just found the graph joz,1.5 bar is reached at about 4250rpm.:thumb:

Same spool-up as a... well my... 20g then.

Not worth changing really.... Unless your car is one that inherently makes good power. Ergo, if it is, then you could make around 400bhp. In which case it could be worth doing. But it's all ifs and buts, and you wouldn't know until you done it! :(

why would you say its not worth doing?
surely if it has similar spool up but assuming large power and torque gains compared to my measly 338/316,its well worth doing as my car would be alot quicker,a likely gain would be in the region of 40-50bhp and around 50lbft!!! with similar spool.:cuckoo:

to add.......i have a newage sti jdm short motor with v4 type r heads.

Oh I say old chap a lovely motor. Like it alot, I had a white wrx uk classic before my V5 STI but my dad wrote it off!
Car looks lovely in white.

Its good to read the standard gearbox is still going strong and engine internals. Im begining to think a 20g would be preferable to an 18g. I only really want to make it pull harder from 3rd onwards mainly for overtaking and motoways.

Of sorry 99gw - I asummed you was at 360bhp and similar torque! :cuckoo:

Yes! Then certainly with that bottom end, I would do it in a thrice! :) TBH, I don't know how you've resisted!?! :D

I'd prob get a SC40 though. Has a billet comp wheel that's 33% lighter than normal. Only sleeve bearing though (but then so has a TD05H 20g). From memory, it's about 300 quid more than a harvey or AF 20g, so choice is yours....

Joz what about a sc42 just running on a lower boost, I'm led to believe that it has similar spool to a VF28

Yeah the sc40 is about £1500 all in, I was tempted too but when you can get a fully forged classic for around 6K it puts it into perspective. Hence why I am looking for an older and cheaper TD05. I just dont fancy a new age (no offence) they dont do it for me. If the engine goes bang because of the increased power then so be it. The forging process will commence! and bring on 450 brake!!

Yeah RJ, that would indeed be my choice! :)

BUT.... It's getting on for twice the price of a harvey and AF 20g (and also a fair bit more than SC's own SC40). But it does have roller bearings.

Cost does come into it for 99gw... He's demonstated on this thread already that he's a tight cvnt - hell, he was after my own 20g! :D :lol: (Plus he wanted my Prodrive bb for free! :D). Ha ha.

lol at the timing. Kirk has echoed my sentiments. :)

What are Harvey's and AF's 20g's like in comparison to a vf28 spool wise? As my next purchase is going to be a turbo for my V5 type R

Prob. very similar to mine e.g. 1 bar around 3.5k and 1.5bar around 4-4.2k I expect(?), so obviously, the VF28 much better spool-up, of that I'd be certain.

Harvey's inlets and outlets are fully ported from memory. Or it might just be a ported w/g(?)

But both his and AF's are pukka items and will produce the numbers (unless you just happen to have a lemon of an engine that don't take well to modding/don't make boost)...

you mean your fooked backbox?:hjtwofing:D
i held back as everyone says"20g is really laggy"!.i was also told my a vf48 would make more power than it did:Whatever_
joz....do run an aftermarket boost controller?ie avcr?

ps,if anyone gets offered a prodrive backbox on here for £40... do a runner!:D

When Duncan mapped my car he reckoned it was a good un :D decat and induction kit on a simtek at 320-330. So I might be better of saving a little more for a sc42 or a md321h(?) to keep the similar spool

Should make 350-360 IIRC.


No. Don't need one with Simtek. ECU more than capable of sorting the boost out.


lol

so if i ran a 20g with apexi power fc is an avcr needed?

350-360 will be made on a 2.5 but not 2ltr!(on vf48)

Yes, an AVCR works great with a PFC - ask JGM. :) Allows the mapper to get the most out of the map.

Do you you already have the A'PEXi 3bar MAP sensor? If not, then make sure you get one with the AVCR (it's actually part of the AVCR's full kit IIRC, along with the A'PEXi 3port BCS). Because otherwise, it don't work well with the OEM MAP sensor :(.... IIRC from JGM's imparted knowledge.


I'm sure mappers on here have got 350+ on a VF48 on a 2.0... :wonder:

yes ive already got it all,not fitted. i dont want to use meth and dont know what is the best route to go,im also looking for approx 360/350 +.if id known what i know now i would have just got a 20g in the first place..:brickwall

still on 440s at mo joz.

Such is the steep learning curve of performance car ownership.

If we knew it all off the bat, The Matrix mind-program stylee, then we'd all make the right choices, first time, everytime. :(

If you get a 20g variant, get 650s if you can. Or 740s.

Or get your own 440s - or another cheap set - flowed by LP to 930cc.

when you selling it then?:D

<<< Post #21

;)

:thumb:
cheers joz;)

might be due some new "sparkies" by then!:Whatever_:)

I'm still oohing and ahhing over whether to go the TS SC42 Billet route. Hmmmmn.................

Damn damn! :(

So what's the real difference between a VF28 and VF 29?

I expect the VF29 has a slightly smaller exh. housing(?), seeing as it was fitted to the MY99/00 WRX. (STi had the VF28 which, I'm assuming, is the 'larger' of the two).

But in reality, on the road, bugger all difference in feel. And both are mappable to the 310-330 bracket.

dont be a pussy!
get it done...:D:norty:

Ulterior motive for you, eh? :D ;)

your turbo is proven!:D