BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

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NukeKS14
240sx Wannabe
Posts: 109
Joined: Thu Jan 09, 2020 8:33 pm
Location: Northeastern KS

BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by NukeKS14 » Fri Apr 10, 2020 1:51 pm

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(pre fuel-upgrade picture)
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Calculated comp. ratio-> 9.59:1 (10 mils off head/deck for flatness)
Wiseco 9.0:1 pistons, .020 over
Manley H-beam rods
ARP main/rod studs
Calico coated ACL rod and Clevite77 main bearings
Tomei 1.0mm headgasket
rotating assy fully balanced
BC Stage 2 cams on OEM valvesprings.

ID1050x injectors in Radium top mount rail (Base fuel pressure set to 50#)
Aeromotive 340lph in-tank fuel pump, hard wired.
MSPNP2 ECU
Maxima COP conversion running BKR7E-11s at .044 gap

CXRacing 11ga ex manifold, downpipe converted to 90mm V-band
3" Turbo-back (no cat)
Turbosmart 45mm wastegate, open dump
BorgWarner S257 SX-E .82 A/R ex housing.

I was previously running an Ebay T3-T4 and I can't describe how much of an improvement this Borg Warner is. I would highly encourage anyone to check our their matchbot app if you're looking into upgrading turbos.

Can't wait to get the chassis sorted so I can get on track with this.

TwoDoorDime
Driving Mom's Station Wagon
Posts: 31
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Location: San Diego

Re: BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by TwoDoorDime » Wed Apr 15, 2020 5:48 pm

This car must be an absolute riot with that power! any pictures of the car itself?
Youtube Channel Second Chance Builds

NukeKS14
240sx Wannabe
Posts: 109
Joined: Thu Jan 09, 2020 8:33 pm
Location: Northeastern KS

Re: BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by NukeKS14 » Wed Apr 15, 2020 7:42 pm

https://forums.nicoclub.com/introductio ... 23712.html

Half assed build thread on nico.

Its a hoot but i'm taking it easy on the stock tranny and axles. I have a N/A Z32 tranny and diff sourced i just need to go pull them. J30 axles w better rzeppa cv joints and game on.

TwoDoorDime
Driving Mom's Station Wagon
Posts: 31
Joined: Mon Feb 27, 2006 7:13 pm
Location: San Diego

Re: BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by TwoDoorDime » Thu Apr 16, 2020 9:55 am

Oh i see an LS fan as well. I was a GM tech for years, have a few LS powered cars. Great s14!
Youtube Channel Second Chance Builds

NukeKS14
240sx Wannabe
Posts: 109
Joined: Thu Jan 09, 2020 8:33 pm
Location: Northeastern KS

Re: BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by NukeKS14 » Thu Apr 16, 2020 11:50 am

Thanks. My dad has worked for GM the past 30+ years so i got a ton of incentives. Had hoped to best it with the 240s output but i did not. I am within about 15whp though.

I have a Backdraft AC cobra replica finding a home in my garage eventually with a SBF 392 as well. I have an affinity for greasy rwd cars with gobs of torque (that also handle well). Not brand loyal at all but I keep coming back to Nissans for some reason.

TwoDoorDime
Driving Mom's Station Wagon
Posts: 31
Joined: Mon Feb 27, 2006 7:13 pm
Location: San Diego

Re: BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by TwoDoorDime » Thu Apr 16, 2020 3:38 pm

I am in the same boat! My foxbody sits right next to my LS swapped rx7 and it next to my single turbo rotary rx7 etc etc. I don't care about the brand just like rwd cars. I mostly like beaters but have had some nice cars as well.

At what power level did you hurt the stock bottom end?
Youtube Channel Second Chance Builds

NukeKS14
240sx Wannabe
Posts: 109
Joined: Thu Jan 09, 2020 8:33 pm
Location: Northeastern KS

Re: BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by NukeKS14 » Thu Apr 16, 2020 9:40 pm

No dyno numbers, tooling around with the MS. Went out on a summer day to dial in the ebc. Aimed for 10# and touched 12 on a boost spike when boost cut kicked in. Damage was done. Got home to find a quart and a half of oil had fled my engine by way of the valve cover breather. Guessing you saw the pic. It wasnt horrific. Pulled ugly compression numbers and knew the gig was up. Im pretty convinced it was binding from thermal expansion, too small of gaps. Just some hairline cracks on the ringlands for 1 and 3 cylinders.

The dueling walboro setup PO had in the fuel tank didnt help. If youre going to y pipe two fuel pumps use check valves kids!

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p00t
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Re: BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by p00t » Thu Apr 30, 2020 8:45 pm

Great numbers and nice build. What was different between the ebay turbo and the Borgwarner?

Definitely worth letting it wind up to 7k by the looks of it.
Current Experiment: APS SR56, Methanol Injection, & Built Block

NukeKS14
240sx Wannabe
Posts: 109
Joined: Thu Jan 09, 2020 8:33 pm
Location: Northeastern KS

Re: BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by NukeKS14 » Sat May 02, 2020 12:20 pm

My IP address keeps getting blocked for some reason...


Thanks for the kind words.

The China-bay turbo was a claimed T3/T4, .63 A/R stamped on exhaust housing. I fought and fought to keep the 5 bolt exhaust flange on the downpipe from leaking at the turbo. It also surged pretty badly any time I even thought about letting off on the throttle. Bov is plumbed in to the hot pipe maybe a foot and a half from the compressor. I think it was a turbo issue. I'm skeptical of what the ACTUAL A/R and trim of that turbo are. I am too lazy now but I may go out with a micrometer this winter and do some measuring and figure out for myself.

I think most people aren't well versed in the BW sizing so I'll compare it to Garrett; This BW is right at I believe a GT 3076, maybe a touch larger, with 90mm V-band conversion. .82 A/R exhaust housing in this case.

Big differences I noticed immediately were the exhaust note, anti-surge comp housing has eliminated surge, and the powerband. I can hear the cams at idle, there is a little bit of a lope now. Not anything like the LS in my camaro but I can tell it's there where I couldn't hear anything before. And it's deeper and a bit louder. On the T3/T4 I was in boost at cruise on the highway pretty much. I cruised at a higher throttle position as well. Now, I'll cruise at 80-85Mph at 20% or less throttle and at a decent amount of vacuum. (55-70 kPa ish) I can tell the engine is breathing a lot better. Visual comparison of the exhaust housing says everything. I feel the car pull strongly and smoothly through to redline now. I don't know it's a truly analogous comparison as I wasn't running a quality T3T4 but I won't go back. I could see maybe going to an EFR bb turbo from BW in many years but this is perfect for now. I don't feel like there was an appreciable difference in spool. I can tell maybe 200-400rpm difference in delay but the turbo still only has less than 5k miles on it.


I plotted the compressor map from 2k to 7k RPM in 1000RPM increments. points are 5, 10, 18x3 and the 7kRPM plot is at 28psi to see what the 'ceiling' is on this turbo.
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We weren't seeing IAT get above 90s on the dyno (my sensor is in the cold pipe, just at the outlet of the intercooler.) Tells me that compressor map is pretty accurate as I'm running the el cheapo EMUSA FMIC that came on the car.

exhaust housing for illustration
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NukeKS14
240sx Wannabe
Posts: 109
Joined: Thu Jan 09, 2020 8:33 pm
Location: Northeastern KS

October update (407HP | 398 ft/lbs)

Post by NukeKS14 » Mon Nov 02, 2020 6:05 pm

So I got busy and never got around to actually updating this for my new setup. My CX manifold cracked at the collector where the wastegate is. I said screw it and did what I should have done in the first place, and ordered a good quality Full-Race manifold. I also switched to a .78 A/R divided hotside. I gained a TON of spool and torque throughout the powerband with the Full-Race twin scroll manifold. Then I blew up my stock KA transmission 2 days later (passing a semi in 5th.) She's got a VG transmission from a 1994 NA Z32 now and is running stronger than ever. I'm hitting 21 PSI on straight pump gas. It's ridiculous how responsive this setup is.

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The orange curve is my old peak run on the CX manifold and .82 A/R undivided housing. Peak torque went up 16 ft lbs but everything comes on about 300 RPM sooner and it's available throughout the powerband. I'll be upgrading to Tomei cam gears next year and shifting to an E85 tune. The engine runs smooth to redline now which is actually 7500 RPM but power is falling off quite a bit after 6500ish.

Still running .044" gap on the spark plugs (BKR7E-11s) on the Maxima coils with no blowout at 21psi. Solid setup. Excited to see what next spring has in store when I can get back to the brakes and suspension.

alan-n
Knows Some Stuff About 240's!
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Joined: Tue Jul 03, 2007 3:40 am

Re: BW S257SX-E 412WHP/383TQ @ 18.5#, 93Octane

Post by alan-n » Sat Nov 14, 2020 8:14 pm

Great stuff this will be the turbo I'll be going with on my rebuild with z33 transmission. Something with quick spool for HPDE track days.

Alan
'95 240SX; BWS366; Kelford 272/272

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