scooby4181

Hi,own an MY98 uk turbo,and was wondering which would be the best suited turbo unit for my mods and needs.
car already has Apexi power fc ecu,TD04 standard turbo,ported headers,STi 8 top mount intercooler,complete decat,all mapped to 1.1 bar.
Mods that i will be carrying out next will be 440 injectors,3 port boost solenoid,and fuel pressure regulator,i want to keep the top mount,and i have narrowed the turbo choice down to a TD05 16g or a vf35.
I am aiming for power of 330 bhp ish and similar torque figure.I do like quick spool up time,but also like to feel power kicking in,i am running standard gearbox and clutch,and obviously dont want to blow the gearbox,trying to make a decision,can anyone help me !!!!

jiffthejiffmanjaffa

iTrader: (10)

TDo5 16g.

Quick spool up, nice power quick not a wild turbo so it will last and as also not as expensive as alot of others.

Damocell

iTrader: (1)

VF28 is a good choice, makes for a quick road car and can be had for £150

Damo

scooby4181

bttt

scooby4181

bttt

Keith Collings

iTrader: (3)

I have an MY98 and am going down the same route as you except I'm fitting a Hybrid FMIC in the next few weeks. Already have an Apexi, Harvey's ported headers, and uprated exhaust.

I have just fitted a VF35 based on advice for early spool and targeting 320 BHP. I've got it booked for a re-map and RR session on the 27th so will hopefully have some supporting facts

scooby4181

bttt

nom

VF35 would be my choice there - 330 is right in its 'happy zone'; the TD05 wouldn't quite have reached it. You should get earlier spool with the VF35 over teh VF28 & lag should be non-existent between gears. VF28 you may find a laggy after the TD04, though. Andy Forrest does a version of a TD04 good for around 320bhp, I think - might be worth adding to your shortlist?
Gearbox & clutch problems are heavily driver-orientated rather than power/torque - sudden loading (slamming gears carelessly or, to a lesser extent, sudden application of power via the engine) will be what breaks them. From that point of few, 300bhp fast-spooling turbos may give bigger problems that 400bhp laggier units. I ran 400bhp/lbft for 20,000 miles on the standard 30,000 mile clutch/gearbox, which has now done 60,000 with no obvious problems (I've dropped to 350bhp since as it's plenty for road use & I like the quicker spool ).

silent running

But the TD05-16G ultimately flows more than the Vf35 and is the bigger turbo. So how would the TD05 not have reached 330 if a VF35 can? BTW I have had both myself.

harvey

iTrader: (48)

VF35. Good spool and on top of the job at 330 bhp with more to come on a good installation.
Good luck on yours Keith and I look forward to the feedback.

nom

Yes - the TD05-16G hasn't reached its full flow which means it's laggier that necessary for the power (a general rule is to always get the lowest power turbo to what you want - i.e. if you want 330, don't get one that can do 370). I don't have the compressor map handy for the TD05 but I think it may not even have reached its peak efficiency zone when flowing for 330. As the request was for 330 & minimal lag, the VF35 fits the bill nicely (330 it's very comfortable with, 350 is possible on pump fuel with nicely sorted supporting mods, and I've seen 390 but that was cheating on - I think - 109 octane fuel + WI + rather high boost...).

silent running

I do have a compressor map for it knocking around, and basically the TD05 has the widest efficiency island at around 1.1-1.2 bar boost. Hence why I don't really think it's a solid 350bhp turbo and is right 'in the zone' in the mid-low 300s. The VF35 is a good turbo though, I just wondered whether it might be running out of puff at the top end at the target power level. I know my 16G is very responsive indeed on Harvey's ported headers and up-pipe, hits 1 bar at around 2900rpm and 1.45 at 3400rpm IIRC. It doesn't feel like a big turbo to me.

deansscooby

what turbo would be best for my set up, full decat from turbo back green pannel filter.
just been for a remap today to map the mods in and on my00 only got 240.8bhp.
maper said turbo may be on the way out so what should i fit only looking for 280ish bhp.
so please only state whats needed to hit the 280, the td04 is on at mo.
cheers for any advise.

deansscooby

been told td05 or vf34 any body with any info

nom

TD04 is perfectly good for 280 & can be picked up cheap (really cheap!). TD05 & VF34 are for higher power - obviously that means they can do 280, but you'd find boost comes in much later (and a little slower) than the TD04.

Interesting on the TD05 map - will need to pull it out to have another look - I'm obviously forgetting things! . 1 bar at 2k9/full at 3k4 does mean it comes in later than the VF35 though, but that may be the headers & up-pipe as I don't know what Harvey has done to them, although would assume 'porting' means 'porting' so shouldn't raise the boost threshold!

fireblade37

iTrader: (1)

silent running

Just to clarify, the ported headers and up-pipe definitely brought everything on earlier, probably by around 300-400 revs IIRC. So without this the '05 would be much more of a 'big turbo' feel. That compressor map posted above is the one I used, and it seems I did remember right, it's most comfortable at around 1.0 to 1.1 bar boost (or 2-2.1 PR)

harvey

iTrader: (48)

Thanks for that feed back. Anything you can do to improve the VE and obtain performance improvements without throwing boost at the engine has to be the way to go.

silent running

Well I'm trying to see what's the most I can get out of a 16G this time round Harvey, hence porting the heads and doing an STi valvetrain conversion, plus changing the Autobahn FMIC for a Hybrid. This should give the forged lump every chance to make good power even at moderate boost, so with the wick turned up, I should be able to make decent numbers. People say a 16G can manage 350bhp, but I wonder how many really do?

Damocell

iTrader: (1)

Not to hijack the thread but have you changed the FMIC to the Hybrid yet?

If you have what difference have you noticed or when you do could you please post your findings

Damo

harvey

iTrader: (48)

There are TD05 16G installations about with 350 bhp and a little over but remember there is always a spread of power on various installations. Some engines are more willing than others for no apparent reason. Even on a very willing engine I would take 350 bhp as the top target. Getting there or beyond would be a bonus.

Unless the FMIC installation is done in isolation without other mods the comparative figures are a bit meaningless. Also remember the vagaries of different RR set ups and even the same RR on different days.

Can you do the FMIC comparison on that mod only?

silent running

Not really. There are lot of variables in the mix there. Physical spec prior to the bottom end failure was standard 2.0 v4 WRX block with early hydraulic tappet heads, Walbro, 440s and FPR@3.5bar, Autobahn FMIC, TD05-16G@1.45 bar, Samco inlet pipe, mildly ported inlet manifold, ported/wrapped headers and up-pipe, sports cat downpipe, H&S/Prodrive remaining system. The things that will change now will be the block (now a forged 2.0 CDB with ported/polished STi3/4 heads) and FMIC (to be a Hybrid tube/fin).

The 16G always struggled against the inlet somewhat, giving a lot of compressor surge, as it did when I had a VF35. I never made any good numbers on the rollers. It was most likely a combination of the shoddy Autobahn core and crappy early heads. Hence my target is more to see what the same turbo can make with everything in its favour so to speak. If it can't get close to 350 on this spec, there's something very wrong...

RB5 Boyo

A fella i know got 356bhp/354lbft from his 140K miler UK2000 with the 16G turbo and the car still pulls like a train!!
I have the same turbo so will be hoping for the same when i get to the rollers....i manages 305/302 on the rollers a few months back with my old TD04 and supporting mods, was really happy too

mike799

vf35 would be my choice on that spec

also a direct replacement.

excellent turbo,will make a very quick road car