I may have missed it, what year, engine, and trans do you have?
If stuck with a healthy L05 TBI... Options for 'go-faster' and improved fuel economy?
- Thread starter SpitShine_PL
- Start date
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Waste of time, money, effort, and enthusiasm. The 305 won't pull enough air that the throttle body is a restriction.
I've never seen any dyno proof that the "ultimate TBI mods" does any good whatsoever.
Yes. And the hot-air tube to the passenger side exhaust manifold fall/winter/spring if not year-round. Be sure the thermostatic element in the air cleaner snorkel actually works.
Yes.
He doesn't. This is all for a potential vehicle purchase.
However, the SPID decal is in Post 7.
Yeah the reason I'm asking is the title says "healthy L05", that's a 350. Depending on what trans, there's other options for tuning and gaining performance/MPGs, etc.
Oooops. I screwed-up. Yes, 350, not a 305.
Even with a 350, I'm still not convinced that the throttle body is restricted; or that the "ultimate TBI mods" do any good. I say the cylinder head ports choke flow before the throttle body is a problem.
Even with a 350, I'm still not convinced that the throttle body is restricted; or that the "ultimate TBI mods" do any good. I say the cylinder head ports choke flow before the throttle body is a problem.
Yes, you're probably right on the stock swirl port heads and up to 4,000 RPM. I seem to remember seeing dyno tests increasing HP/torque with those mods, including shaving the throttle shaft, and running up over 5,000 RPM. I just can't remember where I saw it, I'll have to look someday. With the throttle body bored out to 46mm, you get 650 CFM which will support a 350 up to 6,000 RPM. Then you have to add fuel and adjust timing, yada yada yada,
DonYukon
Dont stop until it sounds expensive
Off topic but I love that color
SpitShine_PL
Newbie
Indeed, a word of explanation:Yes, you're probably right on the stock swirl port heads and up to 4,000 RPM. I seem to remember seeing dyno tests increasing HP/torque with those mods, including shaving the throttle shaft, and running up over 5,000 RPM. I just can't remember where I saw it, I'll have to look someday. With the throttle body bored out to 46mm, you get 650 CFM which will support a 350 up to 6,000 RPM. Then you have to add fuel and adjust timing, yada yada yada,
I am zeroing in on a minty transition year, which is supposedly a 96, with the transfer case shifter on the floor, no pass-side air bag, and the L05 under the hood.
And yes, I'm still learning. GM newbie here, was a Chrysler/FoMoCo owner before that (well, a Stellantis client for now... I daily a "Kowalsky White" '16 Challenger with the 6-banger Pentastar... Because why not daily that in Europe?).
If the cyl head ports are more of an issue than the TBI horns... Well, I can hear my wallet whining louder, haha.
My idea was to tweak it a bit, engine-wise, before going hard into modding, and I'm still researching this here and on other forums. Which is why I will probably skip the shorty headers concept in favor of, say, Hooker Comp long tubes, as they seem to provide more benefits, not just 'vroom vroom'; tho they might require a tune for the longer transit time to the 02 sensors.
I'm running on a budget here; the car alone, being mint and nearing the end of its 'refresh' (the current owner is now replacing the A/C compressor and finishing detailing of the interior) is gonna run me close to 10k USD. Some might say, "Import a clean one from Cali" - this is gonna run me a figure close to 10k USD and unlike the L05 K1500 I've been talking about, I can only verify the condition of an import once it rolls out of the container at the port in Rotterdam. The L05 is 120 mi away from me and I can always turn my back on it if I see there's something very wrong about it (a chance of which is now very low).
I need to investigate the TB bore mod and the changes in fuel delivery (pump, injectors, I think) and timing it may require.
Sure, why not skip this and go full blastin' with a Holley Sniper tune kit?... Money!
If you decide to got with long tubes you will need to wrap the pipes to keep the gasses hot. Otherwise your O2 will be off. Unless you run a 3 wire heated O2. Also it's un likely you will see much gain from long tubes. You will never turn enough PRM's for them to proving enough scavenging effects.
Also have you drove the truck yet? It may preform well enough for you, that all of this may be a mute point.
Also have you drove the truck yet? It may preform well enough for you, that all of this may be a mute point.
L31MaxExpress
I'm Awesome
Longer primary length is for low-sped torque, not top-end power. The best headers for torque are tri-y but I do not know if Thorley makes them now.
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