VF35 laggy on newage WRX heads?
 

hello,

We are currently putting together an engine to drop into a bugeye sti shell we were originally going for standard 2001 onwards WRX heads however we have been told with the vf35 turbo this will be quite laggy..so now we arent sure whether to go and spend the extra on the V7 heads with avcs as this will aid spool time of the turbo.

I have recently sold my own 2005 sti type uk and loved how easy it was to drive compared to the older classic wrx models and would like to have as close to that as possible.

main spec of the engine so far...

Sti inlet manifold
sti injectors
sti intercooler
vf35 turbo
sti rebuilt closed deck bottomend using forged parts
walbro 255
equal length headers

Car will be mapped when it is ready to go...

I'm really looking for peoples opinion and experience of fitting the vf35 on newage wrx's and finding out if the spool time is reduced or isit laggy?

cheers
gordon

Many people put the 35's on classics without the avs heads and ive never heard of one being laggy. Although never tried myself

I've run a TD05 16G and a TD05 18G on my bug WRX standard heads without any issues with lag. Does the shell come with looms etc as it was destined to have AVCS ?

Shaun

i have recently fitted a vf35on a wrx and it is quite laggy compared to my sti with the vf35,turbo comes in about 500 revs later for some reason. the car was also fitted with a full decat system,walbro 255,sti pinks,k&n filter and sti intercooler with scoop and undertray then had an ecutek remap by andy forrest.the car still puts out 340 bhp top end just not so good at the bottom.

AVCS does help :D

If you want more low down then it's more cc's you need or a twin scroll :)

Shaun

Cheers for the replies guys, as it was an sti shell the loom will have the connections for the avcs heads however as the car was being mapped with the current part I was hoping it wouldn't matter.

I recently sold my 2005 sti type uk and loved how easy it was to drive with the early spool.

Begining to think it might be easier to go for the sti heads now

Personally I'd go for the AVCS heads........... a few STi's are being broken by scoobyspares at the moment or try somewhere like finch Motorsport :)


Shaun

just looked........doesn't seem to have any at the moment but worth a call

http://www.finchmotorsport.co.uk/page.php?a=3&s=69&p=69

https://www.scoobynet.com/889113-bre...n-7-sti-2.html

https://www.scoobynet.com/full-cars-...-breaking.html

https://www.scoobynet.com/full-cars-...-breaking.html

to name a few LOL

Shaun

Cheers for that..dropped Scott a wee pm

I had a VF 35 fitted to my last Scoob, a MY 00 UK turbo and there was no noticable lag. Maybe it depends on the mapping. :thumb: Steve.

I have AVCS on mine WRX,but mine is JDM WRX which have AVCS.

Now about the plug-in AVCS to your WRX is possible,but not sure if its your ECU can control AVCS,if not you will need JDM WRX ECU or aftermarket ECU like Syvecs,SimTek,Link etc.

VF35 i never tried,but VF34 on mine WRX has been spooly turbo which has similar spool characteristic as mine TD04L.

Yes AVCS will help spool turbo around 300-500rpm from some reports, definitely worth to do on WRX.

Jura

A VF35 is not typically a laggy turbo even on WRX New Age heads. Often the cause of lag is blamed on the turbo when the cause lies elsewhere.
What headers and uppipe are you using as this could be critical to the spool of your turbo.

The shell the engine is going into is a v7 uk sti which has the full loom including plugs for avcs.

The headers are equal length headers.. Unsure which brand they are..possible eBay jobs.

I just need to decide if it will be worth it going down the sti heads or not.. Trying to keep costs down as I'm running out of money lol

But you will need ECU which will control AVCS,not sure if will work UK STi ECU on your engine.

As above ported headers with Harvey up pipe,will bring spool to lower RPM.

Yes is worth down the route of AVCS,in my view.



Jura

Thanks Jura.
If money was not an object STi heads and ECU are a better starting point because you have better valves and cams but there are plenty WRX road cars that have been made in to very fast cross country vehicles with the VF35, proper mapping and supporting mods.
Without more information about your headers I cannot comment further but this is usually the cause of poor spool and response. Are the headers one piece or is there a set of headers and a separate uppipe? Is there a flexi joint, slip joint? How about a photograph if you want more assistance.