NB built BP4W, GT2560R, 16-17psi
 

Numbers : 296.22whp @ 5950rpm / 302.6 ftlb @4700rpm
84.5mm wiseco 8.5:1 , cometic hg
Manley rods, arp head/main studs
Squaretop/bp5a cam, bone stock head
FM manifold, 2.5" dp, custom 3" exhaust borla xr1
Vibrant 12800 fmic, 2" hot/2.5" cold piping
Hydra 2.5 Ems, stock ignition coils
Rc550 injectors, dw200 pump
Supermiata 4 puck, 6 speed, 3.9 torsen

Couldn't get the tq to read, kept getting a bad signal for the pickup but it's in the neighborhood of 300ft/lb. 16-17psi the turbo is literally tapped out, just like Ken Hill I couldn't get it to hold more than 16psi to redline. It's closer to 18psi in the mid-range. Timing is 15* tapering up to 20* at redline. It was 74* outside today, if it was the dead of winter the car would make more than 300. I really wanted to break 300 but it's just really hard to do with a FM manifold and 2560 with 2.5" downpipe. I've been driving this car with this tune since last summer, just wanted to Dyno it to find out where it was at.


https://cimg5.ibsrv.net/gimg/www.mia...2eaf805596.jpg

That's awesome numbers from a 2560, we almost have the same setup, except the turbo and IM.

Thanks man, I've been running this setup since June of last year. It's been great. What turbo are you running?

I was running a Chinese BEGi 2871 on my original setup and now I am running a Disco Potato, a 2860. A little fasterspool up than the Chinese 2871. So far I am happy with the 2860. Running it at about 19psi but haven't dynoed it yet. I'm probably close to 300hp.

Yea Ive never been a fan of the Chinese T28 stuff. They work but they are laggier and in a lot of cases make much less power. Are you running a GT2860RS or the newer GTX series? Definitely get back on the dyno with the new setup, @19psi Im sure you will be right at 300whp or more.

I'm running the GT2860RS, the disco potato. I found a good deal and I couldn't pass it up. Yes, definitely will get back on the dyno.

Interesting, I was able to hold 20 psi at 7200 rom in my old nb2 on a 2560. Wonder if the wga is allowing the puck to blow open.

Yea I wish it would hold 18-19psi to redline. Before the built motor went in I was getting really bad creep with the old engine, so I ported the WG and now I have the opposite problem..lol. I didnt port the hole all that much I mostly made a channel to the WG so the exhaust gasses could find the WG exit easier. I also bought a 1bar WG can, so I dont think its getting blown open, it will hold 18-19psi until about 5800rpm where it will drop to 16psi be redline. I have tried tightening the rod but that just increases the boost in the 3700-5800 area before it drops back down to 16ish from 6400-7300rpm.

I was thinking that maybe I have reached the flow limit of the compressor eariler since I do have a 84.5mm bore, Squaretop, and BP5A cam that all are increasing the flow needed at the compressor. 296whp is pretty good for a 2560R, if I was able to hold more to redline I dont know that it would net me much more whp. The 2560R compressor flows 34-35lb/min @ 1 bar, and with drivetrain loss Im probably around 330hp at the flywheel which when checking the compressor chart shows Im right at the surge line.

Did you ever dyno yours @20psi? Wondering what you made.

His was VVT, 8.5:1, squaretop. There isn't a flow difference worth discussing between the two motors in question. :)

Interesting. I know Ken Hill also couldn't hold more than 16psi to redline and he made 295whp. Overall I'm happy with 296whp. Adding 4 more psi might gain me 10 hp I think this turbo compressor is just maxed out.

Yeah you're making good power, i wouldn't sweat it.

Definitely. Part of me wants to get something like a gtx2867 and the other part says keep it how it is. Right now it probably won't break stuff, it hits full boost @3600rpm and is just super fun with the broad powerband and good response.

More power = more breaking stuff = car sucks.

Since I didnt get a torque readout from the pickup I plotted the torque based on rpm/speed at Various points on the dyno chart. To my surprise I made 301ft/lb @4300 rpm. So my actual numbers were 296whp/301ftlb. The car is hitting 19psi brefily at 4200-4500rpm and then settles down to 17ish until 5800 then it tapers down to 16psi from 5900-7200. I wish this turbo had just a little more compressor to hold the boost to 7200 better.

You could try a water injection setup and spray into the compressor, that would get you over 300. I wouldn't worry about the compressor wheel, they aren't that expensive. Great numbers Andy!

I could do a WI setup, but the next logical step Im planning on is 1000cc injectors and e85. There are multiple stations right near my house that sell e85. Im curious how much ill gain with e85 on my setup since Im already pushing the turbo pretty hard already.

If you have e85 I would use it for sure. Only reason I suggested WI is because spraying pre turbo shifts the compressor map to the right so it would act like a larger compressor.

If anyone's curious what the tq plot looked like here it is. I used the k Miata gear calculator and a program that derives tq from HP and rpm and graphed it on the hp plot. Full boost is achieved @ 3500rpm @18-19psi. Tapers to 16psi by 5700 and holds to redline.
https://cimg1.ibsrv.net/gimg/www.mia...56ebfced4d.jpg

I'm heading to the dyno this weekend with a similar setup. Stock long block, BP5A cam, begi cast manifold, 2560, 3" down pipe and exhaust, sheet metal intake. I've been tracking it at 14psi for a couple of years but my goals this weekend is to verify the torque output and try to stretch that 225 ft/lbs all the way to redline. I'm trying to keep the rods inside the block so it'll take some fancy footwork.

Ran mid 12's @ 108 on this setup.

Nice, I actually stumbled across one of your acceleration videos on youtube the other day...your car moves out pretty well. Holding 225ft/lb to redline is going to be tough I think. If you are holding 225 ftlb at redline I would think you would be close to 300whp. The problem with the 2560R is that past 5500rpm tq drops off pretty quick I think the turbine side just gets choked up with that small wheel on the hotside. I was only able to hold 205-210 ft/lb to redline and that was running 16psi at redline. Maybe your sheetmetal intake manifold will be the difference maker. I look forward to seeing your results, definitely post them up.