Stock Downpipe (Cat) and Front Pipe Question

varge

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For what it's worth, we spent the whole day at the dyno today with Angelo, and it proved to be quite hard to get past 255whp on the dynapack on the TD03 and the stock exhaust, so there may be a good indication that the stock dp/cat are now becoming a serious restriction, although the TD03 was happy to provide steady pressure at high RPM and some serious flow in g/s over the improved Si turbo, which did not translate into ponies at higher RPM :)
I may consider having a custom 3" to 2" downpipe with a free flowing cat at some point.
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For what it's worth, we spent the whole day at the dyno today with Angelo, and it proved to be quite hard to get past 255whp on the dynapack on the TD03 and the stock exhaust, so there may be a good indication that the stock dp/cat are now becoming a serious restriction, although the TD03 was happy to provide steady pressure at high RPM and some serious flow in g/s over the improved Si turbo, which did not translate into ponies at higher RPM :)
I may consider having a custom 3" to 2" downpipe with a free flowing cat at some point.
If you're going to get a custom downpipe made ,may i suggest make it gradual or tapered for the best of both worlds.
Start at 3" for the first 90degree bend , go to 2.75" for the second one for the downpipe. Then start the front pipe at 2.75" and slowly go to 2.5" and keep it there .(Or go back to the stock 2") But i would keep the 2.5" size for the very last section of the front pipe.
 
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The 10whp gain with the front pipe was due too their previous dyno pulling timing Because of heatsoak.
So they said there was no hp gain.
I was also watching their videos ?,i didn't saw the exhaust video yet.
This is true. But you missing another part of the video. The 10lb-ft of torque that was gained on the lowend. THIS is why I ended up purchasing the AFE rear downpipe (Front Pipe) after watching the video. For racing purposes, this will help turbo spool up and my 60ft time. For everyday purposes, I will be able to utilize this lowend torque while driving around moderately, be it to the grocery store or taking the wifey out to dinner. This is something we can feel all the time. :)

Link directly to dyno plot in the video ---- HERE
 
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Right after seeing the video, I ordered the front pipe. It has arrived today. Woot woot! :rofl:

I plan on removing it from the box and comparing the size of it to the 3" (PRL) downpipe that I have side by side tomorrow hopefully (@work now). I will also be comparing the weight of it. I should have posted up the weight of the stock front pipe somewhere here in the forums. I'll look.

Edit: Found the frontpipe, downpipe weight thread I posted. HERE
Looks like I never weighed my stock parts though. Grrr.....

Honda Civic 10th gen Stock Downpipe (Cat) and Front Pipe Question 20201124_162144
 
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Weighed the PRL Frontpipe vs the AFE Frontpipe. They both came in at 6lbs even. That surprised me considering PRL's pipe diameter difference.

In the pics below, the PRL is more of a gold/bronze color while the AFE is silver. If you look closely, you can see some heat damage by the PRL frontpipe's flex joint. That's where it was coming into contact with my intermediate axle.

PRL internal diameter is 2.791" (70.89mm).
AFE internal diameter is 2.348" (59.64mm).

I know this isn't info that anyone asked about. If nothing else, I use it to refer to later. Sometimes years down the road. ;)

Honda Civic 10th gen Stock Downpipe (Cat) and Front Pipe Question PRL vs AFE-1


Honda Civic 10th gen Stock Downpipe (Cat) and Front Pipe Question PRL vs AFE-2


Honda Civic 10th gen Stock Downpipe (Cat) and Front Pipe Question PRL vs AFE-3


Honda Civic 10th gen Stock Downpipe (Cat) and Front Pipe Question PRL vs AFE-4


Honda Civic 10th gen Stock Downpipe (Cat) and Front Pipe Question 20201125_055112
 
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Gherbo23

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Weighed the PRL Frontpipe vs the AFE Frontpipe. They both came in at 6lbs even. That surprised me considering PRL's pipe diameter difference.

In the pics below, the PRL is more of a gold/bronze color while the AFE is silver. If you look closely, you can see some heat damage by the PRL frontpipe's flex joint. That's where it was coming into contact with my intermediate axle.

PRL internal diameter is 2.791" (70.89mm).
AFE internal diameter is 2.348" (59.64mm).

I know this isn't info that anyone asked about. If nothing else, I use it to refer to later. Sometimes years down the road. ;)

PRL vs AFE-1.jpg


PRL vs AFE-2.jpg


PRL vs AFE-3.jpg


PRL vs AFE-4.jpg


20201125_055112.jpg
bringing this back to see if you felt that quicker spool or not? I’m catless with stock fp and exhaust besides a vibrant res swap. Wondering if the FP is even worth getting or not. Getting dyno tuned soon so I’d prefer to have all parts on the car by then
 
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bringing this back to see if you felt that quicker spool or not? I’m catless with stock fp and exhaust besides a vibrant res swap. Wondering if the FP is even worth getting or not. Getting dyno tuned soon so I’d prefer to have all parts on the car by then
I can't say if it is worth it or not since I haven't done a back to back comparison with nothing else changed unfortunately. I've done a few other modifications that I am hoping supports airflow (Ex: 27Won Tip and removal of intake manifold 'air straightener'). So I can't say if they have affected the earlier spool more or less than the AFE frontpipe if at all. :( I''m just relying on Edge Motorsports dyno comparison they did. A larger frontpipe can't hurt.

I CAN say that if you enable 'early spool' in Ktuner that it does make a significant difference in acceleration.
 

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I can't say if it is worth it or not since I haven't done a back to back comparison with nothing else changed unfortunately. I've done a few other modifications that I am hoping supports airflow (Ex: 27Won Tip and removal of intake manifold 'air straightener'). So I can't say if they have affected the earlier spool more or less than the AFE frontpipe if at all. :( I''m just relying on Edge Motorsports dyno comparison they did. A larger frontpipe can't hurt.

I CAN say that if you enable 'early spool' in Ktuner that it does make a significant difference in acceleration.
yea I really don’t think the front pipe will make a difference until a turbo upgrade happens. I’ve got my 27won TIP coming tomorrow since I can’t stand looking at a pancake when I pop the hood, and figured if anything, the sound of a metal inlet will put a bigger smile on my face. Planning to add a FMIC with charge pipes, a flex kit, then hitting the dyno. I have a cvt as well
 
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yea I really don’t think the front pipe will make a difference until a turbo upgrade happens. I’ve got my 27won TIP coming tomorrow since I can’t stand looking at a pancake when I pop the hood, and figured if anything, the sound of a metal inlet will put a bigger smile on my face. Planning to add a FMIC with charge pipes, a flex kit, then hitting the dyno. I have a cvt as well

Good luck! Looking forward to your dyno session results.
 

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I've read that the replacing the stock downpipe and frontpipe will allow our Civics to gain horsepower. The downpipe (cat) and front pipes that replace our stock ones are larger in diameter (2.5" to 3") than the stock one (2").

So, looking at the stock downpipe and front pipe, I notice a few things. The stock downpipe (cat) has a large opening and goes down to a smaller opening. Replacing the cat with an aftermarket one I can understand would help you gain horsepower. But why would a larger front pipe gain your horsepower?

I ask because the front pipe is the same diameter as the rest of the exhaust going back to the mufflers. I provided a pic of both the stock downpipe (cat) and front pipe. Look closely at the front pipe. Where is there a restriction? If the diameter of the front pipe is a restriction, so would the rest of the exhaust going back to the muffler as well.

1) So how it is that the front pipe is a 'restriction' and replacing it with a larger diameter front pipe yield horsepower gains?

2) How does going with a larger downpipe and frontpipe gain you horsepower when the rest of the exhaust is a smaller size? Why not go with the same size downpipe and front pipe as the stock exhaust? Or at least the front pipe since the innards of the stock cat can be a restriction?

A lot of folks here are a lot smarter than I so I am just asking a few questions. Some of this doesn't make sense though.

Stock Frontpipe Cat.jpg





Edit:
I just looked at dyno runs of AFE aftermarket downpipe, front pipe and exhaust tested individually and they all added horsepower and torque. Below are the links.

AFE exhaust: 7whp (This was installed first with stock downpipe and frontpipe). HERE
AFE downpipe: 5whp (On lowend. Topend, they were experiencing hp loss due to hot intake temps/ignition timing being pulled. HERE
AFE frontpipe (Or Rear Downpipe they called it): 10whp. HERE
Blog Details on full exhaust setup: HERE
How common is it to lose power or just mess with anything that could hurt the car out of the ordinary when you just have bolt ons? For example: i read putting a oil cooler on could actually hurt you since you’d have to make sure your up to temp. Stuff like that. I know the cvt can’t handle much but I plan on doing most everything to my car for shits and just having a conservative tune. Thanks.
 


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How common is it to lose power or just mess with anything that could hurt the car out of the ordinary when you just have bolt ons? For example: i read putting a oil cooler on could actually hurt you since you’d have to make sure your up to temp. Stuff like that. I know the cvt can’t handle much but I plan on doing most everything to my car for shits and just having a conservative tune. Thanks.
Just stick to the more common bolt ons and stay conservative with your cvt and you'll be fine. Like air intake, intercooler etc.
 

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Thanks! Been looking for info about this for quite some time. It's unfortunate I have not had success with having a PRL frontpipe installed on my CVT because it keeps coming into contact with my intermediate driveshaft. I'm on my 2nd one now. This is good to know.
I know this is old but, what do you mean it was hiitting the driveshaft, I have a CVT and was hoping to install an invidia front pipe. so so are you saying I will have problems after installing?
 
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I know this is old but, what do you mean it was hiitting the driveshaft, I have a CVT and was hoping to install an invidia front pipe. so so are you saying I will have problems after installing?

See this thread for details ---> PRL Downpipe Fitment

The PRL front pipe I had installed was 3" in diameter. I had no luck with it due to it hitting my intermediate driveshaft. First time it was due to not being installed correctly. However, I purchased a 2nd one and had it installed correctly and it hit the driveshaft as well. Other people have experienced the same, with and without it installed correctly.......on a Civic with a CVT tranny. I can't recommend any 3" front pipes to be installed on a civic with the CVT transmission.

So, if the Invidia front pipe is 3" in diameter, I wouldn't recommend it however that is not to say it will not work. I don't know for sure. I'm now using a smaller frontpipe and have had zero issues with it making contact.
 

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See this thread for details ---> PRL Downpipe Fitment

The PRL front pipe I had installed was 3" in diameter. I had no luck with it due to it hitting my intermediate driveshaft. First time it was due to not being installed correctly. However, I purchased a 2nd one and had it installed correctly and it hit the driveshaft as well. Other people have experienced the same, with and without it installed correctly.......on a Civic with a CVT tranny. I can't recommend any 3" front pipes to be installed on a civic with the CVT transmission.

So, if the Invidia front pipe is 3" in diameter, I wouldn't recommend it however that is not to say it will not work. I don't know for sure. I'm now using a smaller frontpipe and have had zero issues with it making contact.
Thank you, also read your thread. my invidia is 2.3 inches, I should be ok, Im going to continue to read your thread. Will install this week, Ill keep you posted if i run into any issues.
 
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See this thread for details ---> PRL Downpipe Fitment

The PRL front pipe I had installed was 3" in diameter. I had no luck with it due to it hitting my intermediate driveshaft. First time it was due to not being installed correctly. However, I purchased a 2nd one and had it installed correctly and it hit the driveshaft as well. Other people have experienced the same, with and without it installed correctly.......on a Civic with a CVT tranny. I can't recommend any 3" front pipes to be installed on a civic with the CVT transmission.

So, if the Invidia front pipe is 3" in diameter, I wouldn't recommend it however that is not to say it will not work. I don't know for sure. I'm now using a smaller frontpipe and have had zero issues with it making contact.

hmm interesting. First time hearing of this. No issues here and I have PRL's dp and fp setup.
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