KA-T build questions I got the pistons and rods but what else?
 

Hey,
Im building a KA-T I have bought a T3/T4 turbo with a .70 trim. I have Jim Wolf ecu made for 50lbs injecters. IM wanting to hit at lest 400hp at the wheel. Here is the list as follows for the engine build wanting to input on what else i should buy...

T3/T4 turbo .70 trim
Jim wolf ecu,
Walbro Fuel pump,
38mm Waste gate,
Crower rods,
Wiseco Pistons, 9:1 comp bored .20 over
Ferrea Valves,
Stock Nissian Springs,
Stock Nissian Retainers,
3angle valve job,
1mm over valves,
Custom Made Intake Plenulem <-- isnt spelled right... ( The part the TB is hooked to, Made it to have short runners... and got rid of that horrific spiral)
Cast iron Manifold for the turbo with center waste gate postion.
3in Exhaust from turbine out let back no cat.
Safc II
Metal Headgasket
Alum Radaitor
Top fead injecters and fuel rail setup with ADJ fuel regulator.

I wanting to know if I should bother Knifeing the crank or not ?
I was going to get SS valve springs and titanium retainers but figured they wouldnt be worth the money seeing as the engine isnt going to see High revs above stock... I dont see how spending 800$ on springs and retainers is going to add any hp.. SS valves I could see the benifet becuase they are going to see high COMP pressure and Heat.

I was told by someone that i would probably need to run 75lbs injecters?
Im going to Dyno it and let them help me tune the SAFC and Fuel pressure.


If anyone can shoot me some ideas on what i should do to better help build the engine please do so... Im wanting to hit the 400hp mark and lower the car weight down to below 2600lbs ...

Thanks

Knifing the crank is a defenite PLUS. It takes out a bit of the rotational stress from flinging the oil around at higher RPM's. You don't want to knife edge too much, you want to keep the crank heavy in order to pull good midrange, and High range HP numbers.
You should also look into an ATI dampener.
If you want a fully counterweighed crank you can give scat a call they make custom fully counterweighed crank shafts, I don't know if they have the KA crank on file.......

Honestly...you can hit 400hp easy without having to knife the crank. Just build the bottom end--I don't know why you would consider knifing the crank, yet not get titanium valve springs and retainers.

Good point :thumb:. Just running boost over 10 psi you would want better springs and retainers.... Regardless of what your rev is.........

co-signed.

It's not that buying the valvesprings would increase your horsepower, they would keep you from detonating your engine. Pushing out that much power your valves would be suspect to the horrors of valve float and if that happened with the setup your talking about.... well let's just say you might notice a trail of oil behind you, and you might have a few interesting dents in your hood in the outbound direction.

For the money that you've invested and power that you expect to be producing I think it's almost a must. Only reason why not is because Nissan happens to build some damn tough engines.

I'm not good with standard measurements but if you want 400 at the wheels, assuming 13% drivetrain loss you're going to want to have about 460hp at the crank. I'd go for the bigger injectors.

Also I couldn't help but notice you didn't mention an intercooler and a blow off valve.

Ah...after reading over the initial post, it seems that you were under the impression that valves, springs and retainers only affected revs, and heat...

Stock valves, under the added pressure and heat could BEND. This is not a good thing. For a stock engine, the stock valves, springs, and retainers are fine for a just that; a stock engine, but once you force more air into your system, you get more power, which will generate more heat, which in turn is what detonation is caused by.

...Check out the Turbo FAQ's and such, they're a good read.

You are going to need to run larger injectors to hit 400whp. You are also going to need a clutch that can handle all your power. Another thing to consider is ARP headstuds and rod bolts. A nice intercooler also so your motor doesn't heatsoak and lose power. Other than that it seems like a good setup that will definently produce the numbers you are looking for.

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.

Yeah, you can find that info at KA-T.org, theres a big thread on it, if you wanna see the rest.

i dont see bearings??!!??

You're not likely to spin a bearing as much as these other items, and with the proper tuning...but I guess it COULD happen--that would be another thing you could consider.

maybe not.. but if your putting all that work into a motor, why not go ahead and put in a nice set of clevite's in for $70 tops and call it a day.?