hey like the subject says... i just got a DP and y-pipe from alamo rotary for the stock twins to go on an FD. here are some pics... i like the DP... im not sure how much i like the modded y-pipe... i may use that as a model and make my own.

 

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im assuming the large one is for the o2 sensor (looks kinda big though) and the other one is for egt?

 

O2 sensor is 18mm x 1.50, so that looks about right.
The smaller one is EGT.  It's looks rather large, so I'm thinking Autometer probe?


-Ted

 

looks nice man ,dp looks really nice ,looks kinda like the pettit one for the 13b

 

yeah im digging the DP but im not sure how i feel about hte y-pipe... the secondary pipe just runs into that curve head on... it might even get directed TOWARD the primary and cause problems... the flow doesnt look right to me, tell me what you think. i wonder if i should call and try to return it??? i wonder if tito will even let me return it??

BTW im going to be using a defi EGT... anyone know if that sensor is the same size as the autometer one off the top of your head? ill try to check the actual size when i get home

 

any initial thoughts on the airflow of the y-pipe? it doesnt look so efficiant to me

 

I say make your own, thats what I'm doing. I'm probably going to follow the basic design of what IronMdnx is using (though I'll try to further improve the merge point a little bit). I figure the best way to go about it is build it like a header

IronMdnx's setup:

 

Doh! Double post. Oh well, I was going to ask how much that DP set you back, anyway?

 

johnisenglish: hey hows it going? the ypipe that is in the picture above is made by alamorotary... its like mine but the merge point looks higher up on the pipe. on mine it just looks like its too low and hits that curve head on.... even maybe angled downward slightly and blowing INTO the flow of the primary which would slow both of them down... id like to see the secondary pipe merge in AFTER the curve... what that should do is create a slight vacuum effect on whichever turbo is not blowing as hard, and in escence "pull" the air from the 2nd turbo pipe as it rushes by it. however i know nothing about air flow charachteristics whatsoever.... that is just what i think would work best, but its based on nothing more than my intuition .

hehe does anyone that has "real" experience with this sort of stuff want to comment??? im just taking a stab at it !

as far as the DP... i think the construction is quite good... i got it used from alamorotary for $100 (or 200... either the DP or the intake pipe was 200 i cant remember, either way cheaper than making it yourself. pettit wanted $300)... its in good shape except for a slight scrape on the lowest part of the pipe. it has a bung for o2 sensor and one for an egt. the hole sizes are about: o2 bung 16-17mm, and the egt is 9-10mm. the only 2 changes i would make if i made the pipe myself would be a less harsh transition @ the bend to aid in airflow (and would help from it scraping on the ground too), as well as making it from slightly thicker tubing (its a little on the thin side) but really not that bad...and also keeps the weight down. Overall its quite well made! i guess that would be my writeup for the DP

-heath

 

Awesome! $100 is about home much it would cost me to make one myself, so if I could pick up another used one that would be an awesome deal. If not, I'll probably buy it from them anyway, as its one less thing to have to fab up.

As far as the Y-pipe goes, I'm just going to put one together U-bends and 45 degree bends. I threw together a model of it in Truespace if you're interested in how everything will fit together. Pretty much you just make a 22.5 degree cut on each bend, weld them together, cut them where their combined diameter is the diameter of the next pipe you're going to weld on, and then weld on whatever extra length of straight pipe you need from there. I'm planning on using 2.5" piping, speaking of which, what's the ID of the one you got from Alamo?



If anyone wants some of these let me know, I'd be happy to build a few more while I'm at it. I can make it out of pretty much whatever material you want as well.

In terms of keeping the charge from one turbo interupting the charge of another, it seems that the ideal thing to do would be to give both turbos seperate piping all the way to the intercooler (which would have two inlets). Once the charge gets to the exiting endtank of the intercooler it wouldn't matter where it came from. I'm trying to fit a V-mount setup in there, so if I do I'll probably go that route, as it wouldn't require all that much more plumbing, however, if I break down and go with a FMIC, I'll be doing the Y-pipe as shown above.

 

there are 2 pipe diameter... smaller ones comes directly off of the turbo, and the large one in the picture above is the collecting pipe... i wont be back home for a few days but ill measure them at that point. to me it seems useless to have a collecting pipe that is any larger than the pipes coming out of your IC because dont you loose pressure when you increase the space the air has to occupy? also, i wanted to ask BNR about some possible new (larger and more efficiant) compressor housings... maybe all that should wait untill i start modifying the turbos.

 

I don't plan on putting any extra money into the stock twins, I just want to use them until I can get the engine itself comfortable installed and running; I'll upgrade to a modest single once after that.

I actually did some research into how I'm going to do my V-mount setup, and I've decided that I'm definetly going to go with a y-pipe over giving each compressor its own piping. I want to do a setup that flows from top to bottom rather then from side to side, as you get greatly increase the efficency and internal flow area of the intercooler by routing it like that. The fact that 95% of the intercoolers out there on imports have these super long cores that flow from side to side still baffels me. However, I think it would be more trouble then its worth to try and keep the charges seperate until they reach the exit endtank with such a setup.

Here's a picture of what I'm planning on doing. I'll be mounting the radiator at a somewhat greater angle in order to get everything to fit. I'll also be relying heavily on my dual 35 row oil coolers to help with the cooling of the engine.



Now I just have to figure out how I'm going to setup the intake piping for the compressors...

Edit: lol, I just noticed what I named the image file

 

where are you getting dual 35 row oil coolers and what brand are they? i think 2 35 row oil coolers is overkill because you cant get enough air flow to use all the capacity.

 

I'm using dual 34 row (sorry, not 35) Mocal oil coolers and a 99 front end, so I'm at least getting a good bit more airflow to the oil coolers then I would with the stock front end. Believe it or not, they're actually not as big as you might think. I'm also trying to duct it as well as possible with aluminum sheet (the same goes for the radiator and intercooler).