RedBadge

I recently did a few runs on the dyno with a 99 Civic Type R. When we swapped the engine, it immediately went in with a so called Mugen ECU, CAI, 2.25" exhaust from the cat back.

Anyway the car put down 158hp at 8500 rpm (real rpm) and 109 torque... both to the wheels on a 2 wheel dynojet. Anyways it's a CTR engine so the rev capability is better than that of the ITR, and I assume because of the better bore/stroke + lower compression and same built block as the ITR bottom.

I was wondering if having a air/fuel ratio ranging from 13-13.3 is good at RPMs between 7800-8600. The powerband never fell off, not even at 8500, and I thought I was being safe, I should have revved to 9000rpm on the AFC and see until when the powerband began to drop and really see what MAX whp is. It feels like the powerband begins to fall around 8700rpm (on VAFC) when driving... but anyways..... I dont know much about air/fuel ratios...... when it comes to what's too lean or too rich for certain setups. The tuners on hand liked the air fuel curve from the runs, they said I guess it was very smooth. But I was with my friend who also just was dyno tuning his Protege 5 wagon with a bolt on turbo kit.. and when the air/fuel ratio went above 12 they said it was too lean. Yet these guys were saying that me having 12 -13.3 from 6000 (vtec engagement) to 8500 was OK. I did always think the car ran rich from day one, but it ran great still and the powerband is great with the setup but after seeing the air/fuel from the dyno I was a little concerned.

Anyways I have a VAFC2 (dyno tuner said that me making the mixture richer at the top of the power band I could still gain something extra even though the program on the ECU had a good air fuel curve already) {he never said anything about it being too lean for safety}. I turned up the fuel 2% from 7500 - 9000 rpm. I know it will never be as precise as getting a tuner to actually make changes on a dyno but..... I don't have the money now and I'm concerned whether I have to worry about being safe with the 13.3 air fuel ratio at about 7000 rpm and above. Would the dyno tuners say it was OK because it was a Civic Type R block? and maybe they thought it could handle a leaner mixture?

My old engine died on me because of lean conditions and I want to avoid a lean mixture at all costs, so your advice is appreciated

Thanks

Dr Pooface

Comparing a/f ratios between a turbo and a NA car is like comparing apples to oranges. Turbo cars generally like to run richer under full boost to help combat detonation. On a NA car detonation isn't as big an issue, so they can run leaner for more power.

PS separating your post structure into smaller paragraphs makes it much easier to read.

ZygSpeed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Waterman128 &raquo;</TD></TR><TR><TD CLASS="quote">I was wondering if having a air/fuel ratio ranging from 13-13.3 is good at rpms between 7800-8600. </TD></TR></TABLE>

Seems like that would be fine for you.
You're good to go.

Nvious R

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">Seems like that would be fine for you.
You're good to go. </TD></TR></TABLE>

What kind of numbers were you looking to gain, it looks a tad low for those mods.

ZygSpeed

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nvious R &raquo;</TD></TR><TR><TD CLASS="quote">What kind of numbers were you looking to gain, it looks a tad low for those mods.</TD></TR></TABLE>

CTR = 1.6 L

IN VTEC

iTrader: (3)

The absolute air to fuel ratio numbers don't really mean much except as a guide while tuning. What you're actually looking for is mean best torque to rich best torque to be on the safe side.

MiraiZ

Try a CTR ecu?...if you need one let me know