What's the Best Throttle Body Size for My LS Build?

Performance & Modifications
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Seeking Advice on Throttle Body Sizes for LS Engines

I’m currently diving into some serious modifications for my LS engine, and I’m really trying to wrap my head around throttle body sizes. I’m aware that different LS variants come with different stock sizes, but I’m not exactly sure how that impacts performance when I start upgrading.

Here are a few things I’m curious about:

  • Stock Sizes: What are the stock throttle body sizes for the popular LS engines? I’ve heard varying numbers and would love some clarity.
  • Upgrades: If I want to upgrade, what size would be optimal for increased airflow? Is there a general rule of thumb for choosing the right size?
  • Performance Impacts: How significant is the performance gain with a larger throttle body, especially if I have other upgrades in place like headers and a new intake?

Also, if anyone has done a build or knows of a good comparison on throttle body sizes, I would appreciate any insights or links to threads/articles! I’m all about that extra horsepower!

Thanks, everyone!

2

When determining the best throttle body size for your LS build, consider your engine’s displacement and its intended use. Generally, a 90mm throttle body is great for most builds, but if you’re pushing over 400 cubic inches, you might want to go larger.

3

Absolutely! I’ve seen guys get too caught up in size and forget about flow characteristics. It’s not just about the diameter; the design matters too!

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Size can get confusing, huh? For most street applications, around 80mm to 90mm is usually effective, unless you’re looking to break records at the track. What do you have in mind for your build?

5

That’s true! However, if you’re doing serious mods and aiming for high horsepower, don’t shy away from larger sizes. It’s all about your specific application!

6

I’ve got a 5.3 with a 92mm throttle body, and it runs like a beast! Just ensure that your intake and exhaust can support it. What’s your setup?

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That’s impressive, Tina! Did you notice a significant difference after upgrading? I’m considering a similar path.

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Keep in mind the overall airflow of your engine. A larger throttle body can overpower your intake if everything isn’t matched. What’s the rest of your setup looking like?

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Good point! It’s a balancing act, really. Make sure your injectors and cam are equally suited to handle the size increase. What are you aiming for?

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Supportive community! Just remember, the larger the throttle body, the more tuning you might need. Don’t forget the importance of ECU tuning to maximize your gains!

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Exactly! It’s all interconnected. Anyone else here had tuning headaches post-install?

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I’m still trying to get used to my new throttle body. It’s like trying to eat spaghetti with a spoon! Just takes practice, right? Anyone else feel this way?

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Haha! That’s a funny way to put it! Honestly, the learning curve can be steep, but it’s worth it in the end. Keep at it!

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Ultimately, it all depends on what you’re trying to accomplish. Think long-term—invest in a throttle body that you won’t outgrow quickly. Just my two cents!

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15

Choosing the right throttle body size for your LS build is crucial! Generally, a larger throttle body can improve airflow but might require more tuning to optimize fuel maps. Too big can lead to idle instability. What’s your engine setup?

16

Absolutely! I installed a 102mm throttle body on my LS3, and while it does increase power, I’ve had to adjust the idle quite a bit. It’s a fine balance!

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That’s interesting, tony! I thought a straight swap would be easy. If I go bigger, how does it mess with my fuel maps specifically? Can it cause lean conditions?

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Yes, wparks! A larger throttle body can indeed lean out the mixture if the fuel maps aren’t tuned accordingly. Always recommend a good tune after installation!

19

Yikes! So it seems like it’s not just a plug-and-play upgrade. What about drivability? Will a larger throttle body make my car feel laggy?

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Good question, ocuevas! A bigger throttle body can reduce throttle response at low RPMs, so drivability may be compromised. My buddy hated his response after switching without tuning first.