Hey all, just put my new setup together and having a few tuning issues i was hoping somebody could confirm some theorys for me.

Here's my setup

B20B4 block Stock except ARP rod bolts

B16a Gen1 Stock head everything except cam gears

Custom made 45mm itb's scrounged up out of RB26DETT throttles and B16a manifold

Link engine management ECU running wasted spark

440cc injectors

Xforce header

I am in the early stages of tuning and seems to be running quite rich in the upper rev ranges and i think it is due to poor fuel atomisation.
I think the main cause of this is because i am running the injectors in the standard location.
My question is, If i were to make a plenum for the itb's would this help my current setup or do i just make a new manifold with the injectors further upstream from the head.

Any advice would be greatly apreciated


Modified by hellbound_hayride at 9:03 PM 11/26/2007


Modified by hellbound_hayride at 9:04 PM 11/26/2007

 

Anyone got any advice??

 

im in no way fashion or form an itb guru but post some pics for these guys to get a better idea of what you want to do...

 

You have fuel control right? Try taking fuel out of the area of the map you are running rich. Just a thought.

Unless you are using ****-poor injectors, atomazation is not an issue.

 

working on photos as we speak.

Yeah have fuel control and am constantly fine tuning, it's getting better as we take fuel out but seem to be well down on power for some reason. from my own research on itb's im thinking that the injector location is the issue just hoping someone can confirm my thinking.

 

the injectors are placed close to the flange like this?

 

Yes the injectors are set up exactly the same to that to that. what are the throttle bodies being used on that unit?

 

The TB's in the pic are off a 20V 4AGE,your setup is using 440cc injectors and the engine is very close to STD I would have used 310cc in a setup like yours and have never found the Link ECU to be a good unit with a setup like yours.
Regards Dyno Dave

 

I agree ^^^ If it's a fuel atomization problem it's not the placement of the injectors that is causing it, it's too much fuel. I have seen dyno sheets of ITB's thrown onto a stock motors that have actually caused a drop in HP & torque numbers. Throttle response was better but other than that there were no gains.

What are the specs for your ITB's. I see that they are 45mm ID but how long are they from the intake valve to the end of the trumpet? This measurement can have a significant effect on what RPM range you are going to see your power. Usually the shorter the runner the higher up you are into the RPM range for power.

Can you post up any pics of your setup?

 

I thought they were 4AGE ones. im working on getting pics but not having much luck. anyone know of a good free image hosting service??

 

I did think that the 440's might be a bit excessive, but i had them lying around so they went in for the mean time.

At present the length from head face to butterfly is 150mm and to the end of the trumpet is 200mm. im not exactly sure on distance to the valve at this point.

If it were to be an issue with runner length then would slapping a plenum help the situation??

 

Photobucket is a good free image hosting site; http://photobucket.com

Adding a plennum may work as a sort of extention to your runner length. You will have to figure out what length and diameter plenum suits your RPM and power goals. The addition of a plenum will restrict the response of the ITB's somewhat.

How rich are we talking here (9-11 AFR) If you add a plenum you will probably run just as rich you are now. Remove some fuel from your High RPM low AFR's before you add your plenum and see if that helps. Rich is better than lean.


Modified by GhostAccord at 10:06 PM 11/27/2007

 

finally pics





As far as how rich, well at WOT my A/F gague goes straight to 10 which is it's richest reading so what the actual is at this point im not sure. At partial throttle im seeing around 11.5-12.3 but seems to run strong, im having the most issues at around 6200rpm where it develops a bit of a miss and continues through to redline which is currently 7500rpm

 

Interesting car!

What dyno are you using?

You a member on nzhondas.com? Havent seen that car before on it.

 

Thanks.

Aaaahhh, road tuning with laptop and link hand control.

I lurk there every no and then but not a member, i only have hotmail so it won't let me join.

 

Nice looking DIY setup!

@ WOT I'm pretty sure that the ECU is going to dump more fuel in automatically. I'm not familiar with the link tuning system that you are using. As long as you can remove fuel from the upper rpm ranges all is good. Adjust your fuel maps so that your running WOT at 11:1-13:1 and have your idle and cruising AFR's somewhere around 14.7:1 (stoich). In doing this your injector duty cycle will be lowered and they should run a bit cooler....not a big bonus but at least your not maxing them out and flooding your engine.... As well you should regain a bit of that lost seat dyno power.

one other note, If you are planning on running these ITB's with filters or a plenum you should do your tuning with them on.


Modified by GhostAccord at 12:27 AM 11/28/2007

 

I would say you'd be bang on the mark with that call, it's getting better every day as we take more fuel out up top. Idle is well sorted and sits at 14.5-14.8 all day and crusing seems to be spot on as well.

Yeah i run sock style foam filters on each runner, they are on and have been throughout tuning, photos are a tad on the old side.

 

wtf is the opening on those damn things, looks too small to me.

 

is your link tuning system map or tps based?

 

Both i think, i know we started with just the map then added a TPS aswell. we may be just running of the TPS now im not 100% sure.


With this setup what would be a safe rev limit and what sorta revs should i have VTEC engage at, currently at 5k

 

The inlets for those ITB's look like crap. Air flow into them is going to suck; you need some kind of velocity stacks to improve air velocity and volume.
The diameter looks pretty small to be feeding a B20VTEC engine as well.

 

I agree that velocity stacks would help the flow.

You don't think that approx. 380cfm per runner is enough for a B20 with a B16a head. Stock that head flows approx. 241.8 cfm @ 0.598 lift. I think there should be enough air flow there for him. I don't have a flow bench so I'm just going by previously posted flow numbers.

Does anyone have any flow bench numbers for 45mm vs 50mm?

 

Agreed, velocity stacks are on the cards, just tryin to figure out all the changes we are going to make and do it all in one hit. will probably start from scratch.

You were saying earlier that you have seen itb's on stock engines lose power, what would be the most beneficial to start with to get the best of the itb's. compression or cams?

 

easiest? cams...let the engine breathe

best? cams and compression

but those throttles are a little on the small side

 

45mm too small?? i wouldn't think so.

both cams and compression are on the list of to-do's it's just a matter of cash flow