JT's 'FCW' Restoring Project and T25 turbo upgrade

catgroom · Post by **catgroom** » Fri Aug 10, 2007 2:51 pm

Dan,yer train tickets to Burnley and some Chemical Guys kit are being DHL to you as we speak!!!

Turbus,the filth in your mind is almost as prevailant as the filth on your engine!Sort it!

JohnTurbo · Post by **JohnTurbo** » Mon Aug 13, 2007 11:56 am

ENGINES ARE DIRTY.

Right now thats over with:-

I'M PISSED OFF!!

The smoke screan returned in force, a few times. Knowing in my heart it had to be my t25...i decided i would indeed pull it off the car and rebuild it.

So again i constructed my special downpipe removal tool, consisting of 1/4" ratchet connected to 1/4" screwdriver handle (which acts as an extra long extension), connected to long extension, connected to short extension, connected to uj, connected to 14mm socket. Lots of other fun too, like access contraints meaing one of the 4 turbo bolts could only be turned 1/8 of a turn at a time.

So anyway, after getting the turbo off, i blowtorched the exhaust manifold, removed it, and then removed the compressor housing.

I dissassembled the turbo spindle, journal bearings, thrust bearing and oil seals.......to find....

The turbine side oil seal (think spring steal ring with a split) had come out of its groove, and worn into an open 'C' shape with pointy tips, instead of a split 'O'. This would be fine, but it had riden up and destroyed the groove it sits in. It was a l_l shape, and is now a l__/ shape.
Whats the significance of this? The turbine shaft/wheel and thus the turbo is a write off.

BEWARE CHEAP EBAY TURBOS!!

So until 11pm last night, i was building myself a hybrid turbo. It consists of a t25 centre section, t25 compressor wheel/housing, T2 turbine wheel/shaft/housing. And new bearings and seals.
It looks identical to Jamo/Martin/rocket's hybrid.

It feels fine, and hopefully i should only be fractionally out on balance. - If that means 75k rather than 150k its not a big problem, and i'll know how good i've got it by how much it whistles.

I'll probably buy another t25 at my leisure....since i put all the work/money into the turbine housing/elbow now, so i may as well.

The good thing i suppose is i'm very confident about t2 and t25 turbos now. I know exactly which parts are the same etc.

rpruen · Post by **rpruen** » Mon Aug 13, 2007 7:25 pm

JohnTurbo wrote:So again i constructed my special downpipe removal tool, consisting of 1/4" ratchet connected to 1/4" screwdriver handle (which acts as an extra long extension), connected to long extension, connected to short extension, connected to uj, connected to 14mm socket. Lots of other fun too, like access contraints meaing one of the 4 turbo bolts could only be turned 1/8 of a turn at a time.

I know that feeling, sorry to hear of the turbo buggerage

Just be glad you don't have a T3, to remove mine I have to strip the turbo in situ. Once the center is out, then you can get to the two lower nuts with a spanner, even then it's the 1/8 turn dance. In all removal and refitting is about 8 hours or so

Downpipe removal, yes I have that too, the bigger turbo gets in the way a bit there too. However my egine is 20mm further forward, so there is a bit more room for some things.

JohnTurbo wrote: The turbine side oil seal (think spring steal ring with a split) had come out of its groove, and worn into an open 'C' shape with pointy tips, instead of a split 'O'. This would be fine, but it had riden up and destroyed the groove it sits in. It was a l_l shape, and is now a l__/ shape.
Whats the significance of this? The turbine shaft/wheel and thus the turbo is a write off.

BEWARE CHEAP EBAY TURBOS!!

Beware Saab 9000 turbos anyhow, it turns out the engines have an oil pump made of early 480 gearbox stuff. To make up for the crap oil pump they used a very fine strainer in the sump, this cloggs if you don't look after the engine 100% perfectly. Leading to low oil pressure, and lots of sick turbos going cheap.... Bit of a bastard, as Edd has a T25 in much the same state as yours

It seems like a good candidate for swaps, because the turbos are cheap and plentifull... Unfortunalty there is a reason for that, and it's not good.

Just thought I should share that.

On the plus side the exhaust part of the Saab 900 T3 is easy, just machine the elbow to fit the cone on the turbo outlet, and bolt the elbow on. The manifold side needs more port matching, and new bolt holes drilled in the turbo (to match the studs on the manifold). The big downside is having to move the engine 20mm forward so the sodding great compressor housing doesn't hit the anti roll bar.

The 900 also has a proper oil pump, so the turbos are likley to be in better condition.

I hope that the project goes well from now on at least.

Richard

JohnTurbo · Post by **JohnTurbo** » Tue Aug 14, 2007 11:54 am

Thanks for your comments Rich.
T3 is more than i'm after really. I just want a wider power band. Going to have a go at getting another t25, but this time be a little more careful. If the hybrid runs well enough i might not bother.

Speaking of which....here it is. Not too bad to install - the standard flange has a little more clearance. The car starts up fine, no smoke or scary noises, and revving hard makes the actuator twitch. So far so good.

Not been able to take her out for a run, as my father's been patching up a hole in the inner arch. Rather than go the welding route my father (who excels at this kind of thing) very kindly panel beat a piece of plated steel to shape and pop riveted it in, after waxoyling the hell out of the inside.

It looks much more proffesional in the flesh, but this should give some idea...

To further improve the strength he then scuffed up the old and new metal and fibreglassed around the outside. The repair should be very nearly as tough as a welded in piece, and much less susceptible to re-rusting.

Saddly, as mentioned elsewhere, its looking unlikely that the car will be mot'd in time for the lakes, as i'm busy both tonight and tomorrow night.

rpruen · Post by **rpruen** » Tue Aug 14, 2007 8:11 pm

JohnTurbo wrote:Thanks for your comments Rich.
T3 is more than i'm after really. I just want a wider power band. Going to have a go at getting another t25, but this time be a little more careful. If the hybrid runs well enough i might not bother.

The T3 is a bit laggy too, the supercharger helps here, without it (I tried with it disabled) the car is very odd to drive, more like other turbo cars I guess.

I'll be interested to see how the hibrid works out. Maybe you could send it off to be balanced? I don't know the cost, but it would be worth checking out.

Next time I take my turbo apart I will try to remember to take a picture of the turbine next to a T2 one. The sixe diff. is quite impressive. To give some idea, the T2 is about loo roll middle size, and the T3 bean can size.

Shame about the MOT

unfortunalty setbacks happen.

Hope it goes well enough now though.

Richard

aibast · Post by **aibast** » Wed Aug 15, 2007 6:50 am

I'll soon take a pic T25G vs T2

. So you can see the difference. T25G has a T3 exhaust side, the older style elbow from 480 doesn't fit on these. So made that thing to.

martinholmesuk · Post by **martinholmesuk** » Wed Aug 15, 2007 7:52 am

Not a good picture but you get the idea.

JohnTurbo · Post by **JohnTurbo** » Wed Aug 15, 2007 1:08 pm

The t25 turbines about the diameter of the top rim of a coke can. A fair bit bigger than the T2.

With regards to the balance issue, the following document is quite interesting. In short, the turbine/shaft and compressor wheel are balanced individually. It sounds like the final balance is much less important because of this. - It follows, since grinding a flat on the nut is:-
a) a very small mass of material
b) hardly any distance from the centre of rotation
The product of m and d therefore will be small, so they must be pretty close even before this.

Will soon see anyway.

[quote]TURBOCHARGER BALANCING

FACTS AND MISCONCEPTIONS

One of the most important parts of building a turbocharger that will operate quietly and efficiently for a long time is being sure that the rotating components are properly balanced. The problem is that many people do not know what Ã¢â‚¬Å“properly balancedÃ¢â‚¬

JohnTurbo · Post by **JohnTurbo** » Thu Aug 16, 2007 11:46 am

Well...

I took the car out for a very quick spin last night. I gave the pedal a good stomping and heard the most awful screaming noise!!!

It was the other half. hehehe

The turbo sounded/felt/pulled fine. I'd say its a bit laggier than the pure t25, but i didn't drive long enough to say for sure. It sure as hell accelerated anyway.

Just lots of body work to look at now. Rust bubbles etc. Rustier underneeth than EVU was too, saddly. Looking forward to having a cat that doesn't rattle like a bowl of bolts too c/o Rohan the Bruce after the meet.

JohnTurbo · Post by **JohnTurbo** » Wed Aug 22, 2007 9:04 pm

Well, as many of you will know, I tried and failed to take FCW to the meet....it failed its MOT. I was, admittedly, very sad to leave her at home.

Mot failure was due to loose NS ball joint, and high CO. For that i needed rohan's cat...or a so i thought. Actually i think it was more likely my dead lambda sensor. (See my thread in the guides section)

So...

Thats rohan's cat. This is what was left of the bolts and lambda thread after extraction from it.

Took some doing to get them out. The bolts i thumped ground and drilled!!!

Tonight i also did the ball joint. For comedy reasons i had a look in haynes. In TOP comedy stylee there was only four steps.

1)jack car up
2)remove wheel
3)undo two bolts through balljoint
4) remove nut, and use splitter on the joint

that was it!! Lol. In actual fact you cannot do this without removing the driveshaft, and that has a whole lot more steps!!!

Anyway, just waiting on delivery of my 15quid ebay lambda and its good to re-test.

JohnTurbo · Post by **JohnTurbo** » Wed Aug 29, 2007 2:43 pm

MOT PASSED> IN YOUR FACE OPPRESSION!!

hehehe.

Ooof!! Is that thing fast too!

JohnTurbo · Post by **JohnTurbo** » Tue Oct 02, 2007 8:30 pm

Insured.
Tax'd

My nissan blew up.

480 time!! ~YYYYYYYYYYYeeeeeeaaaahhhhhaaaa!!!!!!!!!!!!!!!!!!

VanDerGraaf · Post by **VanDerGraaf** » Wed Oct 03, 2007 7:17 am

Go on my man!
It's about time!

VanDerGraaf · Post by **VanDerGraaf** » Wed Oct 03, 2007 7:18 am

Actually, what happed to your Primera? Timing chain snap?
They are usually pretty bomb proof....

JohnTurbo · Post by **JohnTurbo** » Wed Oct 03, 2007 9:09 am

Its proably the head gasket. I'm having bizarre overheating issues. Got two days off to investigate it.

lee · Post by **lee** » Sat Oct 20, 2007 6:32 pm

come on me old son. there nout that yam mates across at the homdv won't help yam with should yow need it son.

Loads of work gone in so far dude. Hope you are enjoying it though.

A word of advice though dude. If you need to pay for anything by cheque you need to sign it

MrE · Post by **MrE** » Fri Nov 09, 2007 1:41 pm

Hi john, i haven't been on the forum for ages. Just read through this thread and i found it amazing you've basically done exacly the same as Rich and i did to my engine. Saab T25, then built an adaptor plate 10mm thick with the three stud PCD offset to make the old type 480 turbo split housing fit at the right angle. Interestingly we went done the route of machining the adaptor and the 480 housing with tapers to match the saab outlet, then using exhaust gum in the joints. Later it dawned on me we should have used the three stud gasket the same as you appear to have done. I also machined the exhaust housing exactly the same to fit the 480 exhaust manifold, bastard of a job....

Results were reasonably impressive but as Rich mentioned Saab turbos just won't hack the boost. I tried three different centre cartridges (70 squid a pop second hand) and all ended in clouds of blue. Usually a big stalligmite of burnt oil under the exhaust housing and oil splattered everywhere.

I'm back to the standard turbo currently running as much boost as it will stick and it is pretty rapid currently. Went to a couple of drag meets reasontly and did a 1/8 of a mile time of 9.88 secs @ 74 mph. Note! this is not 1/4 time!! A RS focus run a 9.7 and a twin turbo supra ran a 9.3. Not bad! I'll try and get some videos and pics downloaded on another thread.

I'm in the mids of buying a rather special turbo for my 480 which will cure the T25 issues.

JohnTurbo · Post by **JohnTurbo** » Mon Nov 26, 2007 11:12 pm

Sorry for the slow reply Ed...I didn't notice your reply, as you may not notice this!

I'm currently running a hybrid on there as explained above, and haven't got round to fitting another pure t25. It seems to run fine with the hybrid, but only tried it upto about 10psi.

I'm not working on the ca at the moment but hope to soon. I'll fit my EBC then and have a real push.

JohnTurbo · Post by **JohnTurbo** » Mon Jan 14, 2008 11:44 pm

Hey hey!!

Well for some reason i've dug my 480 out of the garage once more.

I've painted and fitted a new front spoiler. (Thanks Lee!!)

I'm halfway through fitting martin's old stainless backbox, and stainless DECAT to it. The box has a mild steel tube which is a bit buggered and is causing me grief! Hopefully should finish up next weekend.

Also plumbed in my EBC in the engine bay. The control boxes and tubing in the cabin need wiring in.

aibast · Post by **aibast** » Tue Jan 15, 2008 6:51 am

I know your smoke screen problem first hand. My problem that killed of turbos was a stock by-pass. So the compressor surge just killed them.