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Regardless tho, nice numbers and I bet that's a damn sexy setup under the hood!
Also, plz crank up the boost and make some use of that built motor... I'm still on a stock 174k mile block waiting for the executioner to come but he still hasn't shown up.
Regardless tho, nice numbers and I bet that's a damn sexy setup under the hood!
Also, plz crank up the boost and make some use of that built motor... I'm still on a stock 174k mile block waiting for the executioner to come but he still hasn't shown up.
Good power for a gt2860rs, spools a bit late, but solid power numbers.
Its a semi built motor on pump gas with factory pistons out of a 94 miata, i dont think i can turn it up much higher without getting detonation.
I have not really seen any one go past mid 300 hp on pump gas. mostly E85 for >350hp.
plus mechanical empathy for my 5 speed. i dont like 6 speed gearing.
i normally run 15psi street ~280ish hp, and 10-11 psi 250hp wastegate only on track.
is the GT2860RS really hitting that late 4500rpm? I have seen plenty of dynos where they hit much sooner than that. Great power numbers but where is the spool?
He has a cast log and a sub-par downpipe, we do a tubular/straight mandrel 3" setup regularly and they do spool similarly to OPs sheets. Ive found that on stock NB pistons 290whp is the pump fuel limit on my dyno. 17psi/14* or something like that.
He has a cast log and a sub-par downpipe, we do a tubular/straight mandrel 3" setup regularly and they do spool similarly to OPs sheets. Ive found that on stock NB pistons 290whp is the pump fuel limit on my dyno. 17psi/14* or something like that.
Get some flex fuel and put another 50hp in OP
Dann
How much more timing do you typically get away with when using 8.5-8.6:1 CR? Im running 8.5:1 Wiseco/ GT2560 @ 15-16psi but running 17-18* any more timing and the motor gets a little more noise on the knock sensor.
ooh let's play the dyno game: ca 91oct, ultra low timing and relatively low boost 6258 on a 4w. the spud aint touching this. barely any ebc duty too, you can see by how slowly the boost feeds in
why are we comparing whp when talking about spool? post up the plot you keep referencing, we want to see the curves
I hope it's not the one I think it is
100whp@3000rpm, just like a spud on a tubular with a 3" straight through on it.
Even the big GTX2867r 0.86 keeps up with the 6258 and makes big numbers, whats the 6258 record, btw?
2867r compressor map goes to 48lb/min, 6258 goes to 43lb/min.
I once tried a GTX disco with the tial V band 0.59 housing and hit 1 bar at 2200rpm on a vvt.
Dann
I would like to believe 15psi @ 2200 rpm but the engine cant physcially ingest that boost at that low of an rpm. It would be surging at that low of an rpm.
You're getting this with a snakey manifold though right, Dann? If so, you're comparing something shiney with a tank. The cast manifolds have proven far more durable than even well built snakey manis. I remember seeing some pretty solid dyno's of 2860's on absurdflow setups, but i remember that quite a few of them cracked.
why are we comparing whp when talking about spool? post up the plot you keep referencing, we want to see the curves
I hope it's not the one I think it is
Comparing WHP at the same set of rpm points on 2 motors is as good as comparing torque at the same RPM, and more important than pressure.
Here is a dyno in KW with HP added in red. It's 23hp per solid horizontal line. Absolutely dead stock NB8B with bolt on kit. There are no tricks to get it on early, just an internal gate and MAC valve to raise boost from 12 to 15psi.
As you can see 15psi, stock everthing, comparable low end and the turbo is clearly not struggling.
The big GTX2867r is similar yet makes in excess of 450rwhp. This is a pistons, rods, valve springs pump VVT car on E85, no porting, no big valves, stock inlet, compression etc.
I also tuned a EFR 6758 on a built NB8a, with a tubular manifold and 3" exhaust and the results are the 2nd image.
The big GTX2867r is similar yet makes in excess of 450rwhp. This is a pistons, rods, valve springs pump VVT car on E85, no porting, no big valves, stock inlet, compression etc.
I also tuned a EFR 6758 on a built NB8a, with a tubular manifold and 3" exhaust and the results are the 2nd image.
When you say "comparable" what does that mean? I mean if a 10-20 swing is considered comparable, then yeah I guess they are comparable. Most consider that a big difference. Also most would pick Krackens cast log over your tube-style manifold for durability, and because your setup only fits RHD cars. And that's ignoring transients and curves which your plots clearly ignore because most don't even have the torque curve in them. They could get to the 100hp@3k setpoint very differently and those dyno's won't demonstrate the reality. I have to ask: if this is "your dyno" why on earth don't you have it set up to read like every normal dyno under the sun? I'm trying real hard to have a productive discussion here
check this out:
if the above compare was done sloppy you could say "they're the same". but when overlayed and compared precisely you can see that there's a wild difference. I can dig out more plots and efr vs gtx plots too. they simply outperform. Just a few months ago you were saying exactly this too. Changed your mind?
I guess everyone can just make their own conclusions.
The EFR is good, transients are good and its certainly not worse than a GTX.
I think the fanboyism here is a bit strong, but its certainly a good turbo.
You dont need a torque curve displayed if youre comparing hp at the same rpm points. And if someone really wanted to know they could just calculate it at any point they want. Accurate rpm and power is shown.
If the gtx line drops like 35% in price, then I see the point you are making. Otherwise, sure, the more expensive (by a lot) gtx line is outperforming the efr line, buuut, the efrs are pretty good, and under 1300 dollars. Plus, they save even more money by not requiring a bov, or flange welding costs..etc.
09-04-2018, 04:20 PM
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