SDS Install Complete (sort of)
04-11-2002, 06:42 AM
#46
Race Director
At a mininum, you'll also need a 0-5v TPS (Porsche is 0-1v). I'm going to use an op-amp circuit to convert the stock Porsche unit into 0-5v (simpler than fabricating and aligning a mount for a GM TPS). And also perhaps a air-bypass fast-idle solenoid.
Check out Rage2's posts over past couple months on his install. The photos are also great resources.
Check out Rage2's posts over past couple months on his install. The photos are also great resources.
04-11-2002, 09:03 AM
#48
Race Director
Just a little solenoid that vents additional air around the throttle-plate into the intake for faster idle at cold start-up and when the AC is on. Haven't heard of anyone having problems with their stock idle-stabilizer though. But if you need one, a unit like this should work fine with any aftermarket EFI system:
04-11-2002, 12:01 PM
#49
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[quote]Originally posted by Danno:
<strong>At a mininum, you'll also need a 0-5v TPS (Porsche is 0-1v).</strong><hr></blockquote>
I don't *think* I changed my TPS. When using MAP mode you actually don't need a TPS sensor. You do need it to setup the point when you're completely off throttle for fuel cut, as well as the "acceleration pump" setting (enrichment on throttle).
<strong>At a mininum, you'll also need a 0-5v TPS (Porsche is 0-1v).</strong><hr></blockquote>
I don't *think* I changed my TPS. When using MAP mode you actually don't need a TPS sensor. You do need it to setup the point when you're completely off throttle for fuel cut, as well as the "acceleration pump" setting (enrichment on throttle).
04-11-2002, 01:42 PM
#50
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Rage is right, the stock TPS is fine, you just need to figure out which 3 wires get connected and the SDS manual details this procedure. I'm not using an idle bypass of any sort. The car idles fine (no ac though). You also don't need the direct fire coil pack version. I used my stock distributor and coil with the MSD 6A ignition trigger system. Total cost 1169.00 (SDS with 3bar map) plus 140.00 for intake.
04-12-2002, 02:10 AM
#51
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[quote]Originally posted by Russ Murphy:
<strong>plus 140.00 for intake.</strong><hr></blockquote>
I take it you mean the piping for the turbo/air filter set-up. Where did you get it from????
<strong>plus 140.00 for intake.</strong><hr></blockquote>
I take it you mean the piping for the turbo/air filter set-up. Where did you get it from????
04-12-2002, 01:19 PM
#52
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South Florida Motorsports, a Turbonetics dealer.
Had I realized at the time that Lindsay Racing has most of those silcone reducer pieces I would have gotten it from them.
Had I realized at the time that Lindsay Racing has most of those silcone reducer pieces I would have gotten it from them.
04-12-2002, 06:59 PM
#53
Race Director
"I don't *think* I changed my TPS. When using MAP mode you actually don't need a TPS sensor. "
That's for the SDS unit, which was one of the reasons I went with them. Great phone-support too.
I think with the others like Electromotive TEC, Motec, etc. you have to install a GM 5v TPS?
Russ, for that price, did you get the coil-packs too?
That's for the SDS unit, which was one of the reasons I went with them. Great phone-support too.
I think with the others like Electromotive TEC, Motec, etc. you have to install a GM 5v TPS?
Russ, for that price, did you get the coil-packs too?
04-15-2002, 06:45 AM
#55
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danno can you answer my first post in this issue on my chip fueling question, thanks if you know anything about the k29 vs. k27 fuel flow rates and how it related to my stock injectors, and fuel pressure(my post is the long one and i ask for your help in it) later
04-15-2002, 09:18 AM
#56
Race Director
Ok, I'll give it a try, but it would be nice if someone can post compressor-maps of K27 and K29 turbos. So let me see if I understand your two different configurations:<ol type="1">[*]K29 & K29 chips w/o MAF = rich low-end, OK high-end[*]K29 & K27 chips w/MAF-4/ARC2 = OK low-end, lean high-end[/list=a]
Hmmm, it's tough to play process-of-elimination with this because we've got a cartesian product of 4 factors giving us 16 possible combinations of these parts you've used. But we've only got 2 cases to examine. I'm assuming you've kept the following constant between these two configurations: fuel-injectors, fuel-pressure, and boost? If not, we're looking 128 possible combinations now.
First lets look at fuel maps to see that the chips really aren't reponsible for the fuel differences. Without looking at your actual chips, I'll make a guess:
It's the end-points that are the most important because they determine the minimum and maximum amount of fuel you can deliver. And they will be pretty much the same for both set of chips. There will be a minimum fuel level for idle, say... 8% or so. At the high-end, they both will reach the maximum allowable reliable limit for injectors, around 80%.
Typically when you go to a higher-flow turbo, like a K27 to K29, you'll need to raise fuel-pressure along with the new chips. The chips are then programmed to dial back the injectors at low & mid-range RPMs so that the new fuel amounts at higher-pressure matches the previous amounts. Yet the high-end will still reach the 80% limit of the injectors. At this point, you'll get more fuel with the K29 chips with the identical injector duty-cycle because you've got more pressure.
But these chip comparisons become irrelevant when you add the ARC2 because you can reshape the fuel-curve to create a custom fuel-curve with either set of chips installed. So your problem is not the chips.
One of the things about fuel-injectors is that they do not operate reliably at high fuel-pressures. Something around 70psi is about maximum. So if you're running 22psi of boost, then idle pressure should be 70-22=48psi (3.3bar) max. Then at high-RPM when you get to 80% injector duty-cycle, if you're lean, then you need larger injectors. Increasing the fuel-pressure won't help because injectors will operate unreliably. Additionally, increasing fuel-pressure by 20% will only yield 9.5% more fuel delivered.
What I think got you mixed up was the addition of the MAF4 kit. The K29 earlier was probably really being held back by the stock AFM and going to the MAF4 gave you a significant increase in flow. So now your injectors are maxed out and you'll need larger ones.
Hmmm, it's tough to play process-of-elimination with this because we've got a cartesian product of 4 factors giving us 16 possible combinations of these parts you've used. But we've only got 2 cases to examine. I'm assuming you've kept the following constant between these two configurations: fuel-injectors, fuel-pressure, and boost? If not, we're looking 128 possible combinations now.
First lets look at fuel maps to see that the chips really aren't reponsible for the fuel differences. Without looking at your actual chips, I'll make a guess:
It's the end-points that are the most important because they determine the minimum and maximum amount of fuel you can deliver. And they will be pretty much the same for both set of chips. There will be a minimum fuel level for idle, say... 8% or so. At the high-end, they both will reach the maximum allowable reliable limit for injectors, around 80%.
Typically when you go to a higher-flow turbo, like a K27 to K29, you'll need to raise fuel-pressure along with the new chips. The chips are then programmed to dial back the injectors at low & mid-range RPMs so that the new fuel amounts at higher-pressure matches the previous amounts. Yet the high-end will still reach the 80% limit of the injectors. At this point, you'll get more fuel with the K29 chips with the identical injector duty-cycle because you've got more pressure.
But these chip comparisons become irrelevant when you add the ARC2 because you can reshape the fuel-curve to create a custom fuel-curve with either set of chips installed. So your problem is not the chips.
One of the things about fuel-injectors is that they do not operate reliably at high fuel-pressures. Something around 70psi is about maximum. So if you're running 22psi of boost, then idle pressure should be 70-22=48psi (3.3bar) max. Then at high-RPM when you get to 80% injector duty-cycle, if you're lean, then you need larger injectors. Increasing the fuel-pressure won't help because injectors will operate unreliably. Additionally, increasing fuel-pressure by 20% will only yield 9.5% more fuel delivered.
What I think got you mixed up was the addition of the MAF4 kit. The K29 earlier was probably really being held back by the stock AFM and going to the MAF4 gave you a significant increase in flow. So now your injectors are maxed out and you'll need larger ones.
04-15-2002, 12:37 PM
#57
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Tecart,
Take a look at the vltage signal at your mass-air sensor.If you go above 4.85 volts you will start running lean at the top end becasue the DME can no longer use the voltage input.Basically the DME freaks out.
You do not need to run a TPS with the TEC but it is good to use it,especially if you are using the TPS for throttle enrichment or idle or both.We use TPS acceleration enrichment because the TPS sensor is a much better sensor to use then the map for this purpose.MAP sensors fluctuate quite a bit and they are somewhat erratic.Trying to dial in fuel based on MAP along can be somewhat difficult.The TEC also has a TPS/MAP blend feature which uses a bit of both sensors to dial in the throttle enrichment.
Take a look at the vltage signal at your mass-air sensor.If you go above 4.85 volts you will start running lean at the top end becasue the DME can no longer use the voltage input.Basically the DME freaks out.
You do not need to run a TPS with the TEC but it is good to use it,especially if you are using the TPS for throttle enrichment or idle or both.We use TPS acceleration enrichment because the TPS sensor is a much better sensor to use then the map for this purpose.MAP sensors fluctuate quite a bit and they are somewhat erratic.Trying to dial in fuel based on MAP along can be somewhat difficult.The TEC also has a TPS/MAP blend feature which uses a bit of both sensors to dial in the throttle enrichment.
04-15-2002, 03:34 PM
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thanks danno, as a last thought can a k29 autothority chip deliver more fuel to the injectors or control them to deliver more fuel at any rpm or boost level more than the arc 2 can? Does the arc2 control the total fuel range that custom chips can be made to do or are they controlling the same parameters of fuel width? I just wonder if a custom made k29 800 cfm chip fuel map can make more power or fuel delivery at any rpm over the arc2? again this isnt that much of an issue w me as im getting bigger injectors soon but this subject makes me wonder which is the best way to add more fuel with stock injectors the k29 chip custom set or the arc2, ive tried both for over 4 years now and i still think the chip flowed more fuel the the k27 chip i got now with the arc2, or the other possibility is god yes the maf kit adds about 30-40% more air into the motor like you sorta think
04-15-2002, 09:34 PM
#59
Race Director
Nah, nothing you can do with chips or ARC2 in your situation will solve your high-end lean problem. No matter what you do with the chips or ARC2, the high-RPM duty-cycle will still max out at 80-85%, that's it! New chips will still run into this limit; no tuner in their right mind will sell you a chip that drives the injectors over 90%. Based upon the high-RPM duty-cycle and the highest fuel-pressure you can run with those stock injectors, you're just not getting enough fuel to match the K29's flow (22psi, yikes!).
As some other data samples of this situation, 290-300rwhp is the limit for stock injectors. I hit it at 12psi on my stock injectors as did Russ Murphy. David Salama fought it for a while and Rage2 maxed out at 8.5psi. This is simply a physics phenomenon that can't be overcome.
As some other data samples of this situation, 290-300rwhp is the limit for stock injectors. I hit it at 12psi on my stock injectors as did Russ Murphy. David Salama fought it for a while and Rage2 maxed out at 8.5psi. This is simply a physics phenomenon that can't be overcome.
04-15-2002, 11:41 PM
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Danno,
What do you mean 300RWHP is max w/stock injectors? I've been making 320-330RWHP w/stock injectors for 2 years with out any problems. I sent you my dyno results. That was with one of those inefficent K27#8's. Respectfully, I see posts on the list making statements like you can't make over 350RWHP without EFI then you will see the same person saying "sure you can make 400RWHP with a MAF". I am beginning to wonder if the number of venders on the list out number the consumer? This list is a GREAT INFO/SALES TOOL, but only when the list is credable. Regards,PAUL
What do you mean 300RWHP is max w/stock injectors? I've been making 320-330RWHP w/stock injectors for 2 years with out any problems. I sent you my dyno results. That was with one of those inefficent K27#8's. Respectfully, I see posts on the list making statements like you can't make over 350RWHP without EFI then you will see the same person saying "sure you can make 400RWHP with a MAF". I am beginning to wonder if the number of venders on the list out number the consumer? This list is a GREAT INFO/SALES TOOL, but only when the list is credable. Regards,PAUL