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Sorry for the potato pic but it's legible Virtual dyno is pretty damn good.
I just decided yesterday to go dyno my car for the heck of it. Not bad result. I wanted 400whp but my mbc drops boost to redline I need a ebc. Motor is a built bp with a 84.5 bore, stock 4w head, FM manifold and downpipe, gtx 2860 .64 a/r. Running my own little mix of 93 and vp octanium.
I was gonna go for more but when I built the motor 2+ years ago I didn't surface the head. I used a cometic hg and it's been fine but yesterday it was pushing coolant, not horribly bad but I know it needs a resurface and a OEM hg this time around. Let that be a lesson to anyone who thinks they can get away without a head resurface even though they know better. Lol my mistake. However I'm gonna build a head now so it's not really a loss lol. Cat still runs fine at 20psi just didn't like higher boost, but it will.....it..... Will.
Also for all those people who love early tq you should love my car. It makes tq super early. This turbo is almost instant spool.
...yup i know what I'm upgrading to when my 2560 gets boring
Here youll like this comparison. My old 2560 vs 2860. Same dyno one year apart. We didnt rev out the 2860 all the way because HP peak was already at 6300 so thats why the 2560 graph carries out farther but the spool is damn near identical. GT2560R @18psi vs GTX2860R Gen2 @22psi Spool as you can see is identical and that just shows you how much better the GTX stuff really is.
Very nice looking plot, congrats. You can likely lean it out some, high 10's is pretty fat
yea, my wideband shows 11.5 on logs but his dyno showed it a lot more rich. Not sure which one to believe. I have my hydra WB and a Prosport EVO and they both showed i was right in the 11s.
Regarding the boost up top, I tried several wastegates ( from 10 psi until 18psi spring twin port) and using boost @ 100% and couldn’t pass 21psi up top too. I guess the turbo just can’t flow anymore.
Regarding the boost up top, I tried several wastegates ( from 10 psi until 18psi spring twin port) and using boost @ 100% and couldn’t pass 21psi up top too. I guess the turbo just can’t flow anymore.
Hmm, so you are using a ebc and even with 100 wg duty it still won't go higher than 21? Yea the most I've seen mine hold up top was 22.5psi. I do have .64 hotside I wonder if that has anything to do with it. Looking at a compressor map it looks like it could do 25psi before it's totally out of air.
Hmm, so you are using a ebc and even with 100 wg duty it still won't go higher than 21? Yea the most I've seen mine hold up top was 22.5psi. I do have .64 hotside I wonder if that has anything to do with it. Looking at a compressor map it looks like it could do 25psi before it's totally out of air.
Thanks for the post.
You could pull the hose from the wastegate (plug it) and carefully find out the maximum potential. Just have to be careful around 4500 RPM for too much. This presumes the gate does not blow open, which would then only work with a higher spring or 4-port controller.
DNM
Last edited by DNMakinson; 09-20-2020 at 08:30 AM.
Reason: 4-port comment.
You could pull the hose from the wastegate (plug it) and carefully find out the maximum potential. Just have to be careful around 4500 RPM for too much. This presumes the gate does not blow open, which would then only work with a higher spring or 4-port controller.
DNM
Yessir I could most definitely try that. I have overboost protection so it would be totally safe to see what it will do up in the higher rpms. I could just be at the limit of that turbo compressor. Looking at the map it peaks at 44lb at 1.5 bar. Above that it starts to flow less when you add pressure. So I could just be at the limit of the compressor. My built head with +1 valves could help gain some efficiency when that goes on. And I can still lean it out a little. My goal is to make 400whp on this turbo.
Boost is the measurement of the restriction of flow. So it's not just the flapper being pushed open that could cause this.
I have a 2.5" downpipe that I'm gonna ditch and weld up a 3". Honestly the .64 hotside might be the restriction here, I'm gonna find out what the bigger valves and springs and retainers will do. Gonna unshroud the valves as well. So will be interesting.
I'm not gonna go with a .86 hotside I like the instant response too much. I still think I can hit 400 on it, but only time will tell. I'm having fun trying to unlock the last 25whp to get to 400.
Looking at the compressor map... it looks tapped to me where you are at. I think you did quite well. You could ~maybe~ get more with a larger displacement motor, but not a lot more.
Looking at the compressor map... it looks tapped to me where you are at. I think you did quite well. You could ~maybe~ get more with a larger displacement motor, but not a lot more.
I agree with you for sure. I'm hoping to find 25whp with the +1mm valves and maybe some more timing as I was not at MBT yet but getting close. Should be fun. But yes the map is pretty much maxed out at 1.5-1.6bar I agree.
Hmm, so you are using a ebc and even with 100 wg duty it still won't go higher than 21? Yea the most I've seen mine hold up top was 22.5psi. I do have .64 hotside I wonder if that has anything to do with it. Looking at a compressor map it looks like it could do 25psi before it's totally out of air.
Thanks for the post.
When you’re Working around the “ineficient área” of the compressor map, it’s not the air temperature that’s killing your power, it’s the shaft speed and therefore the backpressure caused to achieve that shaft speed
And that’s why you could run a 2867 and pickup way more power with the same exhaust housing.
When you’re Working around the “ineficient área” of the compressor map, it’s not the air temperature that’s killing your power, it’s the shaft speed and therefore the backpressure caused to achieve that shaft speed
And that’s why you could run a 2867 and pickup way more power with the same exhaust housing.
Another turbo geek like me?! Yes, I totalIy agree. The shaft speed on the 2860 gen 2 is the highest I've seen I'm basically running it up to 175k+ if I'm as far on the compressor map that I think I am. 2867 is an option but I wanna see 400 with this turbo just because it spools so darn well
As I told you before, on the boost side I think you’re on the limit. I even used a two port wastegate, making it close as much as possible without much success. Maybe on colder weather could get a tad more. On the lower rpms I can shoot it to over 25 psi easy.
Your 400 on 98 can be possible with cams, or maybe just cam timing.
What ignition timing are you runing at that boost level?
09-19-2020, 02:03 PM
Gtx2860 gen2-- 373whp/351tq-- 22psi
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