High horsepower, nitrous L6

[Micah]

Hi, everyone. So this is my first post.

 

I'm not new to cars or high horsepower at all. My dad and I run a dyno shop called OST Dyno and focus mainly on the new Hemi cars. I however, love classic Japanese cars. Now, I have searched for this information but no one really seems to be doing what I'm planning (or maybe I just didn't search properly).

 

I want to build a stout L28 and spray the daylights out of it. My questions are these:

 

What head would be best for such an application? There seems to be a lot of different OEM heads out there. Ideas on headwork and to the extent it should be done? What sort of cam?

What compression? I plan on running only E85 or higher and was thinking 13.5:1ish. I need someone with experience here.

Limits of the factory crank?

 

I don't have a horsepower goal. That's just silly. But I want to run mid to low 10's in a car that weighs around or under 2000lbs with me in it.

I have been drag racing my Honda for years and have tuned and done extensive work on many other turbo cars and N/A v-8's below the 12 second barrier. I know what it takes, and the work involved to reach my goals. The L-series are just a new world to me and I need help identifying what works and what doesn't. Thanks in advance!

[Perfect240z]

Good luck on your build. Try this site out, it'll calculate some numbers for you but remember this isn't real life. This will get you started on some of the head combos for your build.

 

http://www.ozdat.com/ozdatonline/enginedesign/

 

or this one works too,

 

http://www.atlanticz.ca/zclub/techtips/calcs/engine%20builder/index.html

 

This site will help too

 

http://www.atlanticz.ca/index.php/tech-tips.html

 

http://datsunzgarage.com/

[Micah]

Wow. What a great reply. It's going to take some time to read all of that info. Just what I wanted!

[johnc]

The Nissan L6 crank is pretty strong. 650 hp in turbo setups is close to the upper limit on power. There are some harmonic issues in the 7,000 to 8,000 rpm range but a good balancer (ATI makes a couple) and forged pistons with lighter, forged rods helps. Compression ratios are good on fuel to about 14 to 1 with the two valve head. You can go higher but not many people do because of hot spots in the combustion chamber. There is no "best" head (remember, on HybridZ there is no best). The P90 has a good combustion chamber design to start from although you'll either need to shave the head .080 or have custom domed piston made to get to your planned compression ratio. If you're going with domes pistons then its probably easier to go with the open chamber N42 head and build the quench in the piston dome.

 

Look at the cooling system mods on this site too. You'll need to do a few things to keep cylinders 5 and 6 from detonating. Also, you'll need to o-ring the block and run a copper head gasket at that compression ratio.