0NORCAL-SS

With my car blowing up and all the warranty talk I have decided to take on a project and give all my feedback here. Seeing headers/non catted x pipe on local c7 z06s give 15 to 20 hp at wheels without tuning and add underhood Temps plus void warranty I want to try something different out and give the community results.

Talking to the dealer about warranty issues they said that as long as cats are not taken out ot moved from oem location I will keep the warranty.

So I shot out a set of stock z06 manifolds to get ported and I will be opening up the inlets on the oem cat pipes. Oem cat pipes most of the restriction is on the inlet. I will port match the inlet to the exhaust gasket and I just need to see if I can modify the pipe going into the cats to get smoother flow.

I will also ceramic coat the oem set up to keep underhood Temps down and will match the corsa coated x pipe I have.

I will do a baseline pull then change the items and do another pull. Then to finish it off install the corsa x pipe and do another pull.

I feel that a ported oem exhaust manifold/cat pipes/corsa mid pipe will be close to what long tube headers give (no tune)without voiding warranty, also the cost should be $1000 to $1200 less than buying aftermarket headers.

I will keep everyone updated.


I attached the inlet of oem cat pipes. You can clearly see you can open up the inlet and also if it works get rid of that flat spot and make it a tapered pipe setup to bthe cats. I just need to see if that can be done when I get car on lift

jdmdohcpower

I would imagine if the gains are near what long tubes provide you would need to tune?

foreverfuelie

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0NORCAL-SS

Long tubes wuth no tune make 20 at wheels. The tune is what picks up more and voids warranty. Same goes for oem setup. You can tune it to get more power but voids warranty.

What I'm looking at is cost for hp gained. I deal with arh for C7s a lot. Done many setups.

For lets say 2 inch headers non catted 2k and with no tune get 20hp vs porting stock manifolds $500 and modding cat pipes 15hp I think that's a good bang for buck combo then add in corsa x pipe prob gain 2 or 3hp it will make it even closer and you still have your warranty. . Corsa x pipe 450 on ebay with porting manifolds looking prob around $1k

This will all be a test and just give me some time and at the same time I'm not saying going with headers is a waste because people who don't care about tuning and voiding warranty will make more power I'm just trying a different route and since I do a lot of testing on the street and I'd love to open hood and say it's a bone stock z06 lol

BoilerAnimal

I thought that the Corsa X pipe removes the rear set of cats ?

0NORCAL-SS

Yes my dealer didn't have issues with that since it won't set off any engine codes. If you remove cats in front it sets off codes and will void it.

jdmdohcpower

If it makes power and is cheap im in. Maybe even get a diablo ghost tune at that point. Would like to see how that turns out with dealers. yes I said it but that's a whole different topic so please don't bring that here

3 Z06ZR1

I think you need you get rid of the 289 cfm stock air intake box and filter
to gain much. Then your not bone stock, Just like if you port the manifolds it's not really either.
The Halltech box is an easy mod and no tuning an the car does everything better. Then if you do port you'll get more out of it.
But none of is still bone stock.

0NORCAL-SS

My thread is for results on exhaust I really don't care about intakes because it's already been dynoed. I'm trying to get more power out of car while keeping warranty and stock tune plus will make car sound more aggressive. Main goal is to see just how well stock exhaust can be upgraded

0NORCAL-SS

Exhaust manifolds are done being ported I should have them here next week. The z06 manifolds are about 4 pounds heavier then the c7 cast iron manifolds. So if someone wants to save 8 pounds they can put c7 msnifolds on.

jdmdohcpower

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Shurshot

Are you going to be able to port the whole length of the exhaust pipe runner, or just match up inlets and exits?

There is a process for doing the inside of the factory header runners that some guys use for trying to set class records called extrude-a- hone or other similar names

I pulled these guys just to share a link and have no idea as to their work quality

http://boneheadperformance.com/extrude-honing/

I will say when I looked into doing this years ago I did not think it was worth the money for the small gain in power

Porting intake systems is another matter and IMO results in a better bang for the buck

0NORCAL-SS

Check out map performance they port out oem.runners and have flow sheets for c7

tail_lights

Kracka

Here are my porting results, which will be magnified with boost: https://www.corvetteforum.com/forums...manifolds.html

johnglenntwo

So unlike those CAI's other than HP/TQ the dyno won't change!?

0NORCAL-SS

Not sure what you mean. If I can get 15 hp out of these while keeping warranty I'll be happy

johnglenntwo

Those CAI's caused lean issues observable on their dyno's AFR's. It is probably really stupid here though, since, this has nothing to do with the MAFS. So just asking and good MOD!
I remember a while back (maybe even in the 80s) someone doing a space age coating in a 240MPH Porsche turbo rally street car all the way through. The believe the driver died, but, the coating did its job well. Much of the heat went right out of the tailpipe!

0NORCAL-SS

here is cfm vs stock
dark blue line ported on each runner
light blue oem
almost 50 cfm on runner 3

johnglenntwo

Absolutely!