Wideband Results

[email protected] · Posted: Fri Nov 11, 2011 8:21 pm Post subject:

with those heads I would not go bigger on the venturis, it will create more problems than it solves.
_________________
Please do NOT send me Private Messages through the Samba PM System (I will not see them). Send me an e-mail to john at aircooled dot net

"Like" our Facebook page at
http://www.facebook.com/vwpartsaircoolednet
and get a 5% off code for use on one order for VW Parts ON THE NEW WEBSITE, vwparts.aircooled.net

mxracer · Posted: Fri Nov 11, 2011 8:42 pm Post subject:

Thanks, saves me tracking down more vents, they came with 28s in them.

So if I'm following correctly with the smaller vents it's creating more vacuum from the increased velocity and causing the mains to come in too soon and "overlap" the idles.

The smaller airs would help correct the mains coming in too soon by restricting the atmospheric air coming thru the main stack and thus the fuel pulled thru the main at lower engine speeds?

[email protected] · Posted: Fri Nov 11, 2011 8:50 pm Post subject:

A+, good work.

mxracer · Posted: Sat Nov 12, 2011 12:06 pm Post subject:

Ok... little more testing today....

I pulled the stacks completely and it still idled in the mid 13s, dropped out at about 24-2500RPM. i could baby it on the idle circuit and keep it running but stayed around mid 13s babying it too. I ran it down a long hill one time to see what I could get out of it and with just a touch of throttle it was 15-16.

Also pulled just the airs like you suggested to someone else a few posts back. If I'm understanding what that does it basically keeps the mains in play but makes it like running 300 airs. When I did that it dropped off at about 3K RPM and went way lean 40s was the highest I saw.

I also played a little and "redneck" restricted the airs. I sealed the top of the airs with electrical tape and poked a hole in the tape. I realize not real accurate but I wanted to see what "smaller" airs would do as well. When I did that it ran way rich. mid 11s to low 12s at cruise and dropped into the 10s on acceleration. I didn't run it too long like that cause it was way rich but it seemed to show what it might do. Again don't know if that was a valid test since there is no way of knowing just how much the airs were restricted.

I have an idea of what is next but would again appreciate input here.

Thanks

Sigurd · Posted: Sat Nov 12, 2011 12:22 pm Post subject:

Adjust the idle AFR with the screws and NOT the jet size. I can make my car idle anywhere between 11:1 and 15:1 with a 50 idle. Jet it so you see 16-17 at part throttle.

When you take the airs out, the main jets come out too. The main circuit is NOT in play here. The point of this is to see when the car falls on its face. You'll see crazy lean (>25:1) when this happens. [/code]

mxracer · Posted: Sat Nov 12, 2011 12:26 pm Post subject:

It is in the 13s as cruise.

I pulled the airs off of the emulsion tubes and dropped the tubes with the main back in the carbs for the second test.

I can also adjust the idle with the mixture screws to 14.1 as you mention but still 13s at cruise.

[email protected] · Posted: Sat Nov 12, 2011 3:01 pm Post subject:

what jet is in operation will be throttle position dependent, NOT RPM.

Did you set the floats, what is your pump and fuel pressure? I don't know why after posting this 1k times, people ask questions without telling us they have done this, because it's one of the first things we are going to ask you to do.

Also, "Cruise" at what speed and gear? 85mph? 45?
_________________
Please do NOT send me Private Messages through the Samba PM System (I will not see them). Send me an e-mail to john at aircooled dot net

"Like" our Facebook page at
http://www.facebook.com/vwpartsaircoolednet
and get a 5% off code for use on one order for VW Parts ON THE NEW WEBSITE, vwparts.aircooled.net

mxracer · Posted: Sat Nov 12, 2011 3:06 pm Post subject:

I did check/set floats at time of install, about 900 miles ago.

Fuel pressure is at 3 psi, regulated by a good Holley regulator, not a cheap dial regulator. Sorry missed the pump question, it's a rotary pump from a FLAPS, 4-7PSI.

I'm with you on throttle position. I posted rpm cause 2500 was referenced a few times. With the stacks out it fell on its face at about 1/4-1/3 throttle.

The "cruise"in the post above was around 50mph in 4th with the airs restricted. I didn't try it on the highway like that cause it was so rich. The "cruise" from my original post was at 70MPH on the highway, that's what was in the 13s.

74 Thing · Samba Member Joined: September 02, 2004 Posts: 2062

1. Make sure your valves are adjuted correctly, floats are adjusted correctly, you set your timing and you verified your fuel pressure.
2. Verify that the jets are the sizes that are on them-often times one or more have been reamed out. Always do this when making a jet change so that you know you are making a change in the right direction.
3. Pull the main/air/emulsion tubes and start the car and warm it up. Then adjust the mixture screws for each barrel to lean best idle after the engine is fully warmed.
4. Set idles-Go for a drive and see if it hesitates/spits/etc-if it does not go smaller on your idle jets (again verify the sizes and warm up the engine and adjust the mixtures-you must adjust the mixtures everytime you make an idle jet change)-continue to go smaller until the engine protests then go up one size and readjust the mixtures and you are done with the idles.
5. Set airs for transition-Put your air and main jet stack in but use a Large main jet on purpose (in your case somewhere in the 140 range would be huge)-now go for a run and monitor the AFR-you know where the idle drops off already so after this you should be in the transition-if it is lean in transition you need a larger air-if it is rich you need a smaller air. Once the transition is nice and smooth move on to the main.
6. Set the mains-go for a WOT pull and the AFR should be in the high 12's low 13's-adjust the mains until you are there.

[email protected] · Posted: Sat Nov 12, 2011 3:41 pm Post subject:

you need to evaluate the idle jet sizing by REMOVING THE MAIN JET STACKS. REMOVE the Main jet, emulsion tube, air jet, and emulsion tube holder. Now you are driving ONLY on the idle and progression. Get them working properly before you do anything else.
_________________
Please do NOT send me Private Messages through the Samba PM System (I will not see them). Send me an e-mail to john at aircooled dot net

"Like" our Facebook page at
http://www.facebook.com/vwpartsaircoolednet
and get a 5% off code for use on one order for VW Parts ON THE NEW WEBSITE, vwparts.aircooled.net

mxracer · Posted: Sat Nov 12, 2011 3:54 pm Post subject:

ok.. thanks John, and 74Thing.

I'll have to get some gauges and reamers. The idles are marked as 50's but when I pulled the stacks (completely) adjusted for LBI and ran it it was still in the mid 13s until it got into the transition and fell on it's face. I guess I'll just get a set of 40 idles and ream them until they are right. I don't want to end up spending a crap load of money on jets that I don't need.

[email protected] · Posted: Sat Nov 12, 2011 4:09 pm Post subject:

From your #s, I'd say your "50s" are somewhere from 55-60.

I have done so many of these, I can tell you that you need 52-53s. Buy those (we have them in stock, Genuine Dellorto) and then you can move onto the air and mains.
_________________
Please do NOT send me Private Messages through the Samba PM System (I will not see them). Send me an e-mail to john at aircooled dot net

"Like" our Facebook page at
http://www.facebook.com/vwpartsaircoolednet
and get a 5% off code for use on one order for VW Parts ON THE NEW WEBSITE, vwparts.aircooled.net

mxracer · Posted: Sat Nov 12, 2011 6:47 pm Post subject:

Ordered up some 52's from your site John. Appreciate the help again.

Sigurd · Posted: Sat Nov 12, 2011 6:50 pm Post subject:

In my experience, having a variety of jets helps greatly in tuning. With reaming, you only get one chance.

mxracer · Posted: Mon Nov 14, 2011 9:41 am Post subject:

mxracer · Posted: Mon Nov 14, 2011 9:56 am Post subject:

Spent most of the day yesterday playing around.

I re-checked and re-safety wired the enrichment circuits closed, rechecked the float levels etc. I think the enrichment circuits could have been a little of my issue. I didn't drill thru the arm and safety wire it that way the first time. My helicopter maintenance discipline from the military is fading. Confused

I think the one carb might have opened up a little throwing things off.

I also kinda verified (via Oxy/Acl cleaners and a micrometer, it's all I have right now) that the 50's are really 50's.

Anyway, I pulled the stacks and got the idle to 14.1 and it popped every once in a while. Drove it around and it didn't pop or hesitate BAD driving around but it did some. So I think you're dead on John that 52-53.

It's a learning experience for sure.

[email protected] · Posted: Mon Nov 14, 2011 11:19 am Post subject:

again, almost every time the engine is not responding as it should there is something else wrong that has not been identified yet. It's often tough to convince people to keep digging to find it, but persistence wins!
_________________
Please do NOT send me Private Messages through the Samba PM System (I will not see them). Send me an e-mail to john at aircooled dot net

"Like" our Facebook page at
http://www.facebook.com/vwpartsaircoolednet
and get a 5% off code for use on one order for VW Parts ON THE NEW WEBSITE, vwparts.aircooled.net

mxracer · Posted: Thu Nov 17, 2011 5:35 pm Post subject:

Quick recap of what I have..

Type 3 Squareback

1904cc, 35.5mmx32mm P&P stock heads, Scat C25 cam, 8.5:1 CR, Tri-Mil OTT exhaust

Dual 40 DRLA currently -
52 Idles - known good now, thanks John
122 Mains = The 122's are at least somewhere between a 120 and a 125 I checked them with a jet gauge and the 120 slid right in but the 125 was too big.
180 Airs
30mm vents
9164.1 e-tubes with the top holes soldered shut
floats checked and are at 5mm with a 12mm drop
fuel pressure adjusted to aprox 2.75PSI (it's between 2.5 and 3 on the gauge)

With the stacks removed and LBI set (Idle AFR is 13.7), at cruise (45MPH in 3rd or 60MPH in 4th) it's at 16.5-17.0 No popping or hesitation.

I drove a loop from the house out onto the highway for 4 miles seems like a million times to get the feel for where the transition is and to get consistent results.

After that I put the stacks back in and did the same loop maybe 8-10 more times. With the stacks in at cruise (60 to 70MPH in 4th) it's 13.7 to 14.2

WOT (in third or fourth) it drops as low as 11.6 If I'm following right I know this doesn't matter just yet as I need to worry about the tip in timing but figured I'd throw it out there too.

I also backed off the accel pumps all the way for the testing.

John, you mentioned the mains coming in too soon before, if I'm following things correctly the next step is to put a small air and large main in and dial in the main tip in?

RPM Tim · Posted: Mon Jan 30, 2012 8:10 pm Post subject:

I realize this is probably the wrong thread for this.. But, anyone want to throw me some opinions on a baseline jetting Question

Swapping from 45Dells to 48IDAs with new heads on the way!! This is going in my strip/street car with specs as follows:
2276, 42x37.5 heads/ signature port by Performance Workshop, FK 89 cam with 11ish:1 cr. Greg has already recommended 42 vents and 1 3/4" header which i will have to pick up but any ideas where to start tuning?? The car does have a wideband wired in so get me started and let the fun begin Dancing

Thanks!

mightymouse · Posted: Wed Feb 08, 2012 1:27 pm Post subject:

Tim,

My suggestion for baseline would be

60 Idles
130 Idle airs
f11 tubes
170 mains
190 airs

What fuel do you plan on running? unleaded 100? or a leaded import blend say 110 octane?

What dist/ignition you gonna run? Prob only need 24 or 26 total advance. less is more with higher CR. You can also tune more spot on with MBT (minimum best timing).

Since you have a wideband that helps a ton. No worries at all, putt around for 15 mins or so so that its 100% warmed up and then do a 3rd gear pull starting around 3k rpm and watch the wideband.
Youll get a feel pretty quick where you need to be headed.

could need between 5 and 15 added either direction on any of that.
say... 65 idle 135 idle air... etc.
sounds like its gonna haul. Youll know what those heads are doing once you see what jets it needs. Smile

Also dont 100% trust the wideband. Do a plug check. Look for detonation and what the burn looks like.
Also make 200% sure there isnt a single leak in your exhaust.
Some big slip joint headers ive simply wrapped them with black header wrap to assist in keeping them warm enough for the joints to seal up when running. Look sick and helps get your tune 100%.

Keep us posted.
_________________
Nothing can stop the man with the right mental attitude from achieving his goal; nothing on earth can help the man with the wrong mental attitude.
Thomas Jefferson

Note to EVERYONE.
Know your ZDDP levels or you WILL lose a cam and lifters.

>Help >Donate >Buy Shirts >Register >Log in	See all Samba banner ads \| Advertise on TheSamba.com

Wideband Results
Goto page Previous 1, 2, 3 ... 25, 26, 27 ... 30, 31, 32 Next Jump to:

Forum Index -> Performance - Engines/Transmissions		Share:
		Print View

	Forum Index -> Performance - Engines/Transmissions	All times are Mountain Standard Time/Pacific Daylight Savings Time Goto page Previous 1, 2, 3 ... 25, 26, 27 ... 30, 31, 32 Next Jump to:
Page 26 of 32