Hi,


Currently the heads are the week point of my engine.
The engine is a rebuilt 2.1 Stroker, using the heads from a UK 2000 Turbo.

I have a new Alcatek ecu.

From what I can find the general upgrade here is to STI 5/6 heads, values and springs...or AVCS.

350 BHP (limit of my insurance) is my current target for this light track car.
Maybe next year 400+ with FMIC.
From what I have read both the heads above are quite capable of these targets, and some more.


Is there any gotchas that I've overlooked that I need to take into consideration when choosing heads?

What Turbo would be ideally suited for this setup?

Woka

 

Heard a lot about v3 cams and are highly desired. But I've also seen some scoobynetterrs running impressive power on totally standard heads, taking 450 +. Avcs is the way forward but expensive. Think you want to worry more about keeping your heads from lifting, maybe uprated bolts if u havent already got them. Have a chat with some tuners, enginetuner, RCM, scoobyclinic etc

 

Hi there

I would say at yours target bhp you should be OK with UK2000 heads as they're not bad heads,beyond 400bhp can cause restriction how big hard to say there

V5/V6 heads are probably best if you don't want to go route of the AVCS,depends what condition of heads you will get,if you want to upgrade then best path is Supertech valves and Supertech spring combo and cams I would keep stock one which seems are pretty capable

With AVCS is bit complicated as you will need get extra loom and you will need speak with yours mapper if he can wire AVCS for you and you will need to have AVCS/VVT-i enabled on yours ECU,which I think cost around £60-£100,please speak with yours mapper as first

Which are best AVCS,I would go with JDM V7 or V8 STI "big port" AVCS,which are best and with stock valvetrain they're very capable,you don't need them to upgrade unless you are planning go beyond 550bhp,maybe more

Really you need choose and decide which will be best,AAVCS I would choose as with them you will have faster spool up than with non AVCS heads,if budget doesn't allow then V6 STI heads are pretty awesome heads

If you will be buying JDM AVCS heads please check condition of the heads and check if they're not cracked around the spark plugs etc

And about the turbo,for 350bhp I would go with SC36 at this level,beyond 400bhp I would go with MDX321T or SC42 turbo those two turbos I would choose there without the questions

Hope this helps

Thanks,Jura

 

Hi,

Thanks for the information. I learn something new from every post. Thanks.
While budget is always an issue, I am flexible.
Although, doing a half arsed job is not in my nature.

Don't suppose you know a rough ball park figure, how much more expensive AVCS are compared to V5?

£1k for V5 vs £2k for AVCS
or
£1k for V5 vs £5k for AVCS

When the time comes the work will be done by RichardHenrys and the mapper Andy Carr.

 

I paid £400 for some Spec C AVCS heads, the custom loom from JTi was around £150, and it was £50 to have my Alcatek updated to run AVCS.

Not a huge amount of money compared to standard STI4/5/6 heads.

Sticking point maybe your year of car, mine is a 99 so inlet manifold fits directly onto newage heads.

 

Hi there

Really you need to decide what you want to do as I said,if I would go then I would choose JDM "Big port" AVCS heads due in stock form they're awesome heads and really upgrading valvetrain like valves or springs you are really don't need if you are not planning go beyond 2.0bar boost for long period time,but still at that boost those heads should be OK

How much expensive AVCS will be against the V5/V6 STI heads hard to say,if you are looking for JDM AVCS heads they're selling for around £400-£600,if you want to add other parts like Supertech valves and springs then you will need to add extra £350 over here,in US this cost around £200 or maybe bit less,cams this depends on you,we are run Kelford cams which has been awesome or Cosworth are great cams too(probably best cams what I know)

Really but still I wouldn't upgrade valves and springs or even cams as those heads(JDM AVCS heads) are awesome there and really is up to you,but I wouldn't do that if you are planning run no more than 500bhp

Same is with V6 STI heads,which are awesome heads and really I would rebuild them if they needs to be rebuild'd

Hope this helps

Thanks,Jura

 

Not a huge amount indeed. A lot less than I was expecting. A lot less.
I don't think it's quite a matter of what I want to do, it's more of a case of what is out there and the if's, why's and don'ts.
I generally don't like making any decisions without consuming as much info on the subject 1st.
I am a strong advocate of future proofing, be this computer software or car mods/upgrades...without going overboard on expense.


My intention is to have a safe, decent road car...that holds it's own, and some, on the track. (I'm not new to motorsports)
Over the last year I've built a "solid" base platform (this is probably quite subjective). Almost all upgrades, bar the 2.1 stroker that was a forced upgrade due to the original engine letting go, have been handling and safety. It's now time to focus on pure power and performance.
From what I gather both v5/6 STI and AVCS will do the job just fine for what I want...it's just getting into the nitty and gritty between the two to make an informed choice.


Thanks for all your input. Going to do a search for JDM heads now

 

I run standard Spec C heads on my 2.1, using an SC46 with a splash of meth it made for a hugely quick car. 518/455