Hi guys,

thinking of buying a td05 18g turbo second hand supplied by Zen performance, my original plans were to get a andy forest or a blouch one , is the zen performance 18g similar i was hoping to achieve 370bhp onn my p1 with supporting mods....just i heeard some turbos dont perform well and wasnt to familiar with zen...


cheers

 

Hi, I have an 18g on my '05 STi supplied, fitted, and mapped by Zen.
No two engine builds are the same so it won't necessarily follow that your results will be the same as mine.
I am running a hyperflow tmic, 255 fuel pump, full decat, RCM intake, 10% bio ethanol and it made 363/358.
From what I've read you might hit 370, you might only make 350, but that will be nothing to do with where you buy the turbo.
However there's more to the story than just numbers.
The 18g spools quicker than the VF35 and hits 1 bar 1000rpm sooner. Nice low down torque and more sustained grunt at the top end.
It's a good mild tweak for a fast road car, and in a lighter car such as a P1 should be very nice to drive.
One thing I will say is that Paul will get the most out of the engine without risking it breaking.
Hope this helps.

 

How does the 18g compare to the 20g? Whats the difference?

 

18g rated upto 375 or thereabouts (earlier spool)
20g rated upto 400 or thereabouts (later spool)

As said above, you can't guarantee a bhp/lb ft figure for any given supp mods/remap/fuel mapped... but it helps you choose the correct turbo for what you want to try to achieve, etc...

 

18G is one awesome Turbo, has a great pull through out the rev range.

 

Which is the better turbo for fast spool up, the 18g or the vf34?

 

Not had a VF34, but..
VF35 to 1 bar 3600rpm
18G to 1 bar 2600

 

OK, thanks.

 

Flippin' 'eck!!!

Didn't realise it spooled that bloomin' early!

 

I just changed the turbo on my car as it was leaking oil on the return and some fins were bent! (I don't know how but it was like that when I removed it)
Now it just doesn't seem as quick or as loud
They are both TD05's but how do I tell if it's 16g, 18g or 20g?? and would it make a difference to how my car sounded???

 

Where/who did you get the turbo from? Is it 2nd hand, etc, etc? You sure you refitted the up-pipe//intake pipe/IC pipe/downpipe/all gaskets, all correctly?

If you have fitted an 18g or 20g it needs to be remapped to make SAFE!!! and get the best out of it! If it is either of these turbos, then that's prob the reason why it feels different - must get it remapped to optimise it. Don't drive on boost and try not to drive much at all until you get it mapped!!! Also you might have too small injectors, etc, etc...


What MY is yours? Is it a MY93-96? Has the turbo got the upturned 90deg 'snorkel' for the intake pipe, etc, etc? If so it'll almost certainly be a MY93-96 TD05H 16g... or possibly the smaller TD04L!

An OEM TD05H or TD04L will have the OEM embossed serial codes embossed on the bottom of the comp cover... Amongst other writing, at the very bottom it should read "TD05H..." (or "TD04L...") - you should be able to see it looking down in the gap by the intake pipe...

 

How much do second hand 18Gs go for then?
Is it worth bolting one onto a WRX or are the engine internals not up to it?

 

Off here I got it, 2nd hand.

They both had TD05H on them but I cant see OEM on the one O took off.

Would it sound different?

 

lol It won't say "OEM"! OEM stands for original equipment manufacturers. It just means it's a std Subaru turbo... BUT...

What MY car do you have? It looks like a STi v.5/6 Wagon in your avatar??? If so, normally these would be fitted with a front entry IHI VF28 as std.! (So a previous owner must've changed it for a TD05!)

Is your TD05H therefore a front entry one? Was the old turbo physically the same size as this replacement? If so, then yeah, it's invariably either an aftermarket TD05 16g with a front entry cover to it, or an early OEM MY93-96 one converted to front entry by means of a new front-entry cover... or still has the OEM cover but with the snorkel chopped off...

Any chance of a pic trying to show the size/shape of the 'snail' and that writing on the cover?

 

It's a 96 sti wagon v2? It's rear entry and they were bothe the same size turbo's

 

Old damaged one below




NEW ONE THAT IS NOW ON THE CAR BELOW

 

What's the history with the "new" one?

 

It was off a car that was breaking but the turbo had only been on the car for 12 months.
It works fine it's just that I put a replacement engine in mine and changed the turbo but it doesn't seen as mentaly fast as before or sound as loud!!!

I'm just hoping that the engine I put in was an sti unit and not a wrx only! It cam out of an sti but you never know!

Rolling road I think is my next move.

 

Well at least you've got the correct turbo for your MY of car etc. - that's that question squared away.

The most obvious thing for it not feeling as spritely, is that it could be making less boost (for whatever reason). Obviously, if healthy, it should perform the same as the previous, same TD05H turbo (as the ECU controls the boost upto a max programmmed pressure level)... But perhaps there is an issue with it!(?)...

Do you have a mate who has a mechanical boost gauge that you could temp. hook up, just to make sure this replacement turbo is making the correct boost target for your car variant? When you establish that first, then you can go from there...

I think the STi v.2 Wagon's boost target is around 13psi (0.9bar) and boost cut happens at 16psi (1.1bar).

 

Thanks for that.

Those settings look about what it was at before so I'll check em when I get out in her next.

I will be getting it mapped at sonme point so this can be sorted then yeah?

Jolly green monster the best option?

 

Yep JGM for the win - I had my Apexi PFC mapped by Simon.

Yeah, unless something terminal with the actual turbo, Simon gives a brief "heathcheck" of the BCS system and replaces any split/perished vac lines with new hose, etc., before commencing mapping.

Any futher issues will no doubt become obvious and 'flag up' when the mapping is embarked upon...

 

Just been and ragged the butt off it and all seems pretty ok now! maybe I was just expecting something bad?

I couldn't see my boost gauge as it's dark but I'm replacing my vac pipes as they are not to pretty.

 

Has your boost gauge not got any on-board illumination then?

Yeah, prob just Placebo effect, as one is always anxious that it's gonna perform at least the same as before (if not better lol)...

 

Well it's dead now!!!!!!!!!
Was cruising up the motorway at 120 and it just lost loads of power and then loads of smoke came out the back!! Limped it home and checked under the bonnet and oil is everywhere! Dip stick is bone dry so I guess it's pretty dead now as I drove 15 miles like that

Back to the garage again
I'm about to get a Lada as they're more reliable!!

 

Don't lose hope yet. It's just your turbo that's dead. A dry dipstick does not mean a completely empty sump, your engine is most probably still fine unless you can hear a rattling from the bottom end.

The dead turbo might make some sound, don't mistake it for a dead engine. The turbo sounds more like a scraping noise while engine bottom end noises are knocking sounds.

 

Yep, most probably the replacement turbo was shagged e.g. to much movement to the shaft, etc.

Whip your intake pipe off - is it very oily inside (rather than the normal thin film residue)? Also, now grab the shaft's nose and wiggle side to side and up and down - chances are it'll be moving around rather a lot (hope so). Also remove the IC pipe - has it got loads of oil in it (rather than a thin oil film again)? If so, remove the IC itself and angle its entry port down into a waste oil disposal barrel - does loads of oil drip out of it?!

If any of the above happens, 90% sure the turbo has failed.

BTW, when the car let go, was the plume of smoke white-blue in colour? If so, another sure sign of turbo failure.

 

The car is in the garage now!
So I can't check a thing.

 

Ok update..

Just spoke to the mechanic and he started the car and said it's not running on all 4 cylinders and there is smoke coming from the exhaust but he needs to do a compression test 1st before he looks in to the turbo.

 

Yeah, even though theoretically the motor should still run, when a turbo catastrophically fails then sometimes the motor won't run. Could be due to compression or whatever, because now the non-working turbo has simply become just a big restriction in the intake system.

I'd defo get him to do those tests I mentioned - it might just be obvious that the turbo's failed, therefore saving everyone's time and, importantly, your labour costs!

 

If he does the compression test then surely if it is the turbo then all 4 pots will have compression?