Help: The best diameter DP/FP for my setup

[RV6]

Shameless plug. RV6 also offers a USA made full 3" DP/FP options with a 300 cell cat. Our main advantage is using a leak free simple to install Vband connection between he downpipe and frontpipe. We went this direction since we were worried about leaking between the bolt holes and tubing since that area becomes very thin when upgrading to full 3" tubing.

https://www.rv6-p.com/rv6-catted-downpipe-and-front-pipe-combo-for-for-17-civic-si.html

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[Civii]

Sent you a PM.

Hmmm, interested in knowing the info

 

[IronFusion]

Hello everyone

My car is a Hatchback FK7 sport model with manual transmission. In a few days, I will order an Intercooler and already has the Ktuner V2 with 21PSI tune.
The next thing on my list is a DP/FP combo but I struggle to decide about the diameter and thus cant decide witch company to give my money.
After reading a lot of topics here and making a small R&D I understood these things and choose 2 companies to focus on them:

PRL: Has full 3" DP/FP combo. Has 300CEL catted option.
27WON: Has 3" DP and 2.5" FP combo. Has 200CEL catted option. Have a small gap in the OEM heat shield after installation.
Catted vs cattless: Still not decided but since I don't want it to be too raspy and loud I think I'll go with catted in the end.
Stock exhaust: 2". As for now, I don't plan to replace it. The only reason that can force me to change it will be too much noise after installing DP/FP combo.
The difference in price is almost none for the cattless and 100$ for the catted.

So now for the questions...
The simple one is - witch combo is better for my setup (FMIC and tune for now)? Not planning to upgrade the turbo in the near future for sure.
The deeper is - what consequences can be to making 3" combo ran into a bottleneck 2" stock exhaust? (it will answer the first one too I guess)
The hardest is - and I know its subjective for every ear - the sound I will get from DP/FP combo installation with the stock exhaust...Is it "rice" as **** or it something I will be able to live with?

Thanks to everyone who spent time reading this
Looking forward for your replies
Sincerely
Prozento

I have the 1st Gen PRL catted kit. I don't think there is a need to swap exhaust given what I've read. Unless you want max flow, my experience has been good with the catted option, and I commend you for considering it. Some CELs may be thrown if not turned off, but to me going catted is a responsible nod to the environment. 1st Gen kit does not have a heat shield, but I feel my increased output contributes more to heat than the absence of a shield. My IC is stock, so you're better off than I am. I've no issues with local heat harming anything. In fair weather, I'm 20-30 degrees over ambient. Above 80... I trend a lot warmer ?
IMO... If you go catted just disable P0420, rather than getting fancy with a secondary + catted displaced O2 fitting.
With my upgraded pipes, I gained performance over stock (even without a tune) and the cabin sound has been pleasantly enhanced without the car sounding like a hobo ricer to the outside world. Regardless of catted or not, I highly recommend taking the opportunity that the upgrade presents, to both wrap the new downpipe as well as consider a turbo blanket. I haven't done either, and my reluctance is I don't want to get in there again and remove stuff.

 

[IronFusion]

Shameless plug. RV6 also offers a USA made full 3" DP/FP options with a 300 cell cat. Our main advantage is using a leak free simple to install Vband connection between he downpipe and frontpipe. We went this direction since we were worried about leaking between the bolt holes and tubing since that area becomes very thin when upgrading to full 3" tubing.

https://www.rv6-p.com/rv6-catted-downpipe-and-front-pipe-combo-for-for-17-civic-si.html

I'm set with my other-brand upgrade... But, could you expand on this? Just curious. I can confirm getting a good angle to torque the connecting bolts to mate the DP to Frtonpipe was tricky, and I needed to loosen and bend the shield away to get the access I could. Someone with access to a lift would have a much easier time. If this is a superior approach that'd aid the community and all brands should adopt... Here's the chance to boast ?

 

[IronFusion]

No offense, what's with the PMs from folks? Feedback for the OP serves as feedback for all. And if a product could be improved, I'm sure manufacturers also gain from the informed discourse. Plus... I kind of want to know what yall are saying
Are yall sponsored, and have a need to preserve relationships? Idk... Maybe I'm an oddball in being frank and assuming it helps all around. I'm critical, but try not to just rampantly flame on bias. ?‍

 

[Myx]

No offense, what's with the PMs from folks? Feedback for the OP serves as feedback for all. And if a product could be improved, I'm sure manufacturers also gain from the informed discourse. Plus... I kind of want to know what yall are saying
Are yall sponsored, and have a need to preserve relationships? Idk... Maybe I'm an oddball in being frank and assuming it helps all around. I'm critical, but try not to just rampantly flame on bias. ?‍

If you are referring to me....then this...

"PRL: Has full 3" DP/FP combo. Has 300CEL catted option.
27WON: Has 3" DP and 2.5" FP combo. Has 200CEL catted option. Have a small gap in the OEM heat shield after installation."

All else being equal, I'd say go with 27Won because they have the 200CEL vs 300CEL. Bigger holes in the cat, less restriction, all else being equal. That's all! This isn't something I am telling everyone or recommending. Just a personal choice based off of those two numbers. For those that are more knowledgable than I (About 90% people here), choose either for your own reasons.

As for the Front pipe, I saw no difference in 1/4 mile times from using a 3" front-pipe and a 3" exhaust to using a 3" front-pipe and using stock exhaust to using stock front-pipe and stock exhaust. No difference! However if you must go with an aftermarket front-pipe, I'd say go with 27Wons (especially if you have a CVT) because it is smaller in diameter and you would be less likely to have problems with it contacting your intermediate driveshaft. I have not been successful with preventing this with PRL's 3" front-pipe. Other's (or everyone it seems) have not had this same issue with it being properly bolted up.

 

[IronFusion]

Makes sense. I just saw 2+ ppl indicating they PM'd. Felt like the cool kids were having a side convo, which made me want in even more

 

[xjoshuax89]

If you are referring to me....then this...

"PRL: Has full 3" DP/FP combo. Has 300CEL catted option.
27WON: Has 3" DP and 2.5" FP combo. Has 200CEL catted option. Have a small gap in the OEM heat shield after installation."

All else being equal, I'd say go with 27Won because they have the 200CEL vs 300CEL. Bigger holes in the cat, less restriction, all else being equal. That's all! This isn't something I am telling everyone or recommending. Just a personal choice based off of those two numbers. For those that are more knowledgable than I (About 90% people here), choose either for your own reasons.

As for the Front pipe, I saw no difference in 1/4 mile times from using a 3" front-pipe and a 3" exhaust to using a 3" front-pipe and using stock exhaust to using stock front-pipe and stock exhaust. No difference! However if you must go with an aftermarket front-pipe, I'd say go with 27Wons (especially if you have a CVT) because it is smaller in diameter and you would be less likely to have problems with it contacting your intermediate driveshaft. I have not been successful with preventing this with PRL's 3" front-pipe. Other's (or everyone it seems) have not had this same issue with it being properly bolted up.

Prl 76mm vs 27won 80mm

So technically 3inch vs like 3.15. 27won slightly larger albeit only a tiny bit.

 

[xjoshuax89]

I have the 1st Gen PRL catted kit. I don't think there is a need to swap exhaust given what I've read. Unless you want max flow, my experience has been good with the catted option, and I commend you for considering it. Some CELs may be thrown if not turned off, but to me going catted is a responsible nod to the environment. 1st Gen kit does not have a heat shield, but I feel my increased output contributes more to heat than the absence of a shield. My IC is stock, so you're better off than I am. I've no issues with local heat harming anything. In fair weather, I'm 20-30 degrees over ambient. Above 80... I trend a lot warmer ?
IMO... If you go catted just disable P0420, rather than getting fancy with a secondary + catted displaced O2 fitting.
With my upgraded pipes, I gained performance over stock (even without a tune) and the cabin sound has been pleasantly enhanced without the car sounding like a hobo ricer to the outside world. Regardless of catted or not, I highly recommend taking the opportunity that the upgrade presents, to both wrap the new downpipe as well as consider a turbo blanket. I haven't done either, and my reluctance is I don't want to get in there again and remove stuff.

The interesting thing to look is that the exhaust perhaps might not need changing on a stock turbo making under 275 but could be different when you upgrade the turbo and push 300+. Havent seen any dynos for that.

 

[xjoshuax89]

If you are referring to me....then this...

"PRL: Has full 3" DP/FP combo. Has 300CEL catted option.
27WON: Has 3" DP and 2.5" FP combo. Has 200CEL catted option. Have a small gap in the OEM heat shield after installation."

All else being equal, I'd say go with 27Won because they have the 200CEL vs 300CEL. Bigger holes in the cat, less restriction, all else being equal. That's all! This isn't something I am telling everyone or recommending. Just a personal choice based off of those two numbers. For those that are more knowledgable than I (About 90% people here), choose either for your own reasons.

As for the Front pipe, I saw no difference in 1/4 mile times from using a 3" front-pipe and a 3" exhaust to using a 3" front-pipe and using stock exhaust to using stock front-pipe and stock exhaust. No difference! However if you must go with an aftermarket front-pipe, I'd say go with 27Wons (especially if you have a CVT) because it is smaller in diameter and you would be less likely to have problems with it contacting your intermediate driveshaft. I have not been successful with preventing this with PRL's 3" front-pipe. Other's (or everyone it seems) have not had this same issue with it being properly bolted up.

Interesting. Any pics?

 

[RV6]

I'm set with my other-brand upgrade... But, could you expand on this? Just curious. I can confirm getting a good angle to torque the connecting bolts to mate the DP to Frtonpipe was tricky, and I needed to loosen and bend the shield away to get the access I could. Someone with access to a lift would have a much easier time. If this is a superior approach that'd aid the community and all brands should adopt... Here's the chance to boast ?

This is a stock flange designed for a 3" tube. As you can see there is very little surface area between the hole of the flange and the bolt holes. If it isn't lined if perfectly it will leak and be prone to blowing out. 5mm is less than 1/4" of sealing surface. This is why we only offer our downpipe in a 2.5" outlet to use with the factory front pipe or a 3" vband that works with our front pipe. This allows for a good seal and allow for easy install.

 

[bbeem]

This is a stock flange designed for a 3" tube. As you can see there is very little surface area between the hole of the flange and the bolt holes. If it isn't lined if perfectly it will leak and be prone to blowing out. 5mm is less than 1/4" of sealing surface. This is why we only offer our downpipe in a 2.5" outlet to use with the factory front pipe or a 3" vband that works with our front pipe. This allows for a good seal and allow for easy install.

I've been running your dp and fp for a year now, no leaks no problems, love it. When ordering I went straight for the dp and fp together because although your dp is modular, I would have had to buy the adapter separate when mating up with your fp.

I don't exactally understand the dimensional difference between your 3" I have, and your dp that fits oem fp. And your fp dimensions vs OEM and others. Thanks for helping make sense.

 

[CIVICUK]

I would also highly recommend Wagner tuning for anyone in europe.
Allthough they don't make a downpipe for the 1.5t yet( only the fk8)
Their downpipes use the HJS cats which are widely used in OEM and racing applications.

just came across this thread as i am on the brink of purchasing the wagner tuning downpipe kit as i have heard great things about thier build quality and i am currently running thier comp intercooler. but not sure if you can help with my question but..

they use hjs 300 cpsi on this setup and it actually looks quite beefy like the oem design so would this mean thier catalyst would help with drone and extra engine noise?

 

[Hondanickx]

just came across this thread as i am on the brink of purchasing the wagner tuning downpipe kit as i have heard great things about thier build quality and i am currently running thier comp intercooler. but not sure if you can help with my question but..

they use hjs 300 cpsi on this setup and it actually looks quite beefy like the oem design so would this mean thier catalyst would help with drone and extra engine noise?

Their Cat is 300 cpsi ,oem is 600 cpsi .Any cat helps keep sound down yes,and this one has more cpsi so it will be more quiet then a 200cpsi cat .
It is beefy because it has a large entrance and exit diameters .The largest of all 1.5t downpipes i've found.
For me it was more important that their cat has a Euro 6 regulation so you could pass smogg inspection with this cat.

And in reality the cat itself isn"t such a big restriction as many might think .
27won's test with their downpipe with and without cat showed no power increase .
I would even dare to say the oem 600cpsi cat would perform well if it was retrofitted into a better formed downpipe with only minor hp loss.The oem downpipe shape is what makes it the most restrictive.

 

[CIVICUK]

Their Cat is 300 cpsi ,oem is 600 cpsi .Any cat helps keep sound down yes,and this one has more cpsi so it will be more quiet then a 200cpsi cat .
It is beefy because it has a large entrance and exit diameters .The largest of all 1.5t downpipes i've found.
For me it was more important that their cat has a Euro 6 regulation so you could pass smogg inspection with this cat.

And in reality the cat itself isn"t such a big restriction as many might think .
27won's test with their downpipe with and without cat showed no power increase .
I would even dare to say the oem 600cpsi cat would perform well if it was retrofitted into a better formed downpipe with only minor hp loss.The oem downpipe shape is what makes it the most restrictive.

im hoping a large 300cpsi cat will reduce the cold 1start up noise more than it does on the 27won dp/fp i have heard on youtube they are pretty loud! i also have an ARK exhaust so im aware it wont be as quiet if it was paired with stock. i have enquired to see if they will ever sell the cat on its own as im not too bothered about the frontpipe. it would be nice to know if it would just bolt onto oem frontpipe but i think that would create a serious bottleneck would you say?

oh thats a bonus if it helps you guys with emissions, to be honest i thought most catted downpipes were efficient for emissions tests hence why they made catted versions and not just race versions?

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