Asking other tuners if they monitor for knock throughout the whole tuning process while applying different loads?

I started to have an interest in this after I bent all six of my rods. The interest grew as I watched more and more of these motors sustain damages. My attention was peaked when Switzer started posting some of his times and power numbers with stock internals.

It was just like Ruf back in 2001. His motors were not all that different, however they just make a little more torque. It wasn't long before we pin pointed this to a larger intake that also provided cooler air (reduced heat soak).

I really would not be surprised if Switzer found a way to listen for knock while he tunes through the power ranges.

I find this whole process amazing. In 2000 the holy grail with these motors was 500 hp. In 2004 700 hp was the outer limits with the exception of Gemballa with their 800 hp monster which stood alone. When Excellence did the article on my car in April 2004 I predicted 1000 hp and Dave Colman the author all but said I was crazy. Now 1000 hp has been exceeded and we are looking at 1600 to 1800 hp if the case will stay in one piece.

Like I said ...... one amazing journey.

 

I would sure hope so...

We've also made our in house data logging tool that monitors knock on individual cylinders available to any EPL customer running larger turbos...

 

I'm groggy and it's too early for me, but where is post 3093?
(thanks)

 

click the link its close to the bottom of that build page its on

 

Are you not tuning with some sort of standalone? Regarding knock sensors etc, most/all good standalones usually have this..

 

Please provide us with more information about your ignition system. Some of your suppliers seem to be totally committed to CD ignition systems, but we all know that it can be unwise to generalize. The CD circuitry charges up a capacitor to a few hundred volts, and then that energy is dumped through a transformer to get the thousands of volts required to jump the sparkplug gap. The circuitry is usually fast enough to provide multiple discharges of the capacitor for each ignition cycle. It's a great way of putting lots of electrical energy into the combustion chamber at lower engine speeds. However, some CD systems run into problems at higher engine speeds where there is of course less time to provide multiple sparks. Having one CD circuit and a distributor for many plugs also aggravates the problem. Some CD systems provide substantially less energy to each sparkplug at high speeds than a good multi-coil, "inductive" system.

 

Khan,

We are utilizing the Porsche ECU. Will be able to explain more in about a month or so.

 

Probably by making the load on the engine more linear.

 

I believe it would be easier on the rods, as it is a viscous coupling not a hard clutch.

 

hey CJV.. Dan told me you called Use my cell.. it's been crazy here with the 3.9 stuff

 

Nicely done. After the motor is in, perhaps you will try to incorporate something like the 997's PTM?

 

m42racer,
Both ignition systems have limitations, especially at high engine speeds where there is less time between ignition events. Coil systems need time to establish their magnetic field, but CD systems also need a finite amount of time to recharge the capacitor. If the time between events is short enough, there will not be enough time for the CD system to provide multiple sparks on each plug. It is wrong to imply that all CD systems are better than coil systems because a primitive CD system may deliver less energy to a given plug at high engine speeds than a properly designed multi-coil system. I've got nothing against either type of system, and I don't think there's anything particularly exotic about CD circuitry. I am just curious about how this particular, angelic CD system is better than the factory multi-coil arrangement. Maybe the question that was mostly asked by Todd Z on another thread is more to the point: how much energy can the system deliver to each plug at a various engine speeds? I suspect the typical coil system delivers a fairly constant amount of energy across a wide speed range, until it starts running out of dwell time. The typical CD system can deliver more energy at low speeds and less at high speeds. Hopefully, the high-speed performance of this particular CD system is still better than the factory system.

 

Bill I have not received a response from Neil yet, however I had this prior correspondence.

I have found a new Coil for the CDI system. The present stock Coils are Inductive and have the Igniter built internally. The CDI system requires only a “standard" coil. No Igniter. I have several to choose from, the installation length will be the determining factor.

I will be doing more on this in the next few days to get everything sorted and designed. I have asked Rob to send down the wiring harness so I can see what modifications will need to be done in order to run CDI Ignition. The benefits will be worth the time and effort. So much more energy is produced with CDI and this energy creates greater in Cylinder temperature. It’s this temperature that ignites the fuel mixture and produces greater levels of combustion.

There is a long standing debate over which is better. Inductive or CDI? I personally prefer CDI as I have tested both systems back to back and never have I found Inductive to make more power or better response over CDI. It has always been the other way around.

There are huge technical differences, but to keep it simple, Inductive can only produce Ignition energy based upon the Ignition Coils magnetic field. It is also limited by charge time. As soon as Inductive Coils are charged they have to fire. They cannot sit in dwell otherwise they will overheat and fail.

Based upon a simple calculation Inductive Coils require a certain amount of time to recharge. This is the dwell time. The Coils primary resistance and Inductance along with the charge current set the limit of the Coils output energy. The only way to increase this output energy is to either increase the charging current of the system or the primary Inductance. These increases add to the time it takes to recharge or the dwell required, thus making the engine speed a factor. The CDI system operates completely different. There is no dwell time as the additional energy created by inverting the power is stored in a capacitor. This energy is “dumped” by the system very quickly in comparison to an Inductive system. This high bolt of increased energy results is a lot hotter combustion, which results in more in Cylinder pressure and more loading on top of the Pistons. This is the extra Torque that you feel.

Many will tell you some modern race engines run Inductive. These systems are nothing like street car systems. The biggest difference apart from the parts and technology is you are limited to a 12V system. They use hundreds of volts to drive their systems.

 

I'd be interested in that software Tony Seriously, I'd love something a little lighter weight to monitor a few things vs the Duratec which I find to be a 10pound sledge for a 2pound job... I have Vagcom and Duratec cables even!

 

There are some pretty nasty ignition coils out there if you know where to look. I had very good luck on my Supra with motorcycle coils although from the looks of it mounting them would be an issue on the Porsche motor, best part was the cost. Mercury Marine makes a coil that will apparently fire most anything from what the guys I spoke to told me, that puppy was nasty! Mounting is again an issue but if you've got problems firing a plug mounting can be figured out.