Successful LT5 TB Upgrade Night/Day

Noizyboy · April 10, 2021

My whipple e85 small cam 5.3 truck made 585. Bought the lt5 throttle body off rock auto and had my whipple adapter plate machined by myself. Gotta say night and day difference with 8mm gain. I had the l86 87mm TB before making 585 on E. Bit today without tuning the truck woke up. Just letting yall know the gain for power and throttle response is a must. Boosted boiz that is. Not sure on NA

Whipple adapter plate modded from their factory 91mm bored to 95mm to match the lt5 tb. I reamed the holes with a carbide burr with large flutes to accommodate the aluminum cuts. Overall spent about $160 on tb with 5%discount from rock auto. And my expensive machinist for $70 on the bigger bore match lol. Whatever I wanted it done asap

But totally worth it. Before i could feel the choke with l86 tb (87mm) but after the quick bolt on it was power on tap. As soon as I left the shop bam! I felt like the thing had a pedal commander without the bad reviews. 8mm makes the difference ladies.

Edited April 10, 2021 by Noizyboy
Added info

pokismoki · April 10, 2021

going bigger on a stock truck will make up for the loss of TB opening 83% on our trucks

truckguy82 · April 10, 2021

Yes multiple dyno’s on the vettes and camaro forums confirm that throttle body has real world hp gains.

I’m sure you see a more noticeable improvement with your supercharger.

Edited April 10, 2021 by truckguy82

Noizyboy · April 10, 2021

I'll post more pics for those who are wondering about slapping one on. But yeah just saw last night some folks gaining 15-35whp 10-40tq.

pokismoki · April 10, 2021

do you need the l86 manifold to install the lt5 TB on the motor

Noizyboy · April 10, 2021

From what I've seen the bore is way to small for the lt5 to match to the l83 or even l86. Lt1 as well will need alot of material to be removed to match. I have all 3 TBs (lt5,l86,l83) and not sure if the l83 and l86 are same bolt pattern

Noizyboy · April 10, 2021

L83 TB bolt holes about 97mm apart

L86 TB bolt holes about 104mm apart

This is the MAC bit my tool guy had on his truck and worked effortlessly. PN#98660 1/4 diameter.

pokismoki · April 10, 2021

just slap an adapter plate on and see what happens , butterfly might hit manifold not sure?

DillonHendrix · December 25, 2023

Hey just a quick question! I have a 5.3 with a whipple 2.9 and I have tried two ported lt5 throttle bodies and both will not work correctly so I'm running my stock throttle body still unfortunately but still made

550whp! Any tips on how you made yours work, anything special while tuning? Thanks!

CajunFries · January 3

On 12/24/2023 at 5:09 PM, DillonHendrix said:

Hey just a quick question! I have a 5.3 with a whipple 2.9 and I have tried two ported lt5 throttle bodies and both will not work correctly so I'm running my stock throttle body still unfortunately but still made

550whp! Any tips on how you made yours work, anything special while tuning? Thanks!

Did you changed the intake pipe also? If you did and the ID is different, you’ll need a new tune. The TB alone shouldn’t be too much of a difference.

DillonHendrix · January 9

I actually did change that to a 4" id from factory which is 3"ish if I remember correctly including where the MAF is located and the shop said they corrected for that while tuning for the cam, lt4 fuel system smaller pulley!

CajunFries · January 11

On 1/9/2024 at 1:03 PM, DillonHendrix said:

I actually did change that to a 4" id from factory which is 3"ish if I remember correctly including where the MAF is located and the shop said they corrected for that while tuning for the cam, lt4 fuel system smaller pulley!

What was the problem with the Lt4 TB? Idle? Part throttle? WOT?

DillonHendrix · January 11

Well at idle it was very irregular and was constantly hunting up and down and when you tried to rev or accelerate it was very slow! I got it from Soler performance throttle bodies and the guy has been super cool but he said he's not sure what I could do either!