OVT tune group buy

[MikeM.]

What would need more maintenance? You're just fiddling with settings to allow it to take advantage of a higher grade of fuel.

Think again. When Mazda tuned the Euro spec CX-5 for high octane fuel they managed to get 6 more HP out of it. If the marketing claims are not exaggerated (and I've already shown they most certainly are) then of course it's going to increase wear and maintenance requirements.
There is no free lunch.

 

[Unobtanium]

Skyactiv-G engines have not had a carbon build-up problem that I'm aware of. And we have members on this forum who drive short trips in Canadian arctic weather. Someone in more normal driving/weather conditions doesn't need to worry. Of course, all bets are off with a tune that likely puts HP/torque as a priority over carbon build-up. A small tuner doesn't have the resources to determine under exactly what conditions of temperature, rpm, throttle, valve timing, etc. carbon forms and it would be counter-productive to performance to tune around carbon deposits.

...and this is my main concern/only concern with this tune. Has OVT addressed this in some way?

 

[Chris_Top_Her]

I'm approaching 50k of daily hard driving, I've used a GDI valve cleaner once (prior to adding my catch can), but I've never actually removed the mani to look inside. The jbr catch can I installed caught some oil/blow by ((2thumbs) that much less oil vapor into my cylinder for maximum power), but I also spend a lot of time at high RPM and high Manifold pressgure (indeed, you can easily get close to no vacuum just by going over 3000 rpm). I was trying to find the post where a stock mazda 3 had posted his "catch" but I'm having a hard time doin so.
However I did come across this thread while searching that pretty much sums up OVtune viability. http://forum.mazda6club.com/2-5l-i-...5g-skayctiv-results-technical-discussion.html

It's a VERY detailed account of the OVT tune (on a 2.5 mz6 sky), and even has 4 or 5 links to other users who also reviewed their own tune, within the first post.

 

[Unobtanium]

I'm approaching 50k of daily hard driving, I've used a GDI valve cleaner once (prior to adding my catch can), but I've never actually removed the mani to look inside. The jbr catch can I installed caught some oil/blow by ((2thumbs) that much less oil vapor into my cylinder for maximum power), but I also spend a lot of time at high RPM and high Manifold pressgure (indeed, you can easily get close to no vacuum just by going over 3000 rpm). I was trying to find the post where a stock mazda 3 had posted his "catch" but I'm having a hard time doin so.
However I did come across this thread while searching that pretty much sums up OVtune viability. http://forum.mazda6club.com/2-5l-i-...5g-skayctiv-results-technical-discussion.html

It's a VERY detailed account of the OVT tune (on a 2.5 mz6 sky), and even has 4 or 5 links to other users who also reviewed their own tune, within the first post.

Interesting. No issues using a valve cleaner with this DI motor?

 

[Chris_Top_Her]

Nope. Just have someone ready to apply light throttle if the engine tries to quit. I prayed it in through the pcv line connected to the intake tube. Then you just drive around For a bit, moving up to highway speeds to remove any cleaner/loose junk from the engine surfaces.

 

[Unobtanium]

Nope. Just have someone ready to apply light throttle if the engine tries to quit. I prayed it in through the pcv line connected to the intake tube. Then you just drive around For a bit, moving up to highway speeds to remove any cleaner/loose junk from the engine surfaces.

So, like Seafoam?

The tune is very tempting. Do you know what kind of gains their "bench tunes" net? I don't have a laptop.

 

[Chris_Top_Her]

So, like Seafoam?

The tune is very tempting. Do you know what kind of gains their "bench tunes" net? I don't have a laptop.

It's different from seafoam as is specifically for the valves; it's not made to be put into a gas tank etc like you can with seafoam. This is a what was called a "stage 1" (not custom dialed) map from a Saudi dealer.. less than 91 this just was posted a bit ago.

 

[Unobtanium]

Does mileage improve?

 

[CX5_Pete]

I've been doing some reading and it seems like it got a lot of people interested. Cant wait for a magazine or other 3rd party to verify.

 

[Chris_Top_Her]

Here is one from a saudi dealer, 89-91 blend, off the shelf map (not custom tuned). The curve overall is increased giving more power (driveability) through the rpm range. Also unob looking at the gauge, mp is as low a 5inhg while crusing at 1500 rpm. So at wot or high rpm I can guess the chance of blowby is high. I'll update if I ever find that thread. Here is that dyno sheet I mentioned. Peak gains across the map are over 20. And this is not a custom tune which gives you most gains. Remeber the custom tune is based off your datalogs; ie your driving habit, chosen (consistent) fuel octane, mods, tire/wheel size etc.. things that affect engine load under a given driving condition.

 

[Chris_Top_Her]

Does mileage improve?

Others have reported at least the same to a gain. My average mpg hasn't changed much from what it was before. Around 23 24mpg average, actually the same as my 2.p0op. I don't really drive for mpg specifically, ie a low speed but I do maintain speeds for more consistent mpg when high speed cruising. On the otherhand if I want to get some better mpg I can get a consistent 28ish mpg with the cc on at about 65.

 

[Chris_Top_Her]

Unob i did a short test. 28.8 average mpg over 8 miles with 65mph avg speed. Indicated 74f, probably slightly higher density altitude than standard due to temp and humidity. Highway driven with plenty of elevation change. Cruise controlled. 68mph max, approx 62 low with no hard throttle. One exit/on ramp. I stopped it after i left the highway and had to slown down to city speed. Thats a custom tune (on 93), sri, catback, taller and wider wheels and tires ALL windows down, roof full open, roof rails hood deflector, oem mudflap i weigh 150lb plus 50lb or so hitch, 50lb or so of audio equip including sub/box ( no spare) and about 50 lb of baggage and grocery. All considered drag wise and weight wise i dont think i was at a loss for mpg anywhere. I'd wager the stock induction probably maintains more vacuum at low throttle for better mpg gains. City driving varies too much imo to even make a meaningful estimate.

 

[Unobtanium]

Others have reported at least the same to a gain. My average mpg hasn't changed much from what it was before. Around 23 24mpg average, actually the same as my 2.p0op. I don't really drive for mpg specifically, ie a low speed but I do maintain speeds for more consistent mpg when high speed cruising. On the otherhand if I want to get some better mpg I can get a consistent 28ish mpg with the cc on at about 65.

Sounds like the same as I get stock.

 

[Unobtanium]

Unob i did a short test. 28.8 average mpg over 8 miles with 65mph avg speed. Indicated 74f, probably slightly higher density altitude than standard due to temp and humidity. Highway driven with plenty of elevation change. Cruise controlled. 68mph max, approx 62 low with no hard throttle. One exit/on ramp. I stopped it after i left the highway and had to slown down to city speed. Thats a custom tune (on 93), sri, catback, taller and wider wheels and tires ALL windows down, roof full open, roof rails hood deflector, oem mudflap i weigh 150lb plus 50lb or so hitch, 50lb or so of audio equip including sub/box ( no spare) and about 50 lb of baggage and grocery. All considered drag wise and weight wise i dont think i was at a loss for mpg anywhere. I'd wager the stock induction probably maintains more vacuum at low throttle for better mpg gains. City driving varies too much imo to even make a meaningful estimate.

That's pretty similar to what I get. Close enough that road surface, wind direction, etc. become arguing points.

 

[CC58]

Mazda does a lot of things with valve timing (miller cycle), dual injector cycle, and timing to prevent carbon buildup. I'd be leary of messing with that.

Here are some info:

Carbon Deposit Timing
To eliminate the problem of intake valve deposits that plague current direct gasoline injection engines, the engineers at Mazda determined that deposits are formed when intake valve temperatures fall below 400 degrees C. Measures were taken so that the intake valve would operate above this point to reduce deposit formation.

Valve Timing:
That stratified charge is possible thanks to very fast DI that can inject a little fuel during the intake stroke, then a bit more during the compression stroke, to enable very stable combustion, which in turn allows very delayed ignition timing during cold start.

One other contributor to the engine's efficiency is that it cruises open-throttle at light loads. "It actually runs with the throttle open almost like an Atkinson cycle," Coleman says. “Other companies are doing this as well, but we're more picky about the details. We call it the Mazda Miller Cycle, because the Miller Cycle is our method of obtaining an Atkinson Cycle."

 

[davesxx01]

I've been doing some reading and it seems like it got a lot of people interested. Cant wait for a magazine or other 3rd party to verify.

Well, all the dyno's pictured and reviews are from "3rd party" users. His claims are from what other people and company's have shown. Take Racing Beat's Miata or Good-Win Racing's car.
They both have shown over 40 HP gain over stock,,,,,, with added parts.

Everything shown in links already provided are from other people.

 

[CX5_Pete]

I spoke with someone from Racing Beat and they never dealt with OVT before.

 

[CC58]

No car runs closed loop full time.
All cars run open loop on cold start until the cats heat up and oxygen sensor starts working.

I would hesitate to have a "tune" done on CX-5. Its far more complex than a 1990 Mustang. What problems are possible? Will it cause carbon build up on intake valves? Will it pass emissions? Is it CARB certified? Can you return it to stock for resale? Will it knock causing engine damage? How will engine changes interact with transmission programming? Does it retain the stock cat warm up procedure? Was the atkinson-miller cycle compromised causing it to drop MPG? Then you have the permanent cost of paying for 91 octane instead of 87 octane.

BTW, a "tune" chip on 1990 Mustangs were way over advertised on their actual gains.

 

[Tbot101]

No car runs closed loop full time.
All cars run open loop on cold start until the cats heat up and oxygen sensor starts working.

I would hesitate to have a "tune" done on CX-5. Its far more complex than a 1990 Mustang. What problems are likely? Will it cause carbon build up on intake valves? Will it pass emissions? Is it CARB certified? Can you return it to stock for resale? Will it knock causing engine damage? How will engine changes interact with transmission programming? Does it retain the stock cat warm up procedure?

BTW, a "tune" chip on 1990 Mustangs were way over advertised on their actual gains.

Well sorry for not being more specific. With exception of the time required to heat the 02 sensor on the first cold start, the ECU runs closed loop at any time the engine is running and the 02 sensor has been heated (doesn't take very long).

So far from all of the vehicles tuned globally, the only thing I have ever seen cause an issue is crappy gas quality. Usually only applicable to some international locations.
Will carbon build up on the intake valves? yes, but not at any rate faster than it would stock. (take off your intake manifold and check for yourselves, the skyactiv can relieve some of it, but not all. it still builds up over time).
Will it pass emissions? Yes
Is it CARB Certified? No. People really don't understand just how expensive and the length involved to get it CARB approved. It would cost me more than my entire business work to have something like this CARB approved.
Can you return it to stock? Yes easily. takes flashing your stock map that's it.
Will it knock? Yes and No. All knock is minimized as much as possible but it is practically impossible to make these engines "never knock." they use a very aggressive multi-tiered knock control that is sometimes a little overzealous. So the tune itself wont cause knock, but knock happens occasionally on these engines regardless of what you do. It is so overzealous that it will even "knock" on Pure Ethanol. Which anyone who is a tuner will tell you that is almost impossible to do.
Tranmission programming is unaffected. I know it is something a lot of people request but unfortunately it's controlled by a separate unit.
It does retain ALL stock tune features. BUT the warm up can be disabled (some people really hate the nasty cold start sound with exhaust mods).

I am not trying to over advertise anything, you're more than welcome to look at the various dyno sheets for several vehicles. ALL of which were done on 3rd part dynos.

 

[CC58]

A real test would be before/after 1/4 mile runs at local track. If it really gains 30hp, timeslip should drop three tenths of a second. Of course, the rest of the car would have to remain stock, no removal of spare tire or seats, no other mods to engine, full tank of gas, and stock tires.

Run at least three runs before, and repeat after "tune".

Reason I'm doubtful is back in the day there were "tune" chips for Camaros, Mustangs, and many others. Historically, they all cheated on advertised gains. Its been that way for 25 years.