Exhaust changes: mistake or not?

RN SHARK · 07-20-2019, 12:43 AM

Hey all, I wanted to ask those who track what your thoughts are on my exhaust changes I just made. The reason for the change was to install the Verus rear diffuser, as it did not fit with the FI mufflers.
So I have the Fast Intentions LTH, 12” resonated Xpipe, and had the SS mufflers. I just had the mufflers removed because they interfere with the rear diffuser. I had SS straight pipes installed in their place. The car is now obnoxiously loud, but on track it should sound more appropriate. My concern is the noticeable loss of low-end torque. I’m wondering if this will even be an issue since on track the rpms do not drop below 3000 anyway. I know I could go with 4.08 gears, but that is another big cost I don’t want to do right now if I don’t have to. What do you all think?
FYI-car is rarely driven on the street. It is trailered to and from the track, so not concerned about legality and noise (aside from certain tracks’ limits).

secondnissan · 07-20-2019, 01:38 AM

Fast intentions now has a 10 inch muffler option not listed on their site. These mufflers are 4 inches shorter on the side that faces the front of the car. I have this diffuser as well and I think these mufflers might give enough clearance to run the diffuser without cutting ( which I already did )

RN SHARK · 07-20-2019, 02:49 AM

Quote:

Originally Posted by secondnissan

Fast intentions now has a 10 inch muffler option not listed on their site. These mufflers are 4 inches shorter on the side that faces the front of the car. I have this diffuser as well and I think these mufflers might give enough clearance to run the diffuser without cutting ( which I already did )

This is information I could have used YESTERDAY!

Hotrodz · 07-20-2019, 09:05 AM

You can go with a ported manifold like Motordyne or Z1. I have no experience with Z1 but the with Motordyne you will see an increase in torque and about a 5whp drop on the top end. I don't know that it is worth the extra cash. I'm not sure it is worth worrying about if you if don't see any difference in track times.

2011 Nismo#91 · 07-21-2019, 08:05 AM

I ran/run straight pipes on and off the track. You can retune the car if you really want. While there is some loss low and mid range there is a very small gain top end which is there you'll spend 90% of your time at on the track. Also it sounds great at full rev on the track IMO.

RN SHARK · 08-13-2019, 03:03 AM

A little update: The workmanship on the straight pipes was total garbage. My magnet stuck to the crap stainless and the welds were horrific. Needless to say, I took it to another quality shop and paid about as much as I paid the first shop just to put it back the way it was. At least the first shop refunded my money, so I’m out $260 to get back to where I started from. Now the plan is to buy the Fast Intentions 10” muffler sections only and see if that will work with the Verus diffuser. Ugh. What a pain in the a$$!

NorthStyle · 08-13-2019, 11:05 AM

Quote:

Originally Posted by RN SHARK

A little update: The workmanship on the straight pipes was total garbage. My magnet stuck to the crap stainless and the welds were horrific. Needless to say, I took it to another quality shop and paid about as much as I paid the first shop just to put it back the way it was. At least the first shop refunded my money, so I’m out $260 to get back to where I started from. Now the plan is to buy the Fast Intentions 10” muffler sections only and see if that will work with the Verus diffuser. Ugh. What a pain in the a$$!

Hate to be the bearer of bad news, but unless the FI 10" mufflers sit more towards the bumper then towards the differential then you're about to have a bad time. But good luck!!

RN SHARK · 08-16-2019, 11:50 AM

Quote:

Originally Posted by NorthStyle

Hate to be the bearer of bad news, but unless the FI 10" mufflers sit more towards the bumper then towards the differential then you're about to have a bad time. But good luck!!

They told me the mufflers are 4” shorter towards the front of the car. So they are unchanged from the tip to the muffler. So they don’t sit more reward, but are less towards the differential. Do you think that would work??

07-20-2019, 12:43 AM	#1 (permalink)
RN SHARK Track Member Join Date: Jun 2011 Location: Wake Forest, NC Age: 43 Posts: 618 Drives: 09 370Z, 14 SRT GC Rep Power: 34	Exhaust changes: mistake or not? Hey all, I wanted to ask those who track what your thoughts are on my exhaust changes I just made. The reason for the change was to install the Verus rear diffuser, as it did not fit with the FI mufflers. So I have the Fast Intentions LTH, 12” resonated Xpipe, and had the SS mufflers. I just had the mufflers removed because they interfere with the rear diffuser. I had SS straight pipes installed in their place. The car is now obnoxiously loud, but on track it should sound more appropriate. My concern is the noticeable loss of low-end torque. I’m wondering if this will even be an issue since on track the rpms do not drop below 3000 anyway. I know I could go with 4.08 gears, but that is another big cost I don’t want to do right now if I don’t have to. What do you all think? FYI-car is rarely driven on the street. It is trailered to and from the track, so not concerned about legality and noise (aside from certain tracks’ limits). __________________ ___________ '09 6sp/Z1/PowerTrix/SPL/Swift/SRP/Whiteline/F.I.LTH&CBE/UpRev by Seb/CJM/Stillen/Ings+1/RJM/TrackSpec/Sparco/Motul/Wavetrac/Coolerworx/Verus/CraftSquare '14 SRT Grand Cherokee; '08 TL Type-S

07-20-2019, 01:38 AM	#2 (permalink)
secondnissan Base Member Join Date: May 2011 Location: chicago burbs Posts: 70 Drives: 10 370z 7at Rep Power: 13	Fast intentions now has a 10 inch muffler option not listed on their site. These mufflers are 4 inches shorter on the side that faces the front of the car. I have this diffuser as well and I think these mufflers might give enough clearance to run the diffuser without cutting ( which I already did ) BettyZ likes this.

07-20-2019, 09:05 AM	#4 (permalink)
Hotrodz Premium Member Join Date: Aug 2012 Location: NW, AZ Posts: 9,330 Drives: 10 Nissan 370z Nismo Rep Power: 2684384	You can go with a ported manifold like Motordyne or Z1. I have no experience with Z1 but the with Motordyne you will see an increase in torque and about a 5whp drop on the top end. I don't know that it is worth the extra cash. I'm not sure it is worth worrying about if you if don't see any difference in track times. RN SHARK, Rusty and sx moneypit like this. __________________ *Fast Intentions TT Installed and Tuned by Seb at SpecialtyZ 610whp 560tq:\|Fast Intentions 3" TT-TDX*\|SpecialtyZ/Fast Intentions 72 Row Oil Cooler\|SZ 6 Puck Clutch & Flywheel\|3GsCustoms\|Z1\|Wavetrac\|Hotchkis\|Whiteline \|Blitz\|Fortune Auto 500\|Fujimura\|SPL\|H&R\|TK\|TWM\|RPM Rollbar\|Sparco\|Next Level Performance\|TrackSpec\|AeroFlow Dynamics\|Pioneer\|

07-21-2019, 08:05 AM	#5 (permalink)
2011 Nismo#91 A True Z Fanatic Join Date: Mar 2011 Location: NJ Posts: 2,379 Drives: slowly Rep Power: 33858	I ran/run straight pipes on and off the track. You can retune the car if you really want. While there is some loss low and mid range there is a very small gain top end which is there you'll spend 90% of your time at on the track. Also it sounds great at full rev on the track IMO. Hotrodz likes this.

08-13-2019, 03:03 AM	#6 (permalink)
RN SHARK Track Member Join Date: Jun 2011 Location: Wake Forest, NC Age: 43 Posts: 618 Drives: 09 370Z, 14 SRT GC Rep Power: 34	A little update: The workmanship on the straight pipes was total garbage. My magnet stuck to the crap stainless and the welds were horrific. Needless to say, I took it to another quality shop and paid about as much as I paid the first shop just to put it back the way it was. At least the first shop refunded my money, so I’m out $260 to get back to where I started from. Now the plan is to buy the Fast Intentions 10” muffler sections only and see if that will work with the Verus diffuser. Ugh. What a pain in the a$$! Rusty and Hotrodz like this. __________________ ___________ '09 6sp/Z1/PowerTrix/SPL/Swift/SRP/Whiteline/F.I.LTH&CBE/UpRev by Seb/CJM/Stillen/Ings+1/RJM/TrackSpec/Sparco/Motul/Wavetrac/Coolerworx/Verus/CraftSquare '14 SRT Grand Cherokee; '08 TL Type-S

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