420hp, what engine mods needed?

[Hank S15]

Hey mates,

I was about to sell my S15... but kinda love the darn thing, so I`m keeping it

Want to do some mods on it tho.. widebody kit, en some engine mods.
Would like to take it to about 420ish hp (crank).

So any advice on what to modify on the engine to get this kind of HP figures?
My guess is:
JE Pistons and con.rods.
Fresh new crank and con.rod bearing
Rocker arm stoppers
Apexi Power FC
Walbro fuel pump
GT2871R Top mounted turbo (+kit)
Metal head gasket

Anyone else have any ideas?

Cheers,
Hank

 

[j@garagemac]

what you have stated so far sounds about right but id also say a greddy plenum as the key to hp is effiency and the easyier you can make it for the turbo the better.

not sure a 28.71 will flow 42lb/min of air tho but i aint seen the compressor map so cant speak from experiance on that one .

my choice is always the blitz 450r

hope this helps

kind regards j@wrc

 

[Dazz0i]

think the 84 trim of that turbo will make the power you're after.

JE, you're being brand specific, any reason for that?

Not tempted by a stroker? 2.2? haha

 

[j@garagemac]

i just dont like runing turbos rite to there efficency limit

 

[Yakozan]

here is the specs of a S14a here in Sweden running 465 bhp - 615nm @ 1.6 Bar

[FONT=verdana, helvetica, arial]Engine: [/FONT][FONT=verdana, helvetica, arial]
- ARP rod studs
- ARP head studs
- Eagle H beam rods, modified to carry Clevete 77 honda bearings
- Clevete 77 CLE-CB1780H.-25 rod bearings
- ACL Calico coated main bearings
- Stress bored block to OD 86.5mm
- CP oversize pistons 86.5mm / 8.5:1
- CP piston rings
- 1.5mm cometic steel head gasket
- Modified and polished cylinder head
- MIRA milled valve seats
- Grinded and poliched valves
- HKS stage 1 256 intake cam
- HKS stage 1 264 exhaust cam
- GReddy intake manifold
- GReddy turbo elbow
- GReddy frontpipe modified with o2 bung
- JapTuning 3" cat replacement
- Apexi style dual N1 cat back
- GReddy hotpipe
- GReddy V-SPEC intercooler kit
- GReddy type-r 50mm blow off
- GReddy oilpan
- GReddy profec b spec 2 Boostcontroller
- GReddy full auto Turbotimer
- GReddy TT harness
- Walbro GSS341 HP fuelpump (255L/H)
- 740cc injectors - JECS matched
- Apexi air filter
- Z32 turbo airflowmeter
- 60mm throttle body from a KA24E(240SX)
- Garrett GT3071R-WG Dual BB with modified interal wastegate
- Exhaust: a/r .86 57mm 90 trim wheel
- Compressor: a/r .50, 4" inlet 71mm 56 trim wheel
- TAKA racing steel braided oil/water lines
- Ceramic coated exhaust manifold from JGY with EGT bung
- Setrab 19 row oilcooler with thermostat
- KOYO aluminum Radiator
- GReddy radiator cap
- NISMO thermostat
- Redline Water Wetter
- Apexi Power FC with hand device
- FC datalogit unit
- Zeitronix ZT-2 wideband o2 + EGT, boost and warning module
- CUSCO adjustable engine mounts
- NGK BCPR7ES Sparkplugs
- Global 40Ah small battery


[/FONT][FONT=verdana, helvetica, arial]Transmission: [/FONT][FONT=verdana, helvetica, arial]- OS Giken twin disc clutch TS2BD
- OS Giken release bearing
- OS Giken release bearing sleeve
- NISMO slave cylinder
- NISMO release pivot
- NISMO steel braided clutch line
- NISMO gearbox mount
- Redline MT90 tranny oil
- Cusco 1? way LSD
- Redline 75W90 diff oil
- JapTuning Z32 to SR tranny kit
- 300ZX Z32 Gearbox 5 speed
- JapTuning shortshift
- Custom tailshaft
[/FONT]

 

[Nicely]

You could take a look at the specs of Ken and BenTaylor200's S14s on SXOC. Ben just got 465 at the fly...

 

[channie]

GT2871R Top mounted turbo (+kit)

Not big enough... GT30 size to deal with 420 comfortably... also other stuff...
Injectors 740cc atleast
You probably dont need to stroke it... but it would make it easier to obtain that sort of power...
But definately have the head flowed and a full bottom end re-build
and cams... possibly look at some solid lifters...

and assoiated parts to run the power...

New fly wheel and clutch... depending on how ur gearbox is going... possibly rebuild that or use an S14 one (Less painful to the wallet if it explodes!)
Wider rear wheel...

New engine mounts... A load of bracing... and som coilovers...

oh ARP head bolt kit would be strongly recomended after you pull the engine apart!!!

 

[Hank S15]

Thnx for all the replies.
465hp is a bit over the top for me... so around 400-420ish would be just fine.

As for the clutch.. forgot all about that!
Isnt it true that the 6-speed cant handle a double plate because the synchro rings will fail?

As for being brand specific for the pistons... did a little research and found out that Wiseco and JE are quite affordable.
Don`t want to go overkill... some engine rebuilders create engines to handle 500+ but only keep it at 450hp.

2.2 stroker kit is quite nice... but requiers an other crankshaft... which is quite expensive!

 

[channie]

2.2 stroker kit is quite nice... but requiers an other crankshaft... which is quite expensive!

Depending where you get it from probably would work out the same as getting an OEM one from Nissan!

Its always better to get things that cope with alot more than ur going to be running... Especially turbo and internals... ive always made sure im not maxing out my fuel pump and injectors...

Not to sure about the twin plate clutch... HKS sell them although saying that i did see a note somewhere outlining possible issues...

Besides with 420bhp u'l be ok with a decent single plate Exedy Single Hyper is rated quite high... or Nismo copper mix!

Might also want to look at a new diff... atleast a 1.5 way!

 

[zaero]

dont know about the Greddy plenum, I don't think you'll need it.

 

[Nicely]

Why not just get the circlip issue checked and strengthened if necessary? That's the only potential weakness in the 6MT. The box is better made than the 5MT except for that...

By rights though, you should be fitting a gearbox that's been made to take that power...

 

[j@garagemac]

head flowing on turbo cars at this horse power level is a waste of time and money . i always build engines that if the target firgur is 420 it gets built to take 550 that way it will last forever .

i just dont like seeing people spending needlesly

kind regards j@wrc

 

[channie]

Wouldnt you need to get more air into the car... hence the head flowing??? Or would it just be a casse of bigger intercooler core and inlet???

 

[j@garagemac]

the thing to remember is its forced! induction ,we dont flow heads on evo's till north of 580bhp theres no need . it makes not enough differnce to warrent the cost


kind regards j@wrc

 

[sillbeers15]

Don't forget to increase your engine cooling capacity for anything more than 350hp.

You'll need a bigger radiator and a oil cooler installed to manage the extra heat generated....

And not forgetting brakes upgrade to save your ass!

 

[TriniGT]

Yeah but a port and polish would see boost faster than a regular head. I would also suggest springs, retainers and of course a set of stage or stage 2 cams. If you plan of revving high then also add in a set of solid lifters. Dependent on the application also get a greddy sump, greddy intake would be nice as well and for that power a TS GT3076R along with a TS manifold would be very nice. It all depends on the money you are willing to spend, with what is listed there you can have a very reliable fast spooling setup capable of some decent numbers.