BMW Turbo w/ Antilag :) Video inside

[Jon K]

Quite f*cking loud in person... my dog is still freaked out inside the house.

Launch control/anti-lag here switch activated to build boost on the line with clutch in.

Very cool

http://blowneuroz.com/mygallery/antilag.wmv

[Macv]

omg ****ing hot!

We're still waiting for some drive-by's and powerslides!

[Jon K]

Haha soon enough

[Anton CH.]

How much are you boosting in neutral? It seemed like you wussed out and backed off before it could build boost up.

[Jon K]

How much are you boosting in neutral? It seemed like you wussed out and backed off before it could build boost up.

Between 6 - 8 psi. I didn't wuss out doing anything - merely running this sort of system takes balls. The boost varies because of the spark cut, but the needle dances between 6 - 8 psi.

This is at 2800 rpm and -10 timing. 4500 and -10 timing should yield full 10 - 12 psi for launch. Now I just need axles and slicks to make it hook up.

In case you didn't know, its a system you want to run as short as possible. It kills manifolds, turbos, and mufflers.

[Anton CH.]

Between 6 - 8 psi. I didn't wuss out doing anything - merely running this sort of system takes balls. The boost varies because of the spark cut, but the needle dances between 6 - 8 psi.

This is at 2800 rpm and -10 timing. 4500 and -10 timing should yield full 10 - 12 psi for launch. Now I just need axles and slicks to make it hook up.

In case you didn't know, its a system you want to run as short as possible. It kills manifolds, turbos, and mufflers.

It only takes a large wallet to run ALS. I'd also add a few drive shafts to your list up there. I wasn't aware that you are trying to build a quarter mile car.

[bjl4776]

you could always just two step it and build the 6-8 psi @ 4500rpm. It is much nicer on your hot side and a little nicer on your drivetrain. You still get some balls of the line without melting turbine wheels. You might want to monitor your EGTs if your making your manifold a Jet engine. That is essentially what you are doing.

[Jon K]

It only takes a large wallet to run ALS. I'd also add a few drive shafts to your list up there. I wasn't aware that you are trying to build a quarter mile car.

I'm not - but I will make passes with traction assistance :)

Driveshaft isn't my worry, it's axles.

[Ross]

Jon, Is this done by adding fuel to exhaust?

[Jon K]

Jon, Is this done by adding fuel to exhaust?


It's actually done by retarding the timing negative, meaning you ignite the mixture as the piston is on its way downward, so you have intake, compression, then ignition, then exhaust.

I cut spark, but not fuel, so when I hit the 2-step limiter (2800 rpm) it cuts spark but stays with fuel, to keep the exhaust energy up.

[bjl4776]

essentially yes. He is retarding the timing to the point were he is purposly misfiring when the exhaust valves are open so the combustion expands in the exhaust manifold making the required volume to make the turbo spin fast enough to build boost. Basically putting the car under load without actually moving the car. Turbo drag guys and rally racers use this, but they also have a huge budget to replace all of that stuff after each race.

The alternative method that is completely safe on the car is to set a switchable rev limiter on the car at anywhere from 3k-4.5k. Since not all of your cylinders fire at once it is also putting an artifical load on the cylinders that are firing since they have to work harder to make the engine keep going at that rpm. This makes the required exhaust gas volume required to build boost. It builds about half the boost that antilag setups do, but isnt any harder on your engine than driving it. And of course the shock to the drivetrain when you dump your clutch and your M/T slicks hook up making a 1.5 60'

[Ross]

I'll keep my eyes open for used mufflers for you.

[Jon K]

essentially yes. He is retarding the timing to the point were he is purposly misfiring when the exhaust valves are open so the combustion expands in the exhaust manifold making the required volume to make the turbo spin fast enough to build boost. Basically putting the car under load without actually moving the car. Turbo drag guys and rally racers use this, but they also have a huge budget to replace all of that stuff after each race.

The alternative method that is completely safe on the car is to set a switchable rev limiter on the car at anywhere from 3k-4.5k. Since not all of your cylinders fire at once it is also putting an artifical load on the cylinders that are firing since they have to work harder to make the engine keep going at that rpm. This makes the required exhaust gas volume required to build boost. It builds about half the boost that antilag setups do, but isnt any harder on your engine than driving it. And of course the shock to the drivetrain when you dump your clutch and your M/T slicks hook up making a 1.5 60'

Well I do have the limiter set at 2800 rpm. Setting a "rev limiter" is a relative term. I can have it cut fuel, I can have it cut spark, or I can have it cut fuel and spark. Cutting fuel, or fuel and spark, will not create any load as energy through the exhaust is cut. Cutting spark only, which is what I am doing, flows energy (unburnt fuel) through the exhaust.

[Jon K]

I'll keep my eyes open for used mufflers for you.

My track setup consists of a straight pipe

[Ross]

Okay, axles and driveshafts then.

[Jon K]

Okay, axles and driveshafts then.

Are you just throwing the driveshaft in there or do you have practical experience with the amount of torque it takes to break/twist our driveshafts?

[Ross]

I just threw it in to be funny but expect you will find out for yourself.
I used to be able to change a u-joint on the side of the road in 15 minutes.

[Jon K]

I just threw it in to be funny but expect you will find out for yourself.
I used to be able to change a u-joint on the side of the road in 15 minutes.

We already know what it takes :) About 750 hp / 650 tq with MT 10.5's and the shaft can break. I don't intend to make that power and if I do I sure as hell won't be launching it with MT's

[MPD47]

We're still waiting for some drive-by's and powerslides!
I already told Jon I'd supply the camera equiptment, tires, and fix anything I broke (unlikely that anything would, but the offer still stands). He declined. His car will never drift or do any serious power over. I'll have to take care of that with the wagon.

[Jon K]

I already told Jon I'd supply the camera equiptment, tires, and fix anything I broke (unlikely that anything would, but the offer still stands). He declined. His car will never drift or do any serious power over. I'll have to take care of that with the wagon.

Haha tell that to PT and Blake (blake today) :) Ask PT about the local muscle car meet that I did burn outs at ahha.

[MPD47]

Burnouts =! power over.

[bimmerd00d]

I think it's time for a repaint Jon, maybe something like this?

http://tenyearsofmylife.com/images/20040626.jpg

[Alan_525i]

BMW driveshafts aren't as strong as you think...

Clutch drop on a 750iL with a six speed out of a 850CSi. Street Tires. I'm sure it was abusive. With the mad crazy power you're making, Jon, it might be possible. ;)

http://www.robertlevinson.com/seven/take_a_look/images/ds1.jpg

[Jon K]

Burnouts =! power over.


!=

I get the back out plenty, I assure you.

[Macv]

I get the back out plenty, I assure you.

Without a video, its all talk :D :D

Get on it damnit

[Anton CH.]

We already know what it takes :) About 750 hp / 650 tq with MT 10.5's and the shaft can break. I don't intend to make that power and if I do I sure as hell won't be launching it with MT's

It ain't the horsepower that breaks drive shafts. ALS system with some slicks will put a lot of instantaneous torque on the driveline.

[Jon K]

It ain't the horsepower that breaks drive shafts. ALS system with some slicks will put a lot of instantaneous torque on the driveline.
Ok thanks for clearing that up...


?

I know, thats why I mentioned torque.

[winfred]

but if he can load the driveline by slipping the clutch a little just before leaving the line the parts don't get shocked and will take more load, it's the slack that really tears up stuff


It ain't the horsepower that breaks drive shafts. ALS system with some slicks will put a lot of instantaneous torque on the driveline.

[Jon K]

but if he can load the driveline by slipping the clutch a little just before leaving the line the parts don't get shocked and will take more load, it's the slack that really tears up stuff

Thats the ticket - and the truth is the guys who break the driveshafts are launching from 5,000 rpm all out clutch dump. The key is to either stage with the e-brake or slip the clutch real nice. I intend to do the latter once I try to make some passes.

[MPD47]

!=

I get the back out plenty, I assure you.
http://www.mturck.com/rofl.gif
I'll believe that when I see it. :p

[Jon K]

http://www.mturck.com/rofl.gif
I'll believe that when I see it. :p

How do you think I went thru my 17x10s only having them on for summer and fall?

[bjl4776]

You will build boost if you set a fuel and spark boost limiter but you will have to set it higher at around 4.5k so see noticible boost levels and it will probably won't be more than 8lbs but probably more around 6 depending on your turbo. It doesnt send unburned energy into your exhaust, but since your not firing on all cylinders you are putting a load on the cylinders that are and causing an increase in exhaust volume. Its a two step, not an anti-lag, im sure you've seen it

[MPD47]

How do you think I went thru my 17x10s only having them on for summer and fall?
A lot of burnouts at PT's house and some daily driving. I'm lucky if a set of tires lasts me 3k much less 2 seasons.

[Jon K]

A lot of burnouts at PT's house and some daily driving. I'm lucky if a set of tires lasts me 3k much less 2 seasons.

Burn outs in PTs right - during those seasons I am at school. I drive the car about twice a week. I don't care - I know how I drive.

[Alan_525i]

Such tension between you two...

[MPD47]

I don't care - I know how I drive.

http://www.mturck.com/rofl.gif

[NovceGuru]

"No my balls are bigger", "No mine are"

heh