LOW PSI on KATs?

Your premier source for information on the Turbo KA: KA24E-T and KA24DE-T (KA with aftermarket turbo kit)!
240sxrunner
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why does everyone with KATs run with way low PSI like 6-8?? cant it go up anymoe???


george
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cuz the comprssion on the Stock motor is too high for turbo and it would detonate if you ran much more than 10psi

S13Ka24e
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Also if you want to drag or do auto-x then people use 100 or 104 octane and then you can run higher boost. But for daily drving if you want to run pump gas then you have to turn boost to 6-8psi to pervent detonation. But a stock Sr20det only runs 7psi so 6-8psi is not that low.

ADAMHU
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i am running 12psi on my kat

george
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Adamu you are running 12 cuz you have a badazz fuel and engine managemenmt syetem. people who run the JWT crap cant run that much boost as effectively as you.

Matthew
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Wow, it's weird reading a forum for a different type of car, but since when is 9.2:1 high compression for turbo?I realize that FMU's are not reliable at higher PSI, but i cant imagine stopping because 9.2:1 is too high.Does anyone here run larger injectors with a S-AFC instead of a FMU here?Just curious.

george
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9.2:1 is high when you consider the crappy pump gas we have to use

S13Ka24e
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ka24de has 9.5 to 1 compression. I don't think an FMU works too well over 7psi. There are lots of people here who use S-AFC and larger injectors.

TruboostPerformance
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I run 10psi daily driven, with SAFC, Vortech FMU(12:1) and silivia injectors, and it runs perfectly fine, no bucking , nothing no detonation at all, runs like stock until you hit boost then it runs like a bat out of hell, what are you guys doing wrong here? A dyno works wonders...12:1 a/f under boost...

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C-Kwik
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I know of at least two stock KA's running 15 psi on JWT systems. 10 psi maybe a limitation with 370 injectors, but upgrade to the MSD 50lb(525cc) injectors and Cobra MAF and 15 PSI should not be a problem on pump gas (assuming the motor is in good condition). Those that run 6-8 PSI are either running 370 injectors and just being conservative, or they are running a FMU and can't handle more boost without detonating.

ADAMHU
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i am ditching my system as we speak and getting a custom JWT system with 72lb injectors...to allow me to run more boost 15psi+

:)
ADAMHU wrote:i am running 12psi on my kat

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turboweege
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a couple quick questions for you turbo ka gurus:1. how do you set the boost to only 5 psi, would you just use a manual boost controller?2. are there any sohc to mitsu style turbo manifolds available?3.can dsm 450cc injectors be used in a ka24e? thanxluigi

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turboweege
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also, does the ecu have to be reprogrammed to run the turbo setup or will the safc take care of that?thanxluigi

96_S14_SE
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I would say with an upgraded fuel pump to a walbro 255, and a 12:1 FMU, would be safe up to 6-7 lbs.

Im going to run 8 and use 370 TT- Z injectors, fuel pump, and see if the s-afc will work good for this, it should.

As far as adjusting it you could use a boost controller or just find a wastegate with only a 6 to 7 psi setting (alot of internal ones are in that range).

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C-Kwik
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turboweege wrote:a couple quick questions for you turbo ka gurus:1. how do you set the boost to only 5 psi, would you just use a manual boost controller?2. are there any sohc to mitsu style turbo manifolds available?3.can dsm 450cc injectors be used in a ka24e? thanxluigi


You would need a wastegate that is sprung to 5 psi or less. You can buy different springs for external wastegates, but springs made for 5 psi may not be available for larger wastegates. You can not use a boost controller to lower boost below the wastegate's set level. Boost controllers work by impeding flow to the wastegate to fool it since it will read a lower pressure than the actual pressure. You can not raise the pressure in the signal line without an outside pressure source.

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WDRacing
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The stock nboost on the RB20 is around 8 psi. I run my car at 28 psi with the help of Alcohol injection. With a decent kit you can add 8 psi more of boost. I'm really surprised more of you guys don't run alcohol. Oh by the way my injectors are stock as well as my MAF.

I figure with the same kit I use you guys could run 15 psi all day. Or until the alcohol runs out. I run 20 psi at low boost and 28 at high boost with alcohol.

WD


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