best bolt on performance mods

[rich weyand]

Hi Rich. I assume that you have to weld a bung in the exhaust system for the sensor? A sensor kinda simular to a o2 sensor is what give you your readings ,Right?
Thanks for your advise.

Yeah, a muffler shop will braze a bung into the exhaust pipe behind the header flange (with headers), or after the manifold flange for a manifold, for $20 or so. They have to do that with all the systems they replace on EFI cars anyway, so this is not a new thing for them. They should also chase the 18mm threads with a tap when they are done. It is not "similar to" an O2 sensor; it is the same thing as you would have on an EFI car, though, since it is more general purpose than the OEM sensor on an EFI car, it will probably be a higher quality sensor.

 

[Jacknife]

Yes.

Thaks Bob, just making sure I was on the right track. I would like to see a thread on using A/FR meter & adjusting carb. Of coarse I have always done it the shade tree ways. I tried doing search but have not found nothing yet.

 

[firebane]

Thaks Bob, just making sure I was on the right track. I would like to see a thread on using A/FR meter & adjusting carb. Of coarse I have always done it the shade tree ways. I tried doing search but have not found nothing yet.

Wideband is to see how your carb is running at idle, cruise and WOT.

At certain condtions you should have a specific air to fuel ratio and once you know what your air to fuel is you then modify jets and rods to correct the carb and get your air/fuel into the proper area.

Problem with this is that its VERY time consuming.

 

[Jacknife]

Yeah, a muffler shop will braze a bung into the exhaust pipe behind the header flange (with headers), or after the manifold flange for a manifold, for $20 or so. They have to do that with all the systems they replace on EFI cars anyway, so this is not a new thing for them. They should also chase the 18mm threads with a tap when they are done. It is not "similar to" an O2 sensor; it is the same thing as you would have on an EFI car, though, since it is more general purpose than the OEM sensor on an EFI car, it will probably be a higher quality sensor.

Thanks Rich, I appreciate the advice. Looking into one of these maybe. Just doing some homework & research before spending the $$. Been looking to try and download the owners manual for one maybe, no such luck yet. Thanks again.

 

[Jacknife]

Wideband is to see how your carb is running at idle, cruise and WOT.

At certain condtions you should have a specific air to fuel ratio and once you know what your air to fuel is you then modify jets and rods to correct the carb and get your air/fuel into the proper area.

Problem with this is that its VERY time consuming.

I am sure it is time consuming. I do feel that it is worth it thuo. I really believe in having everything tuned right, Thanks for the help.

 

[Green79Scottsdale]

I was going to post more along the lines of what Rich posted, but my three year old son hit enter for me, then it was time for a nap for him. Tuning with a wideband is one my list of might do this coming year. I also might do a TBI swap. Or I might do nothing. Only time will tell. I will post a write-up when and if I do it.

 

[Jacknife]

I was going to post more along the lines of what Rich posted, but my three year old son hit enter for me, then it was time for a nap for him. Tuning with a wideband is one my list of might do this coming year. I also might do a TBI swap. Or I might do nothing. Only time will tell. I will post a write-up when and if I do it.

Oh I understand all that. Would make an interesting read if you decided to tune with wideband & do a write up.

 

[rich weyand]

I'll tell you what I did.

First, I got a wideband meter (I got the NGK) that was not a "bolt it into the dash" kind of thing, but something I could hook up and set on the dash while I drove and tuned for a couple weeks, then take off once I was set. Once you have it set up, it is pretty much a done deal.

Then I hooked it up and just drove the truck normally, with half an eye on the readings. With the Edelbrock 1406, I was lean at cruise, rich in power, spot on in the secondaries, and rich at idle. Also, the cruise to power circuit transition was way late, because it is run by vacuum and these engines when cammed for torque pull a lot of vacuum.

So I replaced the pop-up springs in the Edelbrock to get the cruise to power transition to occur at a higher vacuum level so it would kick in sooner when I got on it.

Then I bought a whole bunch of rods from JEGS with the understanding I could return anything that was unopened. From the Edelbrock tuning chart in the manual, I had to go rich on the cruise (up in the chart) and lean in the power (left on the chart), so I picked a tune point and set it up like that. I ended up going two sizes smaller on the primary jet and changing the rods, per the chart, and got pretty close on the AFR, then played with different rods.

Finally, I leaned out the idle to spec. The numbers I aimed at are 13.5 idle, 14.5 cruise, 13.5 power, and 12.5 secondaries, and I hit them spot on. My gas mileage went up 20%, and my power and smoothness of power delivery and throttle response all improved markedly over the stock tune.

Why 13.5 on idle? Because at the very low stack velocity through the carb at idle, the mixture going into the manifold is not completely uniform, and if the charge any cylinder gets is over about 17:1, it will miss. So an average AFR of 13.5:1 means no cylinder will ever see over 17:1, and you will get a smooth idle under a wide range of conditions.

 

[Jacknife]

I'll tell you what I did.

First, I got a wideband meter (I got the NGK) that was not a "bolt it into the dash" kind of thing, but something I could hook up and set on the dash while I drove and tuned for a couple weeks, then take off once I was set. Once you have it set up, it is pretty much a done deal.

Then I hooked it up and just drove the truck normally, with half an eye on the readings. With the Edelbrock 1406, I was lean at cruise, rich in power, spot on in the secondaries, and rich at idle. Also, the cruise to power circuit transition was way late, because it is run by vacuum and these engines when cammed for torque pull a lot of vacuum.

So I replaced the pop-up springs in the Edelbrock to get the cruise to power transition to occur at a higher vacuum level so it would kick in sooner when I got on it.

Then I bought a whole bunch of rods from JEGS with the understanding I could return anything that was unopened. From the Edelbrock tuning chart in the manual, I had to go rich on the cruise (up in the chart) and lean in the power (left on the chart), so I picked a tune point and set it up like that. I ended up going two sizes smaller on the primary jet and changing the rods, per the chart, and got pretty close on the AFR, then played with different rods.

Finally, I leaned out the idle to spec. The numbers I aimed at are 13.5 idle, 14.5 cruise, 13.5 power, and 12.5 secondaries, and I hit them spot on. My gas mileage went up 20%, and my power and smoothness of power delivery and throttle response all improved markedly over the stock tune.

Why 13.5 on idle? Because at the very low stack velocity through the carb at idle, the mixture going into the manifold is not completely uniform, and if the charge any cylinder gets is over about 17:1, it will miss. So an average AFR of 13.5:1 means no cylinder will ever see over 17:1, and you will get a smooth idle under a wide range of conditions.

After Taking monitor off of vehicle, I assume that you remove the sensor & plug the hole with threaded plug. I am assuming that one could have each of his vehicles set up, where he could hook up A/FR monitor and tune then remove & plug hole in exhaust.
Then tune each vehicle?
Or is there something that I am Missing?

 

[rich weyand]

After Taking monitor off of vehicle, I assume that you remove the sensor & plug the hole with threaded plug. I am assuming that one could have each of his vehicles set up, where he could hook up A/FR monitor and tune then remove & plug hole in exhaust.
Then tune each vehicle?
Or is there something that I am Missing?

Nope, you got it. The sensors have a finite lifetime, so you pull them and cork the bung. You can tune up any vehicle with a bung you can mount the sensor in. Use a high-heat copper anti-seize compound on the thread so the sensor or the cork don't rust in place. And the bung has to be on the upper half of the pipe so the sensor drains condensation and doesn't collect it.

 

[Jacknife]

Nope, you got it. The sensors have a finite lifetime, so you pull them and cork the bung. You can tune up any vehicle with a bung you can mount the sensor in. Use a high-heat copper anti-seize compound on the thread so the sensor or the cork don't rust in place. And the bung has to be on the upper half of the pipe so the sensor drains condensation and doesn't collect it.

Okay Great. I Thank each of you for your advice.

 

[Don5]

Thanks Rich for explaining the A/F meter. I had never heard of it until I read a posting by you concerning the use of one. I will probably pick one up sometime. In the old days we never used one and the guys that could "tune" a q-jet were considered geniuses.

 

[rich weyand]

It's definitely the way to go. I was surprised by how far off I was, and how much difference it made to be dialed in to the numbers.

 

[neginfluence04]

Do you guys speak English because I have no idea what y'all are talking about BTW where do I get blinkers fluid at

But in all seriousness I need a tune on mine asap

 

[Don5]

Do you guys speak English because I have no idea what y'all are talking about BTW where do I get blinkers fluid at

Blinker fluid is located in aisle 15 up on the top shelf to the right at O'Reilly's.