Jetting Adjustment for Sea Level ?

Aubrey N Bruneau · 05-13-2009, 08:44 PM

I imagine that this is probably pretty mundane stuff for most of the guys here

My car runs a pair of 1405 Edelbrock AFB's ( 600 CFM )
We tuned on the dyno in Calagary ( 3500 ft... actually measured 4000 on the barometer )
Current jetting is 92's on all 8 corners, using 7552 metering rods.

Need to make appropriate "enrichment" for sea level.
I don' have the equipment or experience to make the fine tuned changes there, so I need to get a safe, but power making mixture.
It will take no leaner here, as it is.

I'm thinking of bumping up to 95's in the secondaries, and dropping to a 7347 metering rod in the primaries.
Not sure if that's enough though ??

hope you guys can help ?

Dinsdale · 05-13-2009, 10:45 PM

Coming to Mission Aubrey?

Aubrey N Bruneau · 05-13-2009, 11:08 PM

Sure hope so !
Been trying to for 4 years now ( it IS a 1500 mile round trip for me ! ).
Watching the weather, and saving money.

MBogina · 05-14-2009, 04:27 PM

We use the 9636 Federal Mogul 625 cfm carbs, essentially the same components as your Edelbrocks. If the DA changes 3000 feet, rejet one jet size (ie 92's to 95's). If you would rather swap metering rods, a difference of .003-.004 in the metering rod tip is roughly equivalent to a jet change of one size. if you are borderline lead at 4000+ DA, and the air at Mission is in the area of Sea level or better, you would be safer by jetting up 2 sizes in the secondaries, and one size plus a rod change in the primaries.

Bob Gullett · 05-14-2009, 05:25 PM

Think that old truck will make it over the mountains? See you in Mission.

Aubrey N Bruneau · 05-14-2009, 11:50 PM

Heck YEAH, Bob... aint no girly-man small block in there ya' know

Thank you, MB.
That is kind of what I was thinking, but my "thinking" on this subject, at this level ( pun intended ! ), has no basis in experience !

Now, I gotta get a jacket

Bob Gullett · 05-15-2009, 07:51 AM

Quote:

Originally Posted by Aubrey N Bruneau

Heck YEAH, Bob... aint no girly-man small block in there ya' know

Thank you, MB.
That is kind of what I was thinking, but my "thinking" on this subject, at this level ( pun intended ! ), has no basis in experience !

Now, I gotta get a jacket

And Pants.

But I'll still run faster than you with my girlie small block LOL

Aubrey N Bruneau · 05-15-2009, 09:01 AM

Quote:

Originally Posted by Bob Gullett

And Pants.

doh!

Hey, be thankful I'm going... you guys need incapable drivers like me down there, with our "slug cars",
so you can have have a higher car count, and more wins.

05-13-2009, 08:44 PM	#1
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Jetting Adjustment for Sea Level ? I imagine that this is probably pretty mundane stuff for most of the guys here My car runs a pair of 1405 Edelbrock AFB's ( 600 CFM ) We tuned on the dyno in Calagary ( 3500 ft... actually measured 4000 on the barometer ) Current jetting is 92's on all 8 corners, using 7552 metering rods. Need to make appropriate "enrichment" for sea level. I don' have the equipment or experience to make the fine tuned changes there, so I need to get a safe, but power making mixture. It will take no leaner here, as it is. I'm thinking of bumping up to 95's in the secondaries, and dropping to a 7347 metering rod in the primaries. Not sure if that's enough though ?? hope you guys can help ? __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409

05-13-2009, 10:45 PM	#2
Dinsdale Member Join Date: Oct 2004 Location: Canada Posts: 313 Likes: 0 Liked 6 Times in 2 Posts	Re: Jetting Adjustment for Sea Level ? Coming to Mission Aubrey?

05-13-2009, 11:08 PM	#3
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Re: Jetting Adjustment for Sea Level ? Sure hope so ! Been trying to for 4 years now ( it IS a 1500 mile round trip for me ! ). Watching the weather, and saving money. Attached Thumbnails __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409

05-14-2009, 04:27 PM	#4
MBogina Junior Member Join Date: Nov 2002 Location: Olathe, Kansas Posts: 8 Likes: 0 Liked 0 Times in 0 Posts	Re: Jetting Adjustment for Sea Level ? We use the 9636 Federal Mogul 625 cfm carbs, essentially the same components as your Edelbrocks. If the DA changes 3000 feet, rejet one jet size (ie 92's to 95's). If you would rather swap metering rods, a difference of .003-.004 in the metering rod tip is roughly equivalent to a jet change of one size. if you are borderline lead at 4000+ DA, and the air at Mission is in the area of Sea level or better, you would be safer by jetting up 2 sizes in the secondaries, and one size plus a rod change in the primaries.

05-14-2009, 05:25 PM	#5
Bob Gullett VIP Member Join Date: Mar 2002 Posts: 1,102 Likes: 56 Liked 464 Times in 113 Posts	Re: Jetting Adjustment for Sea Level ? Think that old truck will make it over the mountains? See you in Mission. __________________ 68 Chevy11 327 F/S

05-14-2009, 11:50 PM	#6
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Re: Jetting Adjustment for Sea Level ? Heck YEAH, Bob... aint no girly-man small block in there ya' know Thank you, MB. That is kind of what I was thinking, but my "thinking" on this subject, at this level ( pun intended ! ), has no basis in experience ! Now, I gotta get a jacket __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409