Installed the MD 5/16 ISO this weekend - after the install I went out for a 5-mile nice drive just to be sure everything was nice and set and then I went WOT and well........I'm not that impressed. Does the ECU need time to learn the new fuel/air ratios before the hp jumps up - or did I some how manage to flub up the install? I don't feel 12-15hp.....

 

Did you happen to reset the ECU?

 

not unless I did it w/o knowing - was I suppose to, as I did not read that in the directions?

 

I'm not sure of an ECU reset is necessary. The ecu is capable of retarded timing if low octane gas is used on the fly...so more air flow shouldn't necessarily require a reset.

As far as feeling the 10-15hp...in an 5AT the hp is probably harder to notice due to a slight disconnection from the power unlike in a manual. That and 10hp...added to 280hp...not very significant...my butt isn't that sensitive

I don't have my spacer installed yet though, so I could be entirely wrong on all of this!

 

I am only running 87 Octane as that is all I ever run.....

 

then you car is already pulling the timing. Stop wasting your money moding it if you arn't even using the proper gas. It's not that hard. The manual and gas tank both say <basically> 'INSERT PREMIUM UNLEADED HERE STUPID'

lol


don't know about later years, btu there's an immediate effect on 03s above 4k - before when it'd rev that high it'd feel like it would choke off, like it wasn't getting enough air. Now it just rips through. Very good mod, a/t or m/t

 

I can understand that most people will feel it and some people won't, but in every case, the gains are guaranteed to be there.

 

Why buy mods if you're going to skimp on gas? You're already shooting yourself in the foot performance wise if you do that. Start putting at least 91 in.

Maybe you don't feel it as much because power is added across the rpm range, not just up top.

 

FYI, if the VQ35 is anything like the VQ30, you're loosing about 10-15whp from 5000rpms+ running 87 octane.

 

Exactly.

 

Many people run regular on the G because it 'seems alright'. Using the butt-dyno to save themselves money, while the engine is never running optimally.

 

The car and the gas are paid for by my company (mods by me) and at the 3k-4k miles I drive a month the costs of Regular vs Super adds up fast. I'll throw in a tank of 91 next time around and see what that does.

 

It does make sense that you will notice more of the spacer effects by using higher octane gas.

Reason is that your ECU is pulling timing based on the amount of ping it hears in the engine. So even if you can flow more air with the spacer, the weak link in the system is the fuel which effectivly puts a glass ceiling on the power output.

By taking out the fuel based power limitation, the new limit is set by air flow capasity/efficency. And this is where bolt on's have their effect.

 

Now this is the type of answer I was looking for. THANKS Motordyne!!

 

I don't have mine around now but I'm quite sure it was in the instructions.