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patdog
12-06-2006, 09:56 AM
What sort of gains would I get if I were to get a 3" system from the turbos on my legnum? Im also going to get an after market cold air box put in.

Wodjno
12-06-2006, 10:02 AM
What sort of gains would I get if I were to get a 3" system from the turbos on my legnum? Im also going to get an after market cold air box put in.
If you are still running at standard boost then you probably won't get any performance gain at all. Infact you will probably lose some mid range torque. This would be through lack of back pressure.
If your running higher boost levels, then it will allow for the exhaust gases to escape faster under the increased pressure and you should see improved performance over the stand exhaust system.

Kenneth
12-06-2006, 10:04 AM
What sort of gains would I get if I were to get a 3" system from the turbos on my legnum? Im also going to get an after market cold air box put in.

With full system and intercooler, you are looking at up to 30kW at the wheels on standard boost control. I would be careful about CAI (cold air intake) for the VR-4 as it seems that it is easy to screw up the air flow through the MAF and cause fueling issues.

Kenneth
12-06-2006, 10:06 AM
If you are still running at standard boost then you probably won't get any performance gain at all. Infact you will probably lose some mid range torque. This would be through lack of back pressure.
If your running higher boost levels, then it will allow for the exhaust gases to escape faster under the increased pressure and you should see improved performance over the stand exhaust system.

You seen my dyno graph Glenn?! I only have exaust and intercooler. (and yes, was using standard boost control)

Wodjno
12-06-2006, 10:09 AM
You seen my dyno graph Glenn?! I only have exaust and intercooler. (and yes, was using standard boost control)

No i haven't Ken.. Where is it ? Do you have a link.. !
Did you have a Dyno run with just the Zorst ? Also i was thinking of increase over being decatted, not with standard cat in place.. :thinking: Which reminds me, i gotta stick my BDA decat back in sometime.. :2thumbsup

patdog
12-06-2006, 10:26 AM
I was thinking more or less moving the battery to the boot and putting my pod filter where the battery was in a cold air box, with some tubing going down to the bumper for extra flow.

bradc
12-06-2006, 10:46 AM
Pat, thats a very good idea, make sure you keep the air intake as cool as possible.

As for the full exhaust system, I only gained about 6kw extra at max power, but a little further on in the rev range my car made an extra 11kw at the wheels, this was with an otherwise stock car. If my car had other mods such as a boost controller I beleive the power increase would be much higher as Kenneth indicated.

Paul C
12-06-2006, 12:02 PM
I have a contact who used to make Cold air boexs to barrier cone filters on bmw's.He built them from scratch givining in some cases about 10bhp(with kn cone filter).

Kenneth
12-06-2006, 10:17 PM
This is my dyno sheet. Blue is the first run I did. As you can see, I had some issues. Changing the plugs fixed the ignition problems.

The blue peaks at 153kW. If you were to follow the trend in that graph, you might have got about 160kW if I had not had ignition problems.

That blue run was done with the following:
Decat pipe, 600x300x76 intercooler (attached to standard pipe work)

The red run... the only differences here are the plugs and the exaust system. Both runs were done on standard boost control. unfortunatly the red boost curve is wrong as there was a leak in the boost attachment they were using to measure the boost. at peak power, boost is probably ~12psi though. This increase of about 1.5psi is of course where a fair bit of the extra power comes from, but hey... it is still a direct result of the exaust system.

Kenneth
12-06-2006, 10:18 PM
now add a little boost...

patdog
13-06-2006, 06:28 AM
Im probably getting the exhaust in the next week or so, I'll then probably get an intercooler and cold air box put in together, in a couple of weeks. Ill get metal tubing for the intercooler as the rubber ones expand with your boost. hopefully my car will perform a bit better from then on :)

patdog
20-06-2006, 11:20 AM
I just got the exhaust done, it seems to have more torque in the low end. All i can say is that its loud, and i like it....

bradc
20-06-2006, 11:43 AM
Who did it for you, and does it go the whole way down to the turbos, or just to the cat?

patdog
21-06-2006, 12:14 AM
I had it done at Lightning motorsport in hamilton, its 3" straight from the join where the 2.5" from two turbos meets up. Cost me $600 all up including Dytech muffler.

VR4 MAD
21-06-2006, 11:54 AM
I had it done at Lightning motorsport in hamilton, its 3" straight from the join where the 2.5" from two turbos meets up. Cost me $600 all up including Dytech muffler.

Glad to see you got the car back in one piece. Some others on here haven't been so lucky. See this thread: http://www.clubvr4.com/forum/showthread.php?t=16248

Maybe you mightn't have gone there if you'd seen that thread beforehand.

They also often use TradeMe to look for new exhaust work.

But glad that you're pleased with the work you got done and the price seems really good too.

:happy:

bradc
21-06-2006, 11:58 AM
yeah it sounds like a good price, how loud is it? Did they just do the 3" section, or did they do the pipes before the turbos meet up?

patdog
22-06-2006, 11:22 AM
Its 3" from the join, it was originally going to be $650 from the turbos, but they couldnt do it from the turbos, so they did it from the join and only charged me $600 for it because of that. Its pretty bloody loud, it has the annoying drone in the mid range though... I had my car serviced the other day, and the mechanic told me that my legnum is on its way out :'(

patdog
22-06-2006, 11:34 AM
Im pretty sure that the previous owner of my vr4 hated it, because not long after i got it it ****ed out, and i got it all fixed and now all the other stuff is gona die on me, Ive already fixed a vast amount of things on my legnum and i simply can not afford to have the things that will go wrong fixed when they do :sad3: , I will probably just sell it off to get rid of it and try and save to get a another vr4.
I love my VR4 :(

P.S. Need i say more about the previous owner than the fact there was an amount of hello kitty things in the car when i purchased it.... BIG MISTAKE ON MY BEHALVE, I SHOULD HAVE THOUGHT TWICE :deal2: /pan

Kalle
22-06-2006, 02:17 PM
It can't be 2,5" from the turbos original! More likely 2"

I have just fitted a 3" exhaust directly from the turbos with a racecat and I must say that it feels a lot more powerful in high revs :D Sounds meaner too.. :evilgrin:

It was not possible to do a join like on this fellow member:
http://www.soederman.se/colt/images/GalantGalleri/galant154.JPG
I think that is 2,5" to the join and then 3".. please correct me if I'm wrong

patdog
22-06-2006, 08:29 PM
Im not completely sure what the diametre of the pipe is from the turbos, but I know that my system was from the join.

bradc
22-06-2006, 08:57 PM
thats my car :D mine are 2.5", then join to 3"

Pat - go into my Gallery there are another couple of pics there.

leggyvr-4
05-07-2006, 05:39 AM
Hey guys, i'm a new member on here, only got my legnum about 3months ago, so i'm still learning.
i'm thinking about doing an exhaust on it soonish, but i'm not sure how it will sound, what size to go for etc.
its the tiptronic model, how do they sound with a bigger exhaust on it? also what size is the best to go for to give the best performance? also what size is the original system that comes factory?

Sorry for all the questions but i'm still learning and any help would be much appreciated!

patdog
09-07-2006, 07:58 AM
mine sounded really deep, kinda like a old v8