LT5 throttle body vs LT4 ported TB

AMOR · 09-15-2022, 10:57 AM

I’m planning to do Rotofab intake (standard, not big gulp) with dry filter and also E85 flex fuel kit together with a tune. Does it make sense to upgrade the throttle body at the same time? And if so, should I go with factory LT5 tb + adapter or a ported LT4 tb? Thanks!

ZLE dude · 09-15-2022, 01:49 PM

LT5 throttle body is larger than a ported LT4. I'd just go with the LT5 if your getting tuned (which you should be if doing flex fuel). Stock is 87mm, ported is usually around 89mm effectively, and LT5 is 95mm.

AMOR · 09-15-2022, 01:54 PM

Quote:

Originally Posted by ZLE dude

LT5 throttle body is larger than a ported LT4. I'd just go with the LT5 if your getting tuned (which you should be if doing flex fuel). Stock is 87mm, ported is usually around 89mm effectively, and LT5 is 95mm.

I thought LT5 tb can’t be installed straight through 95mm, it has to be with an adapter to work with a stock lt4 manifold, no?

MartinLe · 09-15-2022, 05:37 PM

Quote:

Originally Posted by AMOR

I thought LT5 tb can’t be installed straight through 95mm, it has to be with an adapter to work with a stock lt4 manifold, no?

Yes.

ZLE dude · 09-16-2022, 08:58 AM

Quote:

Originally Posted by AMOR

I thought LT5 tb can’t be installed straight through 95mm, it has to be with an adapter to work with a stock lt4 manifold, no?

Correct. I forgot that when I ordered the 125 flex kit from Jannetty it came with the adapter for the TB. I'd still go LT5 though.

KingLT1 · 09-16-2022, 09:02 AM

It doesn't gain much until you open the snout up on the supercharger.

09-15-2022, 10:57 AM	#1
AMOR Drives: Camaro Join Date: Apr 2021 Location: Miami Posts: 105	LT5 throttle body vs LT4 ported TB I’m planning to do Rotofab intake (standard, not big gulp) with dry filter and also E85 flex fuel kit together with a tune. Does it make sense to upgrade the throttle body at the same time? And if so, should I go with factory LT5 tb + adapter or a ported LT4 tb? Thanks!

09-15-2022, 01:49 PM	#2
ZLE dude Drives: '18 ZL1 1LE Join Date: May 2020 Location: KY Posts: 219	LT5 throttle body is larger than a ported LT4. I'd just go with the LT5 if your getting tuned (which you should be if doing flex fuel). Stock is 87mm, ported is usually around 89mm effectively, and LT5 is 95mm. __________________ 2018 ZL1 1LE - Summit White, PDR, Rotofab CAI, 95mm TB, CSP 2" catless LT's, JMS Voltage Booster, AEM X-series WB, DSX flex fuel sensor, Banks Data Monster, Tuned by Ted Jannetty, 5% Tint, Blackvue DR900S-2CH, Diode Dynamics lighting, IGL Kenzo ceramic coating

09-16-2022, 09:02 AM	#6
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,800	It doesn't gain much until you open the snout up on the supercharger. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

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