My Tuning Adventures

Author Topic: My Tuning Adventures  (Read 10345 times)

Offline Chryco Psycho

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Re: My Tuning Adventures
« Reply #15 on: July 27, 2016 - 09:59:30 PM »
I am going to quit answering ?? for a while I am sleep deprived & going through rough times making mistakes

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Offline CUDA JAS

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Re: My Tuning Adventures
« Reply #16 on: July 28, 2016 - 10:53:49 AM »
I am going to quit answering ?? for a while I am sleep deprived & going through rough times making mistakes

Sorry to hear that CP.  I hope things turn around for you.

Jason
74 'cuda 360/727



Gearhead: car nut, automotive enthusiast, one who loves hot rods, muscle cars, hot trucks, burnin' rubber and neck snapping performance. 

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Offline Chryco Psycho

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Re: My Tuning Adventures
« Reply #17 on: July 28, 2016 - 11:40:43 PM »
Everything turns around if you live long enough & in a long enough time line the survival rate for everyone drops to zero .

Challenger - You`ll wish You Hadn`t

Offline brasil

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Re: My Tuning Adventures
« Reply #18 on: July 31, 2016 - 03:39:57 PM »
@  chryco    true words !

@ all    pulled the 6.5 PV...   the 6.5 PV is way to big for a low vacuum engine...  now have the 4.5 PV installed...
runs better...and needs less fuel also.

Greetings Juergen

Offline Chryco Psycho

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Re: My Tuning Adventures
« Reply #19 on: July 31, 2016 - 08:40:04 PM »
 :2thumbs:

Challenger - You`ll wish You Hadn`t

Offline CUDA JAS

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Re: My Tuning Adventures
« Reply #20 on: August 01, 2016 - 10:17:33 AM »
@  chryco    true words !

@ all    pulled the 6.5 PV...   the 6.5 PV is way to big for a low vacuum engine...  now have the 4.5 PV installed...
runs better...and needs less fuel also.

Greetings Juergen

Funny. that our results were so different.  I did not have a 5 or 5.5 so I went back tot eh 6.5 for now.  No more lean spike.  but I think the 5 or 5.5 would be better.

Might try it our in the near future.


Jason
74 'cuda 360/727



Gearhead: car nut, automotive enthusiast, one who loves hot rods, muscle cars, hot trucks, burnin' rubber and neck snapping performance. 

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Offline brasil

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Re: My Tuning Adventures
« Reply #21 on: August 01, 2016 - 02:55:17 PM »
@ cuda jas

with the 6.5 PV  I noticed that the car gets to much fuel ( without touching the pedal !)  because the 6.5PV opens to soon..  in my case.  I have only 9-10 inches of Mercury @ idle in Drive ... so the 4.5  or a 5.0 is better for my set up

Greetings Juergen

Offline CUDA JAS

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Re: My Tuning Adventures
« Reply #22 on: August 01, 2016 - 03:52:19 PM »
@ cuda jas

with the 6.5 PV  I noticed that the car gets to much fuel ( without touching the pedal !)  because the 6.5PV opens to soon..  in my case.  I have only 9-10 inches of Mercury @ idle in Drive ... so the 4.5  or a 5.0 is better for my set up

Greetings Juergen

I have a little less than 10 inches of vacuum at idle in Drive, but the 4.5 created a huge lean spot everywhere.  Just seem to spike lean when ever I hit the throttle.

I guess I could have increased the accel pump to cover the lean spot, but not sure that is the way to go. 

Jason
74 'cuda 360/727



Gearhead: car nut, automotive enthusiast, one who loves hot rods, muscle cars, hot trucks, burnin' rubber and neck snapping performance. 

Just call me a gearhead!

Offline CUDA JAS

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Re: My Tuning Adventures
« Reply #23 on: August 02, 2016 - 01:21:48 PM »
Well that did not work out so well.

I finally had a chance to take a spin on the highway after the jet change...man it really leaned it out.  At 70 mph, turning 2500 rpm or so, the AFR meter was reading 14.0 and higher.

I think that is a little too lean for me.  It was so lean that after that short run, (I hit the first exit) it did not run quite right.  A quick backfire through he carb as I got on the throttle after the off ramp.  I am guessing things got a little hot in the engine.  :22yikes:

So, I am going to go back up on the main jets (70s from 68s). 

I am also not convinced the 6.5  PV is working, So I may change that back out while I am in there.

Jason






74 'cuda 360/727



Gearhead: car nut, automotive enthusiast, one who loves hot rods, muscle cars, hot trucks, burnin' rubber and neck snapping performance. 

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Offline brasil

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Re: My Tuning Adventures
« Reply #24 on: August 02, 2016 - 04:47:10 PM »
Hello Jason...

My  carb has the 68 Jets in front and 71 jets on the sec. side.....  the accelerator cam is the orange one..
and the PV is the 4.5 PV

While cruising the AFR is  around 14.3 to 15.0  when I accelerate   the AFR goes down to 13. - 13.2   WOT is 11.4

so ...I think that´s o.k.   

If you have AFR 14  while cruising that is good..    why going richer ??  Only under Lload...you need a rich mixture

Greetings Juergen

Offline barnett468

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Re: My Tuning Adventures
« Reply #25 on: August 02, 2016 - 04:53:02 PM »
Hello Jason...

My  carb has the 68 Jets in front and 71 jets on the sec. side.....  the accelerator cam is the orange one..
and the PV is the 4.5 PV

While cruising the AFR is  around 14.3 to 15.0  when I accelerate   the AFR goes down to 13. - 13.2   WOT is 11.4

so ...I think that´s o.k.   

If you have AFR 14  while cruising that is good..    why going richer ??  Only under Lload...you need a rich mixture

Greetings Juergen

Don't use the gauge as your only source of tuning because if you do it will never run right. Use how the car runs and the spark plug color also.

If the porcelain on the plugs looks nearly white, it is screamin lean irregardless of what any gauge says.


Offline CUDA JAS

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Re: My Tuning Adventures
« Reply #26 on: August 02, 2016 - 09:06:34 PM »
Hello Jason...

My carb has the 68 Jets in front and 71 jets on the sec. side.....  the accelerator cam is the orange one..
and the PV is the 4.5 PV

While cruising the AFR is  around 14.3 to 15.0  when I accelerate   the AFR goes down to 13. - 13.2   WOT is 11.4

so ...I think that´s o.k.   

If you have AFR 14  while cruising that is good..    why going richer ??  Only under Lload...you need a rich mixture

Greetings Juergen

Yeah fair enough I guess...some of the things I have read say that 14.XX is too lean but I guess at cruise it should be ok.

I think I was just surprised to see it on the AFR meter.  I was more surprised about the pop through the carb as I got off the highway.  I also had a past experience running very lean, pre AFR meter, had too much timing, and the car got super hot on the highway.  Stopped, changed the timing (disconnected the VAC adv) and car cooled off and ran much better.

Maybe another drive is in order to see if it does it again.

If the porcelain on the plugs looks nearly white, it is screamin lean irregardless of what any gauge says.



I know reading the plug has its place...but I am not sure it works for a street car, to much part throttle driving that muddies the water so to speak.

I have also heard that todays fuels can cause problems reading the plugs.

I think at this point I will go by the AFR meter, BUT I could be swayed.

The other thing I may go back to is the timing...right now, my total timing comes in around 3000 rpm.  My cruise rpm on the highway is around 2500 never much higher.  Would the timing coming all in around cruising RMP make any difference?.


Jason 
74 'cuda 360/727



Gearhead: car nut, automotive enthusiast, one who loves hot rods, muscle cars, hot trucks, burnin' rubber and neck snapping performance. 

Just call me a gearhead!

Offline barnett468

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Re: My Tuning Adventures
« Reply #27 on: August 02, 2016 - 11:13:13 PM »

I know reading the plug has its place...but I am not sure it works for a street car, to much part throttle driving that muddies the water so to speak.

I have also heard that todays fuels can cause problems reading the plugs.

I think at this point I will go by the AFR meter, BUT I could be swayed.


If the porcelain on the plugs looks nearly white, it is screamin lean irregardless of what any gauge says.

It works fine for a street car if you know how to do it . Since you don't know how to read plugs, simply post a photo of the front plug from each cylinder and I will tell you what I see.
.
« Last Edit: August 02, 2016 - 11:17:03 PM by barnett468 »

Offline Chryco Psycho

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Re: My Tuning Adventures
« Reply #28 on: August 03, 2016 - 12:21:17 AM »
increasing the accel pump with the lower PV is potentially a better way to go

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Offline CUDA JAS

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Re: My Tuning Adventures
« Reply #29 on: August 03, 2016 - 09:58:07 AM »
increasing the accel pump with the lower PV is potentially a better way to go

Yeah I think that is my plan.

I think I over reacted when I saw the results of the change to the 4.5 PV.  I was not expecting the lean spot, so I figured it was a mistake.

Now that I have time to reflect on it, it makes more sense.

As I cruise around on the street, or highway, throttle input is minimal, and vacuum is high, so the PV SHOULD be closed.  As I tap the throttle, vacuum is still high and the PV should remain closed. 

Logically the slight throttle input would create a lean spot.  A larger pump shot, by going to a larger nozzle should cure the lean spot (hmm sounds like what the accel pump is designed for).

I guess I am just so used to using the larger PV, that the lean spot is masked by the PV coming on too early!

Jason

74 'cuda 360/727



Gearhead: car nut, automotive enthusiast, one who loves hot rods, muscle cars, hot trucks, burnin' rubber and neck snapping performance. 

Just call me a gearhead!