Revision 3 Stock AFR readings?

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Revision 3 Stock AFR readings?

Post by MR2T_Jake »

Hi all,

Breaking in my new engine and been told small amounts of boost should be given occasionally (0-7psi) and kept under 3500rpm.

It all seems super healthy and has not missed a beat in the 430miles i have driven.

I installed a AFR gauge when the forged engine went in and have tried learning to read it. Been doing well so far but wanted to get a general idea of what other people see.

So a 3rd gear pull up to 3500rpm making around 5-6psi (NOT WIDE OPEN THROTTLE) gives readings between 13-14:1 AFR, 5th pulls give around 15:1 and go to around 14:1 at 5-6psi.

Does this sound about right? I would assume WOT would drop the numbers down to a more rich mixture, but I can't replicate this while I am breaking in :)


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Re: Revision 3 Stock AFR readings?

Post by jimi »

Black is not a colour ! .... Its the absence of colour
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Re: Revision 3 Stock AFR readings?

Post by MR2DI4 »

Your probably going to have to wait another couple of hundred miles and then put your foot down.
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Re: Revision 3 Stock AFR readings?

Post by MR2T_Jake »

MR2DI4 wrote: 27/04/21 19:06 Your probably going to have to wait another couple of hundred miles and then put your foot down.
I am, but wanted to know if these reading are "normal" or "expected" for the conditions im putting it under?
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Re: Revision 3 Stock AFR readings?

Post by Voivod »

MR2T_Jake wrote: 27/04/21 13:25 Hi all,
Breaking in my new engine and been told small amounts of boost should be given occasionally (0-7psi) and kept under 3500rpm.
Who's told you that? Rev2 on freshly build 10psi all day long and at least 4500 to 5500 rpm

The best thing is to take the car on a bendy twisty roads..plenty acceleration and deceleration
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Re: Revision 3 Stock AFR readings?

Post by MR2DI4 »

Probably pays to listen to the engine builder, running in is still a requirement depending on the tolerances its built to. You wouldn't buy a new race bike without a bit of running in and I wouldn't recommend 14,000rpm off the showroom floor. Still not thrashing mine until its done 1500km.
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Re: Revision 3 Stock AFR readings?

Post by Voivod »

MR2DI4 wrote: 30/04/21 2:03 Probably pays to listen to the engine builder, running in is still a requirement depending on the tolerances its built to. You wouldn't buy a new race bike without a bit of running in and I wouldn't recommend 14,000rpm off the showroom floor. Still not thrashing mine until its done 1500km.

Well..that's quite obvious that the engine builder who advised to run the engine at that revs is at least 200 year old..you'll find many of them would tell you to run mineral oil of something like that 90w80 and tell you that modern oils it's to slippery or similar crap. :rofl: This Myths has been Burst at least 20 years ago...again if you listen them you'll walking in sandals in the winter..or even worse.

I don't say that you've to revvs the "censored" out of the brand new engine..but drive it harder then anyone says!
There are some videos... in many manufacturers that test their engines well above what I've mentioned from brand new. Any of that bullshit is a Grandpa Talk!

p.s In fact those that were driving as a Grandpa took longer to break inn :th:
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Re: Revision 3 Stock AFR readings?

Post by MR2T_Jake »

The person who told me my break in procedure is probably one of the best in the Performance Toyota scene, so I think I will continue to take his advice on break in rather than blow a newly forged engine by going against the information given by someone with years of experience in building these engines.
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Re: Revision 3 Stock AFR readings?

Post by jimi »

MR2T_Jake wrote: 04/05/21 11:16 The person who told me my break in procedure is probably one of the best in the Performance Toyota scene, so I think I will continue to take his advice on break in rather than blow a newly forged engine by going against the information given by someone with years of experience in building these engines.
As would I :th:
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Re: Revision 3 Stock AFR readings?

Post by Voivod »

MR2T_Jake wrote: 27/04/21 20:54 I am,but wanted to know if these reading are "normal" or "expected" for the conditions im putting it under
Why don't you ask the person who's build your engine? As you've said earlier "probably one of the best in the Performance Toyota scene" :D

I'm sure he would give you the best and correct answer or explanation..will be better sleep at night too.:laughing
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Re: Revision 3 Stock AFR readings?

Post by Voivod »

jimi wrote: 04/05/21 12:51
MR2T_Jake wrote: 04/05/21 11:16 The person who told me my break in procedure is probably one of the best in the Performance Toyota scene, so I think I will continue to take his advice on break in rather than blow a newly forged engine by going against the information given by someone with years of experience in building these engines.
As would I :th:
Yeah..plain and simple! :laughing
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Re: Revision 3 Stock AFR readings?

Post by MR2T_Jake »

I had asked my engine builder, his answer was that these numbers are fine for the rev range and low boost i am putting through.

But my question was if this is normal numbers for these cars, not what is safe :)
I can't figure out how to put in an image here, so this is my cry for help. :confused1:
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