Converter Troubles / Tail Lights

[Ichikaze]

For starters, i'll try to avoid all newbie troubles and just say i'm a novice under the hood. So anyone who takes the time to help me out with this, i'll definitely appreciate the knowledge shared.

That said, i bought a used '97 Nissan 200SX SE 5-spd. Worked great for a while, but i've been having spiraling troubles. It started with the clutch cable, next came a short from a bogus alarm system practically dangling by threads, then came the alternator and battery troubles. All fixed and taken care of thanks to a mechanic friend of mine who's running through the knowledge with me as well as helping fix it at the cost of parts alone.

Where i'm at now is the catalytic converter. The dilemma i'm having is this: I can't straight-pipe it from the engine, or at least i don't think i can, because my manifolds are welded on directly to the converter. Here's a pic for specifics:http://www.autopartswarehouse....7.jpg[Edit; link was bad]

Most converters are shooting one pipe in and one pipe out, and they tend to lie in the rear. However mine is in the front, and has 2 manifolds shooting in with 1 pipe hole coming out.

If i can straight-pipe it, i'd prefer to do that so i can get better flow. For that i'd need ideas.If i can't straight-pipe it, should i risk knocking out the filter wall inside the converter? Will it work that way, and is it worth buying a new converter only to knock the wall out and risk that? Even if the check engine light comes on, my mechy has the tools to bypass that. Personally, I want max output so i'd rather leave the converter off, but if i have to use it then i don't care to leave the filter-wall in.

Also, i have X-mas options and before i go for looks, i want performance and upgrades. Recommends for engine/electrical work first? I still need to check this car's history. It's got a whopping 11 person history report. Spare me; i'm a poor college kid.

Also, about the tail lights. I have had an insane amount of trouble finding altezza lights for a 97 200sx. I have heard that the 95-98 sentra tail lights are mountable; can anyone please confirm this?? And even if they were mountable, what am i to do about the lights the remain on the trunk? After all, they are split half way...

Thanks in advance,Ichi

[Edit 2: Oops, i might have posted this in the wrong area. Let me know and.. well, if you can move it i'm sure it'd save time. Otherwise, copy & paste ftw.]

[nametakennow]

You could gut that cat. I've seen the results and it works fine.

Here's the deal.

That's your precat. IMO, if you want to nix it, buy a header. Hotshot made one, but they're still on a hiatus as far as I know. Do some Googling and you may be able to find another. I'm sure OBX or someone copied the Hotshot design. Since that's your precat, if you really want to delete the cats, you'll need to get rid of the actual cat too. Unfortunately, you won't pass emissions if they have them in your area. If you do get a header, move the second O2 sensor behind the actual catalytic converter under the car OR use a spark plug defouler to make it read clean. If you delete both cats you'll have to use the defouler method. True straight pipes are going to be LOUD on this car, so I'd suggest you use a straight-through resonator and muffler to get the most performance whilst avoiding an obnoxiously (and possibly illegally) loud car.

Here's the other issue.

You have a GA16DE in there. There are some mods for it (intake, exhaust, header, even cams), but you're not going to see a lot of power out of them. If you really want some performance, you're going to want to swap, and your best bet there is an SR20DE/DET/VE. Check the sticky at the top of the Sentra section for more info on your options there. The swap isn't very expensive if you do some research and bargain hunting.

Suspension and other parts are the same between all of the 200SX/Sentra models from 95-99.

Lastly, I wouldn't go with the Altezzas. I've seen them on Sentras and never once have they looked good. Heck, I haven't seen them on any car and liked them save the IS300.

All of that said, given that you're a poor college kid (I am too), I think you'll get the most out of just doing some simple stuff (intake, exhaust, suspension, good tires) than anything else. It'll seriously make driving a lot more fun. Then, down the road when you've got a degree and a real job you can look into swapping or flat out buying a new car.

[Ichikaze]

Ok, i think what i'm going to do first is try to gut the precat then. If it works, it'll save me money from having to buy A) a new pre-cat and B) a header, since the gutted precat would act as a header anyway.

I guess more than anything i've kind of been wanting to rush this because not having a ride really does suck, but it isn't something i can rush.

Also, to be on the safe side, what i'll do then for xmas is just ask for money. Aside from car parts, i didn't really have anything i wanted anyway, so having extra cash for might be future needed car parts will be a good way to go about this.

Funny enough, i DID happen to find an SR20VE engine with less than 40k miles on ebay. Actually 2 of them, and it seems they're both turbo (i've got entirely too much to learn about cars yet). Unfortunately, they range from 1 - 2k, offers accepted though.

A question about the headers. I am finding lots of headers for SE-Rs on ebay; will these headers not fit an SE? (I can guess it would have to do with different engine sizes)

[Ichikaze]

Ok scratch that. I took the time and did some research, and i found the Hotshot headers you were talking about. I also found a page about installing a setup for the whole exhaust system; headers, the base converter on the underside, the resonator muffler, and even putting the O2 sensor behind the converter like you were talking about. It makes more sense now that i actually checked it out.

I understand the precat concept a bit more now as well. Thinking about it, i can't help but feel what a scam it is to have more than one cat on a car. My mechy said that some cars even have 4?? Outrageous yo.

So right now i'm gonna go with this setup. The hotshot headers and a Random Tech converter for the rear. I've got the understanding of that connection in my head so far.

What comes after that..? Also i might as well go ahead and ask the purpose of O2 sensors. Also, will i need to find extra piping myself?

[nametakennow]

A gutted precat on the stock manifold will not make as much power as an aftermarket header.

If it's a VE, it's not turbo. That'd be a VET, and that'd be a PITA to get going.

SE-Rs have the SR20DE, so no, they will not fit.

Of course, now I've read post #2, so you can scratch some of that info since you figured it out yourself...

Some cars do have 3 or 4 because they emit more. An efficient high-flow cat will provide the same level of cleanliness with more power.

The purpose of the first O2 sensor is so that your ECU can keep track of how completely the air/fuel mixture is burning and make adjustments accordingly. The second is purely an emissions item to make sure that your precat is working properly. By moving the second sensor back behind the actual cat, it will see a clean reading even without a precat. If TX has a strict visual inspection, it's possible to get cited for moving the second O2 back, but insofar as I know, CA and VA are the only states where that's ever happened.

Extra piping meaning what? If you chop out the cat and use the aftermarket one, you'll end up with the same amount of pipe. Any exhaust shop should be able to do this without having to add more pipe. The HS header will include the midpipe between the header and the cat, so you shouldn't need anything there either.

However, I have to remind you that Hotshot is in transition indefinitely, so good luck finding a header from them. I'd check ebay for knockoffs. OBX and, I still shudder to say it, SSAutochrome have improved quality significantly such that they're viable options if they make a Hotshot knockoff and, since both those would use stainless steel, they won't rust, unlike the HS. OBX headers generally don't include a midpipe. An exhaust shop should be able to make one. 2.25in piping and a flex pipe would do the trick well in this situation, but some company may make a midpipe you could use. I know Megan Racing does for some cars.

What kind of catback exhaust setup are you looking at? A header and aftermarket cat will just get choked up unless you replace the catback as well.

[Ichikaze]

Well today i get a call from my mechy saying the gutted precat did actually work as a header, so my car is up and running aside from a 75A fuse which i need to make sure my tak is stable.

As for the catback, i havent researched into it yet to see what brands are available for SE's. What do i want to look for as far as brand name quality?

When you say put the 2nd O2 sensor behind the actual cat, do you mean on the side that would hug the underside of the car?

[nametakennow]

Yes, it needs to be underneath the car. Put it on the side or top of the pipe if it will fit and it'll be fine.

Gutting the cat does have the same effect as a header, but the lack of smoothness of the path through which exhaust air travels combined with the relatively small diameter of the piping is choking off some power as compared to an aftermarket header. Header is just another word for an exhaust manifold. The design is the issue here.

I believe all Sentra/200SX models 95-98 had the same set of hangers, but don't quote me on that. VRS makes a good one, BRM *might* have one, Thermal, Stromung, or if you want a more high-pitched tuner sound (but still not too buzzy) you could go with a Greddy, Stillen, or HKS. I think all of those have applications for your car. 2.25in piping would be as big as I'd go on a GA16, any bigger is a waste of money.

[Ichikaze]

Gah. Most of the catbacks that i'm finding are for 2.5 - 3 inch piping. I forsee my engine being robbed of power unless i find something 2.25. I swear, SE's are robbed of attention. Parts availability is so limited V_V

I found a pacesetter catback but it's 2.5, the same for a Megan R type. No luck when i search for Stromung or thermal.. i'll keep checking.

[nametakennow]

There's a lot of controversy as to whether piping that is "too big" will rob you of power or not. Regardless, bigger systems are generally more expensive, so at the very least it's a waste of money.

That said, I'd call BRM to see if they have a 200SX system - http://brmusa.com/Contact_brm.htm. Otherwise I'd suggest VRS - http://vrsexhaust.com/VRS_CAT-....html

Those prices include a resonator, I believe, but you can contact them to be sure. If you don't have a resonator it will be LOUD and have a buzzier tone to it, so if need be just ask them to include one. They're straight-through designs, so you won't lose power. The bigger it is, the quieter you will be, but even a long one isn't going to make it a whisper, so don't be afraid of being too quiet. Check out the exhaust thread (there's a link in the sticky up top) to see what I mean. I have a medium-length (13in) resonator and it's still loud enough to piss people off when I want to or go unnoticed when I don't, even without a header.

[Ichikaze]

Ah man! Very badass on the sites, thanks much ^_^ I emailed BRM, but now i see that it says call so i'll do that as well. Seriously thanks on the VRS site though, i couldn't find anything in my size selling directly; 'twas a pain yo. I also emailed http://www.2kracing.com; they have a header listed but there's no specs on it. Is 2.25 a standard size that would most likely be made? I checked, and it seems that that's the size i'm rockin' as well.

Part of the controversy i came across was that anything bigger than 2.25 would make it so the that there wouldn't be enough backpressure? The feeling would be 'too loose'.

But yeah, i don't have such major cash to setup such something expensive anyway. I'll have to stock up funds. And as you said, i want to have fun with this so it'll mean going cheapside for now. I just wish my selection were bigger, but actually researching for the parts is awesome too. I love picking up this knowledge. I was standing outside with my mechy looking at the engine thinking.. "man, this work is a replica of a brain". Definitely, thanks for everything so far.

[nametakennow]

Most headers for 4cyl cars have a 2.25in midpipe.

Yes, the backpressure thing is the point of contention of the subject. Run a search on it if you're interested, it's definitely an interesting debate.

You can spend hours on the internet pricing stuff out and deciding what you want to do. It's fun up til you realize how little money you actually have... at least, that's been my experience. The actual turning wrenches and, even moreso, the results, are definitely where the fun is, though.

[nissantech06]

Most headers for 4cyl cars have a 2.25in midpipe.

Yes, the backpressure thing is the point of contention of the subject. Run a search on it if you're interested, it's definitely an interesting debate.

You can spend hours on the internet pricing stuff out and deciding what you want to do. It's fun up til you realize how little money you actually have... at least, that's been my experience. The actual turning wrenches and, even moreso, the results, are definitely where the fun is, though.

We've had our own little discussion about this before. I have seen the same diameters in piping, they get bigger with the V6s.

[nametakennow]

For clarification:

I know my Nissan midpipe (and the stock catback) is ~2in. I was referring to what an aftermarket header would have. I'd be willing to bet that the GA16's stock piping is between 1.5 and 2in.

Oddly enough, the OEM catalytic converter is 2.5in in and out. Again, I bet the GA16's is about the same or lightly smaller.