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L28et help me choose Comp. Ratio, camshaft and Turbo for best synergy


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82 280zx

 

I basically need to choose a

 

Piston set and comp. Ratio

Camshaft

Flywheel weight

And Turbo

for the best synergy.

 

Doing my first high performance engine build

 

I can't decide holset hx35/hy35 or arizona z car t3/t4oe 60. Trim

I like the idea of water cooled turbo btw is that necessary?

 

I want to build the turbos boost pattern to match the powerband of the cam.

 

I want to get a custom cam grinded from a NA cam by "elgin cams" and I have a list to send him of my turbo specs, piston compression ratio and head cfm's etc.

 

He grabs all that info and makes a perfect cam to synchronize everything.

 

 

Pleaaase DATSUN GODS

I need HELP and ADVICE other then the research I've done filling out the list for my engine build!!!

 

Shooting for 350-400hp for drift/track car i can mash on reliably all day.

 

 

 

I have MS3 and a innovate o2 sensor

P90 head that will have a mild bore

Bored out presmog intake/exhaust

Isuzu large npr intercooler

Big fuel pump and fuel rail and 450cc injectors

 

 

I need help choosing a set of pistons and their CR. Want forged ones

Can't decide super low comp. or high comp. for more low end torque

I want to keep my 3.9 final drive

 

I need help deciding what flywheel to use if I should go light or not

If I go high compression I'll go light I guess?? If low compression keep it heavy to balance torque/hp ratio?

Edited by jomz shakes
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350-400 hp is basically a factory engine with more fuel and air.  I'd put money into your cooling and lubrication to make it more reliable.  You are looking for basically the same thing as I am.   I think you'd be throwing money away with forged pistons and a custom cam for that power level.

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Gotcha gotcha. Well I've got an NA cam to grind. It costs only 170 to do it.

 

With that and ported head with ported intake runners do you think I would be gaining closer to 500??

 

I guess I'd rather have more power and be able to turn it down for reliability.

 

Then turn it up for drag or something.

 

I'm allready beefing up the axles and stuff for high power.

 

Is head work a waste of money too for 400 hp??

 

 

I guess I'm at this cross road

 

Do I get head work done and pop my p90 head onto my stock NA bottom end with the flattop pistons and call it a day

 

Or

 

Do I replace the pistons and install arp hardware along with it

 

 

 

 

Or not do any headwork, pop the stock p90 head on and leave the bottom end alone?

Edited by jomz shakes
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I am no expert but you have a lot of reading to do. 300HP in 2300lb car is a lot. 400hp things will break trans axels etc. flat top pistons and high boost is not a good combo. Grind is only 170 plus rockers, springs, pads. Porting and cam help but not as much compare to a NA engine

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I'm going to disagree with malibud, headwork is very important to make reliable power in a turbo.  But the stock L28ET is well equipped to make 350-400 hp reliably.  More than that really requires more flow accomplished by headwork matched with a good cam.  Reliability is related to heat management, so if you can keep intake temperatures down with good intercooling and appropriate turbo selection, you can run healthy spark advance and avoid detonation.

 

For more power, headwork to increase flow can make higher power levels without ridiculous boost increases, so it's easier to (again) keep heat levels down.

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I have headwork and a cam with a stock turbo bottom end.  A holset 351cw made 400whp at 20psi.  Same dyno but with a stock head I made 315 at 25psi.   That is just a ballpark difference of course but that should give you an idea of what you can do with a head.  I would install arp headstuds if you're changing the head anyway.  That's my $0.02

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That's some good info Bernardd. These guys defiantly know more than me. But stock engine at 300 hp that's pretty amazing.

I have only had my turbo 240z for a little over a year. Now trying to dial in a a new borg warner EFR turbo and electronic boost controller . Flat tops and turbo does not work well from what I understand ? seems like detonation..but quick spool   

And the trans I understand is good for 350ish ? 

Side note:

What cam and head work did you have done ? Who did it ? Approx cost ? thanks

I have a n42 head that has been ported unknown cam. Thinking about maybe switching cams 

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Ok so I'm gonna keep my flattops and keep my bottom end stock.

 

Gonna put a unshaved p90 on my F54 w flattops should be around 8.3cr.

 

Battling pre detonation w a stock sized Headgasket to utilize the flattops quench.

A wide band o2

Megasquirt 3 for fuel and spark

A ported free flowing head

 

I need to find a turbo that can boost efficiently and not raise temps.

I want the t3/t4 everyone talks about.

 

How do I find out what size parts to use in it to match my custom "a" grind cams powerband.

 

What trim? How do I find out exactly what turbo to have arizona z car build?

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Side note:

What cam and head work did you have done ? Who did it ? Approx cost ? thanks

I have a n42 head that has been ported unknown cam. Thinking about maybe switching cams 

 

Elgin cams and robello racing for the cyl head

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You need to define your power goals to size a turbo appropriately.  The stock T3 0.63 exhaust works well for most power levels up to 360-400hp.  There are a number of T04 compressors that may work for you, I have an old one that is not the most efficient, the V1/V2 (T04B), the T04E 50 trim is a good choice for that power level, but there are many options.

 

I was looking to get headwork with oversized valves done, but I was told there may be too much shrouding by the small bore of the factory block to get the full advantage of the larger valve.  I suppose you could eyebrow the bores, or maybe I was given incorrect information.

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