PerformanceTrucks.net Forums

PerformanceTrucks.net Forums (https://www.performancetrucks.net/forums/)
-   GM Engine & Exhaust Performance (https://www.performancetrucks.net/forums/gm-engine-exhaust-performance-21/)
-   -   4.8 + LT's = More Harm than good? (https://www.performancetrucks.net/forums/gm-engine-exhaust-performance-21/4-8-lts-%3D-more-harm-than-good-384078/)

SlvrSierra4.8 01-21-2007 08:08 PM

4.8 + LT's = More Harm than good?
 
Did a search and couldn't find much so here goes.....On a N/A stock cammed 4.8 w/ basic boltons is a set of LT's really worth the upgrade? I am currently running a 3" Corsa Sport catback and just wondering if the addition of LT's will be overkill for my application? I have heard opinions that the swap can actually hurt my low end performance enough to not warrant the swap? Anybody have any dyno numbers from a 4.8 header swap? I know most say LT's can gain as much as 25+ on 5.3 & 6.0 applications, but I haven't seen any charts on the 4.8. Would like to get some opinions on this, especially from those that are running LT's on a 4.8 truck and what the overall impressions were?

dry_kill 01-21-2007 08:13 PM

i put LTs and a ORY in my truck and gained a second, went from 16.9 but that was on 20s with the tailgate and spare, then after just LTs on stock tires with tailgate off and spare off i went 15.9, maybe gained .5 or .6

SlvrSierra4.8 01-21-2007 08:21 PM


Originally Posted by dry_kill
i put LTs and a ORY in my truck and gained a second, went from 16.9 but that was on 20s with the tailgate and spare, then after just LTs on stock tires with tailgate off and spare off i went 15.9, maybe gained .5 or .6

Damn, not bad. Was that w/ the Corsa too, and on the stock tune?

NyteSnyper 01-22-2007 01:31 AM

Well, not sure if this will help you out or not, but I'll post my experiences up...

Had a bone stock Silverado RST (came with CAI, shorty headers, exhaust and the 4.8, yay!) put a TR224 in it... found out that the shorty headers weren't enough for good "breathing" for the cam, got pacesetter LT's.... now, there was a definate feeling of loss on the low end, however, the top-end pull was absolutely amazing compared to the shorties... then got it tuned for the cam and lts and pulled a 14.4... was pretty happy with the truck. I'd recommend getting some LT's just for the fact that it will compliment later mods on down the road... I could deal with the "dogginess" that they added to the down low, but i only really feel it in DD situations...

SlvrSierra4.8 01-22-2007 12:59 PM


Originally Posted by NyteSnyper
Well, not sure if this will help you out or not, but I'll post my experiences up...

Had a bone stock Silverado RST (came with CAI, shorty headers, exhaust and the 4.8, yay!) put a TR224 in it... found out that the shorty headers weren't enough for good "breathing" for the cam, got pacesetter LT's.... now, there was a definate feeling of loss on the low end, however, the top-end pull was absolutely amazing compared to the shorties... then got it tuned for the cam and lts and pulled a 14.4... was pretty happy with the truck. I'd recommend getting some LT's just for the fact that it will compliment later mods on down the road... I could deal with the "dogginess" that they added to the down low, but i only really feel it in DD situations...

Thanks for the info NyteSnyper, the dogginess down low is my main concern, and since a DD situation is what I am usually in this was what I was somewhat worried about. Was it really that noticeable at low speeds and normal around town driving? I know that is where the 4.8 lacks anyways so to make the low end power worse, wouldn't necessarily be a good thing.

white1 01-22-2007 01:05 PM


Originally Posted by NyteSnyper
Well, not sure if this will help you out or not, but I'll post my experiences up...

Had a bone stock Silverado RST (came with CAI, shorty headers, exhaust and the 4.8, yay!) put a TR224 in it... found out that the shorty headers weren't enough for good "breathing" for the cam, got pacesetter LT's.... now, there was a definate feeling of loss on the low end, however, the top-end pull was absolutely amazing compared to the shorties... then got it tuned for the cam and lts and pulled a 14.4... was pretty happy with the truck. I'd recommend getting some LT's just for the fact that it will compliment later mods on down the road... I could deal with the "dogginess" that they added to the down low, but i only really feel it in DD situations...



What kind of converter did you have? Just teh swap to the TR224 with a 4.8 and no converter will make it feel like a dog down low. With or with out LT's

TarheelZ 01-22-2007 01:19 PM

I also 'felt' a loss of low-end when the LTs went on my 4.8 but the cam I went with helped out some when it was installed. It's a small Lunati (212/216). I'm sure my setup would've been better served by 1 5/8 instead of the 1 3/4 primaries, but I really like the Dynatechs.

white1 01-22-2007 02:37 PM

Only issue I had with my LT's was my 6th or 7th tranny disliking them about 12 hours later. :bang:

NyteSnyper 01-22-2007 05:27 PM


Originally Posted by white1
What kind of converter did you have? Just teh swap to the TR224 with a 4.8 and no converter will make it feel like a dog down low. With or with out LT's

No converter needed.... i got a 5-speed... :drive:

:)

Well, I cannot speak from experience as far as an automatic goes... however, it was noticeable before and after... to me, it wasnt horrific, just needed to adjust my driving habits a small bit to compensate... in an automatic, you probably wont notice at all...

white1 01-22-2007 07:13 PM


Originally Posted by NyteSnyper
No converter needed.... i got a 5-speed... :drive:

:)

Well, I cannot speak from experience as far as an automatic goes... however, it was noticeable before and after... to me, it wasnt horrific, just needed to adjust my driving habits a small bit to compensate... in an automatic, you probably wont notice at all...



Just do a clutch drop at 3000 RPM then. Shouldnt notice a low end loss


All times are GMT -5. The time now is 08:34 AM.


© 2024 MH Sub I, LLC dba Internet Brands