sawood12

Sounds great but doesn't the stock system rely on the use of a single port wastegate? The problem with single port wastegates is that they crack open before max boost pressure is reached meaning more turbo lag. You may fit a stronger spring but the problem with springs is that they are rated as force per unit of distance e.g. x lb's per inch. This problem with this is that you still get a displacement with a lighter force, therefore the wastegate cracks open and bleeds pressure. You can't get around it even with a fresh wastegate. Having a pressure differential across a diaphram is a much better way of controlling the wastegate valve short of having an electronically controlled servo to actuate the valve.

Is there a way of still retaining the DPW with this system. I noticed such a vast difference when I fitted my DPW there is no way i'm going back to single port wastegate. I feel the 6 degrees of ignition retard is a pretty effective warning that something is wrong. It feels like you've dropped the car into first gear from about 70mph. You'd have to be on a suicide mission to keep the throttle nailed while that was going on.

TurboTommy

I don't quite understand.
You can just increase boost via letting less boost pressure to the CV with different, smaller sizes of restrictor bolts, and the KLR/CV combo can still do its job if it encounters knock. Yet people are still getting rid of this stock setup to go to aftermarket boost controllers.
So, how would the end result be any different if you get the KLR to change the duty cycle of the CV to increase boost?
Or, what am I not understanding?

Porschefile

The main point would be that the stock KLR cannot physically read or understand anything past 1bar. With the aftermarket pressure sensor Transaxle is talking about, the KLR/DME would actually be able to be re-programmed to read and function in a similar form as stock, but at higher boost levels. That's the theory at least, but it certainly makes sense.

The only down side I can see is the stock single port wastegate, as previously mentioned. It's a bit late and I really can't remember enough about the whole KLR/cycling valve setup, but I think it would be worthwhile to examine whether or not the stock system could be modified to function with the cycling valve as stock, just with a dual port wastegate. The stock .2bar wg spring is weak and, IMHO, runing an aftermarket DPW w/ something more like a ~.5bar spring would still be relatively conservative under boost protection mode, but would offer a bit more towards keeping the wg closed more of the time.

Excellent work Transaxle! It's nice to see someone coming up with ingenious and realistic mods like this.

marcoturbo

Great upgrade. Will it be marketed ?

sawood12

My first mod was to install a LR DPW and MBC thereby bypassing the cycling valve. I retained stock chips but set up my max boost to stock (0.75 bar) as I knew the stock chips couldn't handle higher boost. This setup gave me an instant improvement both in terms of the way the boost came in and in overall power. My car achieved 239bhp at the flywheel just by adding a DPW on an otherwise standard car, therefore the single port wastegate is costing you at least 19bhp (assuming I was achieving stock power before). Unfortunately this setup kicked in the KLR ignition retard procedure on cold days. I believe this wasn't due to knock but was due to how early and quickly the boost build tricked the KLR into thinking I was overboosting so that is how I know the 6 degrees of ignition retard is a very sudden and violent decellaration. However now I have installed chips and a 3 bar FPR to allow me to run higher boost I am not 100% happy that I am no longer protected by the 6 degree knock/overboost system so I would like a system that would allow this safety feature to be retained. I'm not bothered about the 'boost dump' feature as I know from experience that 6 degrees of ignition retard definitely gets your attention!

How would this work with the SciVision MAF kit discussed over on the other thread? I assume once you change over the small circuit board you would need the new KLR chip - but will it run with the DME that comes with the SciVision kit? Also do you need to buy a KLR chip to suit the intended boost pressure you intend to run or will the 22psi KLR chip handle any boost level upto 22psi?

Transaxle

The KLR is a precise boost controller that is able to retard ingnition and reduce boost in case of knocking. I don't know any other boost controller for the 951 with these capabilities. That was the reason for me to enhance it with a different sensor.

The standard KLR/CV/WG setup works fine up to 17 psi for me. But you should check the standard WG if the spring is still strong enough to hold .3-.4 bar with the CV disabled.

Transaxle

Perfectly...

First is to replace the KLR sensor board. That needs some soldering skills. Then you need to reprogramm the KLR to your desired boost curves. I showed my version for a stock K26.8 in this thread. It works fine for me up to 17 psi in a solid stock environment. Finally you have to adjust the DME to the new boost levels.

But again - this is currently just development.

rberry951

I just wanted to add a note here. If this is determined to be something that there is a market for and further development warrants a product offering, I will work with Tom to incorporate the KLR tuning ability into Maxtune as well, and MAXhpkit will probably handle the DME chips and support for this on the US side.

Regards,
Russell

Oddjob

You were hitting the overboost protection, which is a function of the DME, and the limits are mapped on the DME chip (aftermarket tuners remove or set the parameter infinitely high, so you will never hit overboost). Its a hard fuel cutoff, which causes the car to dramatically stumble.

billthe3

So, like how long till we can buy/get this?

/anxious

sawood12

Thanks for that clarification. So it seems the KLR only looks for knock and not overboost. It seems a bit odd and inconsistent that if the KLR detects knock and retards timing and the knock is not stopped it then attempts to kill boost via the CV and wastegate instead of commanding the DME to cut fuel. This seems like a much more effective way of cutting boost especially since there is a time out situation where it wont allow you to build boost for a period of time after the initial event.

Anyway I still like the idea of upgrading the KLR pressure sensor to at least retain some of the knock protection features on applications where an external boost controller is used for DPW applications. I'd like to see this in a plug and play kit form.

Transaxle

This is not completly correct.

The 'hard' overboost protection is done by the DME. It looks at a load/rpm based map and cuts fuel when the actual load value is larger then allowed.

This is a safety function since this should never happen with a correctly working KLR.

The KLR itself switches into permanent failure mode (LED code 3-2) when the boost is out of control, closes the CV and retards timing 6° all the time.

Jfrahm

This is great. I have had several modded turbo cars as daily drivers and have found that in my climate a system like the DME/KLR is essential if you drive the car on hot, humid days. It also protects you if you get a questionable tank of gas (Regular from the Premium pump.) I have run knock controlled boost and I like that setup, you can see right on the boost guage if you are getting into dangerous territory. On my old Saab I could switch on the water injection when I saw I was not getting full boost also. I did not need it on cool days and when the head was still cold. On hot days I could see boost stop at 11 psi, hit the water injection and watch it instantly go up to 15. With my current car I have an MBC but on hot days the ECU runs out of timing authority and I can get knock easily under normal driving conditions. I'm always turning back the boost and worrying that I've already caused damage.

Having a knock sensitive system calibrated for the 951 will be great, knock is too hard to hear and if you see the boost drop you know what is going on. Many people are probably already running with a bunch of knock and timing retard and not aware of it at all. I was thinking of trying Saab APC or Trionic on a 951 to get those benefits.

-Joel.

sawood12

Joel, What setup are you running? I can't see how you can run KLR knock protection with elevated boost pressures and DPW. My current setup is the Promax Stage 3 which I believe doesn't have the knock & overboost protection and runs an ultra-safe AFR to prevent knock and rely's on the external boost control to prevent overboost. Also I believe that other kits out there effectively disable the safety features so how can you achieve it?

I've thought about the SciVision system and the more I get into it the more it sounds like a good solution (if you are not after big HP and things like semi-sequential injection), especially with this KLR pressure sensor mod. But I want to get rid of the airbox and i've not read anything that says the SciVision kit can be installed with a cone filter behind the headlight. So many people use the Vistesse kit and rave on about it but does that offer knock and overboost protection?

sawood12

Joel, What setup are you running? I can't see how you can run KLR knock protection with elevated boost pressures and DPW. My current setup is the Promax Stage 3 which I believe doesn't have the knock & overboost protection and runs an ultra-safe AFR to prevent knock and rely's on the external boost control to prevent overboost. Also I believe that other kits out there effectively disable the safety features so how can you achieve it?

I've thought about the SciVision system and the more I get into it the more it sounds like a good solution (if you are not after big HP and things like semi-sequential injection), especially with this KLR pressure sensor mod. But I want to get rid of the airbox and i've not read anything that says the SciVision kit can be installed with a cone filter behind the headlight. So many people use the Vistesse kit and rave on about it but does that offer knock and overboost protection?