OFT Tunes - V4 uses the same tune for both EL and UEL header designs?

[InstaGib]

I've been doing quite a bit of reading leading up to the spring, when I plan to do summer tires + alignment + brakes + Tomei UEL headers + OFT tune. Now I understand that the V4 tunes use the same tune for both EL and UEL headers, but my question is why/how?

In the past these were broken out into separate tunes, which makes more sense to me as wouldn't the exhaust valve timing be different? I've also read that V4 suffers from worse fuel economy, so now I'm wondering if I should just stick to the V2 tunes, or if there's just something I'm not understanding here.

I've tried to search for some info related to this, but I'm having some trouble digging through posts, so please feel free to redirect me if this has been discussed in detail before.

[steve99]

Yes you could use older v2 tunes

[InstaGib]

Originally Posted by steve99

Yes you could use older v2 tunes

Sure, I understand that, but why the change at all? If the tunes could have been the same between header designs without performance/reliability concerns, then why were they originally split into EL/UEL specific tunes?

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[tomm.brz]

i think v4 are mostly tuned for OFH uel header
if you use them with other headers is mostly a compromise

[InstaGib]

Originally Posted by tomm.brz

i think v4 are mostly tuned for OFH uel header
if you use them with other headers is mostly a compromise

Do you have a source for that? This is the first time I've heard of this, and I can't even find anywhere to buy the Open flash Header any more.

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[tomm.brz]

mostly because the cam timings for. v4 are identical to the OFH v2 tunes Shiv released time ago

[steve99]

Originally Posted by InstaGib

Sure, I understand that, but why the change at all? If the tunes could have been the same between header designs without performance/reliability concerns, then why were they originally split into EL/UEL specific tunes?

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their is some advantage having specific cam timings for each type of header, but the difference is not great unless you have very different design header like ace or p-tuning


saves time not having many different tunes for little advantage

[InstaGib]

Originally Posted by steve99

their is some advantage having specific cam timings for each type of header, but the difference is not great unless you have very different design header like ace or p-tuning


saves time not having many different tunes for little advantage

Okay, that's kind of what I suspected then, thanks.

Are there changelogs or anything like that, that I can read over?

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[steve99]

Originally Posted by InstaGib

Okay, that's kind of what I suspected then, thanks.

Are there changelogs or anything like that, that I can read over?

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The older v2 tunes came with a readme file but not the V 4 only jnfo will be on the openflash support website or compare v4 tune to stock rom in romraider to see changes

[thornad]

I've got a TOMEI EL header, and using OFT v4.3 Stage 2+ at the moment, but from what I read on the forums, it seems the v4 Stage 2 has the AVCS of v2 EL tune, while Stage 2+ is closer to v2 UEL AVCS.
The only difference in v4 between Stage 2 and Stage 2+ seems to be the AVCS and Primary Open Loop Fueling tables.
So, for a decat EL header would it make sense to use Stage 2+ (which is for decat ) but with the Stage 2 AVCS ? Or same thing, the Stage 2 tune (EL) with the Stage 2+ POLF table (decat) ?

[tomm.brz]

try EL cam timings from stg2 V2
they work good

[NicFromTheNorth]

@thornad, which AVCS tables did you end up using?

[J95]

Originally Posted by tomm.brz

try EL cam timings from stg2 V2
they work good

Do you mean stage 2 works better than 2+ for EL decat headers? I have some EL 4 2 1

[thornad]

Originally Posted by NicFromTheNorth

@thornad, which AVCS tables did you end up using?

I got a Wayne tune eventually, but I did try the v2 EL AVCS tables and liked them better than v4 (everything else was v4).