FINISHED 928 TurboSport kits! S3 & S4: Pictures!
07-13-2006, 10:10 AM
#62
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I tried it both ways actually. Chips are ok if you're very careful about how you boost your car with the turbo. If you're rolling into boost from a low rpm, higher gear, chips are a no-no as the excess in timing will cause a little detonation as your boost gauge pegs @ about 2500rpm or so. If you're street racing or track racing, where your rpm's are much higher as you come into boost, you're much safer, however, you really should be running a higher octane if you plan to chip/boost your car on the track as the temperatures are a bit higher. For a higher rpm street racer, you're probably safe as long as you have 93 octane or so, as I never saw/heard/any sort of detonation.
Herr-Kuhn: I have a cat that looks like that: an F2 long-hair snow bengal: Jose Canseco has his brother.
Herr-Kuhn: I have a cat that looks like that: an F2 long-hair snow bengal: Jose Canseco has his brother.
07-13-2006, 12:22 PM
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Mark..."as I never saw/heard/any sort of detonation." which is exactly the kind of detonation which kills engines not to imply that your car was BUT with out fail those who have had broken rings typically say.." I never saw/heard/any sort of detonation." Porsche felt the NEED to add knock sensors in 1987 BEFORE advancing the timing on their 32 valve 5 liter engines to squeeze out more power the vacume operated advance on the 85-86 Ignition brain was simply not smart enough to hold the ignition timing close to detonation it has no way of knowing if or when the advance is too much. The main reason that chips "help" the 85-86 is that the increased ignition advance increases acceleration but at the same time reduces the safety margin and greatly increases the possibility of detonation.
07-13-2006, 04:29 PM
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Originally Posted by MarkRobinson
I tried it both ways actually. Chips are ok if you're very careful about how you boost your car with the turbo. If you're rolling into boost from a low rpm, higher gear, chips are a no-no as the excess in timing will cause a little detonation as your boost gauge pegs @ about 2500rpm or so. If you're street racing or track racing, where your rpm's are much higher as you come into boost, you're much safer, however, you really should be running a higher octane if you plan to chip/boost your car on the track as the temperatures are a bit higher. For a higher rpm street racer, you're probably safe as long as you have 93 octane or so, as I never saw/heard/any sort of detonation.
Herr-Kuhn: I have a cat that looks like that: an F2 long-hair snow bengal: Jose Canseco has his brother.
Herr-Kuhn: I have a cat that looks like that: an F2 long-hair snow bengal: Jose Canseco has his brother.
07-13-2006, 04:51 PM
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With over 20 1/4 mile passes (with/without intercooling) & 7k miles in the Texas heat + allllllll the other 928SCs/TS's out there running more boost than I on factory 20 year old engines, most all w/o issues, I'm not worried.
Spark plugs tell the tale, & I'm experienced there + Justin from Tuning-concepts.com is a great friend of mine & tunes some of the fastest cars in the world: he's happy with my arragement too.
No chips on those dynos, though I have run them on the street before. Cold plugs (2 ranges down from stock), efficient turbo-sizing, low-restriction exhaust, intercooling, & conservative timing with 93 octane fuel (in Austin), no worries mate.
Mark
Spark plugs tell the tale, & I'm experienced there + Justin from Tuning-concepts.com is a great friend of mine & tunes some of the fastest cars in the world: he's happy with my arragement too.
No chips on those dynos, though I have run them on the street before. Cold plugs (2 ranges down from stock), efficient turbo-sizing, low-restriction exhaust, intercooling, & conservative timing with 93 octane fuel (in Austin), no worries mate.
Mark
07-13-2006, 08:12 PM
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On the 16V setups with distributor, I make a modification to the vacuum advance to pull out timing on boost. About 1 degree for every psig of pressure. All in all it works well, but you do have to be cautious. It is a balancing act...boost vs. advance vs. octane. Step over the line and kiss your ring lands goodbye. In fact I just modified this 84 distributor for the Euro-Kuhn-Callaway hybrid 4.7 liter Twin Turbo. The hell project, all my suppliers let me down...every one of them. This car should have been running 3 months ago!
I'll be burning a new ignition setup for the 32v TT setup...probably pull 6-8 degrees out of it on even low boost. It would be bad practice to have the knock sensors working all the time.
Mark, many have commented on Puss-Monster...apparently she has many "twins". Her cranky attitude is evident in the photograph. She is nearly as moody as my ex-wife, but the benefit with the animal is I can toss her out on the deck when she gets cranky. Same holds true for the English Setter.
I'll be burning a new ignition setup for the 32v TT setup...probably pull 6-8 degrees out of it on even low boost. It would be bad practice to have the knock sensors working all the time.
Mark, many have commented on Puss-Monster...apparently she has many "twins". Her cranky attitude is evident in the photograph. She is nearly as moody as my ex-wife, but the benefit with the animal is I can toss her out on the deck when she gets cranky. Same holds true for the English Setter.
07-14-2006, 10:10 AM
#67
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Funny! Yes, I'll be retarding boost via the SMT6 after 5.8psi, probably to the tune of 1psi for every pound of boost as well. Should be plenty-safe.
BTW: Male dogs & cats are less moody.
Mark
Should be plenty-safe.BTW: Male dogs & cats are less moody.
Mark
damn Zoltan 
07-16-2006, 07:59 AM
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mark, i'd be interested in the spec on the turbo. the t61 you use is it a master power or garrett? what turbine a/r? i'm going to be building a rear mount were the rear muffler is now. i was thinking a .68 turbine a/r would be optimal with the added heat /expansion loss putting the turbo all the way back where i'm locating it.
just wanted to add, you kit looks great. love the polished stainless.
thought it might be worth mentioning but anyone interested in boosting their 928's (or anything for that mater) should really consider an addition of a wideband o2. they are dirt cheap these days. without you are shooting in the dark. i have an AEM wideband and it was under $300 with sensor from ebay. no more guessing where your a/f is of waiting to hear detonation. also many have had great sucsess with alcohol/water injection over intercoolers. the bad is that is consumable unlike an intercooler but where space is a premium it's a good alternative. side by side the alcohol/water out performs the i/c (ofcoarse it would be nice to have both) as there is no heat soak issue's with the alky/water. many are using windshield washer fluid also. just some food for thought as i didn't see much talk about this stuff.
just wanted to add, you kit looks great. love the polished stainless.
thought it might be worth mentioning but anyone interested in boosting their 928's (or anything for that mater) should really consider an addition of a wideband o2. they are dirt cheap these days. without you are shooting in the dark. i have an AEM wideband and it was under $300 with sensor from ebay. no more guessing where your a/f is of waiting to hear detonation. also many have had great sucsess with alcohol/water injection over intercoolers. the bad is that is consumable unlike an intercooler but where space is a premium it's a good alternative. side by side the alcohol/water out performs the i/c (ofcoarse it would be nice to have both) as there is no heat soak issue's with the alky/water. many are using windshield washer fluid also. just some food for thought as i didn't see much talk about this stuff.
07-16-2006, 10:03 AM
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The kit looks good. Its a first run prototype and if you are like me you will fab a few more before you are satisfied.
Dont take my comments in a negative way and also Jim is right. He knows what he is talking about and it is from experience.
Take my comments as constructive criticism. Also these comments are not just aimed at you but anyone who is considering a turbo buildup.
I have built 3 different turbo setups for 928's and drove them for 4 years with no internal engine problems. That said the first thing i did prior to fab was talk extensively with 2 Porsche turbo builders down here who gave me very good advice starting off with you should be driving a 930. That guy had built the 900+ HP S4. The other guy builds 600+ hp 944's and $80G 930 race engines.
You have a lot working against you on a late unmodified engine.
High compression and cast pistons is #1, fuel control, timing control, so so rods according to prototech although they are forged, weak drivetrain, but I assume you know about that, small injectors and a lot of other odds and ends, like you cant run leaded race fuel with an O2 sensor.
IMO you can run on an unmodified low compression engine safely up to about 8-10 psi all day long with 93 octane but I had a tec. I did it for 4 years with no internal problems. 12 psi is pushing it depending on your setup. 16 psi is probably too much for cast pistons.
If you are not in total control of the spark and injectors you will have problems. A stand alone is mandatory IMO with a CR over 8 or over 10psi and allows total control of spark and fuel and no guessing. Also with that TEC you should be running 45-50# injectors and a wide band O2 sensor. With a stock S4 engine you will have to custom tune it to stay out of trouble either a custom chip or SA system.
Without total control you never know exactly what your engine is doing, so you are basically just guessing. No data feedback and that is very important. You probably can get away with that at 8psi but not at 16psi.
The #1 thing that will kill your engine is detonation which I am sure you know. For that reason alone I would put an exhaust temp gage on every kit and make sure the system is tuned for 1300F max under boost. Right now it sounds like the knock sensor is probably controlling spark enough to keep you out of trouble.
If after installing an exhaust temp guage you see a spike, you have a lean area and a problem that needs to be addressed.
The best thing of course is to........
Build an engine. 944 turbo pistons, custom rods, 8:1 and you would never have to worry about the internals.
Use a tecIII or other stand alone system. That system actually has a automatic feedback loop from a data log. Motec is best but hard to program.
As far as the air filter, do yourself a favor and remove the windshield washer bottle and put it there. The inlet looks like its aimed in that direction anyway.
That turbo although probably okay for the track would not be my choice for a street setup. I ran a custom to4 on my last car, good for about 500hp, and it spooled up in 1st gear at 1300-1400 rpm and was strong through 4500. A street turbo that spools at 1300-1500 rpm is a blast to drive and very quick.
I am still not sure where the turbo is mounted, but it looks like it is low and back. In that case you are not gravity draining. Forget an electric pump. They will constantly burn out. I had one sump pump car and the best thing IMO is to build a small sump oil tank under the turbo and run a belt drive stock car products rear end cooler pump (basically a single stage of a dry sump) in the location of the air pump.
As far as octane, race gas is mandatory in a high compression car. 10:1 CR is not ideal for a turbo car and most importantly with cast pistons. You can probably run 8 to 1 and stay out of trouble if you dump enough fuel in to keep things cool but over that is too risky.
To be very safe an 8:1 engine at 8 psi you need 93 octane. You can push that if you have TEC spark and fuel control and use extra fuel to cool the charge.
A 10:1 engine running at.....
8psi needs 100 octane
12 psi needs 105
16 psi needs 110.
At this point the best thing you could do for safety before you collapse a ring land is to install an exhaust temp gauge.
No negative cirticism intended, but most people installing one of these kits probably have never dialed in a turbo car and I could see a few people turning up the boost and BAM! There goes the head gasket.
Dont take my comments in a negative way and also Jim is right. He knows what he is talking about and it is from experience.
Take my comments as constructive criticism. Also these comments are not just aimed at you but anyone who is considering a turbo buildup.
I have built 3 different turbo setups for 928's and drove them for 4 years with no internal engine problems. That said the first thing i did prior to fab was talk extensively with 2 Porsche turbo builders down here who gave me very good advice starting off with you should be driving a 930. That guy had built the 900+ HP S4. The other guy builds 600+ hp 944's and $80G 930 race engines.
You have a lot working against you on a late unmodified engine.
High compression and cast pistons is #1, fuel control, timing control, so so rods according to prototech although they are forged, weak drivetrain, but I assume you know about that, small injectors and a lot of other odds and ends, like you cant run leaded race fuel with an O2 sensor.
IMO you can run on an unmodified low compression engine safely up to about 8-10 psi all day long with 93 octane but I had a tec. I did it for 4 years with no internal problems. 12 psi is pushing it depending on your setup. 16 psi is probably too much for cast pistons.
If you are not in total control of the spark and injectors you will have problems. A stand alone is mandatory IMO with a CR over 8 or over 10psi and allows total control of spark and fuel and no guessing. Also with that TEC you should be running 45-50# injectors and a wide band O2 sensor. With a stock S4 engine you will have to custom tune it to stay out of trouble either a custom chip or SA system.
Without total control you never know exactly what your engine is doing, so you are basically just guessing. No data feedback and that is very important. You probably can get away with that at 8psi but not at 16psi.
The #1 thing that will kill your engine is detonation which I am sure you know. For that reason alone I would put an exhaust temp gage on every kit and make sure the system is tuned for 1300F max under boost. Right now it sounds like the knock sensor is probably controlling spark enough to keep you out of trouble.
If after installing an exhaust temp guage you see a spike, you have a lean area and a problem that needs to be addressed.
The best thing of course is to........
Build an engine. 944 turbo pistons, custom rods, 8:1 and you would never have to worry about the internals.
Use a tecIII or other stand alone system. That system actually has a automatic feedback loop from a data log. Motec is best but hard to program.
As far as the air filter, do yourself a favor and remove the windshield washer bottle and put it there. The inlet looks like its aimed in that direction anyway.
That turbo although probably okay for the track would not be my choice for a street setup. I ran a custom to4 on my last car, good for about 500hp, and it spooled up in 1st gear at 1300-1400 rpm and was strong through 4500. A street turbo that spools at 1300-1500 rpm is a blast to drive and very quick.
I am still not sure where the turbo is mounted, but it looks like it is low and back. In that case you are not gravity draining. Forget an electric pump. They will constantly burn out. I had one sump pump car and the best thing IMO is to build a small sump oil tank under the turbo and run a belt drive stock car products rear end cooler pump (basically a single stage of a dry sump) in the location of the air pump.
As far as octane, race gas is mandatory in a high compression car. 10:1 CR is not ideal for a turbo car and most importantly with cast pistons. You can probably run 8 to 1 and stay out of trouble if you dump enough fuel in to keep things cool but over that is too risky.
To be very safe an 8:1 engine at 8 psi you need 93 octane. You can push that if you have TEC spark and fuel control and use extra fuel to cool the charge.
A 10:1 engine running at.....
8psi needs 100 octane
12 psi needs 105
16 psi needs 110.
At this point the best thing you could do for safety before you collapse a ring land is to install an exhaust temp gauge.
No negative cirticism intended, but most people installing one of these kits probably have never dialed in a turbo car and I could see a few people turning up the boost and BAM! There goes the head gasket.