Hfc to test pipe - retune needed?
#1
Hfc to test pipe - retune needed?
Hey everyone
So I had my car tuned a couple of months ago and just got some more parts, like a jmfab manifold and test pipe.. If I were install them would I need a retune? What about just the test pipe? I know going from a full cat to a test pipe will need a retune but not so sure about a hfc. Thanks for any input!
So I had my car tuned a couple of months ago and just got some more parts, like a jmfab manifold and test pipe.. If I were install them would I need a retune? What about just the test pipe? I know going from a full cat to a test pipe will need a retune but not so sure about a hfc. Thanks for any input!
#2
Evolved Member
iTrader: (2)
Do you have a boost gauge and wideband? I'd monitor that and log if you have the equipment. You may be ok depending on how conservative the tune you have now. But watch for boost spikes and leaner afr's going to the test pipe due to the more free flowing exhaust. Was the hfc a 100cell? You may be fine I guess it depends on how restrictive the cat was also.
#3
Do you have a boost gauge and wideband? I'd monitor that and log if you have the equipment. You may be ok depending on how conservative the tune you have now. But watch for boost spikes and leaner afr's going to the test pipe due to the more free flowing exhaust. Was the hfc a 100cell? You may be fine I guess it depends on how restrictive the cat was also.
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#8
Do you have a dyno chart of your car's pull? Your biggest risk is on a cold day @ WOT. It is already a risk when tuning is done on warm day and driving hard on cold night, so adding less turbo restriction and you have a big risk of throwing a stock rod on a cold day.
https://www.evolutionm.net/forums/evo-dyno-tuning-results/749194-full-bolt-e85-evo-8-a.html
#9
Evolved Member
iTrader: (1)
The manifold should help spool and test pipe will help spool and top end, so you will risk blowing your engine. Your tuner shouldn't charge you the full amount since he will only adjust for faster spool and top end to keep the torque and AFRs in check. Give your tuner a call and ask for his advice. He should know how aggressive his tune is and tell you if he has enough buffer built into his base maps.
If you are going to risk it and not get a retune, make sure you reset your ECU by disconnecting battery.
If you are going to risk it and not get a retune, make sure you reset your ECU by disconnecting battery.
#10
The manifold should help spool and test pipe will help spool and top end, so you will risk blowing your engine. Your tuner shouldn't charge you the full amount since he will only adjust for faster spool and top end to keep the torque and AFRs in check. Give your tuner a call and ask for his advice. He should know how aggressive his tune is and tell you if he has enough buffer built into his base maps.
If you are going to risk it and not get a retune, make sure you reset your ECU by disconnecting battery.
If you are going to risk it and not get a retune, make sure you reset your ECU by disconnecting battery.
#12
Evolved Member
iTrader: (1)
I see you're on SD and using Omni boost sensor. I suggest not going WOT if you install your test pipe. Definitely turn down your boost 2-3 psi try and mimic your HFC conditions. Before your next tune, get rid of your Omni, they are know to fail. Make sure you also upgrade your 1000cc injectors, Walbro 255 fuel pump & rewire for dual 8V/14V, and evo 9 DV (starts leaking around 26psi).
#13
Evolved Member
iTrader: (1)
Speed density is risky because our stock ECU don't have the capacity to tune in 3D. My opinion of running SD on stock ECU is that it is a bandaid fix and isn't worth the risk if your car is making under 550-600hp. Sure, it can be made to run, but it isn't as safe as MAF at metering the air going into your engine. I recommend avoiding WOT and if you must, make sure your boost is (at minimum) turned down to where you were tuned.
#14
EvoM Community Team Leader
iTrader: (60)
With your current setup, I'd retune. An FP Green can move quite a bit of air and freeing up a bit of exhaust restriction could be a substantial change in flow. If the mani is tubular, you will notice a slower spool but better flow at high RPM, so may be in a different part of the fuel/timing maps.
Being SD complicates things a bit more. If the mani is cast, it may (probably) flow enough, especially when paired with the test pipe to be in different load cells.
You can drive around just fine, but try your best to stay out of boost until you get the tuned fixed up.
Being SD complicates things a bit more. If the mani is cast, it may (probably) flow enough, especially when paired with the test pipe to be in different load cells.
You can drive around just fine, but try your best to stay out of boost until you get the tuned fixed up.