Rollinz

Right guys i'm hoping to find some help on here,
got a massive spec focus rs,
brief spec..
cgi block
wrc rods (1mm shorter than std)
cp racing pistons
Gt35r turbo
custom inlet
ported head
std valves
106 gti valve springs
bigger retainers
custom cams (this is the important bit)
inlet 285 degrees with 10.5 mm lift
exhaust 280 degrees with 11mm lift

now the problem....
when i was on the std cams. it made 545.4 bhp @ 1.5 bar easy,
now fitted the bigger cams and it got to 1.7 bar making 586 bhp and then started sounding like it was surging with alot of noise also through the knock link, now turns out it was valve float...
it was happy until it gets to 5500 rpm area,

i am 100% sure its down to my spring choice and maybe cams selection...

i'm now thinking of going into the ST170 head realm also...
any one got any ideas what will work best??

cheers in advance

xr2wishy

iTrader: (2)

Double valve spring are the answer I'd have thought.
Area six sell them but need extra work.
Don't bother with st170 head, heard they flex or something and don't take to being skimmed well.

lacey

Do you have to machine the head for bigger bucket, just that my mate is having this done to fit double valve spring with yb buckets in a silver top head

J1mbo

iTrader: (1)

545bhp at 1.5 bar on a gt35! Wow

Pump fuel? Whos dyno?

Rollinz

V power
Gr performance, brand new dyno my car was first on after installation and callibration so would say it was pretty accurate :/

Anyone any idea on what double springs are from? Or is it all hush hush and got to go to ian howel?
When i spoke to him other day he just advised me to shim the springs by 2mm but i would sooner go double ....

J1mbo

iTrader: (1)

Seems like more power than a cossie would make at that boost and we know from doing a 570bhp zetec that they are no where near as good as a cossie engine that's all

If its making the power congrats but seems a touch on the high side if I'm honest!

Mark Shead

Why did you only use 1.5bar if it was easy at 545hp.

Mark

Rollinz

Dunno mate, just need to sort out the valve float problem tbh,

Rollinz

When i said easy i just meant it had no problems or issues,

And that was using the std cams,
We didnt try for more as it was more a shakedown before fitting the bigger cams, but now at 1.7 bar its getting valve float, just want to know which would be the best way to stop it

Mark Shead

I would run double springs with the correct seat pressure but as I havent done that amount of work on the zetec I cant recomend what type to use,
The GT35 realy needs good cams and a good flowing head to resist surge.

Mark

Rollinz

What seating pressure will i need mark?
I think the head and cams are working fine, were hitting full boost by 4k rpm, then the valve float start around 5500 and the power just drops off badly and makes a horrible noise ( like surge),
But am i right in thinking if it was surging it would surge more at lower rpm? I.e 4k when its just fully spooled?

AustenW

Use Piper double valve springs from a Rover K series engine if my memory serces me correctly and use a stainless penny washer for a spring seat

Give piper a call

Alternatively Cat cams do a double spring kit for both the blacktop and ST170

If you go the ST170 head route which is a better flowing head IMO you will need to shim the springs to get the correct seated preassure as the valves are a differrent length

For the power you are going to be running if your running std valves, guides and seats they will last 5 mins IMO and will need to be changed for a better material if you want durability

Rollinz

Found some other good info out, which may help other people in the future....
Ive been advised to get he head machined out and to use vauxhall springs and followers,

AustenW

Old news mate, Ian Howell did this over 5 years ago to get bigger buckets in his head


IMO not needed if the cams are specd right, unless your aiming for huge cams for drag racing

Rollinz

No mate happy with the cams ive got, seem to be working fine and making full boost by 4k so happy all there, just need to sort my valve float,

Why you say the std valves/seat/guides wont last?
Its a focus rs head. Sodium valves if im correct ?

AustenW

The engine is producing way more than it was designed for

All serious engines that last use uprated valvetrain items

You will have valves bend / stretch and guides wear excessively as they are production OEM materials designed for a 220bhp engine

I was advised to run Numonic exh and 214N stainless inlets

I also run custom made trojan valve guides (Made by TTV to my spec)

Your also going to need Beryllium copper valve seats

If your planning on using stronger springs and doing any serious mileage with out having to worry about stripping and replacing parts every 6 months.

The extra spring load will stretch your valves if they are oem and your actually planning on driving it for a length of time

Sodium filled are worse for stretching as they are hollow

Not sure that they are on the FRS but still worth changing for a decent material valve at your level


Most people will chime in to say its not needed, but I bet all the serious tuned cars that do milage and that are reliable have done the above mods

Rollinz

I see what your saying mate, i am going to be speccing another head next year as i want to run a very aggresive anti-lag,
But berrylum valve seats.... I dont think they would be of that much greater bennefit if im honest as no matter what mods you do the zetec gead is shit at dispersing heat, so would they really be worth it? Taking into account its very soft and wouldnt like the pounding from a strong spring rate..?

Anyway back to origional topic
I spoke to ian howel earlier
and going to send the gead to him for a double spring conversion, for Ł600 its cheap for the work involved imo,
New guides with some extra machining to use vw stem seals, rover k series double springs as mentioned before, and some modified retainers, hes also going to re-check all the clearences too,
So happy days, onwards and upwards

Maki

I think xe stem seals are used.

AustenW

yes they are

Rollinz

when i spoke to ian other day he said vw ?? so duno.,. he's doing the work for me anyway

AustenW

Ian knows what he is doing, the end product will be first class.

He uses the same machine shop as I use and the workmanship is very good

Rollinz

Austen do you run zetec turbo?
What plugs ypu using?
I could do with some around 9.5 or even 10 heat rating....
Cant find non that fit, is it worth having the head machined down to run a shorter plug?

AustenW

On the last engine I had the head machined and used Motorcraft 701's

I tried every plug on the dyno and these didn't miss a beat, (excellent plug and cheap too)

If you dont want to mill the spark plug holes try the Denso ITV range

AustenW

STD Focus RS Denso part number is the ITV20

They go up in heat range with the number

Try an ITV24 or ITV27

Rollinz

using 27's at the min but there going blue on end.. so after somthing colder
itv27's are aparently same as a 9 rated ngk.?

AustenW

Try Opie Oils, there might be the ITV31 out now

Rollinz

sweet! thanks for that info dude

AstoN_B

iTrader: (1)

Austen you certainly know your stuff.

So many people gives bits and bats of information, sometimes repeating what they've been wrongly told.

Also, i'm surprised you're going for more power Rollinz. 550bhp in a FRS must be pretty nippy!!

I bet 3rd gear is almost useable

Rollinz

Its useable mate sequential boost controler makes it useable lol,

Not really power chasing now mate, just want to hit 2 bar of boost xause the gt35 isnt in its efficiency range until then, so that makes the engine non efficient untill then, lol

E.g @ 1.5 bar it was making 545bhp but only 430lbs of torque,
@1.7 bar it make 568bhp, but the torque shot up to a staggering 500 lbs

AstoN_B

iTrader: (1)

I was thinking you'd definitely need some electronics to make it drive well.

Is it mapped to only reach full boost at nearly full throttle?

I wasn't implying you were chasing power, it seems you've already cured that itch lol.

Are you using a standard RS box? I can't even imagine what a torque biasing diff would feel like with that much to play with Horrible i'd say!

Rollinz

Haha, yeh std rs box lol
Tbh its pretty brutal, worse most of all in 4th strangly lol, but just hang on tight and wooooohooooo lol,

Got various setting on boost controler,
1. Gain set to 100% and bang full boost at 4k rpm and hold on tight,
2. Gain set to 50% hits 1.3 bar and then slowly rises to set boost

Cant wait to be able to run more than 1.7 bar
We wanna push it to 2.5 bar just to see what it will do but i only want 2 bar to use,

My target ever from when i started the build 3 years ago was 550,
Hit that so anything else is a bonus

But... I do also wanna sell it now lol
As i got another project in mind
106gti... Cross with evo 7

danneth

Your projects take way to long, stick with this and get it used

AstoN_B

iTrader: (1)

I have to admit, as mental as it sounds i really want a go. mate had a newshape focus ST he'd tweaked to about 350bhp and millions of torque. It was all over the road after fitting the new diff

Deffo needed setting up better. But it was savagely quick for a more or less standard looking st with splits on.