First I will say I did a TON of research for exhaust for the C5 corvette before I bought something. Hours or reading this forum and others. A lot of the threads I read were 10 plus years old..... Yes I know our C5s are dated and well.... let’s face it obsolete 🤷🏻‍♂️. But since I took so much knowledge from this forum and since manufacturers designs and processes change over the years, I wanted to add my opinion with current 2021 data. I chose LG because of their consistent rock solid reputation and constant praise from owners. Over the years I have installed several sets of LTs on different V8 engines, so the process was not intimidating to me. In fact it can be done with a few simple hand tools. Now onto the install!

I was impressed with the overall quality and presentation of the exhaust and the stout quality of the stainless exhaust pipe used In The kit. The headers were fairly easy and straight forward to install. I placed both of them from the top. The steering shaft, D/S valve cover and ALT were removed to make room for the header. The pass side went in with minimal fuss. Lifting the motor may help but wasn’t needed. Unfortunately this is where the fun ended. The Cats were and still are back ordered with an extended ETA so I had a set of 400 cell ceramic cats made so I could finish the exhaust (I wasn’t informed of this back order and had to call and figure out what was going on). The O2 extenders were also not included with my kit so I had to wait for shipment of those too. 😑

During my research, I found a common complaint of all slip fit exhausts (LG included) to be the band clamps. Well this is still the case.... they are a pain and Copper RTV is highly recommended to aid in sealing the slip joints. I also recommend you do the final tightening by hand with the car running so you can hear and feel when it is fully sealed. Overall the exhaust is nice but it requires numerous adjustments with back forth attention and has been a marathon project. However it does sound good. Now the dab readings..

Specs: 2004 C5 base Borla Atak axle back, 400 cell hi flow ceramic cats and LG pro 1-3/4 LT system. Otherwise 100% stock.

dB readings are as follows:
All outside readings were taken at exhaust level at 5’-6’ distance from tips.

Cat delete: Warm idle 78-80 dB
Cat delete: Cold idle 90-92 dB
400 cell ceramic: cold idle 80-84 dB
400 cell ceramic: warm idle 74-76 dB

2004 C5 base stock manifolds and H-pipe with pup cats in tact. Borla Atak axle back.

Cold idle 80-82 dB
warm idle 74-77 dB
Interior At 70mph (3.15 gears): 55dB

Unfortunately my car is still on jacks waiting for my O2 extensions to arrive before I can finish the install. The car is a beast when reved up to around 2k and a huge difference over just an axle back. I’ll update my finial impressions and dB readings once I get it on the road...

 

I've had LG for 11-12 years catless with Magnaflow. Love them. Did you use your phone for the reading?

 

I can relate to your trouble getting components, I ordered AR headers and was told about 3 week build time. Monday will be 8 weeks and as of now no ship date.

 

No, I used a dedicated and calibrated sound meter. (Sper Scientific model 850014)Glad you haven’t had any issues. Once I get everything finally buttoned up, hopefully they will last for the rest of the time I have the car!

 

the headers and or exhaust kit use to be manufactured by Borla for LG. Not sure if that still applies today. However with the current state of precious metals lots of things manufactured with raw metals are taking additional time.. or so I’m being told.

 

All these wait time horror stories are making me glad I went with Texas Speed. They came with all the clamps and free O2 extensions. Arrived in WA 7 days after placing the order.

 

Did you remove the air system when you installed the headers if yes did you pull the intake to get the pipe from behind heads ?

 

Corrected lol

Can't really compare Texas Speed to brands like LG lol.

 

Why? What's really different?

 

Should have gone eBay brand to save some more money lol.

IF you are seriously asking....I'll play

Fit/form/function of a good header like LG
Form collector vs proper marge collector
If it fits it ships vs properly designed headers.

I've seen TS headers on a C6...welds look terrible. fitment was iffy and hung way too low.

 

nope. I kept all that in tact.

 

I removed the intake when installing my headers, regardless of header brand. Makes life much easier. IIRC, there is a nut/stud on the back of the block that holds the metal tube.

It's worth the effort to remove the intake.

 

the pass side A.I.R tube was a pain. I want to keep all the Emissions equipment, especially the cats operational so nothing got deleted for me.