gtodoug

Back in late January I called LG motorsports to see if they had any C6 Z06 exhausts laying around. My QTP cutouts had broken 3 times and I wanted a way to have a loud/quiet exhaust. I figured the NPP option would be a good alternative due to it's simplicity and reliability. I already had a Borla Exhaust on the car and hoped I wouldn't lose any hp when comparing the OEM system vs. aftermarket.

Anthony @ LG was the rep who took the phone call and was asking me my motor, compression, and overall setup of my car. I'm thinking.....dude, do you have the exhaust or not? Anyway, after about 30min of talking to me about my setup he asked if I would be intrested in switching headers. Now, I alreay have American Racing 1 7/8" catless headers on the car at this point, why would I want to switch? As far as I'm concerned I have a 403ci stroker motor and I think that I would need the additional airflow that the 1 7/8" header provides right? Well, he made me a great deal and allowed me to trade-in my AR headers and I came out of pocket for the balance.

I asked Anthony what type of power did he think I would gain. His exact words were: " you'll pick up 20-25lfb ft of tq under the curve and gain 10-15peak, you may lose 5hp or so by doing the swap though." I thought for a minute and figured that sounds reasonable. Lose a few peak for more power under the curve. I was extremely skeptical though. Most of the comparisons I've seen are done in house and I know how to trick a dyno just like anyone else. As soon as I got off the phone, buyers remorse set in. Oh well I thought to myself, worst case scenario is that I'll lose a few hp, and have a brand new set of headers.

Well it has been several weeks and I've just now got around to installing the headers and getting on a dyno.

Ok, a couple of facts. I went to the dyno to make a hp pull and get a clean tq reading before the swap. My previous dynos would only occasionally get me an accurate tq reading. Previously my car made a true best of 515ish. That particular dyno sheet has a spike from hitting the revlimiter at the end of the pull. My basline before the swap was 505whp/450wtq. The car has consistently dyno'd just over 500whp so the 505 from the new dyno sat with me well.

Honestly, how much could I expect to gain by putting a smaller header and adding cats to the car? I figured the car would make 490ish and 455tq peak with gains of 10-12wtq under the curve. I figured that to be a more realistic gain than what Anthony quoted me and what I would accept as justifiable swap.

I was able to get on the dyno where Jeremy Formato of FasterProms would help me squeeze some more power. There wasn't much power to be picked up by tuning to be honest. I think 1-2whp peak and 5-6wtq from the first "after install baseline pull". We cleaned up the fuel map and called it a day. I rushed home as I was late for an appointment. When I reached home and I overlayed the graphs.......

HOLY COW!!

I couldn't believe my own eyes. I verified to make sure it was my new graph and my old graph. I'm still in shock! The car pickedup 18wtq peak and 34wtq peak under the curve!!! This is over a 2500rpm range. I got kicked off the dyno before we could work on the 2000-3500rpm range. I did lose 2-3hp over 300rpm in the power peak area but I'm also running cats on the car where previously I was not. We tuned from 3500rpms to redline. The graph speaks for itself. There is still some power left to be had with some fine tuning and street tuning.

This power is for real guys. This is from 2000 miles away, installed here with my own eyes. The previous tune was done by me and the new tune was adjusted by Jeremy Formato. Keep in mind these results are going from catless headers to headers with cats. If I wasn't using cats the gains would be greater.




I want to thank Anthony, Bobby, and Lou over at LG for selling a product that really works! Thanks especially to Anthony who took the time to ask me some questions and not just give me what I want. We all modify our cars in the quest of going faster. Having quality reps like Anthony on your staff Lou teaches guys like me that sometimes to speed up, you need to slow down and really evaluate your setup. I may be calling you guys for cam advice to see what you'd recommend to pick up some more tq. You guys have been great and I really do appreciate it.

Let me know what you guys think!

Dougie

vettethret

Wow, thats impressive!!! I wonder if the results would have been different on an LS3 with the cathedral port heads! very nice.

Sativa

I've been trying to decide whether to go with LG Pro's or American Racing headers. You just helped me make my decision!

C6400hp

There was never a doubt in my mind that LG Pros were the right headers for me.

gtodoug

Thanks guys, I'm all smiles here. I still can't believe it. I think this helped make up for lazy cam that I was running. If I had gone with something that would generate more low end tq I might have been able to hit my tq goal of 500wtq.

Dougie

Retrotech

Great numbers Doug, your car was a bear before and now more torque!
I m not sure I am ready for another passenger seat ride

I am looking forward to seeing it go down the track.

I went from LG longtubes to American racing headers. Both are great products, and I did lose 18 lbs or torque from 3K up I gained 5 HP up top on the AR. Same dyno, same tune, all else equal.

LG lives up to the promises they make with every product they sold me they told me as well.

After the weld broke on the LGs after 400 plus passes I should have had them repaired or bought new ones.... live and learn.

LG Motorsports

You should have called us, they would have been under warranty

We will repair at no cost if you have any issues.

Thanks guys, I am glad that the LG Headers worked out for you. And the fact that you ADDED cats when you didn't have them before is really impressive.

Thanks

LG

mowton

Certainly is a remarkable improvement. Congratulations

2 quick questions

1. You signature says you had cats? Where they taken off?

2. If I understand, you went from 1 7/8 AR's to 1 3/4 LG's. Do I have that right? Question is, what is the opinion as to what would happen if the AR's were 1 3/4 and further to that, if the LG's were 1 7/8?

Again congrats on the improvement

Ed

3 Z06ZR1

I think this is what happens with 1 3/4 vs 1 7/8.
Lets see 1 3/4 to 1 3/4. Brand x vs brand y

gtodoug

I hope this answers your questions!

gtodoug

I think someone should do that comparison back to back. I'm partial to what works best for me, as you should do for you.

mowton

Yes, thank you.

One more, did ARH recommend the 1 7/8?

Enjoy the power

Ed

johnodrake

LS3 has rectangular ports. LS2 has cathedral ports...

SpinMonster

Nice results Doug.

The results I had several months ago were slammed by many. I had exactly a 34rwtq gain at 4k rpms too....uncanny. The initial runs before tuning the changes were sick. I car was making so much more power that it was spinning the tires at 70-80 in 3rd gear where the prior headers werent breaking 2nd loose so easy.

My car has the LS3 heads so the gains should be similar. LS3 engines seem to respond well to kooks also. Many people seem to get the same peak numbers but the TQ gains with the LG's arent as easy to see if you just type out the peak HP and TQ. In the graph above the power gains off peak were the most impressive such as 3500-4200rpm which is not the peak TQ point and would get missed if you didnt see the dyno sheet.

The 1 7/8's are a bit lower in TQ in the low end anyway so I would guess the gains against the 1 3/4 would be a closer race. Races are decided on area under the curve, not peak HP so I dont see why someone would trade a few up top for the tq gains over a wide power band.... 34 rwtq is a big jump and easliy felt.

Anyway, before it becomes a pissing match with people crying foul, I wanted to say congrats. I'll talk to you soon.

SpinMonster

We did see 1 3/4 vs 1 3/4. Thats what I had (Kooks 1 3/4 and I went to LG's) and you didnt want to believe it then either. 34rwtq gain then also.

vettethret

My bad, been on the dark side too long, thatnks for the correction.

Joe_G

Wow that is dramatic! I read an article in Car Craft recently that showed similar gains from tuning collector length, though in the article the gains were on an engine dyno reduced when full exhaust was put on - your gains are with full exhaust!

What specific tuning changes were warranted by the LG headers?

mowton

I'll start by saying I too am impressed with the improvement and am happy that Doug has quite a performing car there . The power under the curve, as touted by SpinMonster, is absolutely what wins races, as does torque. It's like in golf, drive for show and putt for dough

I don't believe, at least in my case, I was slamming the results or turning this into a "pissing contest", more I was trying to understand the from-to scenario. I do not profess to know all the air flow physics behind too big or too small, but in this, and I believe in your situations, one common element was you both went from 1 7/8 headers to 1 3/4. Without being able to see the two datalogs of the pull's, one can't extrapolate the headers contribution to the results. I assume that in both cases, the pre and WOT AFR's were the same. Also I am having a bit of trouble understanding the tune timeline. If I got it right, the baseline pulls, with the ARH's, were tweaked to maximum HP/TQ previously. Then after the swap, the car was put back on the Dyno and the tune tweaked based on the new setup, to arrive at the posted results, correct?

Also, it sounds like Anthony at LG and Doug had quite a session discussing the stat's on Dougs car and he suggested a setup. I think that is important for any modification and supporting vendor. I was interested as to whether ARH recommended the 1 7/8 headers or Doug just ordered them based on the assumption that his motor needed more air. Designing the air flow dynamics from end to end is key in providing the engine with it's maximum amount of air, and exhausting the spent as quickly as possible. That plays into this story as well.

Lastly, there is no argument that the LG, based on it's true 32" length will produce more Torque at the low/mid range than ARH. I have seen numbers like 5-10 rwtq. Even per your own post, with all being the same, you state "..it may have been a closer race"; enquiring minds want to know. 34 rwtq seems to be alot (though impressive), and I just believe that there may be more going on than just simply LG vs ARH.

I could care less what header anyone uses, some even go the E-Bay route. All my 401K and stocks are in other area's (though maybe lately I should re-consider those as well ), but I do, as an engineer, like to understand the assertions of one is better than the other and how the results are derived.

Let's not turn this into a header war, but more to try and learn about the dynamics so we can make better choices, and understand what makes our cars go the best. After all, that is one thing we all agree about and have in common

Thanks for listening

Ed

NIGHTSTALKER

Glad I made the right decision....I was a credit card swipe away from picking up the ARH's but something just told me to go with the LG's

gtodoug

Easily felt is right. That 3000-5500 rpm range is the sweet spot. I knew right away driving to the dyno that it was different, but was thinking....placebo effect LOL.

Dougie