Q-jet tuning
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From: Nanaimo BC Canada
Car: 2004 GMC 2500HD
Engine: Duramax LLY
Transmission: Allison
Q-jet tuning
My engine is an 85 305 .40" over, forged flat tops, ported 416 heads, stock cam, stock intake, stock exhaust. Im wondering what may be my best rod and hanger combo. Currently I have a "N" and a "R" hanger and I have "CH" and "DR" rods. I understand that the "DR" rods are somewhat desirable... I have tons of old Q-jets that I have not checked that I can source from so is there anything in particular that I should look for?
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
DR's are good.
The smaller the letter on the hanger, the richer it is because the smaller letters hold the rods up higher than the larger letters. The "N" would be richer of the two you have, so I'd try it. With the DR rods, it may be close. But, you may need a lower letter to get it right.
The smaller the letter on the hanger, the richer it is because the smaller letters hold the rods up higher than the larger letters. The "N" would be richer of the two you have, so I'd try it. With the DR rods, it may be close. But, you may need a lower letter to get it right.
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Re: Q-jet tuning
The DR's are still pretty fat I would get thinner rods.. I think the N hanger would be fine though.
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From: Nanaimo BC Canada
Car: 2004 GMC 2500HD
Engine: Duramax LLY
Transmission: Allison
Thread Starter
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From: Nanaimo BC Canada
Car: 2004 GMC 2500HD
Engine: Duramax LLY
Transmission: Allison
Re: Q-jet tuning
Well Im going to try to find a hanger as close to "B" as I can but I will use then "N" if I dont find anything better. Im having trouble finding any info on the "DR" rods so maybe you could tell me some rods that are a little slimmer than the "DR"s I have several to look through so I would like to know what to look for. Thanks
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Joined: Mar 2000
Posts: 43,187
Likes: 45
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Tech article:
https://www.thirdgen.org/rods
Source for some of the rods:
http://www.carburetion.com/rodshang.asp
Scroll down to the secondary rods section.
Remember the smaller the rod diameter, the richer.
The power tip is only one part of the equation. The reason DR's tend to work well is the taper - i.e., they get smaller quicker.
Yes, you can get smaller power tips. The question is if you really need that, or if the taper is the key. With a 305, you aren't likely to need a smaller power tip than the DR's.
https://www.thirdgen.org/rods
Source for some of the rods:
http://www.carburetion.com/rodshang.asp
Scroll down to the secondary rods section.
Remember the smaller the rod diameter, the richer.
The power tip is only one part of the equation. The reason DR's tend to work well is the taper - i.e., they get smaller quicker.
Yes, you can get smaller power tips. The question is if you really need that, or if the taper is the key. With a 305, you aren't likely to need a smaller power tip than the DR's.
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From: Calgary, AB, Canada
Car: 1982 Trans-Am
Engine: 355 w/ ported 416s
Transmission: T10, hurst shifter
Axle/Gears: 10 bolt, true-trac, 3.73
Re: Q-jet tuning
With a bone stock 305 (stock exhaust, stock cam...) then you'll have stock fuel needs.
I don't see much for mods that would increase your HP to increase you fuel demands. I'm not sure how the ported heads were done, but without the supporting mods (exhaust mainly, but also camshaft), I don't see any extra need.
If the car isn't going lean, you won't gain much from dumping more fuel in.
I don't see much for mods that would increase your HP to increase you fuel demands. I'm not sure how the ported heads were done, but without the supporting mods (exhaust mainly, but also camshaft), I don't see any extra need.
If the car isn't going lean, you won't gain much from dumping more fuel in.
