Evo III 16g, 1g exhaust manifold, 1g O2 housing question

[14blazed]

Hey all, I'm about to upgrade to an Evo III 16g and am sort of worried about the fitment with my stock 1g parts. I'm thinking the exhaust manifold will be ok, since it's like a small hole (the 1g manifold collector) opening to a bigger one (the Evo exhaust housing). I'm more worried about where the exhaust outlet meets the 1g O2 housing. All these gasses coming out of a big hole trying to flow into a smaller opening. I know it's 'direct bolt-on' but is this an issue I should be worried about? Does anyone else have the E3 16g with the stock O2 housing? I'm going to try and find a ported 2g O2 housing before I put it on. Hopefully this will control the boost creep. Also, the gaskets, should I get them to fit the Evo, i.e. the bigger 7cm gaskets? Sorry if these are pretty noob questions...thanks for the replies.

 

[Burnett03]

Hey all, I'm about to upgrade to an Evo III 16g and am sort of worried about the fitment with my stock 1g parts. I'm thinking the exhaust manifold will be ok, since it's like a small hole (the 1g manifold collector) opening to a bigger one (the Evo exhaust housing). I'm more worried about where the exhaust outlet meets the 1g O2 housing. All these gasses coming out of a big hole trying to flow into a smaller opening. I know it's 'direct bolt-on' but is this an issue I should be worried about? Does anyone else have the E3 16g with the stock O2 housing? I'm going to try and find a ported 2g O2 housing before I put it on. Hopefully this will control the boost creep. Also, the gaskets, should I get them to fit the Evo, i.e. the bigger 7cm gaskets? Sorry if these are pretty noob questions...thanks for the replies.

evo3 turbo is just like any other 16g really so you will have no troubles. id ditch the 1g exhaust mani though

 

[alex99gst]

i would consider getting a 2g manifold however you can. the 1g manifolds have been known to crack and are quite a bit smaller than the 2g. this might help you see the differences in the manifolds: http://www.vfaq.com/index-main.html

as for the o2 housing, i would definately plan on upgrading and porting whatever you get, putting the 1g o2 housing back on would not be a good idea

 

[14blazed]

Yeah, I'm hoping my manifold isn't cracked and/or have broken studs. I know the O2 and exh. manifold both need to be replaced eventually, I just don't want to drop all the money, although it would be smart to do when I have it all off.

I found a slightly ported 2g O2 housing...will there be fitment issues bolting to my 2.5" 1g downpipe? Should I use the 7cm exhaust housing gasket then with the 1g manifold?

 

[sweet97]

No fitment problems. Use the 7cm gasket.The all steel evo gasket is best and I saw some on ebay for about half I paid the Mitsudealer. $12./$24. Just search under eagle talon.

 

[Talonman]

Id get stainless mani to turbo gasket and turbo to 02 housing gaskets from slowboy racing, never worry about blow out again. I used these and had no leaks at all, the stainless expands more than cast iron so it seals up nice. And they are also sized for 7cm opening from mani to turbo and 2.5" from turbo to 02 housing.

 

[LA97GST]

I hate to bring up a dead thread but I'm in the same boat. I am using the stock 2g mani and as of now the stock 2g O2 housing. After that is a 2.5-3.0 inch exhaust, but people told me the EVO III will not bolt up perfectly like a big 16g will. Is this true?

 

[LessIsMore]

Yes this is true. The turbine outlet is 2.5" on an evoIII 16g compared to 2.125" on a regular 16g. You can port out your stock O2 housing to match the larger turbine outlet of the evoIII 16g. Though I suggest you just upgrade to an evoIII O2 housing which mates up perfectly. Also port your manifold collector to match the turbine inlet of the larger turbine housing.

 

[neuro]

OK, I just did this very setup over Memorial day weekend, minus the 1G manifold. I wouldn't worry about the O2 housing issue, I put my 1g housing back on (despite the smaller size) and so far, it's working out fine. Actually, I haven't had much in the way of boost creep with this setup, maybe a pound or two by redline in 3rd, but that could be because I haven't spent much time retuning my Profec B spec II. When I started with the Profec off, boost stayed at around 9psi, which is the actuator pressure.

The 1G manifold will work, but if you're taking all that off anyway, I'd just replace it with a 2G or Evo III manifold. My 1G manifold was cracked nearly all the way through one runner, so I had to get a new one. Use the bigger gaskets, if you have them. Even IF you get lucky and don't break any studs taking the manifold off, do yourself a favor and replace them, anyway. It's worth the $35 or so for stainless studs and copper locknuts. I cheaped out thinking I got lucky, but when it came time to torque down the studs, the first one I torqued broke right off. Then, I had to take everything back off and order studs, drill out the stud and heli-coil it. I used all stainless gaskets, 7cm for the manifold to turbine housing and stainless Evo size gasket for the turbine housing to O2 housing. So far, I've beat on it pretty good with no leaks!

Using the 1G manifold and O2 is definitely less than optimum, but workable. So far, I'm running 15 psi on a mostly stock fuel system (walbro 190 FP) and it's wayyy faster than it ever was at 16 on the 14b and boost doesn't drop off when you get closer to redline.

So far, no fuel cut and 4 counts of knock max on the logger. Still on the stock downpipe and O2 housing (I know, but I had a huge crack around the wastegate hole on the 14b along with the monster crack in the manifold, so as long as I was in there... ). Should be even better when I replace the O2 housing and dp. Need a new clutch before that happens, though!

 

[90blacktsiawd]

If your worried about the studs breaking on you spray wome liquid wrench on them twice a day for a week ahead of time. They will crack easily and you shouldnt break any of them.

 

[sweet97]

As far as stainless studs go isn't stainless weaker? Or is corrosion between the head and the stud the issue? ark

 

[SethA]

Sweet is right, typically stainless fasteners are weaker than alloy fasteners. Stainless will not corrode into the aluminum though which is what leads to broken studs. Even though the stainless is weaker it will put up with the heat cycling in the aluminum better.

Seth

 

[neuro]

Sweet is right, typically stainless fasteners are weaker than alloy fasteners. Stainless will not corrode into the aluminum though which is what leads to broken studs. Even though the stainless is weaker it will put up with the heat cycling in the aluminum better.

Seth

It seems that in my case, the original studs weren't terribly corroded. The nuts came off fairly easily with nothing but an hour long soak in PB blaster. The threads weren't in bad shape, either. But, once I put some tension back on them with the torque wrench, they started breaking. Also, all of the studs that weren't broken came out easily as well. I figure the constant heat cycling from the past 15 years weakened the metal in the studs, which is why they started snapping when torqued on. It's not like there's a tremendous amount of torque on these (20 ft/lbs). For me, I wished I'd spent the $35 or so on new studs and replaced them before I put on the manifold. But hey, it runs now! And that's what counts.