Frs stock Header (Jig)
 

I made up a Jig for the stock header to swap out the front cat. I copied the one that I saw from Kodenawe47 from the UK. I purchased a nearly brand new head pipe off ebay for 80.00. I will be able to keep mine new and in tack for later on. I will be at my friends exhaust shop next week and he is going to help me fab up the cat replacement. He learned very well from his father as his dad used to hand make all the exhaust for the older street going Panoz roadsters built up near Road Atlanta. If all goes well hopefully we will be able put the new collector in and (test pipe) without having to keep test fitting the head pipe. If it works out seamlessly and strait forward, this will save me a few dollars until I decide on a supercharger or turbo unit next year. I will post updates hopefully next week. Regards Steve

Good work so far, however the cat is not the problem with the stock header. Tube length and diameter are bigger issues in terms of power production.

Hahahahahaha

The turd stuck in my toilet isn't what keeps it from flushing, it's the piping diameter.

Interested to see the results!

Eat healthier

I was illustrating that the header cat is easily the most restrictive part of the entire exhaust chain.

Not arguing that. Why do all that work when u can get a used, proven header for 300 bucks?

I was simply responding to the bit about the cat not being the problem.

I admire the DIY spirit but I'm inclined to agree about getting a nice used aftermarket header. Resale on a used part isn't likely to move much.

Yeah, it always the original owner who takes the hit. I speak from experience.

Most restrictive, sure. But the primary/secondary lengths/diameters are also not optimal for making the best N/A power. There's a lot more power to be had with a better design than just removing/gutting the cat.

Some people prefer to spend time rather than spending money. :thumbsup:

I have a habit of thinking in FI terms, sorry. :bonk:

Agreed, but I think OP is more looking for the cheap way out regardless, and I really wonder about the gains of most cheap aftermarket headers. Dyno error and all that.

I can tell u from experience that a good header and proper tune will wake these cars right up. Definitely more than anecdotal results.

I would connect the fixture to the other side head flange also. The side with flex joints will move once you cut the cat out. :)

yup, big difference - that said, not sure $300 will get you those differences. not all aftermarket headers are equal. I'm betting properly modded stock headers would produce better results than many low end headers out there (not to mention fit/finish/build quality)

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Pfft! Like you would know anything about welding headers!;)

I agree. Nothing fits like oem. Oem will probably outlast them all as well. My point is that all this effort could be directed at a used aftermarket header and would yield better results. Obviously there are a few short tube offerings that are worth shit but every now and then a good one shows up in the classifieds.

I 100% agree, some really well built long tube headers can be purchased for around $500ish used, and with a proper tune can really change how the car drives.

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I appreciate the insight. Now that I am sitting here looking at it, Jdl, you are correct I should run a piece across to the other side. What do you think, If bolted another small plate to the other side and instead of welding that all together as one unit, I could additionally bolt a stout piece of flat stock from one plate to the other one side. Then when we do cut out the cat if there were any amount of deflection from the expansion joints, this would help to keep everything even more tolerant. I am not an engineer by any stretch of the imagination, just trying to keep the ole gray matter in ops chk mode. Do you thing that would be enough? Again thanks for your input. Steve

hey don't listen to us armchair "engineers" over here, you don't know the real life results until you build it and test it. I've been waiting for someone capable to do this and document it, thanks for stepping up.

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Do you have a build thread? If no considere to make one and document all you done there with pics. Some people here like to see custom/DIY works on this cars

Teseo, I haven't yet but I sure will. Thanks so much I will keep you posted. Best regards Steve Ultra and Jdl I didn't stress the jig just centered bored the holes and bolted everything up nice and tight on the cross over brace and plate. Thanks I finished it up this morning. My Invidia over pipe will be in tomorrow so on tues I will spend the day at my friends shop. I will post so the finished unit hopefully by the end of the week. Regards Steve

Hey, Steve. On your jig, like @JDLAutoDesign said, you want to reference everything to that opposite flange.

I like your style! Keep it up!

Just dropping in an update. I am gonna try and get by to pick up the cat less stock header tomorrow. I post some updated pics.

Modded FRS cat head pipe.
 

I picked up the de catted head pipe today. I think he did an amazing job on the collector. I went ahead and had another bung put in for future upgrades. I forgot to weigh it with the cat. I weighed it after the mod and it weighed 13.4 lbs. When I get my stock one off tomorrow I will weigh it for comparison. Based on my jig I am striving for it to bolt right up without any tweaking. I'm installing it with my Invidia overpipe, stock front pipe and invidia Q300 exhaust. I will update the final setup tomorrow. Thx Steve Sorry about the pics being inverted, I am not the most computer savvy.(Ha) I am going to learn by this weekend how to rotate them correctly. I take them in the normal position with my I phone, but for some reason here lately when I send them from my phone to my computer they seem to be coming out like this (DDDooohhh). I apologize in advance.

Looks good!

Frs stock Header (Jig)
 

I finished up the frs de catted head pipe today. I re flashed with Shivs stage 2 (EL). It operates perfectly. This in combination with the Invidia overpipe is for just about spot on. I did pull the front bumper and do the snorkel tube mod per Chase at Grimmspeed. As a side note mine is a 2015 model I took my time and the bumper came off with out a hitch. I did replace the 2 push pins behind my side markers with 5/16 fender nut plates. The bumper went back on perfectly no side bulges or popping out of place as I have read about 2013 models. I took it out for an hour long trip in the north Ga mtns. My seat of the pants dyno is really a great improvement over my previous set up. It pulls like a mule strongly now from 3000 to 4000 then keeps building the linear power all the way to the redline. Since I went back with the stock exhaust shields the heat is no problem. I have zero rattles its nice and quiet just remarkable with the new improved midrange punch. I approached it just like I set up my old VFR 800 interceptor. Intake/power commander/ by Doebeck/ and cat delete with a Staintune exhust. This was a big midrange wake up on my old bike and seems to be just the perfect combo for my FRS. All together I have 110.00 in the total mod, this is including the biggest expense of the stock cat/headpipe from ebay. Thanks again to this forum for giving this idea and all the continued friendships and support. Best regards Steve

Thanks Ultra I appreciate it. Steve

You had me going for a minute until I see you started a new thread.

We can ask @ichitaka05 to merge them for you if you like.

http://www.ft86club.com/forums/showthread.php?t=111174

It's really cool that you got all the heat shield to fit. Minimalism.

Thanks Ultra- Me with a computer is dangerous (ha). Still in a big learning curve. Thx Steve

Looks great sroby. I've been planning a similar project, so I'm happy to hear you've got it running and providing gains. I don't think I'll be able to get it done as cheap as you though!

I have a few questions about the construction of the tubing you (or your fabricator) used to replace the cat:

1. For the "collector" tube, what inner diameter tube did you use?

2. Did you achieve the "oval" end shape of the collector tube by simply squeezing the end of the tube to flatten it out a bit?

3. Did you have to do any work inside the collector tube to create a nice merge, like weld in a separating plate, or did you just clean up the merge that already existed in the upstream part of the manifold?

Oh, and how does it sound?

I had a great improvement by punching out the stock cat in some spare headers with the OFT stage 2 EL tune. I wish we could run our cars back to back on a dyno and see what the value of doing all that extra work is!!

Rameus, Jazz, thanks, My guy used a Y connector/Stainless that he gets from his vendors He told me the name of the collector and it escapes me at the moment. I want to say Vortex brand . I will see him on Monday and verify. He heated it up and has a real trick mandrel bender and was able to put the slight bend in it. Because I wanted to install all of the factory shields, he cut the factory mount end off of the stock cat about 2 inches left the tabs on for the shield. He then had to take about a 3 inch long piece of stainless tube weld the collector on to it and then the factory mount. With this it mounted up to my Invidia over pipe still utilizing the factory studs. He knife blade cut the inside of the collector to help smooth out the exhaust gases as it enters the last slight bend before the overpipe. I was asking him about just gutting the cat. He was telling me its been done all the time and works decent. Was he was explaining to me was that that large amount of exhaust entering into the now gutted cat body, will somewhat get bottled necked and cause those super heated exhaust gases and shockwaves to decrease backpressure slightly. Not to mention you get a lot more noise as the outer wall of the cat without the ceramic core is thinner and as I have done on my old dodge neon ACR its ringy type of a sound. When I was Solo 1 and autocrossing the Acr the noise would get on my nerves. I wound up doing the same thing putting in a test pipe and it just sounded a whole lot more smooth. Like I say my seat of the pants dyno tell me more power. It will be a couple of weeks before I have her on the dyno and will report back the findings. I can confirm that now with the complete set up I am running the dip that I felt between 3 and 4 thousand to me is totally gone. It seems to pull harder in 3- 4- 5 till redline. I have never ran it over a 100 mph yet as I just turned 3000 miles on the clock. Since I have it all finished for now I hope to do a track day November at Barbermotorsport or Road Atlanta. I would love to check out the new North Ga motorsport complex, but it way above my paygrade. Unless I could get an invite by one of the members. Even then I think it runs over 300.00 God I miss my Air Force days around the west coast where there were so many tracks to have fun and very inexpensive. Will report back soon Thx Steve

If anybody on the forum wants to use the jig I have made, You are more than welcome to use it. Just pay the shipping and I will send it to you. We can bounce it around, When you are finished just send it back or pass it onto the next member for their use. I don't know if that's breaking any forum rules somebody pls advise me if so. Keep in mind the intent would be for off road use only. Anyway just let me know, I have al the hardware and I will right down some directions on the way I mounted to the head pipe for proper fitment. With me utilizing the Invidia over pipe it mounted up exactly as the stock over pipe. Absolutely no exhaust leaks and nice and quiet no raspy header ping. You can really hear the intake now with the modded snorkel and the grimmspeed intake I am using. Its a good sound in that sense to me. Thx Steve

That's a nice job. Im glad you had a tuning solution as well. Even expensive headers give minimal gains without calibration.

Lantana, Thx partner. Regards Steve

Wow, thanks for all that info sroby.

If you do find out the name of the collector your fabricator used, please let me know.

Thanks for the general offer to lend your jig. A large part of the reason I am doing this project though, is to practice my own meager fabrication skills, so I'm intent on building my own :)

Was it a Vibrant collector?

The beauty of this is you can make it super cheap by flashing on the OFT maps via rom raider :O