trouble tunning 660's

[HondaEatingTSi]

well I can tune the high settings fine but at idle it is very lumpy. I have a 2g mas with 2 honeycombs removed. if any ones has any tips other than the ones rre has it would be great

 

[McGruffAWD]

last time i heard you shouldnt remove the honey combos from a 2g mas...i bet if you put them back in all will be well.

 

[Chameleon]

nnnnnoooooooooooooooooooo do not remover the honey combs... you only do that on 1G's mas...
that is your problem put them back in and your car will be fine

 

[BatmanGSX]

These guys have no idea what they are talking about. Yes, you can remove the honeycombs on the 2G MAS as long as you have an AFC. The only reason they say not to remove them is that you really don't need to until you are pulling in 50lbs/min or more and because doing so makes AFC tuning a little more tricky for low throttle, but on a 1G it's going to be tricky anyway because it's a different size than stock. The only honeycomb you need is the big one in the middle, it is mandatory to keep that one so I hope that is one of the two that you kept.

Let's do this logically:

First off, realize that no matter how many mods you have you won't need anymore fuel at idle/low throttle than you do with a stock car, so you need to keep fuel volume near stock.

Okay, a stock 2G MAS flows around 22% more unmetered air than a stock 1G, so right there you are at +22% on the AFC, with all but the center honeycomb removed you get around 5% more so now you are around +27%. But you have 660s which are 46% larger than stock. So you need 27% more fuel but you have 46%, so now you need to go negative on the AFC settings, to around -19%. Is that going to be perfect? No. But it should give you somewhere to start, -19% across the board. Work from there.

Low throttle settings are more mathematical than anything else. Unfortunatly even a stock car isn't going to be perfect at low throttle so that really screws with tuning. Watch your cruising knock, some will always be present but make sure it's not excessive, and also add throttle nice and easy, if you get a lot of knock when the gas is depressed you may need to add fuel to get better tip in, however this is going to screw with your cruising, make you rich, if it was good before. Low throttle = butt.

2G guys are lucky, they can leave the MAS the way it is until around the 450hp mark. On a 1G you start messing with the MAS and the injectors and it screws with everything because while injectors are a known size change the MAS never is.

 

[HondaEatingTSi]

Thank you.

 

[TrustGs-R]

batmangsx:

that's some good stuff, your 'wiseman' title serves you well...but i'm curious what you would think about a good base fuel setting for this setup would be at idle:

-95 4g63
-nd 660s
-nd 150lph pump
-mas screw flush, lower and side hc's removed.

I have an safc and know every car will be different, but i'm still trying to tackle idle fuel, and was hoping maybe you have some insight.

thanks for your thoughts

 

[BatmanGSX]

Low = -43% across. Try that and mess with the 1000rpm setting until it idles. It will probably be higher than -43%.

 

[TrustGs-R]

that's so odd... It seems to not like being under +21 at 1000 low. Any lower and it seems to studder when i try to drive it (in the 1K range).

Did you take into account i have my lower and side HC's removed and MAS screw backed out flush?

 

[fast_talon]

On my 1G I am using:

ND 660's
Walbro 255 HP
2G MAS, Screw is flush, and honeycombs are all intact.

I dont have an afpr yet (on back order). I have my SAFC set to -27 at at 1k. My idle is a little lumpy even at that setting.

 

[BatmanGSX]

Originally posted by TrustGs-R
Did you take into account i have my lower and side HC's removed and MAS screw backed out flush?

Did you tell me you did? Then no, of course I did not. That will give you around 5%. So -43 - 5 = -38. And I already told you it wouldn't idle at -43%. -21 sounds better.

 

[BatmanGSX]

Originally posted by fast_talon
On my 1G I am using:

ND 660's
Walbro 255 HP
2G MAS, Screw is flush, and honeycombs are all intact.

I dont have an afpr yet (on back order). I have my SAFC set to -27 at at 1k. My idle is a little lumpy even at that setting.

2G MAS on a 2G is a lot different than 2G MAS on a 1G. Keep that in mind. Also you guys have to remember that at idle the ECU likes to see between 28 and 38hz. Lets say you have 28 and you take out 43% for 660s, the ECU then sees like 15hz, that ain't gonna fly. The tradeoff is being a little rich at idle.

 

[TrustGs-R]

ya i mentioned the Honey combs in my first post....but that dont matter...i appreciate your thoughts.

I find it hard to believe that i should be at a negative setting on my afc tho! RRE adds +39 on the afc with 550's and a ND pump. I had to add +49 when I just had the pump alone. Does this sound right?

 

[BatmanGSX]

Originally posted by TrustGs-R
ya i mentioned the Honey combs in my first post....but that dont matter...i appreciate your thoughts.

I find it hard to believe that i should be at a negative setting on my afc tho! RRE adds +39 on the afc with 550's and a ND pump. I had to add +49 when I just had the pump alone. Does this sound right?

+49!?!? No, that is totally wrong. You should never be adding fuel with the AFC you should always be using injectors large enough that you can keep everything negative. Adding fuel is counterproductive to one of the main purposes of an AFC/Larger injectors - to get better timing.

 

[TrustGs-R]

i agree with everything u just said...but RRE says:
"
2G Turbo
16G Turbo, RSR Cat Back, RSR DP-no cat, Filter, 17psi, Front Mount I/C, Denso in tank pump,
550cc Injectors, Side and Lower honeycombs out, Adjusting screw backed out flush

Low Setting:
1K +39 2K +13 3K + 6 4K +3 5K +3 5.5K + 3 6K +3 7K +3
"
from: http://www.roadraceengineering.com/newafcsetting.htm

And I realize every car is different...but not a +39 to -21 difference! hehe. I think they're right...there's just a lot more air on the low RPMS when u remove the HC's and flush the mas screw.

(http://www.roadraceengineering.com/eclipsetech/2gmasadjustment.htm)

 

[fast_talon]

On my 1G there is no way that I would be in the + on my AFC with these 660's. I conservately set my low AFC settings around -15. I was running way rich. I basically tuned with my data logger and EGT's.

Besides the idle, how does the car run, and how are your logs looking?

 

[TrustGs-R]

the rest of my logs are peachy...low throttle anyway haha...

still working on boost tuning and idle.

 

[MaineDSM]

Batman's right, unless you are over 400hp, you shouldn't touch the honeycombs or the screw on the 2G MAS in a 2G. It's calibrated perfectly from the factory.

You screw it up, and you'll have crap like the +40 at 1000rpm to deal with.

 

[TrustGs-R]

400hp soon to come. pulling the HC's made a good gain on my car. I'll be running a MAP system in the future...but it's a good mod until that happens.

i just wish i knew where the ecu wanted my idle fuel....tuning boost is easy.

 

[MaineDSM]

Originally posted by TrustGs-R

i just wish i knew where the ecu wanted my idle fuel....tuning boost is easy.

Well, your honeycombs are gone, so the chance of you getting it to idle decently is pretty slim. I think if you play around with the AFC, you may be able to get it to run ok... the real solution would be to put the honeycombs back in and get a standalone or DSMLink if you have a 2G.

Good luck.