[Dmoney2SS]

Is it worth porting an LT5 throttle body or could I get away with an unported 95mm? I’m planning on just doing a simple bolt on build for now, that being lt2 manifold 95mm tb and possibly a rotofab, also would I need a spacer for it or would it bolt right up?

[6spdhyperblue]

I run unported lt5. I tried a few different ported lt5s.

[Dmoney2SS]

Originally Posted by 6spdhyperblue

I run unported lt5. I tried a few different ported lt5s.

Was there any difference?

[Joshinator99]

Run the unported 95. Ported versions can be a nightmare to tune and aren’t worth the aggravation. If you need more airflow than a 95 then simply buy a 103.

[Dmoney2SS]

Originally Posted by Joshinator99

Run the unported 95. Ported versions can be a nightmare to tune and aren’t worth the aggravation. If you need more airflow than a 95 then simply buy a 103.

Do you know if I need a spacer to run it? With an LT2 IM

[Fstlane]

189 bucks on Rock Auto....genuine GM part

[6spdhyperblue]

U need a spacer unless you widen the holes on the throttle body and then port the throat of the intake and cut beyond the o-ring

[Fstlane]

Ok to try to provide some clarification. I have a stock LT5 throttle body from Rock Auto it is a GM Stock part on a ZL1. I used an adapter plate from
https://www.solerengineering.com/generalmotors.

Car runs great....still in the process of tuning and I have not had the car on a dyno yet as I am still adding a few things.

Listen to Josh....he knows what he is talking about.

[Joshinator99]

Originally Posted by Fstlane

Ok to try to provide some clarification. I have a stock LT5 throttle body from Rock Auto it is a GM Stock part on a ZL1. I used an adapter plate from
https://www.solerengineering.com/generalmotors.

Car runs great....still in the process of tuning and I have not had the car on a dyno yet as I am still adding a few things.

Listen to Josh....he knows what he is talking about.

Thanks Fstlane.

I think that adapter actually looks pretty good…less restrictive than others I’ve seen.

[Daily1LE]

Just curious, is there any benefit at all with a 95MM LT5 TB mated to a LT1/2 IM? Both have to be choked back down to 87mm so I wonder what is the point of the 95MM TB?

I just picked up a LT2 IM manifold myself and am in this similar debate on if I run my stock TB or a LT5, but failing to find any reason to run the LT5 on a stock LT2 IM.

[6spdhyperblue]

If the lt2 is ported, the throat should be larger than 87mm

[radz28]

I can attest to ported LT5s can be over-ported pretty easily and the resulting tuning necessary to get it to behave can be not fun...

[EliteLT1]

mm

Originally Posted by Daily1LE

Just curious, is there any benefit at all with a 95MM LT5 TB mated to a LT1/2 IM? Both have to be choked back down to 87mm so I wonder what is the point of the 95MM TB?

I just picked up a LT2 IM manifold myself and am in this similar debate on if I run my stock TB or a LT5, but failing to find any reason to run the LT5 on a stock LT2 IM.

I'm running the LT2 IM unported, with the 95mm throttle body, also unported.

My logic (shoutout to EssMotorsports on youtube) is that for any throttle position besides WOT, the larger throttle body will allow more air to flow. For example, you will get more airflow with a 95mm TB at 50% throttle than you would get with an 87mm TB at 50% throttle. Probably more of a throttle response benefit in this case

At WOT, the 87mm TB still has the plate and shaft blocking part of the opening (effectively reducing airflow below a true 87mm opening), while the IM opening is always the full 87mm diameter circle. In this case the TB is the limiting factor for airflow. Going to a 95mm would make the IM opening the limiting factor

Unless I'm misunderstanding how they measure the TB, this makes sense to me. But I don't have any comparison numbers isolating only the TB differences

[wang970305]

Originally Posted by EliteLT1

mm

I'm running the LT2 IM unported, with the 95mm throttle body, also unported.

My logic (shoutout to EssMotorsports on youtube) is that for any throttle position besides WOT, the larger throttle body will allow more air to flow. For example, you will get more airflow with a 95mm TB at 50% throttle than you would get with an 87mm TB at 50% throttle. Probably more of a throttle response benefit in this case

At WOT, the 87mm TB still has the plate and shaft blocking part of the opening (effectively reducing airflow below a true 87mm opening), while the IM opening is always the full 87mm diameter circle. In this case the TB is the limiting factor for airflow. Going to a 95mm would make the IM opening the limiting factor

Unless I'm misunderstanding how they measure the TB, this makes sense to me. But I don't have any comparison numbers isolating only the TB differences

Im confused... the IM opening is choked back down to 87mm, how come the 95mm TB would work better than the stock 87mm tb