Harrop Eaton TVS Supercharger

I'll leave this one to the experts... as in, those who have an intimate understanding of the engine and code.

*cough* @OVTune *cough*

 

OVT deleted it as an option on the MT tunes. It is a simulated Atkinson cycle. It is only in that cycle for part of the rev range even on the stock tune.

 

Yeah...

 

Literally just a few posts up dacon said "CAN NOT", as in "impossible". Whether or not Magnusson has given up is a different matter since they don't seem to want to comment on the development. I don't care if I can get a supercharger from Magnusson or Harrop I just want more power out of this aluminum can engine. Some people are satisfied with the power output from the stock engine. Good for them. Everyone is different.

 

Lol yeah but he don’t count


Missed that post, apologies. 1 person thinks it’s impossible and another thinks you just shouldn’t

 

I'm waiting for the diesel taco. Then it'll have a turbo already. I'll just have to swap it for a bigger one. Then add propane Injection.

 

Ha! Yup and they're welcome to do what they want with their rig. I just wanted to dispel any misinformation.

 

Just look at the amount of time and research the ov guy has done to get a stock engine tune. Any fi platform will take even longer since you have less of a baseline to work with.
Soon someone will put fab with the tuning and get something out. From what I read think the ov guy is looking for fab help so should be soon.

 

Harrop is an Australian company......and we know how they do super chargers down there......clutched for the MPGs.

 

The cam shaft is variable timing , controller by the ECU, using electric oil pressure solenoids to control the valving via a very interesting oil-actuated device that is fully explained in the vid I linked.. The ECU decides when to advance or retard the timing. It is not a physical function of the cam lobes. Dual VVTI just means the ECU can control both intake and exhaust valve timing.

The engine is called a “simulated Atkinson cycle” because is it physically just an Otto engine. The simulated Atkinson cycle is turned on and off by the ECU via programming. Those wishing for a “good old Otto” already have that under the hood, and most the time the 3.5L engine just runs the Otto cycle.

If you can reprogram the ECU, successfully, you could theoretically disable this feature. All super charger kits come with new ECU tunes, even for normal cars. My understanding is the new 3.5L OEM tune is very complex and may be more than some option houses want to bother with.

This video is the best one I’ve found to explain how the Toyota VVTI Variable Valve Timing works. I realize it’s filmed in a junk yard in Russia, but this is truly great resource. If you watch it, you will understand how an engine can be a “simulated Atkinson cycle”, and how reprogramming could also prevent that valve timing sequence from being callled for.

Best information on the net to explain VVTI vvvvvvv

https://m.youtube.com/watch?v=T0G5KLN4a_w

 

I’ll add that it’s not in Otto most of the time, really depends on your demand. Don’t try to fancy it up, if it ain’t managed as an Otto, it AINT an Otto.

If it WAS as simple as calling it an Otto, there would be 75% less complaint threads.

Y’all just CAINT

 

It is an Otto cycle engine, full stop. The “Atkinson” thing is the tarting it up, which is why they can’t call it an Atkinson Cycle Engine (because it isn’t) but must say “Simulated”.

You’re a smart guy but you got this backwards. You gotta get back on your game.

Time for a test: man or woman?

 

Irrelevant because I DO NOT CARE if it’s a man OR a woman.

Check. Mate.

 

The correct answer was “your mother”

 

***
SHIT
she+he=it. The new gender...

 

I see your point. I will counter with-

Your trucks engine has an infection. Remove it, then you can get the fake boobs.

 

Will you still have to press the ETC Button?

LOL!

 

When I got my first Tacoma at 18 years old (a '99 Prerunner) I actually thought the ECT button was a button-activated supercharger, man I got ripped to shreds on Yotatech when I talked about it on there. This was back in 2004, pre TW days.

There I finally got that off my chest

 

Here are some gifs of actual Atkinson cycle engines that do not use VVTI to simulate different compression and expansion strokes via VVTI and an Otto engine. These are the real deal.

It would be cool if a true mechanical
Atkinson engine was what was under our hoods:


His first design (using opposed pistons to change the size of the combustion chamber during the stroke)


And his second design, using two crankshafts to again change the size of the combustion chamber during the cycle.