Rb26dett Issues

[stormtrooper]

So! After taking it to see Aaron at InTune, turns out not only has the gasket gone on the cat, the flanges and gaskets back from the cat are leaking aswel. I've lost about 2-3psi top end now coz of it heh. Looks like I Have 2 choices, either I can replace the flanges and gaskets, bout $500 total, or I can get a 3.5" xforce system cat back stainless steel system for bout $1500 installed.

[Ten Four]

Lol, thats the best excuse to get a new exhaust

1500 installed for an xforce system sounds a touch pricey...

HKS Hi-Power

Apexi N1

Imo>XForce...

[stormtrooper]

Requires new cat though aswel, so as the front pipe can marry up to cat properly. At the moment it's 4" front to 3" cat, hence the extra price.

Well, doesn't actually require a new cat, but different cat will supposedly be able to marry up to the front pipe better

Edited September 8, 2009 by stormtrooper

[stormtrooper]

Going to grab a replacement gasket from Xspeed this week and replace it on saturday myself. Looked over the zorst last night and from what I could tell there was nothing leaking past the cat itself (on the back end). Replace it and see how I go

[stormtrooper]

Replaced the front pipe -> cat gasket yesterday. The old gasket on the flange was black as night and was on both the top and bottom, back and front of the gasket. Definately blown out. Replaced it with a nice shiney new one and fitted it back up with high temp gasket goo. Beautiful. No more leak coming from the gasket. However! One of the f**king welds holding the Cat pipe itself to the flange where it marries the gasket to the front pipe flange, has a bloody leak in it It's not a huge leak, VERY minor but could feel it when I had my hand over the join when I had the motor running testing it. Damn. Well, I've re-gained about 2psi aswel and should hold till I can afford to replace the system heh.

[SLIPPERY]

That cat in there is a metalcat so it's not a cheapy to just throw away for the sake of it plus it would have only done 10000km max. Chris, if you want a replacement stainless exhaust look up some old threads from Kermit. He should be able to do you a stainless cat back, tucked right up to the body for 6-700. He's very fussy about his work and he put the cannon on your car. Do recommend!

Hopefully he still does the work

[stormtrooper]

Nice one I gave her a little boot today on the freeway on the way into work (sat back at 80, 3rd, foot down to 100) and hit full 16psi again. Was an exhaust issue.

I'll probably do that too Travis. The only thing I am worried about is that when I pulled the cat/front pipe apart, the actual internal diameter of the front pipe is about 1inch larger than the internal diameter of the cat pipe. So I am just worried that it could be a potential bottle-neck in the system. Wouldn't mind some people's thoughts on this too (if you have any thoughts that is considering barely anyone raised an eyebrow of interest to help out in the first place).

[stormtrooper]

Ok, seems like I havn't regained all boost again. It holds full boost most of the time but when she hits around 75-80+C water temp, starts "flapping" at about 14psi+ (like hits about 14-15 and the needle sits there swinging back and forth a little). Wondering if this could be a cracked hose or something that is expanding to let air out when it's hot as opposed to being constricted when it's colder?

[SLIPPERY]

i dont think going from 4 inch to 3 inch is going to cause a bottleneck. There simply isnt enough gas to cause such a high pressure restriction in a massive 4 inch pipe.

Also, dont go by what the greddy gauge tells you, that thing is affected easily by bumps in the road and stuff. It juts around everywhere haha I always looked at the read out on the boost controller

[syfon]

Try the intake manifold gasket - that's what the problem was on mine

[stormtrooper]

Ah nice one. Yeah from what I have noticed it will hit full on the boost guage, then drop down a little and bounce back and forth as you said. I changed out the coilpack on #1 cyl yesterday too and she seems happier at higher revs now aswel. I know that on Rb26DETT motors the front 3 cyls power the front turbo and same for the rear 3 cyls with the rear turbo, could something like limited spark from the dodgy coilpack cause the front turbo to not fully spool or to pike out a bit at high revs/high temp? Rather random thought but still thought I'd ask it hehe.

[Ashy Larry]

Take it to a decent workshop.

[SLIPPERY]

+1

[stormtrooper]

I just read too much into things sometime and like to throw it out there in case.

The boost controller doesn't lie, the guage does.

Cleaned the AFM's out with degreaser then Mass Airflow Meter cleaner yesterday but still hunting when she's hot. Think it IS time for a retune. Nuff said Close thread heh.