B20vtec dyno figures

**Edgeauto** · 13-01-2007 08:30 PM

Hi all, we finally got the LS back on the dyno for a tune. Was wondering what are the latest results for all the other B20vtec out there?

Mods ATM
Mild head porting
Type R cams
Skunk 2 Cam gears
ITBs we made from a set off a 20v Toyota

Prior to fitting the cams we made 123fwkw un-tuned, before the tune we made 129fwkw after fitting the cams and gears but after tuning it we made 133fwkw and gained 10fwkw in the midrange.

U can watch the video @ http://www.edgeautomotive.com.au/Download.html

Cheers Grant

**MaskedAP1** · 13-01-2007 09:17 PM

i have post this at another thread here, not the lastest outcome for the b20vtec, but it worth to check out

**fatboyz39** · 13-01-2007 09:17 PM

nice vid. Stock b20 bottom end?

**Edgeauto** · 13-01-2007 10:54 PM

Yep totally stock. the whole car inc buying it in the first place has cost around $7000

**Edgeauto** · 13-01-2007 10:58 PM

Originally Posted by ProECU

very nice result.

More interesting however is how sensitive your motor apprears to be to lightest changes in a/f

Next time ur on the dyno, tell Brett you want to tune to 13.5 a/f

Sounds and looks impressive. Good Job

We had a play but the gain was minimal

**muhhan** · 14-01-2007 01:28 AM

Just trying to get my head around understanding tuning and reading dyno print outs.

Am I right in saying that the aim is to get the AFR curve to be as flat as possible and you were trying to get the ratio to be 13:1? When is the AFR considered to be too lean? Is there a general rule of thumb? I'm assuming that lean AFR is good up to a point and then if you go beyond it is bad for the engine as it causes too much heat leading to detonation? Do you specifically listen for detonation with any special devices when tuning the car?

Where the AFR started to creep up to 13.5 @ 5835rpm and again at 6660-6945rpm am I right in thinking that the power curve flattened out a little? Are these 2 things related or am I just drawing insignificant/wrong conclusions? Is there any reason why the AFR would start to creep up?

I actually noticed there was less black exhaust fumes as you got further and further into the tune and started to refine the AFR. Is this a direct result of improving/stabilising the AFR?

Thanks for letting me come along and watch. Very informative!

**b20b** · 14-01-2007 05:50 AM

i noticed on one of your dyno graphs that when your engine was near its peak power figure that the curve went flat for quite a while...

i have a b20vtec with quads and it did the same ...when it got close to its peak power the curve went flat and did not drop off for quite a bit longer thean yours..
It had great mid range but i would lose that if i tried to move the peak power up in the rev range to try and get rid of it flat lining

I thought it was starving of air ....thought it was the exhaust tried every thing.... never could work it out
Eventurly took off the quads and super charged it
Torque to burn and it still fells like it NA

**fatboyz39** · 14-01-2007 08:27 AM

Originally Posted by Edgeauto

Yep totally stock. the whole car inc buying it in the first place has cost around $7000

thats very impressive results

**EfiOz** · 14-01-2007 01:04 PM

Good numbers!!

What size are the ITB's? Diameter and length from trumpet to inlet valve?

**Edgeauto** · 14-01-2007 02:03 PM

Originally Posted by EfiOz

Good numbers!!

What size are the ITB's? Diameter and length from trumpet to inlet valve?

dia is 45mm the length is about 300mm, i will get a precise measurement of the length when i get a chance if you want. If you want some pics PM me your email and i will send you some.

**Edgeauto** · 14-01-2007 02:08 PM

Originally Posted by muhhan

Just trying to get my head around understanding tuning and reading dyno print outs.

Am I right in saying that the aim is to get the AFR curve to be as flat as possible and you were trying to get the ratio to be 13:1? When is the AFR considered to be too lean? Is there a general rule of thumb? I'm assuming that lean AFR is good up to a point and then if you go beyond it is bad for the engine as it causes too much heat leading to detonation? Do you specifically listen for detonation with any special devices when tuning the car?

Where the AFR started to creep up to 13.5 @ 5835rpm and again at 6660-6945rpm am I right in thinking that the power curve flattened out a little? Are these 2 things related or am I just drawing insignificant/wrong conclusions? Is there any reason why the AFR would start to creep up?

I actually noticed there was less black exhaust fumes as you got further and further into the tune and started to refine the AFR. Is this a direct result of improving/stabilising the AFR?

Thanks for letting me come along and watch. Very informative!

Your pretty close to the mark, AFRs started aty about 11:1 thats why it was blowing black smoke. The 13.5:1 are there cause we didnt feel the need to change them, they more likely caused raised area rather than the dip.