Td05 vs vf34 night and day?
 

As above is the difference night and day? Sick of the lag on my 16g.

Get some properly ported headers on mate

I ran a TD05 16G on my bug.....ported and wrapped Harvey headers and de-ccat up-pipe and mapped by Bob Rawle....... I didn't find lag a problem.

Boost leak? headers leaking ?

The VF34 will spool faster as its a ball bearing turbo but not sure it's worth it over your 16G

Shaun

See I've thought about these ported headers but have always thought, how much difference realistically can they make? Surely it's subtle?

Vf34 lagless, got to be the best turbo for 360 bhp, pulls like a train..all the way to the rev limit.

just sold my vf34, and have got a md321t. car will be mapped on thursday
lets see how laggy this bigger turbo really is compared to the vf34
vf 34 left md 321t right
Attachment 56019

wiley

Agree with VF34 on AVCS is probably nicest turbo...On non AVCS tried and must admit great too.

Wiley on yours without AVCS will be laggier,but how much you will see...

Jura

16g lag..... Should have hardly any.

They are Brillent little turbos

I agree if you have lag, you have another problem, BB turbos spool at best 2 to 300 rpm like for like, the VF34 is a larger turbo, it will spool later, I expect by 200 RPM

I think it's because when I bought the car it had a td04. Used to be on full boost not much over 2500rpm, now the td05 16g isn't on full boost til about 3750rpm. I hate planting my foot an nothing happening for those couple of seconds, although I hated the way the td04 was hailing off at 5000rpm! I need a medium ground! Thought a vf34 sounded good, I'm guessing I won't get such a strong kick back in my seat as I do with the td05 though?

Strange I get 1 Bar at 2800 to 2900 RPM, I only have a lowley 93 WRX, lol

depends how its mapped, as I am sure u can get the bost on early than that.

Ha I think you would get a big surprise mate,mine was mapped on a vf34 a while back and made 354/340 and in a classic it was rapid.

Considering it's running simtek I would have expected that turbo to be working harder than that?

The TD05 16G is not a laggy turbo. Compared to a much smaller TD04 it may appear laggy. It is generally capable of 340-350 bhp (TD04 280-295) with all supporting mods, depending on which set of rollers you go on. In my experience the VF34 is a 360 bhp capable turbo and it does not spool noticably better than the 16G.
There are many reasons for apparent lack of response.
Start by finding a level piece of road, 4th gear, 1500 to 1600 rpm. Foot flat on the floor. Do this several times from the same starting point in each direction to take care of any wind or gradient issues. After several runs, the point at which you hit 1 bar will stabilise. Let us know where you get 1 bar.
Causes of poor spool can be lack of attention to detail in the map, poor intercooler core or pipework, lazy turbo worn, inefficient exhaust system, unlikely but ported headers and matched uppipe certainly help but I would be looking for the root cause.

+1 for Harvey's comments

Thanks guys, will try the 4th gear thing out in a bit and see how it goes and let u know.

Harvey, I've been reading on an old thread that u ran 585bhp on a standard classic 5speed box, is this true???!!

Right did a few runs on the same stretch of road earlier, I get 1 bar of boost between 3400rpm and 3500rpm. It looks as if full boost which is about 19psi, isn't achieved til about 4000rpm. Ok, I am using cheap gauges but I can tell when full boost comes on without looking at the gauge as you can feel it obviously. The other thing is I would prefer to stick with a td05 than use a vf turbo as I've read on numerous occasions that it will be much stronger when I get my anti lag activated! Thoughts on my turbo figures then??

Its a bit low, as said I think ou should get 1 Bar at 3K min. Malbe the map is opening the boost sol a little, or the boost sol is sticking.

God knows, taking it back to my mapper in jan, I did get a brand new r spec 3 port bcs fitted the day it was mapped?

Have you changed BOV or anything ?

Nah, still running the hks ssqv, my mapper said it would be fine and it was mapped while fitted to the car

I allways wanted to use a manual boost control, on my car, but found it not to control the way I wanted it ( it kept creeping. now i have change my eccu I get the boost on early and it has much more low down grunt. The way its mapped can have a big effect.

Maybe your Ecu was mapped with gearbox in its mind so it deliveres torqeu differently since 350 is damn near gearbox limit (or only matter of time till it blows).

When my dad had a 16g on his WRX it was a bit laggy, but honestly nothing terrible. Felt awesome to be honest! He did have tubular headers though...

Yes that is true. The car ran 585 bhp on Race Fuel and coincidentally 535 bhp and 400 odd ft.lbs of torque on Optimax. (That is how long ago it was). The TY754 is a far stronger gearbox than most people give credit for. The TY752 by comparison is relatively fragile. The same car, my STi 6 Wagon, was also winner of Scooby Shootout all these years ago but at that time may only have had around 500 bhp. I did numerous drag starts at Elvington and New York Raceway and the only thing I ever broke was the centre diff and that was because a clown who was supposed to be an expert at the time fitted the wrong rear diff (ratio). That screwed the centre diff and it was on investigating that problem I found I had a different front and rear drive ratio which explained the interesting handling characteristics cornering at speed. The other transmission issue I had was not directly related to the TY754 box but twice I rived the centre out of an AP Racing Uprated Clutch. The centre of the metal cover was literally torn out so there was no drive. The same car now uses the latest STi box with a clutch from America but I am now looking at Triple Plate.

Exactly correct. The mapping can have a big influence on the perception of lag or a lazy turbo.

As regards the gearboxes it is all very well everybody jumping on the Subaru box being weak but they do actually need to differentiate between the TY752 and the TY754.

Oh ok so what box would I have in a my00 uk turbo 2000? And what do you think about my boost characteristics?

My mapper did say that I would have a linear torque curve?

Out of interest, which gearbox would a 2005 WRX have?

Where can I find your boost characteristics? A graph with torque/boost/revs otherwise I don't know what I am talking about.
Subarus MY93 to 98 had TY752 gearboxes. Subarus MY99-00 had TY754 gearboxes with a much stronger casing which prevents flexing of the gearshafts. The TY754 gearbox was then carried on for New Age five speed. (Designations changed at a later date but the strength of the box 754 onwards is a mega improvement over the 752 which were easy to damage).
Any box TY752 or TY754 with a VB reference is a Jap box and VN relates to UK/Europe.
UK/European boxes have a 1.1:1 drop gear so the front diff generally is 3.9 and the rear diff 3.545. The Jap boxes have a 1.0:1 drop gear ie. the same gear, no conversion so Jap cars may have 4.44 front and rear, older ones may have 4.11 front and rear and you can even have 3.9 front and rear.
The 6 speed gearboxes are stronger again and superior to the TY754.