Exhaust Manifold Replacement

[KrayzieFox]

My stock manifold finally cracked, or I have a serious exhaust leak where it mates to the head, but either way I have decided to upgrade to a Thunder V2 manifold and I'm thinking about doing the install today. I've done the install before when I was doing the turbo install in the first place, but I got everything already assembled. The manifold, turbo, and s-pipe were all bolted up and I just put them in as one piece.


What I wanna know is if anyone here has managed to replace the manifold and unbolt the turbo without removing everything. I kinda don't feel like unbolting the exhaust & the turbo lines, but I will if I have to. Just curious if anyone has found a better way to do it.

Will I need new studs for the turbo? If so, what size are they?

 

[KrayzieFox]

I just took another look at the Thunder manifold and it doesn't appear to use studs on the turbo flange. So to all you guys who have this manifold, did you just use some heat resistant bolts instead?

 

[justanothermp5]

i just used regular bolts and nuts from the hardware section in lowes, there still holding up good after 5 months

and whenever i take my turbo out i always have to take them out as a set, s pipe, mani, and turbo
it really sucks though cuz i have to take the coolant lines and other crap out, but that was the least time consuming way for me to do it

 

[shane02pro5]

I supported my dp from below and straps around the comp housing from above. Plenty of room and takes very little time like this.

Also used studs with lock washers and nuts on top and bottom of the turbo flange.

Also hope your not running much boost with that mani since they are notorious for cracking.

 

[yudkib]

i know the ARP studs are the same size as the exhaust mani... m8 x 1.25 x 38mm. i have the threading specifications from them directly if you want to translate them over and buy grade 5 stuff.

 

[KrayzieFox]

I supported my dp from below and straps around the comp housing from above. Plenty of room and takes very little time like this.

Also used studs with lock washers and nuts on top and bottom of the turbo flange.

Also hope your not running much boost with that mani since they are notorious for cracking.

Can you elaborate on this a bit? How did you gain access to the nuts that bolt the turbo to the manifold, especially the ones in the back? I'm like half-way done taking off everything and it would be nice if I didn't have to continue.

And I'm really starting to reconsider if this manifold is gonna be worth it. I found out that my stocker isn't cracked, but the two leftmost bolts came undone and fell out so I have a massive exhaust leak there. Should I just retighten the stocker and sell the Thunder or install the Thunder and sell the stocker? I run stock boost, but I have heard of even the V2 Thunders cracking.. I REALLY REALLY don't wanna do this again as I'm moving to an apartment in a month and won't have anywhere to work on my car for at least a couple years.

 

[Hotch3]

I'm pretty sure I have the same leak. But I'm not 100% sure. If the exhaust is leaking out of the manifold I will have a drop in boost in addition to the exhaust noise, correct?

I just had my flex pipe replaced thinking that it was the only leak. Wrong.

I'm currently getting about 5.5lbs of boost right now and have the terrible exhaust noise. does this sound feasible?

One more thing. If my mani happens to be cracked, how much is a new one/what would you sell the Thunder for?

 

[shane02pro5]

You can se where the leaks are coming from if you sprinkle baby powder all round the mani and see real quick when you crank the car up.

Krazie: I put a block supporting the dp from underneath. Used 2 1" nylon straps or rope or heavy twine looped it around the turbo comp housing and tied off at the front of the vc where there is a bracket and another looped around the top of the dp to the power steering bracket. The rear bolts are a b**** but after a few times you develop a technique and some ground up cut off and/or bent 13mm wrenches to get to them.

I re-welded my Thunder mani 4x so I got pretty good at swapping it in and out.

 

[KrayzieFox]

Shane, thanks for all the advice but I just went ahead and took everything out lol. The oil feed line was the biggest pain in the ass, as always, but everything else came right out.

So now I'm just waiting for the turbo gasket to arrive and I can install the new manifold. I kinda think I should take this chance to do some other maintenance as well though. Maybe new WGA? I really wish pope had the downpipes ready by now, this would be a PERFECT opportunity for me to install it. Oh well.. that'll have to wait until this fall.

And Hotch3, I will sell you the stock manifold for $150 (it's not cracked after all, I'll take pics to verify) and the Thunder is going on my car. Unless you throw me an offer I absolutely can't resist..

 

[yudkib]

i was supposed to be taking one of the test spots since i needed to do my mani, but i sold my spot... i dont know if anyone claimed the last tester.

 

[rmak_14]

I found out that my stocker isn't cracked, but the two leftmost bolts came undone and fell out so I have a massive exhaust leak there.

That's the 2 exact bolts that fell out of mine! =(

 

[rmak_14]

I found out that my stocker isn't cracked, but the two leftmost bolts came undone and fell out so I have a massive exhaust leak there.

That's the 2 exact bolts that fell out of mine! =(

 

[KrayzieFox]

I found out that my stocker isn't cracked, but the two leftmost bolts came undone and fell out so I have a massive exhaust leak there.

I'm pretty sure I have the same leak. But I'm not 100% sure. If the exhaust is leaking out of the manifold I will have a drop in boost in addition to the exhaust noise, correct?

That's the 2 exact bolts that fell out of mine! =(

We fail at torque specs..

http://www.mazdas247.com/forum/showthread.php?t=123707285

 

[yudkib]

that's stickied too! how does everyone miss that.

 

[KrayzieFox]

I installed mine before the sticky came.. but I knew all along it wasn't done right. This next time will be different

 

[theEZV]

soooo....how much for your thunder?? lol

 

[KrayzieFox]

soooo....how much for your thunder?? lol

Sent you a PM, not sure if you're really interested or not. Respond if you are, I'm really starting to lean towards the Steed more than anything so it would be nice if I could get this sold to help me afford it.

Thanks for everyone's help & feedback.

 

[joghia]

Got my Steed installed last week and it's a DAY AND NIGHT difference from a cracked Callaway mani to a mint new Steedspeed. Top end is very much improved and it looks sexy on top of that.

 

[KrayzieFox]

How was the install? Is it any easier to access the bottom bolts than on the stocker?

 

[shane02pro5]

Trust me it's a b**** you just need a technique. To get the bottom nut on the rear drivers side I used a piece of tape layed in an open ended wrench the was cut in half to get into position and have enough clearance for a 1/4 turn and actually get the threads started. The rear passenger side I put the nut on the tip of my index finger and slide it along the flange and let it kind of fall into position since you can only get one finger on the nut to get it started.