possible bad idea: crush bent FMIC pipes?

biggreen96 · Post by **biggreen96** » Tue Sep 19, 2006 9:34 pm

I am evaluating my piping options and this came up since it cheap.
bad idea? if so does anybody ideas for budget piping? pvc?

I want the hot side to be smalller diameter than the cool side. Maybe 2.25 and then up to 2.5 and then to 2.75 at the throttle body. I got this idea from the latest SCC and the mr2 project car.

dscoobydoo · Post by **dscoobydoo** » Tue Sep 19, 2006 11:45 pm

Technically mandrel bent pipes flow better. That does not mean you can't use crush bent pipes.

biggreen96 · Post by **biggreen96** » Tue Sep 19, 2006 11:49 pm

I sorta want to do it regardless and when I'm not so poor, go mandrel to compare.

free5ty1e · Post by **free5ty1e** » Wed Sep 20, 2006 4:48 pm

I was looking to get crush bent exhaust pipes made for the turns I needed for my FMIC... but when I went to the local exhaust shop and inquired, I was shown their new press-bending machine, which was also cheap. A 7' section of 2.5" exhaust piping bent into 5 90-degree elbows cost me $35. It later was cut apart by a hacksaw and took care of the entire piping project along with silicone couplers and truck radiator hoses).

biggreen96 · Post by **biggreen96** » Wed Sep 20, 2006 7:49 pm

so is crush bent the type with the ripples in the bend? I definately want press bent then. Was the piping pretty heavy though?

free5ty1e · Post by **free5ty1e** » Wed Sep 20, 2006 8:30 pm

It was exhaust piping, so yeah I guess it was heavy. I didn't put all 7' of it in the car, I cut it up to make couplers and used the elbows as needed. There was still more than half of it left, they just sold the pipe in 7' sections and press-bent it for free.

The press-bent pipes just have a little indentation on the inner side, much better than crush-bent.

biggreen96 · Post by **biggreen96** » Thu Sep 21, 2006 11:42 pm

Well I went down to the exhaust shop and they bent me a scrap piece of 2.5 and it did not look bad at all. And they told me 24 dollars for 8 feet! damn good deal.
Shipped my turbo to deadbolt today for repair, slowly this is coming together.

azn2nr · Post by **azn2nr** » Fri Sep 22, 2006 9:38 pm

possible bad idea???? sorry, astethics aside, imo its a really really bad idea

free5ty1e · Post by **free5ty1e** » Fri Sep 22, 2006 11:21 pm

Jason - which, the crush-bent or press-bent elbows?

I don't see a problem with the press-bent pieces, they hold their shape (and boost!) way better than flexible silicon or rubber elbows. I say use the cheap exhaust piping where you can and fill the rest with cut-up NAPA preformed truck radiator hoses. The most expensive part of my install was the intercooler, which was $75 or so on eBay. Piping cost me very little.

Edit: here's a photo I have already hosted, see that bend in the upper right of the image? That's press-bent 2.5" exhaust piping:

dzx · Post by **dzx** » Sun Sep 24, 2006 8:47 pm

To be on topic..It seems like going to an exhaust shop and getting some of their piping seems like the best solution for you.

free5ty1e, you're brave to be running the stock VF11 at 17psi. When I had my car on the dyno a while back, the tiny turbo didn't make any power past 13psi and my car was the same as it is now except for the larger T3/T4.

Very clean setup on that car, but what do the windows get washed with?

206er · Post by **206er** » Sun Sep 24, 2006 11:14 pm

there is a guy on ebay who sells mandrel bends for very cheap, especially stainless stuff. search for "u-bends" on there, or also jegs and summit have a huge selection.
I bought a mandrel U bend at the exhaust shop and they charged out the ass for it.
the generic fmic pipe kits from the ebay rice companies look like a very good deal. a bunch of aluminum mandrel bends for a very good price, hot damn.

free5ty1e · Post by **free5ty1e** » Mon Sep 25, 2006 12:00 am

dzx wrote:To be on topic..It seems like going to an exhaust shop and getting some of their piping seems like the best solution for you.

free5ty1e, you're brave to be running the stock VF11 at 17psi. When I had my car on the dyno a while back, the tiny turbo didn't make any power past 13psi and my car was the same as it is now except for the larger T3/T4.

Very clean setup on that car, but what do the windows get washed with?

It's not the stock VF11, it's got the t-bird compressor side on it, and I'm also up at 5000 ft elevation (used to run 15 psi at sea level)... a/f ratios and egts seem fine just fine

There is a Ford washer bag I got off eBay for like $7 hanging behind my passenger side headlight, and it's got the stock Legacy washer pump zip tied nearby. Takes a second for it to actually start spraying, it's got a decent amount of hosing to fill first, but it does its job.

Exhaust shops definately charge out the ass for mandrel bends. But press bends are cheap and so is the exhaust piping, not to mention widely available. If you can plan out your piping completely in advance, I suppose you could order pre-bent pipes... I liked having all the bends and extra pipe, I just cut it up as I needed it.

azn2nr · Post by **azn2nr** » Sat Sep 30, 2006 10:39 pm

press bent isnt ideal (at least to me) ehtier but is better than crush which as far as intercooler piping goes just shouldnt be used. ive never spent much money on mandrel bends which to me are the best since they arent as turbulant for the air. my new stuff is all mandrel aluminum.

biggreen96 · Post by **biggreen96** » Sun Oct 01, 2006 12:24 am

going the press bent route will allow me to reduce the number of coupling points as well. I can roll my car to the shop which is only about 2 blocks away and fit the piping exactly to the car. I think I can do it in 4 main pieces:
- Throttle body to fender well
- fender well to FMIC
- FMIC to other fender well
- and that fender well to compressor outlet.

biggreen96 · Post by **biggreen96** » Mon Oct 02, 2006 12:21 am

some progress...

the paper template is copied to my aluminum so I just need to cut and bend and drop it at the welding shop.

azn2nr · Post by **azn2nr** » Wed Oct 04, 2006 5:19 am

throtle body to fenderwell if you go counter clockwise flow will take at least 2 if not 3 piecs. it depends on if you move your battery or not. some story if you go clockwise actualy. and in truth you really shouldnt go clockwise if your going to use a wrx clocked turbo because the outlets are really close to the trotle body. that causes issues with heating the charge after it goes into the intercooler and melting your tb coolant lines. just things to think about

biggreen96 · Post by **biggreen96** » Wed Oct 04, 2006 6:34 am

the turbo to intercooler pipe shouldnt get hot enough to melt the coolant lines. did you melt yours? Did you clock your 39?

I plan to wrap the pipe passing over the turbo, or shield it somehow.

I have a tiny battery that will give me the room to route it through that area.

I didnt really think about how much the engine moves around and how much room the pipes will need to deal with that.

azn2nr · Post by **azn2nr** » Sat Oct 07, 2006 6:52 pm

its not the coolant lines its the cold charge pipes but like i said it depends on wheather or not you go counter or clockwise

biggreen96 · Post by **biggreen96** » Mon Oct 09, 2006 4:02 am

I dont understand this part of your posty post.

azn2nr wrote: ...and melting your tb coolant lines.

I'm going clockwise.

neonglh · Post by **neonglh** » Thu Nov 30, 2006 9:03 pm

IC pipes are blowthrough, so from a performance standpoint, any restriction is power loss, but..... its not going to be much. The ripples in the charge pipe are no worse then having some extra bends in some custom piping, they will still flow just fine.

When you have a turbo blowing air through, this stuff matters alot less. The supercharged guys that are using draw-through will want to worry about this much more then we have to. It will be fine for you're application.

--mark

biggreen96 · Post by **biggreen96** » Thu Nov 30, 2006 10:00 pm

hey thanks for the input.

It's hard to justify spending so much on mandrel when press bent will acheive nearly the same outcome. I will give an update as soon as I get my turbo back from deadbolt ( going on 2 months now!!)and get all the piping whipped up.

neonglh · Post by **neonglh** » Thu Nov 30, 2006 10:03 pm

I dont think mandrel bends are too much more expensive though. When I did both my intercooler piping and exhaust on the neon, I just picked up some 180 mandrel bends from summit racing, for like 20 bucks each, and used a chop saw for any cuts. It was < 100 for my entire 3" exhaust system w/ a 6" flex pipe, and then my IC pipe was like 40 bucks before the cost of couplers and clamps. Thats not too bad at all, especially compared to pre-cut setups.

--mark

biggreen96 · Post by **biggreen96** » Thu Nov 30, 2006 11:08 pm

for like 20 bucks each

I will be able to do my entire system for 24 and change at the bruneel tire place here that also does exhaust work. So yeah it seems to be a bit more cost effective. woot.

Imprezive · Post by **Imprezive** » Fri Dec 01, 2006 2:57 am

If you ask me, its not worth it. I mean you are spending lots of $$ for the FMIC (or not if oyu got a deal or something) and you are undoubtedly upgrade a whole bunch more stuff so why cheap out on the FMIC piping?

I'd rather just do the mandrel bends and do it right. Sure the lumpy bends from a crush bender might not hinder performance that much but every detail counts when trying to make more power, you shouldn't skip over things like this just to save $40 or $50.

biggreen96 · Post by **biggreen96** » Fri Dec 01, 2006 10:51 am

just to clarify I am not doing crush bent, I will be doing press bent. no way in hell would I have the ripples in the bend.

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possible bad idea: crush bent FMIC pipes?

possible bad idea: crush bent FMIC pipes?