For all you Turbo junkies

[Houdini]

http://www.turbobygarrett.com/turbobygarrett/index.html<br><br>The new improved web site for your viewing pleasure. Please read the Turbo tutorials from beginner to expert. Note all the new Turbo designations for Garrett turbos and what the letters and numbers mean. It even gives you a brief description of each Turbo and the engine sizes it works best on. This is excellent reading for anyone that wants more Turbo knowledge even if they have no intention of upgrading or switching Turbos.  

[F1 LOTUS]

For those who are interested

ALS – Anti-Lag System

The two-litre flat-four engine is fitted with Prodrive’s ALS . This has been derived from the same system currently used on the Prodrive-designed Subaru World Rally Car, but modified for use on the road. ALS can keep the turbo on boost at low engine speeds, giving the car immediate throttle response and improved performance by using more of the engine’s 575 Nm of torque throughout the rev range.

In tests, it has been shown to double engine torque at low revs, enabling a test car to accelerate from 30 to 50 mph in the same time in third gear as it would without the system in second gear.

Turbo-charged engines tend to run with a rich fuel mixture and, as a result, some of this fuel remains unburnt and ends up in the exhaust. At low engine speeds, when turbo-lag is experienced, the anti-lag system can introduce ambient air into the red hot exhaust manifold causing this fuel to spontaneously combust. This increases the manifold pressure, spinning the turbo back onto boost. In the Subaru World Rally Car, this gives Petter Solberg instantaneous response throughout the Impreza’s rev range.

Prodrive spent six months developing the system on an engine on a transient engine dynamometer at its Milton Keynes test facility. During this time engineers managed to achieve closed-loop control of the turbo boost and make it work in a road car application. The system is so refined that it can control the turbo speed to within one per cent at almost any engine revs.

"The system is not ready for production yet, but it has shown great potential. It will make P2 far more flexible to drive as without the turbo-lag you don’t have to drop down a gear to get the acceleration you want," said Hemming.

As well as enhancing the performance of turbo-charged cars, in the longer term it could provide a solution to the downsizing of engines in cars and so help improve fuel economy and reduce emissions.

[Sy V]

Now that sounds - brilliant!

[Houdini]

How ALS works:

The ignition timing is retarded with 25-30° or more and the air/fuel mixture is made richer at low throttle opening and low load. With the ignition timing delayed, the air/fuel mixture reaches the exhaust tubes mostly unburned, because the exhaust system’s temperature is higher than the flash point of the air/fuel mix, the unburned fuel explodes in the exhaust tubes. The turbo is accelerated by the increased temperature/pressure and the rotational speed of the turbo is kept high. While ALS is engaged, full boost is available the moment the throttle is opened.


Some downsides:

An immediate increase in exhaust gas temperature (800°C to 1100°C+) whenever the system is activated puts greater demand on all turbo-system components - reliability becomes a major concern; the turbocharger and exhaust-manifold tubing must be made with the best available materials, driving the cost higher. ALS is prohibited from use in certain racing series.

Yes it works and isn't cheap. There are other ways to decrease lag without the downsides except for expense that is. Garrett has patents on some technologies that may or may not go into production that greatly reduce lag but they need lots of testing. The issue of lag is really not as big an issue as most people think since 99% of turbo owners never really explore the limits of the there turbo car/truck anyway, so they are furnished and designed with smaller turbos to give good drivabilty. Racing and hot street cars it can be an issue though. In Europe where 50% of all cars sold are small diesplacement Deisels the concentration is on advancing turbo systems for decreased emissons and increased Diesel performance, which is a whole new direction and ball game. Audi as you know just announced there new Diesel entry for the 24 hours of LeMans and the ALMS series in the US. We worked with Audi for the last 4 years helping develop the turbos for that engine in parrallel with there regular race efforts. A little off the subject, but Audi plans to try and promote high performance Diesel engines for the US market starting this year. So food for thought, what would it be like to have a high performance Diesel engine in an Elan? Personally I'm not sure I could get past the clatter.

[Dovey]

An elan with a diesel engine If lotus ever use diesel I'm going to hethel with a shotgun!!! Lets keep diesel engines where they belong, in buses for poor people. Stuff emissions, the enviroment and the hippies, they're just a shower of twats.
Sorry, soapbox moment

[Doc Fizzix]

Very nice! I just found this and read through the online tech info, this was very helpful, thanks

[F1 LOTUS]

An interesting UK website, their insulating jackets for turbo's look neat.
Here's a little project for our resident turbo expert, Houdini!...?
http://www.owendevelopments.co.uk/news/story.asp?NEWSID=24

[nitroman]

If I showed this picture to Dwight at Stage-Six it would set his brain to spinning until he had a working version of it. Seriously! Can you imagine my new Elan with 4-motorcycle-sized turbos?

The really great news is that on projects that excite his imagination he'll construct at cost or even a slight loss through sloppy billing.

[Houdini]

That looks really cool! I mean it, that looks really cool! Not sure if it's worth pursueing though. I have a very very tiny turbo in my garage in pieces that was an experiment. We also have some very small turbos that could possibly work in this situation but other than cool factor (which counts for alot) in car circles, I'm not sure there is much to be gained unless the turbos are matched to the engine perfectly.

Lets get real, Garrett is the only turbo manufacture with a dedicated racing program and if this was a major performance advantage you'd see it on race cars first. Right now the only multiple turbo applications you see start at one turbo per 3 cylinders and go up from there. We have one racing application that has a 1600 cc engine in a water craft that puts out 600 BHP. A nicely tuned manifold to one turbo can do wonders.

Are you willing to pay for 4 turbos with 4 seperate water in/out lines and 4 oil in/out lines? On top of that any turbo that small is still using journal bearings and not ball bearings. If I had the bubget and a spare car I might think about doing it for giggles but I wouldn't expect any miracles.

[F1 LOTUS]

Perhaps one advantage would be getting the turbine closer to the heat source and thus minimising losses? Ultimately the cylinder head casting should have the turbine housing(s) as an integral feature with the turbine blades as close to the exhaust valves as possible??? Y-e-a-h! Combine this with infinitely variable valve timing and we're on our way to recouping some of the 40% of heat energy that disappears out our exhaust pipes???

[nitroman]

I agree it's show-car stuff only unless you're Bill Gates.

[Houdini]

You know it can be done but I think the hardest part would be to syncro all the turbos so all the boost control is exactly the same. Kind of like fine tuning multiple carbs.

[nitroman]

Naw that's simple. Just have an external wastegate for each that is not electronically or vacuum controlled but instead controlled by the pressure of the spring in it, in other words, mechanically controlled. The mechanic can artificially apply pressure to each external wastegate BEFORE installation and adjust the nut (which exerts force on the internal spring) so that he knows they will each open and therefore divert the exhaust flow around the 4 turbine wheels at the same time. Even if they are SLIGHTLY off the 4-turbos are all compressing air into the same intake so all cylinders will be running at the same pressure & fuel-load.

It can be done, even by an independent shop. It's just needlessly complicated & expensive; basically costs times 4.

[F1 LOTUS]

This may be interesting to the more ambitious boosters, it's basically a build-your-own ECM, for about $170.

http://www.bgsoflex.com/megasquirt.html

[Enright]

I've heard about these (but don't ask where from - it's a bit embarrassing)! Apparently they show a lot of potential and Megasquirt have a load of "template" programs for the ECUs that you can download then tailor to optimise your engine.

But although they seem like a real bargain, all those who trumpet their benefits have yet to achieve the perfect setup.

Unless your name's ESM (or at the very least Bosch), then I'd be very skeptical about re-inventing the wheel. Too much potential for it all to go horribly wrong and to end up with melted pistons or burnt out valves.

[nitroman]

Quad-turbo candidate?
http://cgi.ebay.com/ebaymotors/VERY-SMALL-TURBO-FOR-GO-KARTS-OR-BIKES-NEW-N-R_W0QQcmdZViewItemQQcategoryZ33742QQitemZ8044582423

[nitroman]

Another blow-gas-through go-boom turbo. Cool car though. http://cgi.ebay.com/ebaymotors/Ferrari-Dino-246-Magnum-Replica_W0QQitemZ4622118912QQcategoryZ7251QQrdZ1QQcmdZViewItem

[F1 LOTUS]

This looks interesting, may be worth trying?
http://www.microblueracing.com/turbo_news.php

[Houdini]

This is "The Nuts"!
http://www.lateral-g.org/sandlin/

I'm impressed 8 times over!

[Ashaman]

OK, I hate to ask, but what in the world is the point of all that?? One turbo per cylinder? All that extra weight....all that extra piping! Log-headers?? Egad.

I can't even figure out the intake & exhaust path. Looks like there are at least 4 cylinders on that header, do they combine and then separate again before the turbo? Weird, I can't imagine tuning that thing.

A work of art though, anyway. Just maybe more abstract art Definitely one of the wildest setups I have seen