Backfoot100
Full Access Member
- Joined
- Aug 18, 2017
- Posts
- 374
- Reaction score
- 644
- Location
- Florida
- First Name
- Eddie
- Truck Year
- 1986
- Truck Model
- C1500 Suburban
- Engine Size
- Carbed 350
My square is an 86 C1500 Sub that is pretty much a bone stock 350 except for headers, dual exhaust, air pump delete and a Cliff Ruggles carb rebuild kit w/throttle shaft bushing install.
I tuned it up with a cap, rotor, plugs, and a set of MSD wires.
I've been running it like this for several months. It runs great but I keep thinking I should be getting more out of it.
Ive been reading threads about removing the flame arrestor if you have one (which mine does). I still don't understand the reasoning for why this air cleaner has it when most others dont but it is what it is.
Well this weekend I removed that damn thing and got out the vacuum gauge to do a little fine tuning. The as-is tune was 17" vacuum @ 12 degrees. Pretty good for a 33 year old smogger and a ear tune, save for the timing light. I turned the idle screws out two full turns and the vacuum jumped to 19" and the engine was noticeably smoother. Couldn't get it any higher but still very happy with it so I took it for a spin.
Now purely by means of my ass dyno, it had noticeably better throttle response and was much stronger through the off-idle to midrange RPM's. That QJ just sounded much gooder too.
In all fairness it was a short ride and I didn't get a chance to open up the old girl but I was really amazed at how much stronger it ran.
I know from past experience that two inches of vacuum didn't account for that much improvement but at the same time it certainly didn't hurt. The flame arrestor (or lack there of) I'm sure made the biggest impact.
The moral of the story here boys and girls is to make sure you use everything available to you to get the best results possible. And if you have one of those constricting monstrosities in your air cleaner I would encourage you to loose it immediately if not sooner.
I tuned it up with a cap, rotor, plugs, and a set of MSD wires.
I've been running it like this for several months. It runs great but I keep thinking I should be getting more out of it.
Ive been reading threads about removing the flame arrestor if you have one (which mine does). I still don't understand the reasoning for why this air cleaner has it when most others dont but it is what it is.
Well this weekend I removed that damn thing and got out the vacuum gauge to do a little fine tuning. The as-is tune was 17" vacuum @ 12 degrees. Pretty good for a 33 year old smogger and a ear tune, save for the timing light. I turned the idle screws out two full turns and the vacuum jumped to 19" and the engine was noticeably smoother. Couldn't get it any higher but still very happy with it so I took it for a spin.
Now purely by means of my ass dyno, it had noticeably better throttle response and was much stronger through the off-idle to midrange RPM's. That QJ just sounded much gooder too.
In all fairness it was a short ride and I didn't get a chance to open up the old girl but I was really amazed at how much stronger it ran.
I know from past experience that two inches of vacuum didn't account for that much improvement but at the same time it certainly didn't hurt. The flame arrestor (or lack there of) I'm sure made the biggest impact.
The moral of the story here boys and girls is to make sure you use everything available to you to get the best results possible. And if you have one of those constricting monstrosities in your air cleaner I would encourage you to loose it immediately if not sooner.
