To tune or not to tune..

Not true.

Without going too deep the whole octane thing (there are many threads on that already), Octane acts as a delay fuse. The higher the octane, the higher the pressure the fuel can endure before autodetonation. The 3.5 ECU can sense the type of fuel and compensate timing (ie compression) to match. However, it doesn't take advantage of running higher octane fuel. On the stock Tacoma, running 87 gives the same performance as 91.

Some aftermarket tunes do take advantage, but at the disadvantage that is not as flexible with fuel choice. You tune for a specific octane and stick with it. (at least it used to be, I'm not up on the latest tunes)

 

It damn sure won't alter compression. That's determined by bore and stroke primarily and very little by cam profile. The tune can do nothing with these. I doubt the tunes even affect the cam timing advance and if they do it would only be how soon the advance hits, everything else is mechanical.

 

I know what you're saying, but cylinder pressure can absolutely be altered by the intake cam timing on the 2GR-FKS. And yes, the tunes can definitely affect cam timing (via phasers).

 

Yes, octane allows higher compression and delays the onset of detonation.

Timing has absolutely nothing to do with compression. Nothing. Timing is the point in crankshaft rotation the the spark is made to start the burn. Starting the burn sooner (to a point) will help insure that maximum cylinder pressure occurs just after TDC, which makes the most power of the burning gas.

 

No offence to anyone but I do not trust these KDmax, kruzer or whatever else they are called. These tunes were made from OV tunes SFOB. Mat from OV tune knows his shit and I only trust him.

I settled on premium SFOB, I haven’t even tried premium base tune, SFOB have been that great.

 

I’ve got about 600 pounds of extra weight and e load 33s. I can still get better than advertised fuel economy, go figure.

Of course, I drive very conservative but still.

 

Its always those that think their smarter than the engineers, you need to look out for. Toyota needs folks like you.

 

All tunes for the 3rd gen are built on the same platform as you know (VFTuner - which is Mat/OVTune). Since KDMAX Pro, and its improvements up to the current release, are built from VFTuners supplied base stock files what's the concern?

 

Yes, intake cam timing absolutely alter cylinder pressure, that's why you feel the kick in the pants @ about 3600 RPM, which is when the VVT advances the intake cams. I haven't read where anyone claims to be altering when VVT occurs (which does happen in the ecu) and I don't believe they can alter how fast or slow VVT happens. That's done by oil pressure and a valve. When VVT occurs would be dictated by cam profile and maximum benefit would probably be a small window of RPM.

The tunes affect spark timing, because that's controlled by the ecu and would be tied to throttle position among other parameters.

 

I know you are happy with your stock tune, so I was i.

Drive a tuned truck and see how much better all around it is. My engine even starts quicker and it idles smoother, that says a lot.

Edit: stock tune on my 2007 4.0 SOHC Ford engine was smooth as butter. I understand it is simpler engine but still. Fords tune just felt way more refined that my tacos stock tune.

 

We can alter when (RPMS) the VVT kicks in but to date it's an on/off switch so far.

 

There were some bricked ECUs from shared tunes, not gonna name then.

I simply don’t trust TW tuners. Mat is a professional and does this for a living.

 

Yeah, I've been wanting to tune and will probably go the same route as you but its almost overwhelming when there's a new tune popping up every few months.

 

Me and my 325+ happy owners would like your trust as we professionally offer products licensed from Mats tools via the KDMAX Pro group. This....is me: http://www.tacomatuning.com

I'm not saying don't be weary...trust be verify is very important. I just tune a customer who was very unhappy with their custom tune that got at a cut rate a few months ago. The "tuner" did not even unlock the VIN. So yeah, there are bad apples out there....but please consider the good apples....they work hard and support those who are looking for a solid improvement in their trucks.

 

Again, that's just not true anymore. You're forgetting that by default this engine can adopt a pseudo Atkinson cycle, delaying intake so that essentially half of the stroke is empty. The ECU controls the valve timing and can use it to alter detonation pressure. It's not just spark advance anymore.

 

That's my understanding of the VVT, that at a certain RPM range, a signal is sent to open a valve, which supplies oil pressure to the advance mechanism, which would make it either on or off. I say range, because there are probably several parameters which would help define optimal occurrance of cam advance. I've noticed mine hits between about 3550 and 3850, depending on how hard I'm in the throttle, rate of acceleration, and gear to name a couple.

 

KDMAX Pro and it's prior releases have been around for years now. With thousands of trucks on the road and improvements at the VFTuner platform gives us more to work with I can see the offering improving wherever we can. There are some solid choices out there but we continue to work hard to provide the best support and tune improvements possible. We are here for you if you are looking for a solution!

 

I know there are tons of happy customers and that’s awesome. Keep it up.

Still though, i would never flash a shared tune. I’m a strange guy haha.

 

I know, there are dozens out there now.

I’m very happy with premium SFOB on 94, my truck is a freaking beast on it, even with all this weight.

 

VVT advances the intake cams to open the intake cams earlier when the engine gets to a point that it needs to breath sooner to maximize intake charge and velocity.