1999 Forged Bottom FM2 w/ MS1
#21
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Gutted cat is killing you too. Unless you have a peice of pipe in it to smooth the innards out.
It probably had more flow prior to you gutting it actually.
Change that system to a sanitary 3" tube (polished inside as well as out) and profit 20whp over the entire RPM range. the cheated bends and short radius is hurting, the 2.5" it hurting, the cheated bends really hurt, the gutted cat is killing you. sorry, but this is why your dissapointed in your numbers.
It probably had more flow prior to you gutting it actually.
Change that system to a sanitary 3" tube (polished inside as well as out) and profit 20whp over the entire RPM range. the cheated bends and short radius is hurting, the 2.5" it hurting, the cheated bends really hurt, the gutted cat is killing you. sorry, but this is why your dissapointed in your numbers.
#22
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With that exhaust setup, 225whp at 13psi isn't too far off. You have something funky going on at 6k+, let's see the timing map and datalogs. I bet you're crossing from the 183 cells into the 212 cells and the 212 cells are way retarded across the board.
#27
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If any of you had actually tuned a car using vics, you'd understand that it makes no difference above 5500rpm. Cute, though.
Two problems here:
-flat timing to redline. The maps on my 2554r rose from 13-14deg at tq. Peak to 20+ degrees at redline. Turn up the timing past peak torque.
-fuel rises at 6500rpm at 212kpa. By like 5%. Ridiculous. With power falling, you need less fuel at high rpm, not more. All the T25 cars I've touched get less fuel at 7k then they do at 6k.
Add 2deg of timing above 5500, 3deg above 6200. Then fix fueling, I bet it's like 10.5:1 at 6500+. Those two are worth like 15+whp.
#30
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If any of you had actually tuned a car using vics, you'd understand that it makes no difference above 5500rpm. Cute, though.
Two problems here:
-flat timing to redline. The maps on my 2554r rose from 13-14deg at tq. Peak to 20+ degrees at redline. Turn up the timing past peak torque.
-fuel rises at 6500rpm at 212kpa. By like 5%. Ridiculous. With power falling, you need less fuel at high rpm, not more. All the T25 cars I've touched get less fuel at 7k then they do at 6k.
Add 2deg of timing above 5500, 3deg above 6200. Then fix fueling, I bet it's like 10.5:1 at 6500+. Those two are worth like 15+whp.
#31
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I'd start in boost. You need to have a close ear on things. I was able to find det under 6200 in my 2554r car, with the same turbine and a bigger compressor you may find it a little earlier than I did. The fueling in general looks rough up top - some rows it drops, some it climbs.
Search for my 217whp chart, the timing map should be posted. Don't copy/paste, please, but do use it as a template for how the curves should swing up as rpm climbs and torque falls.
#32
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Look at the 3d view for both tables and tell me you don't think it's a disaster. Compare the shapes of your tables to the shapes of mine. I hope you didn't pay anyone for this tune. If you did, post his contact information.
After reviewing the log it's clear that fuel is the main problem, you're all over the place. Our engines seem to like 11.5:1 for torque, fix your fuel table then address spark next time you get on the dyno. Low compression engines need spark angle to come alive.
After reviewing the log it's clear that fuel is the main problem, you're all over the place. Our engines seem to like 11.5:1 for torque, fix your fuel table then address spark next time you get on the dyno. Low compression engines need spark angle to come alive.
#33
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Now that I'm off my phone I can actually view the log you posted. No offense, but the fuel map is a total clusterfuck. Don't touch the timing until you get the fuel totally sorted out. California pump gas makes me more conservative than everyone else on timing, but 18 degrees on a 2560 at 14+psi sounds pretty aggressive to me as well. I would consider taking some timing out and work on the fuel map. You should be able to get the fuel totally dialed on the street, then spend an hour on the dyno finding det and/or MBT at various RPMs.
#34
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which could explain the nice bump in torque in the 4K range and the sudden drop after 6K.
#36
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okay, then nevermind... pretty sure if the butterflies are kept closed past 6K the tq drops off like crazy.
but it appears with boost it doesn't effect it: https://www.miataturbo.net/showpost....6&postcount=14
but it appears with boost it doesn't effect it: https://www.miataturbo.net/showpost....6&postcount=14
#37
I saw this on another forum and thought I'd throw this out there since you're semi-local and there aren't too many dyno days this time of year. Apparently they're just putting it together, I'm sure more info will be available soon...
http://jnjperformance.com/default.aspx
J&J Performance is holding a shop meet and dyno day on the 24th of this month. $35 for two dyno pulls with no AFR.
From 4:00pm-10:00pm.
From 4:00pm-10:00pm.
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