jputz Posted October 9, 2010 Report Share Posted October 9, 2010 Hey everyone found some good info on KA-T.org that I figured everyone might want to read. Anyway heres tthe info. These are the Prerequisites to building a DOHC Turbo. Together we will go through typical setups from mild to extreme to reach the power goals you desire. These are lists of typically used items that are easily attainable by the average person. All setups should have the Air to Fuel Ratio verified on a dyno with wideband or at very least on a track using an in-car wideband setup (NO watching the standard O2 signal and calling it good). If your using pump gas and seeing air to fuel ratios more lean than 11.8:1-12:1, some rethinking on the tuning/fuel setup will be needed. A narrowband guage(typical A/F guage from Autometer for instance) is not complex enough to be a real indication of the ratios inside your combustion chamber. Very Mild Build: around 180 rwhp Turbo Manifold Blow Off Valve Turbo (T25) Downpipe 2.5" is perfectly fine Pipe to connect turbo to throttle body Fuel Control: FMU (not recommended, but doable) Raises fuel pressure per boost to make injectors flow more than normal. SR 370cc Injectors. These can be found at places found at the bottom) Apexi SAFC2 Greddy Emanage Mild power adder, say you want around 200 rwhp. Turbo Manifold Blow Off Valve Small Intercooler (potentially get away with a side mount) Turbo T25/T28/14B, etc. Smaller T2 setups. Usually will be internally wastegated. Downpipe 2.5" is perfectly fine Replacing the Exhaust is starting to be very necessary at this stage, so I would start to shop for that as well. Fuel Control SR 370cc Injectors Apexi SAFC2 Greddy Emanage Back off base timing at distributor or MSD BTM Average: 300 rwhp to 350 rwhp, you have to start to expect a little more lag. This is about the perfect "street car" limit. No race gas, just good honest street car fun that is fully capable of bring home a 12 second timeslip on a good run. Turbo Manifold T3/T04E .50 Trim compressor, .60 trim compressor housing / Stg 3 (aka TA31) turbine wheel, .48 to .63 A/R exhaust housing. Internal wastegate optional but not recommended. Downpipe can still be 2.5", but this is as far as I would want to push that. Front Mount Intercooler (FMIC) It's time to upgrade to a larger front mount as the larger will push more air than the smaller sidemount can cool. Fuel Control 550cc Injectors SAFC2 to control your fuel injectors, along with the stock ecu. MSD BTM At this stage I would be running the BTM to control timing retard. Reflashed ECU-This can be a DIY thing with Megasquirt Tuning or a JWT. Z32 Maf is required, as the stock Maf stops being able to read at around 260 rwhp. Wideband O2 Sensor should be installed for tuning. Block Internals This is where I would start to consider it necessary to replace you pistons. Above Average: 350 rwhp to 425 rwhp Turbo Manifold Blow Off Valve T3/T04E 50 Trim .48/.63 or slightly larger turbo, this is where I would start to make the switch up to an external wastegate. You have the option to reroute it back into the exhaust, or merely "dump" it out into the open. "Dump" is usually a mini exhaust in the form of 1.5" piping routed out to the open. FMIC Larger is starting to be necessary. Typical for setups from here on, are 12"x24"x3" for the core. Downpipe 3", at this point I would switch to the larger downpipe. You can probably get away with it at 2.5", but it will be causing a little bit of backpressure. Moving to 3" piping as quickly as possible is what you want though. Usually it is necessary to have the first bend 2.5" to clear the steering shaft though. Exhaust 3" Block Internals At this stage you'll want to "build" or fortify your block to better handle boost. Previous to this you can walk the line, but here and forward I find it necessary to do so. Forged Rods Forged Pistons Stock Crank Plus your typical rebuild items. Fuel Control Standalone fuel management is recommended at this stage in the game and is absolutely necessary at the next. These allow you control not only very large injectors, but the tuner to have complete control over both timing and fuel. 720cc Injectors. Wideband O2 Sensor is necessary for tuning. Wild Build: 425 rwhp to 600 rwhp. Lag is obviously going to be much more apparent, full boost isn't going to happen until around 4000-5000 rpms or so. Once spooled it will pull very hard. Turbo Manifold Turbo T3/T61/SC61 or GT35R seem to be the typical turbo's in the area. External Wastegate is your only option that should be considered. Blow Off Valve You'll want a good performing more expensive blow off valve to alleviate reverted air when the throttle body closes from pushing against the compressor wheel. FMIC the 24"x12"x3" Core's are still effective in this range. Downpipe 3" is still capable of handling these power levels Exhaust 3" or larger Fuel Control 720cc-1600cc Injectors Standalone Fuel Management Recommeded to switch to Map instead of Maf for reading airflow. Wideband 02 Sensor installed and wired into standalone for adjustments and monitoring. Dyno tuning is very valuable. Block Internals Along with the previously mentioned internals I would add these to the list Cams (per your discretion) Build your head as well Valve Springs Valve Retainers ARP Head/Main Studs Cometic Headgasket or similar Absolute turbo necessities...amongst the aforementioned goodies above. Oil Lines Fuel Pump: The stock pump is decent but not intended for such use. For Walbro 255's being as cheap as they are, anyone turboing their vehicle should upgrade previous to turboing. Boost gauge Here's lists of aftermarket products that are currently on the market Turbo Build Parts: Turbo Manifold (Exhaust Manifold) Ground Zero Motorsports Full Race Peak Boost (release date TBD) Revhard Turbo240.com JGS Precision Realnissan.com Import-AutoPerformance.com Nizzx.com SSAutochrome (not recommended) BOV Tial Greddy RS JGS HKS SSQV Wastegates Tial JGS Turbonetics Block Internals Pistons: Can be accomplished one of two ways, by purchasing ones that are made for the E with their intended compression ratio. The other is to use DE pistons and subtract a full compression point to equal the difference between the E and DE head. (ie 9:1 DE pistons will be 8:1 in an E) Arias 8.8:1(DE) Wiseco 9:1(DE) JE 8.5:1 Ross 8.5:1(DE) CP 9:1(DE) Supertech 9:1 Rods: Any rod that will fit the bottom end of the DE will work with E as well. Crower Pauter Carillo Eagle (release tbd) Bearings Whatever your preference is for rebuilds. Mine is Clevite. Headgasket Cometic Valves Supertech Dual Valve Springs SI Valves Ferrea Valves Retainers Supertech Titanium Retainers Cams PDM Racing Nissan Motorsports Colt Cams Crower JWT Technology Typical Injectors Used on DOHC SR 370cc Injectors SR Upgrade Injectors are available in various sizes between 550cc-720cc as side feed, anything larger usually you'll want to switch to a top feed fuel rail and injector combination. Injector Resistors (To alter low impedence to work with a high impedence ecu) Alight there it is hope that this helps atleast one of you guys out. Got to give a big thanks to veilside180sx over at KA-T.org for the great write-up. Maybe this should be a sticky!! Quote Link to comment
lil89ram50 Posted October 9, 2010 Report Share Posted October 9, 2010 thanks for this info man! Quote Link to comment
Nissan_Boy85 Posted October 9, 2010 Report Share Posted October 9, 2010 This is what I based my build off of. Mind you I have yet to build it, but it seems like very good info. Quote Link to comment
INDY510 Posted October 9, 2010 Report Share Posted October 9, 2010 Cool info............. did you say if this is for a KA24DE or KA24E????? Is there any easy way to lower the compression on a stock KA24DE? Quote Link to comment
DISLEXICDIME Posted October 9, 2010 Report Share Posted October 9, 2010 Why indy its not high Quote Link to comment
jputz Posted October 9, 2010 Author Report Share Posted October 9, 2010 I think this should tell you about CRs. If I am wrong please let me know, I am by no means an expert on this matter but would like to build a turbo KAe so let me know what you guys think. Pistons: Can be accomplished one of two ways, by purchasing ones that are made for the E with their intended compression ratio. The other is to use DE pistons and subtract a full compression point to equal the difference between the E and DE head. (ie 9:1 DE pistons will be 8:1 in an E) Arias 8.8:1(DE) Wiseco 9:1(DE) JE 8.5:1 Ross 8.5:1(DE) CP 9:1(DE) Supertech 9:1 Quote Link to comment
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