1jz Bolt ons

[Ribfeast]

The ceramic turbines of the CT12A twin turbochargers commonly shatter when pushed over 14psi. This either happens by sheer pressure OR by the turbocharger heating enough to melt the resin that holds the nut which holds the compressor turbine on the shaft. The nut comes loose and the compressor either wobbles and shatters, or flies off of the shaft and breaks. It then CAN make it's way through some of your intake piping [ouch] if you are really unlucky.

Sustained high-boost driving (ie repeated thrashing with no cool down between runs) will kill the ceramics pretty quickly, especially on higher boost levels. Putting twin dumps on removes a lot of heat from the turbo area, allowing them to last longer.
I got my twin 2.5" dumps from Newcastle Mufflers for $550 drive in drive out. I think they charge $790 though now.

I'm making 244kW on steel wheel CT12A copies off eBay, but many people have had problems with these (heck, maybe I will too eventually).

[slipway]

like this

[EldarO]

ooooh thats pretty ehehhehe.

unlucky whoevers had a set grenade on them, it was a **** to change the dumps over, let alone remove the fuckers!!!

[big wad]

that photo must be a fake because i have been assured that the twins are the ultimate. you can pray all you like but they all end up looking like that. the single should be running on the hilux this weekend and so far it has cost $1350. cheers bigwad

[Yotaholic]

Bolt on's pretty much sum up my car so I thought I would share the results , it's untuned with all the seals and tbelt etc replaced so it's basic with BPU . As for the dumps I have the same ones and yup there purple ,, well they look like em anyway came from ZW motorsports. I'm seeing 16+ psi on 20 to 30 *c days and 17.9 max at 10* c or colder at night ( it's fall here now ) .. I didn't run the stock y pipe at all so I can't compare but I can say I have no troubles yet and yes the install was a major PITA !! I don't think i'd attempt it in the engine bay . That just screams bad back !!
I guess it's a gamble how long any of these old turbos will last but i'm collecting a few for spares just in case ..

Here are my results with BPU BOLT ON"S ( repost )
16psi untuned after a 7 hr drive and right on the dyno 27 * day





Question .. Has anyone dynoed a stock Jza70 with 0 mods ? I've searched and really i'm wondering how much of a gain are we actually getting . Everyone seems to have something done before they hit the dyno and as for the 280bhp Toyota claims is that in U.S. HP or realworld rwhp ? aka Dyno dynamics vs Dynojet . I'm still trying to get my head around that BS.....

[jak]

that photo must be a fake because i have been assured that the twins are the ultimate. you can pray all you like but they all end up looking like that. the single should be running on the hilux this weekend and so far it has cost $1350. cheers bigwad

?

seriously, the turbos are bettr than you think. Yes they have there flaws, but u cant really put them down, they are making pretty large amounts of power with and without nitrous.

The stock y pipe will kill them for two reasons. 1, it flows like a dog and 2. it traps so much heat its not funny.

A set of dumps and free flowing exhaust really does them the world of good.

On our car, we canot run blow 19psi due to having a 3.5" exhaust system, we have had this setup for a good year now and nothing has failed. If we up the oost, u can see 22-23psi out of them and they still go strong. (this is without dry ice, no more cooling than a normal setup)

with nitrous it hits about 25-26psi bt is kept cool by the nos itself.

ust because a few peoples turbos giv up on low boost, i think most can daily drive on about 16psi comfortably.

Jak

[jampac]

I had 156rwkw on a 1jz with a pod filter, running thru an auto in a soarer. I'd expect a stock jza70 would be pretty close to this.

[1JZ~lux]

What are some of the recommended dimensions a replacement dump/Y pipe?
What diameter pipe if it's 1 pipe does wastegate and exhaust?
What thickness for the pipe?
For how far should the two pipes be kept separate?


Cheers
Dave

[pete05]

Mine are 2.5 inch made from regular exhaust pipe straight from the flange and they collect to one pipe under the floor.

[slipway]

re my above pic whats the worst engine damage you could get from this would the head need to be taken off i dont really knkow so if someone could help me out with this would be great
o and sorry for the thread hijack.

[JZA70 R]

[Mr DOHC]

a small amount OT, cnayone in SEQ got a spare set of turbos, my mates killed his

[hamgatan]

jeez todd. thats some dodgy welding right there on the black dumps...

[Dieseltrain]

Those Black ones look exactly like Lews Dumps? I installed some on my mates soarer....

We spent a bit of time with a dremmel cleaning out the dags on the inside and also filling some holes where the weld didnt make it....

The ones next to them look alot nicer though!

[JZA70 R]

the rough set were one of petes pipes prototypes, i didnt expect much for 300 odd bux am im grateful for his service and chance to test fit them.

needless to say once i found they didnt quite fit i had another set tig welded up and a new jig created. i relocated the o2 sensor and used a slip joint instead of a annoying flange.

both are mild steel.