VAFC Tune... Vtec Dropped to 3200 RPMS. Ummm..
05-20-2011, 12:38 PM
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VAFC Tune... Vtec Dropped to 3200 RPMS. Ummm..
Ok, got the car tuned today. Nice group of guys... but seems they haven't messed around with VAFC's much / Honda's much.
My mods are as follows:
K&N FIPK
PLM HEADER
Cut-off Exhaust Mod.
VAFC II.
Anyway, while the car was being tuned, I asked the tuner where he had the Vtec engagement point at because I couldn't hear the actual cam engagement. Turns out they had it at 3200. I said, "I've never heard of anyone putting it that low before... ever." So, I told them to put it at 5400 just to humor me. The car lost power virtually everywhere... never left the dyno. Significant power and torque loss.
So, the car has been tuned with a wideband and averages 12.4-12.8 and spikes to 13.1 at one point. Regardless, safe (Air/Fuel wise). Safety is important because I don't have the coin to replace an engine anytime soon.
I did some quick searches online when I got back home from the Dyno... and it seems like the consensus is that a Vtec engagement that low might detonate the engine because of a lack of adequate oil pressure.
I called the shop and told them my concerns and they are completely willing to throw it on the Dyno tomorrow and re-tune the car for a higher Vtech engagement. As I said, really nice guys.
I'm happy with the #'s as long as a Vtech engagement at 3200 isn't going to detonate my engine. Would love some feedback.
My mods are as follows:
K&N FIPK
PLM HEADER
Cut-off Exhaust Mod.
VAFC II.
Anyway, while the car was being tuned, I asked the tuner where he had the Vtec engagement point at because I couldn't hear the actual cam engagement. Turns out they had it at 3200. I said, "I've never heard of anyone putting it that low before... ever." So, I told them to put it at 5400 just to humor me. The car lost power virtually everywhere... never left the dyno. Significant power and torque loss.
So, the car has been tuned with a wideband and averages 12.4-12.8 and spikes to 13.1 at one point. Regardless, safe (Air/Fuel wise). Safety is important because I don't have the coin to replace an engine anytime soon.
I did some quick searches online when I got back home from the Dyno... and it seems like the consensus is that a Vtec engagement that low might detonate the engine because of a lack of adequate oil pressure.
I called the shop and told them my concerns and they are completely willing to throw it on the Dyno tomorrow and re-tune the car for a higher Vtech engagement. As I said, really nice guys.
I'm happy with the #'s as long as a Vtech engagement at 3200 isn't going to detonate my engine. Would love some feedback.
05-20-2011, 12:43 PM
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Also,
question about air/fuel. With the VAFCII it seems that even though I set the wide Throttle position at 80%, even if I'm at 40% throttle it still engages Vtec at whatever the Vtec is set at. i.e. I have vtech at 5200 rpms and am barely touching the trottle, hit 5200rpms and it switches to Vtec. Am I missing something? I just don't remember it doing this before the tune.
question about air/fuel. With the VAFCII it seems that even though I set the wide Throttle position at 80%, even if I'm at 40% throttle it still engages Vtec at whatever the Vtec is set at. i.e. I have vtech at 5200 rpms and am barely touching the trottle, hit 5200rpms and it switches to Vtec. Am I missing something? I just don't remember it doing this before the tune.
05-20-2011, 02:26 PM
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05-21-2011, 05:57 AM
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A quick search resulted in this: http://www.hondata.com/forum/viewtop...p=40697#p40697
Granted they're talking about a Civic, but I would imagine that the first statement holds true either way.
Granted they're talking about a Civic, but I would imagine that the first statement holds true either way.
05-21-2011, 05:58 AM
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Once my engine is fully warmed up, I see between 75-85psi of oil pressure by 3k rpm. Thats plenty of oil pressure for vtec if you want it set to 3200. I have mine at 4600, but hey if your seeing gaims with it set that low then go ahead and leave it there. Especially if you Auto-X which it looks like you do from your sig pic. It may actually be beneficial then to leave it way low like that so you arent switching back and forth between cams every time you lift off the throttle.
05-21-2011, 06:03 AM
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O and I also have my high throttle set to 80%. My low throttle is set to 40%. I wouldnt set the low throttle any lower than that or when you upshift and the mixture leans anyways, if your pulling any additional fuel it was cause you to go too lean and the engine to hesitate and lose power when your just trying to cruise around. So low throttle set to 40-50% and high to 80%. Thats also normal to see the car jump into vtec even with just a blip of the throttle if your within the rpm window.
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05-21-2011, 07:19 AM
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O and I also have my high throttle set to 80%. My low throttle is set to 40%. I wouldnt set the low throttle any lower than that or when you upshift and the mixture leans anyways, if your pulling any additional fuel it was cause you to go too lean and the engine to hesitate and lose power when your just trying to cruise around. So low throttle set to 40-50% and high to 80%. Thats also normal to see the car jump into vtec even with just a blip of the throttle if your within the rpm window.
Thanks!
-Mike
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