Dyno tuning with open headers

civicmindedex79 · Sep 27, 2012

Probably a stupid question but I have open headers and looking to get some custom dyno tuning coming up. I must have a oxygen sensor in line which I don't have in my headers. Also I know it needs to be in a sealed pipe about 3 foot long or so. My question is what types of things have yall done to put an oxygen sensor in a open header? Pic for refrence:

muddinmetal · Sep 27, 2012

A good dyno should have a few slip fit test pipes and a clamp in O2 for tuning

civicmindedex79 · Sep 27, 2012

I know he has o2 sensors but not sure on the slipfit pipe since he told me to make sure to rig something up. LOL He has done quite a bit of tuning for us in the past but never seen him have slip fit pipe.

musselman · Sep 27, 2012

Like said a good dyno shop will have some kind of slip fit pipe with a wide band O2 that they clamp in the pipe.

al1tonyota · Sep 28, 2012

If you are going to leave the sensors in them just drill a hole right below the collectors and that will work fine! :gay:

slip fit pipe? What would it slip onto?

ALLJ · Sep 28, 2012

Where you located the guy that tuned mine is doing alot of stuff for Jimmy at EOR he may be able to help you I know he tuned R Keys blaze buggy and several more

muddinmetal · Sep 28, 2012

al1tonyota said:
If you are going to leave the sensors in them just drill a hole right below the collectors and that will work fine! slip fit pipe? What would it slip onto?

I have seen at Walker dyno and Henson's, a few pieces of pipe, some with 3bolt flanges and mufflers and some straight or slip fit with clamps to secure them. I assumed they were for tuning... Either way, a clamp in o2 would have to be better than nothing

greenlion · Sep 28, 2012

Go to the muffler shop and get them to make you a slip fit extension you can attach with a band clamp, then weld a sensor bung into it. Can get the bung from summit, speedway, whoever. Need a little over 12" of pipe past the sensor, depending on how much cam you've got.

civicmindedex79 · Sep 28, 2012

greenlion said:
Go to the muffler shop and get them to make you a slip fit extension you can attach with a band clamp, then weld a sensor bung into it. Can get the bung from summit, speedway, whoever. Need a little over 12" of pipe past the sensor, depending on how much cam you've got.

This is what we was going to do. Only problem is all the curve in the tip and the pipes actially lay against the cage.

Adam I have seen the slip over pipes they are talking about but never for a curved tip. Most I have seen are for straight cut long tube headers. I run a s.d. tune so the o2 sensor won't be left in the buggy.

ALLJ: I have a tuner that worked on it the first time that I am pretty happy with his work but if something comes up I will get with you for his name.

Thanks Everyone keep any ideas coming.

KyTrash · Sep 28, 2012

How does your Speed Density respond ? I know that a Mass Flo will usually be more driver friendly ( good on and off throttle response). I know most Drag cars that are EFI are Speed Density, because they operate at WFO most of the time. Do you have problems with it dieing when you get out of throttle and right back in it ? Hope that I worded this so you can understand it.

civicmindedex79 · Sep 28, 2012

Responds pretty well off throttle and right back but if you off real quick and let it try to goto an idle it does die at times. If you watch from hollytree bounty hill climb it actually had a dead cylinder that while day. It died several times that day but hoping it had to do with the bad coil pack. Overall I am happy with it.

YOUNG · Sep 29, 2012

I would really think twice about running a "spped density" set-up on your LS1. Normally when people change to a SD set-up its because their MAF is a restriction in the intake path and it can't calibrate correctly for the mods done to the motor or the HP of the motor has exceeded the range of the MAF. Now that you can purchase 100 mm MAF sensors these problems are gone. With the type of use that your motor will see instead of just WOT I feel that you will get a better running engine by using a MAF.

Do you have a drive by wire LS1 or a cable for the throttle body? If its drive by wire your tuner can adjust the decel rate in the pcm to "catch" the drop in rpm to slow the rate as it comes to idle to prevent it from dying.

As far as the dyno and O2 sensor the shop will or should have a clamp on O2 that they will place inside the end of your header pipe.

What tuning software will they be using to tune your engine? HP Tuners, EFI Live or LS1 Edit?

civicmindedex79 · Sep 29, 2012

Been running sd tune for over a year now and hadnt had any problems with it yet. It is not dbw and we did alot of work on the tune last time to get the idol right. Lane Culver does my tuning and he has done several buggies around. He uses HP tuners and seems to be pretty damn good with it in my opinion. He does have the clamp on o2 sensors but it needs a long enough pipe to make sure no oxygen pulls back in for misreadings. I run my MAF all the time and if it has trouble idling between summer and winter I can hook an o2 sensor up and let it do the little adjusting it is allowed to do. Besides riding between hills my buggy stays in the 5000 and above rpm range so that is where we did alot of the tuning.

Have you had good experiences with the 100mm MAF? I havent seen anyone that has took enough time to dyno exact same setup with factory and 100mm MAF see more than about 5 hp difference or so. As of now I have no plans to buy an oversized MAF. Any info you got on this I would like read or hear. Feel free to post or send links to [email protected]

Now for the disclaimer: I am by NO means a tuner or engine builder and only know what I have read or learned from the first build on my motor.

ALLJ · Sep 29, 2012

No problem Lane is who I was gonna tell you about super good guy to work with good luck

greenlion · Oct 3, 2012

That's why I thought a band clamp would work. Get the muffler shop to get it close (may have to notch/grind the end of the extension pipe at the turnout) then put them together with a band clamp that will overlap the seam and seal it off.
Like one of these: http://www.summitracing.com/parts/SUM-692300/

I have some 3" pipe laying around the shop if you wanna run it by and try to make something work one eve. May even have another O2 bung laying around.

KyTrash · Oct 3, 2012

Keep us posted, I would like to know more.

Skidkid · Oct 3, 2012

I guess I'm a little lost here but how does your engine run worth a crap without an o2 sensor? I thought it needs them for the computer to meter the air/fuel ratio and ignition right. I now it'll run without them or bad at that but how are you getting by without them?

I read where you guys stated you need 1' to 3' length of exhaust after the o2 location for it to read correctly. No way to run a small tube between two exhaust tubes close to the head and mount one up there? My old Toyota had a Downey header that had this. This way your picking up two cylinders vs just one for a better reading.

Seems to me you must be having running issues if you have to have one installed for a tune.

Just wondering.

civicmindedex79 · Oct 4, 2012

I appreciate it greenlion I keep you in mind.

My engine is speed density tuned. Best way I can explain it is. We put it on a chassis dyno and run it through several w.o.t. runs with the maf and o2 sensors in place. Basically tuner builds a fuel/air ratio map and uploads it in to computer. So when the o2 sensors and maf are not inputing data it has the data plugged in. Advantages I guess are running without the sensors and as long as everything is ok in motor more consistent running.
Disadvantages anytime there is a problem with the motor it doesnt do a whole lot of correcting for air fuel ratio.

With that said I have found that running my MAF all the time seems to help idling. Might just be me but I think it does better. Now I would just like to have a maro body to throw the motor in just to be curious what it would run at track. Or maybe I just need me some 44x19.5 slicks. LOL :driving:

al1tonyota · Oct 4, 2012

That's what I'm talking about I been wanting to run mine down a track for a while! About a 35-37" slick and let her eat :driving:

skipnrocks · Oct 4, 2012

civicmindedex79 said:
I appreciate it greenlion I keep you in mind.

My engine is speed density tuned. Best way I can explain it is. We put it on a chassis dyno and run it through several w.o.t. runs with the maf and o2 sensors in place. Basically tuner builds a fuel/air ratio map and uploads it in to computer. So when the o2 sensors and maf are not inputing data it has the data plugged in. Advantages I guess are running without the sensors and as long as everything is ok in motor more consistent running.
Disadvantages anytime there is a problem with the motor it doesnt do a whole lot of correcting for air fuel ratio.

With that said I have found that running my MAF all the time seems to help idling. Might just be me but I think it does better. Now I would just like to have a maro body to throw the motor in just to be curious what it would run at track. Or maybe I just need me some 44x19.5 slicks. LOL

Wouldn't elevation changes have a dramatic effect on how your engine runs? Out we wheel from 3000ft to 10000ft which I suppose is an issue you may not have.