Headers?

[Meraki Autoworks]

Thats my buddy's z06, sounds insane.

-Josh

Sponsored

 

[honeybadger]

Thats my buddy's z06, sounds insane.

-Josh

Do you by chance have any pics or other info on the setup? Inquiring minds would like to know

 

[Meraki Autoworks]

Do you by chance have any pics or other info on the setup? Inquiring minds would like to know

It was a custom one off set, I think he paid like $10k lol.

-Josh

 

[Volstang]

Here’s a dyno from a 2017 GT350 that I tuned. Car was stock running 93 octane. Dynojet using STD Smoothing 5. Gained ~15hp and 5tq. Could probably play with VCT a bit and smoothing things out and maybe pick up a bit more.

 

[tec548]

Been lurking and reading all I can find. I am planning on ARH headers, JLT intake and Lund tune (unless there are better options?). Not planning on going FI in the future but "if you give a mouse a cookie..."

2 questions really...

1. I know there will be better flow not running cats but can the tune keep the CEL out or will this stay on unless I run the high flow cats for inspection once a year? I have run spark plug anti-fowlers in the past to remedy this as well... any advice here?

2. I'm not sure about the quality of the E85 around here, would a flex tune be the way to go or straight 93 tune?

I'm in Montgomery, Texas and would like to get the most out of these few mods. Also plan on installing myself. Any recommendations on who to buy this all from?

Thanks fellas

 

[NGOT8R]

If you have to choose one, go with the Flex. You will then have the best of both worlds.

 

[NGOT8R]

I actually stay on Flex most of the time and I have all three (91-93 pump gas, Flex and E85R).

 

[Tony_the_Brit]

I recently had Kooks off-road LTH & X-pipes installed with an 93 octane tune by Brenspeed. Everything else is stock. I was doing it in an effort to improve the low and mid-range more than the top end as I tend to drive the track mostly in 4th with only a couple of gearchanges per lap (yep - I'm old & lazy - just do this for fun). Also I was really just curious.

See my dyno chart attached - as you can see the peak numbers are virtually identical to stock (SAE Smoothing 5). I see lots of claims for peak HP & torque and it is noticeable how many use STD and don't mention it at all so be careful that you don't spend a lot only to be disappointed.

The one problem (which I anticipated) was that with the muffler open the car was completely open pipe and ridiculously loud. It also had the typical horrible rasp with the mufflers closed - the car sounded like a Civic with no cats! However I wanted to keep the switched mufflers so had to find another solution other than swapping the OEM mufflers out for non-switchables. At this point I have installed a pair of 4" x 18" Vibrant Performance 1795 resonators in the straight pipe section behind the X-pipe and before the axle.

The pic shows where they are now - but it is a before pic! They don't touch and are a slip-on fit.

Now the rasp with the mufflers closed is 90% gone and the car is OK around town. But if you open the exhaust it is still pretty freaking loud (not surprisingly). Fortunately Gingerman (where I'm going this Sunday 4th) has no sound limits. I'm planning on adding more muffling somehow or maybe the muffler switch controller so I can go to other tracks once in a while but am open to cunning alternative suggestions - anyone. The simplest would be to just add a 2nd set of resonators in the rear section of the X-pipe assembly and barring better ideas I may do this.

That would be here:

As to the performance of the car - I will let you know of my impressions after the weekend. The good news is that the weather forecast is exactly the same temp as the last time I was on the track so it should be a good comparison.

 

[tec548]

Good information and thanks for that. Interested in hearing how it feels on the track. I am afraid of how loud this may get, but I was not planning on doing the long system and leaving my resonators on. Only headers with high flow cats... hoping not too loud.
I would expect in your case a JLT intake would really make some power improvements throughout the whole power band. I think your restriction is the primary intake tube.

 

[Tony_the_Brit]

OK - I was at the track Sunday. General opinion - the car is loud - and sounds amazing. I'm going to try to edit my (bad) video so I can post just the sound. I was only going up to 7,500 but when I changed gear going past the pits it was so distracting that I had to concentrate to not miss my braking point! The video sound does not begin to do it justice. It was just my phone and was zip-tied to the passenger sun visor with the wind buffeting it.

Be aware though that it has totally lost that 350 beat (DaDaDaDa) - now it howls and wails. I imagine that that is due to the non equal-length design of the Kooks LT's.

On the road you would have to leave the flaps closed unless you are way out in the boonies as it is very loud when open unless you are just coasting. When you have it set closed, even with my 18" resonators, it has a bit of a rasp and sounds like a big Civic with no cats (then - I suppose it kind of is). It sounds good at idle though I'm told.

Many tracks have sound limits and this would definitely hit those - maybe from the other side of the track! You would definitely need to get the switch mod that lets you keep the flaps closed even at WOT if you were going to go to tracks with limits - which would make the whole thing pointless.

As to the performance, I gained 4mph on the main straight according to TracKAddict (123 v's 119) and I was pleased to find it noticeably more torquey at low revs in 4th when I was being lazy. That is only seat-of-the pants but it made me happy.

But that sound...

 

[tec548]

Thanks for the write up. I don’t think I can resist much longer. Do you have a cel or any other issues? You are not running any cats are you? Starting with carbon DS next weekend.

 

[Tony_the_Brit]

Thanks for the write up. I don’t think I can resist much longer. Do you have a cel or any other issues? You are not running any cats are you? Starting with carbon DS next weekend.

No CEL - I have a tune from Brenspeed who are here in N Indiana. The car drives as well or better than stock throughout the rev range.

Note that the OEM exhaust is extremely good compared to most cars. Not only that but all LTH setups that I know of for the GT-350 are unequal-length whereas I believe that the OEM shorty's are equal-length which likely undoes some of the LTH advantages. (Although I am not an exhaust expert!)

If you are doing this for sound then OK. But it will sound HORRIBLE when closed unless you add suitable resonators as I did. If you are doing it for power the return is negligible in my opinion, especially if you will be using CAT's.

 

[Rev Happy]

Not sure if some of you guys follow Jamal Hameedi on instagram but he has a video of his old 17 R accelerating and he said it had a custom 4 into 1 equal length manifolds on it. The car sounded like a cross between a 350R and a Ferrari 458...it sounded awesome. Since the car was originally built for him, I'm wondering if he had the headers since new on the car or had them put on after.

 

[Bcobb85]

Not sure if some of you guys follow Jamal Hameedi on instagram but he has a video of his old 17 R accelerating and he said it had a custom 4 into 1 equal length manifolds on it. The car sounded like a cross between a 350R and a Ferrari 458...it sounded awesome. Since the car was originally built for him, I'm wondering if he had the headers since new on the car or had them put on after.

Interested in hearing this. What’s his Instagram name? I’d like to check this out.

 

[Tony_the_Brit]

OK - I was at the track Sunday. General opinion - the car is loud - and sounds amazing. I'm going to try to edit my (bad) video so I can post just the sound. I was only going up to 7,500 but when I changed gear going past the pits it was so distracting that I had to concentrate to not miss my braking point! The video sound does not begin to do it justice. It was just my phone and was zip-tied to the passenger sun visor with the wind buffeting it.

Be aware though that it has totally lost that 350 beat (DaDaDaDa) - now it howls and wails. I imagine that that is due to the non equal-length design of the Kooks LT's.

On the road you would have to leave the flaps closed unless you are way out in the boonies as it is very loud when open unless you are just coasting. When you have it set closed, even with my 18" resonators, it has a bit of a rasp and sounds like a big Civic with no cats (then - I suppose it kind of is). It sounds good at idle though I'm told.

Many tracks have sound limits and this would definitely hit those - maybe from the other side of the track! You would definitely need to get the switch mod that lets you keep the flaps closed even at WOT if you were going to go to tracks with limits - which would make the whole thing pointless.

As to the performance, I gained 4mph on the main straight according to TracKAddict (123 v's 119) and I was pleased to find it noticeably more torquey at low revs in 4th when I was being lazy. That is only seat-of-the pants but it made me happy.

But that sound...

So after 2 more track days I can confidently say that the car is faster than stock - but not much (as you would expect). As always, the Dyno results are really only a tuning aid.

I have followed another GT350 on Gingerman Raceway 3 times now with 3 different "stock" GT350's and each time I find that I'm catching them down the main straight.

Sponsored