a large single? Yes we know it is very hard on turbos and etc but if it would allow us to spool a huge single without standing on the converter for ever it would be useful. Discuss

 

[cfdeng7]

http://www.competitiondiesel.com/forums/showthread.php?t=95023

Found the thread on comp d

 

[7.3psd97444]

Just read through the first few posts...

...that is really cool. I did not know they could do that. Sounds like it could be really harsh on the engine and could not be done with stock internals. Ide like to see charts and graghs on this as well as vidoes of it in action.

 

[7.3psd97444]

Man that thread does not deserve to be closed.

 

[7.3psd97444]

Hey guys

So my buddy just picked up a 08 rclb xl for cheap cheap. Its going to be strictly a drag truck. One of his mechanics is into hondas and imports etc. And brought up anti lag to help spool a big single. I vaguely remember reading on comp d awhile ago about someone doing it on a cr cummins drag truck. I believe he was using a standalone computer. Do we have the tuning capabilities to add a very retarded injection event to continue combustion into the exhaust to spool a large single? Yes we know it is very hard on turbos and etc but if it would allow us to spool a huge single without standing on the converter for ever it would be useful. Discuss

I dont think we can do as in depth as they are with EFI and the standalones on the 6.4s.......yet.

 

[cfdeng7]

I dont think we can do as in depth as they are with EFI and the standalones on the 6.4s.......yet.

That's kind of what I thought but I honestly don't know enough about the current tuning capabilities on the 6.4. It would require some way to enable this "secondary" tuning while staging and spooling and then have the normal timing/injection be applied apon launch. In theory this would allow very quick spooling of very large chargers without beating up the converter. Key words "in theory"

 

[cfdeng7]

Ok so here's my internet engineered theory on this tune. Again I will say I have very little knowledge of the current tuning capabilities and what tables we have access to. And obviously this would be a completely track only tune.

But here it goes. some how we need the ability to inject fuel after the main injection event to continue the burn through the exhaust stroke creating the manifolds, uppipes and turbine housing an expansion chamber for the fuel burning there. This would drive the turbo(s) very quickly in a free-rev state. Possibly be able to use something related to regen in the computer to achieve this?

Now we need the ability to refrence this delayed injection event to boost. So you would tune what boost pressure your truck most efficiently launches, for this post injection to stop and normal injection to continue. Now the motor would actually start making power and you would be on the convertor now. This is when you would go from pre-stage to fully staged and hold the truck back untill green.

You would have to tune the timing and pulse width of the post injection event to create as much drive pressure that is somewhat safe as quickly as possible to avoid melting down the turbine and housing. This would be inherently hard on the turbo but in an all out drag application you have to pay to play. And abusing parts is part of the game in going fast. However if the turbo was sized properly I believe it coulds be done at a relative saftey level. It would also take an enourmous strain off of the convertor which we all know making a convertor to hold up to high horse power and long spooling times is a difficult task.

It would work in the same fasion a 2 step module in a gasser works. It takes the driver's focus off trying to hold the perfect boost pressure and stage the truck before you burn up the converter and allow the tune to spool the truck and the driver focus on driving.

Am I way off here? Like I said I have no idea if we are even capable of this with the current tuning platforms. Or if this would even be mechanically feasible. Is there even an option for a standalone computer? Any thoughts?

 

[cfdeng7]

Another thought is possibly the use of some spray to allow a smaller post injection event that burned cleaner/cooler allowing for a safer spool up. Or possibly even spray directly into the exhaust manifolds as crazy as that sounds. In my head it would cool down the temps to a safer level.

 

[Dzchey21]

Im not sure we have the tuning ability to pull that off just yet, I have been looking thru the mcc stuff and im not totally seeing what it would require to do that, maybe a similar injection event to like what a dpf regen would require might be able to be modified to work, say brake applied or something, i dunno. My buddy racing prostock bikes and thats how he spools is stupid big turbo LOL.


Interesting idea i like the concept just not sure its totally proven

 

[cfdeng7]

That's what I was thinking that something related to the dpf and regen could be modified to allow the post event. However I think the hardest part would be to turn it off at launch. Whether it is boost refrenced which would be ideal or some other method like a push button or the brake switch. Whether that is possible I have no idea.

 

[Dzchey21]

i think the best way to control it would be based on brake pedal position or something like that

EFI live allows for duramaxes to hold full throttle with the brake applied and will only build untill X amount of rpm and hold, as soon as you release the brake it goes to normal full fueling, im not exactly sure how well it truely works as a launch control but i know that you can do it.

 

[Dieselcraft]

Hmm some good thinking here

 

[kyle43335]

My blue truck was injecting into the exhaust stroke. However i had a 1ft flame out of my stack on the pull track.
We added timing,the flame went away, but i did notice a drop in spool up time.
nothing that bothers me enough to pull said timing back out.

 

[7.3psd97444]

The fact that this method isnt even TOTALY proven on the Cummins with the standalones means its prolly far off for the 6.4s.

 

[91turbogsx]

How do you get a compression ignition to fire in the exhaust? We don't have spark to ignite it.

I'm just thinking out loud and it's kinda late for me. LOL

 

[7.3psd97444]

The combustion starts in the shamber with compression but with the adition of more fuel being injected post event the explosion travels out the combustion chamber and into the exhaust manifold/turbine housing(s). Thus boosting WAY more at MUCH less load or none at all. Least thats the way I understand it.

 

[91turbogsx]

But it's not a flame you want in the exhaust. Yes the heat will help but you need the "bang" in the exhaust. The explosion itself is what spools the turbo. Not a late injection flame throwing effect.

 

[91turbogsx]

Your initial explosion has already came an gone when the exhaust valve is open. You need to physically move the ignition process outside the cylinder. Which to me seems impossible on a diesel. When you have an ignition source other than compression then it's feasible.

 

[7.3psd97444]

But by adding the more fuel with supplied air the explosion has NOT came and gone...it just travels...

 

[91turbogsx]

Where does the more air come from after supplying more fuel? The explosive force has put its energy into moving the piston back down. Therefore all your doing is pushing a flame out the exhaust. At least that's how I see it.