white 944 turbo

Rage, I am very interested in the sds system and would like to know which one you are using. I believe there is one which uses the factory distributor and another that uses the sds coils. Which one do you have? and can you talk about what the install is like. Is there alot of fabrication involved? is the wiring and programming complex? how long does it take? If you can elaborate it would be appreciated. By the way, great videos and great car. Anyone else with sds experience please join in.

rage2

[quote]Originally posted by white 944 turbo:
<strong>Rage, I am very interested in the sds system and would like to know which one you are using. I believe there is one which uses the factory distributor and another that uses the sds coils. Which one do you have? and can you talk about what the install is like. Is there alot of fabrication involved? is the wiring and programming complex? how long does it take? If you can elaborate it would be appreciated. By the way, great videos and great car. Anyone else with sds experience please join in.</strong><hr></blockquote>

I'm using the EM-3F system, with coil pack. If you can build the hall sensor bracket (I've got pics on my site at <a href="http://www.virgeweb.com/rage2" target="_blank">http://www.virgeweb.com/rage2</a> ) you can take mine or Russ's base map, and get going quickly. An hour on the dyno + WB O2 logging and you'll be fully tuned. Very easy stuff, as long as you understand the basics of how fuel/ignition/ratios/boost works.

CPTdooberhead

Rage, I just poked through your site for about an hour, awesome! Loved the videos!

Brian McCoy

Heh.. ditto Looks like you have a few friends helping with some 'fun'.

What's it like driving a 951 in the winter up there? (I'm from WY, spent 4 years in college in Bozeman, MT - so I know winter driving). What tires do you run... looked like the car was behaving itself. Something I can't even get it to do right now when the pavement is cool (damn rubber just Wants to be left behind/go up in smoke).

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Russ Murphy

Here's a couple of threads with install and start up details:<a href="http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic&f=18&t=000492&p=" target="_blank">My 951 Mod Story -part II</a>
<a href="http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic&f=18&t=000905&p=" target="_blank">SDS Install Complete - sort of</a>

Danno

Here's the complete series:

<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=18&t=000905&p=1" target="_blank">SDS Install Complete (sort of)</a> by Russ Murphy
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=18&t=001173" target="_blank">SDS Install Complete-part II</a>

<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=18&t=000341" target="_blank">My 951 mod story... </a> by Rage2
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=18&t=000492" target="_blank">My 951 Mod Story pt 2 - 72# injectors installed and dialed in @ 13psi today!</a>
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=18&t=000589" target="_blank">My 951 mod story pt 3 - boost rocks! </a>
<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=18&t=000626" target="_blank">My 951 mod story pt 4 - Dyno Day!</a>

C5Driver951

This question probably best falls to Danno.

If these guys are running into injector issues at 8.5 and 12-13 psi with SDS, why aren't you seeing the same lowered boost levels with your MAP sensor kit? It seems to me your 4" intake tract is quite efficient and should have the same flow characteristics as the SDS stuff.

I'm still debating whether to stay stock and go E-stock PCA racing, or modify for power. I like the MAP, TEC-III, and SDS options.

You what they say about hitting the old crack pipe of boost...

rage2

The turbo that I use is much more efficient than a K26/6. At 12psi 4000rpm, it makes more power (thus using more fuel) than the K26/6 at 18psi 4000rpm. Also, the fuel starvation is more significant at higher rpm's where the K26/6 runs out of steam and creates only 10-12psi of boost even with the wastegate fully shut.

SoloRacer

[quote]Originally posted by C5Driver951:
<strong>This question probably best falls to Danno.

If these guys are running into injector issues at 8.5 and 12-13 psi with SDS, why aren't you seeing the same lowered boost levels with your MAP sensor kit? It seems to me your 4" intake tract is quite efficient and should have the same flow characteristics as the SDS stuff.

I'm still debating whether to stay stock and go E-stock PCA racing, or modify for power. I like the MAP, TEC-III, and SDS options.

You what they say about hitting the old crack pipe of boost...

</strong><hr></blockquote>


Joel,

Comparing boost numbers between different turbo's is pretty much meaningless. A psi of boost on a K26 is not the same volume of air as a psi boost on a large T04. Think of it this way. Imagine a garden hose and assume it has 30 psi of pressure forcing the water out. Now imagine a 5 ft culvert with water flowing out at only 5 psi of pressure. Which one will fill a 500 gallon tank quicker? The culvert of course because it's flowing more water. By the same token Rage's turbo flow's more air at lower pressure than a stock turbo. That is why he makes more power. All this talk of "boost levels" is really meaningless unless you are comparing equal turbo's. A pet peeve of mine is when guys who don't take the time to learn about turbo's say things like "You're car is only making 15 lbs of boost. That's nothing....mine is putting out over 30. My car will waste you." and then I take a look at their hockey puck sized turbo and try to explain to them that they are actually getting less air into the engine than I am and thus making less power. Not eveyone understands but hopefully there are enough guys out there who do and can try and educate the ones who don't. Guys bragging about boost levels is like guys who brag about the wattage of their speakers - it's a figure that doesn't matter much. What's more important is the size of the turbo/amplifier that is driving those boost levels/speakers.

Danno

"Comparing boost numbers between different turbo's is pretty much meaningless. A psi of boost on a K26 is not the same volume of air as a psi boost on a large T04. "

Yup, SoloRacer's right on. Once you remove all intake restrictions with a MAP sensor, the turbo will be free to provide more flow. However, boost-level is not correlated with the total air-mass entering the engine; just an indicator of restrictions in the system (starting with the turbo). The higher the restrictions, the higher the boost for any given volume of air-flow. With a turbo-swap, I made more power@ 12psi (270rwhp), than I did with the stock turbo @ 18psi boost (250rwhp+MAF4).

The issue is the turbo's efficiency and how much it heats up the air for any given delivered volume. Making the stock K26/6 crank out 18psi in order to deliver 300rwhp worth of air heats it up to over 300-degrees, reducing density and negating much of the benefits of extra boost. Then you have to dial back ignition to combat the detonation, reducing power even further.

"If these guys are running into injector issues at 8.5 and 12-13 psi with SDS, why aren't you seeing the same lowered boost levels with your MAP sensor kit?"

Well, we are hitting 100% duty-cycle on the stock 34.6-lb/hr injectors at about 6000rpm @ 15psi boost (with cat-bypass pipe). We don't like to run the car beyond that very much because the dyno-charts shows a perfectly flat air-fuel curve up to that point, then jumps up in a straight line at a 30-degree angle towards lean. No amount of adjusting with the MAP-sensor or chips makes a difference at that point because you can't drive the injectors past 100% (best to keep below 80%). In fact, the computer is computing a required injector duty-cycle of 110-130% .

You can try and mess with fuel-pressure to fight the high-end lean, but that's an awfully clumsy way of tuning because it will require a complete remapping of the chips to clean up the idle, low&mid-range richness is the result. SoloRacer's got some clear before & after dyno-charts showing this phenomenon. It shows a delay in the onset of the 100% duty-cycle lean break-out by about 1000rpm, but the mid-range before that is completely wiped out by too rich of a mixture.

"I'm still debating whether to stay stock and go E-stock PCA racing, or modify for power. I like the MAP, TEC-III, and SDS options."

Someone has requested a 'stock' appearing MAP-sensor kit. We're considering offering a Stage-1 kit that uses the stock air-box with a drop-in flat-panel K&N filter instead. A custom pipe can be made to connect the air-box with the J-pipe and completely remove the AFM. Another person had the ideal of gutting out the innards of a AFM to retain a perfectly stock appearance, but then you don't get the 5lb weight savings of removing the AFM. Who says racers aren't a bunch of cheating bastards, eh? <img src="graemlins/jumper.gif" border="0" alt="[jumper]" /> <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />

rage2

[quote]Originally posted by Danno:
<strong>Who says racers aren't a bunch of cheating bastards, eh? <img src="graemlins/jumper.gif" border="0" alt="[jumper]" /> <img src="graemlins/jumper.gif" border="0" alt="[jumper]" /> </strong><hr></blockquote>

Danno, it's not cheating unless you get caught .

C5Driver951

[quote] Comparing boost numbers between different turbo's is pretty much meaningless. A psi of boost on a K26 is not the same volume of air as a psi boost on a large T04. <hr></blockquote>

This is true, but it's not what I was trying to get to. If I remember reading correctly Russ tried to max out his K26/6, but ran out of injector duty cycle around 12 psi. This was before the more efficient turbo. Rage, however, ran out at 8.5 psi because of his turbo's superior flow. Of course, Rage may be a bad example to use in this case as his car's motor has a lot of things done to make it more flow efficient.

I just want to know if the guys running the Link-MAP combo are running into the same issue. If they aren't, why not? It seems the high rpm fuel starvation issue would come into play here. I also realize the 3bar fuel pressure regulator helps in this regard.

I could care less at what boost level I make the RWHP to make me happy, I'd just like to do it at 12.5 fuel air ratio without detonation. Additionally, I have no desire to do it at some astronomical fuel pressure. I'm not much into bench racing, just going fast on the road course.

I want to have a plan where I want to go before I start modifiying the engine.

Thanks
Joel

C5Driver951

You guys beat me to my last reply. I had to help my three yr old with something earth shattering...

[quote] Well, we are hitting 100% duty-cycle on the stock 34.6-lb/hr injectors at about 6000rpm @ 15psi boost (with cat-bypass pipe). We don't like to run the car beyond that very much because the dyno-charts shows a perfectly flat air-fuel curve up to that point, then jumps up in a straight line at a 30-degree angle towards lean. No amount of adjusting with the MAP-sensor or chips makes a difference at that point because you can't drive the injectors past 100% (best to keep below 80%). In fact, the computer is computing a required injector duty-cycle 110-130% .

<hr></blockquote>

I get the feeling one should go directly to 55 or 72 lbs injector with the MAP or standalone right off of the bat. I know it's cheaper to use the fuel pressure, but I'm leary of that.

I know people have made 300 rwhp with the stock turbo, but I'd rather have torque and stay more efficient.

[quote] Who says racers aren't a bunch of cheating bastards, eh? <hr></blockquote>

If you're not cheating you're not trying...
I think doing the MAP with the stock stuff would leave too much restriction, and that's what I'm trying to avoid. Although, it would be pretty cool to blow the doors off of a modded 930, lift the hood, and show them a stock looking set-up.

Alan C.

Joel'
I went straight to 83 lb. injectors with my Tec3. A friend with a very similar system went with 55 lb. injecotrs and ran out of fuel. After one weekend he went to 83 lb. injectors. Near flat fuel curve at 12.5 AFR out to 6800 rpm with 20 psi.

Alan

C5Driver951

Thanks, Alan that makes sense.

I'm not planning on going to a 2.8L or larger, but I will likely go with a larger turbo.

That's some serious RPM. What kind of cam and head is he running? Is it a race car or track worthy street car? Mine is about 50%race right now with the suspension being complete.