am building myself a zetec turbo using a black top N/A engine from a focus.

i am now strugling to find a suitable cam choice, can anyone suggest a suitable cam that will fit the blacktop and is the correct profile for a turbo engine? have only seen that kent do upgrades for the RS so far, do any others do one?

 

every zetec turbo i've seen with non standard cams has used 'secret spec' cams

funny how nobody will say what they are.

 

just use the standard ones you got free with the engine

 

yeah everyone says secret spec... prob easier than saying "i just paid a tuner to get me a set and didnt ask what the spec was cos i dont understand it all!"

Std one, nope am doint it properly as if the std ones were suitable then they wouldnt have developed new ones for the RS would they......

 

whats the rest of the engine/turbo spec?

 

engine spec.

JE forged pistons 9.0:1 Cr
Eagle H section rods
ARP bolts / studs throughout
Rover turbo inlet
Fidanza alloy flywheel
Helix custom 6 paddle group n spec clutch
Stage 2 T3 (till it dies then will get roller bearing)
Omex 600 ecu

Still unconfirmed:-
CAMS
VALVE SIZE
INJECTORS
EXHAUST MANIFOLD

 

so you want some secret special ones but don't know what
ring me in the morning and i will tell you which secret spec to use

 

all i asked is who does them so i can look at what spec each is and then come to a semi informed conclusion for there.....

but like i said all i have seen for black top is the kent ones so far....

anyways alot of tuners can ask firms to do a special profile grind for one off applications and this is what most of the secret spec refers to in many cases as tuners are oftern gaurded about giving information so that other people can not simply ring up a firm and ask for "the profile you did for joe blogs last week please" instead of going through the company that commisioned the grind.

 

You say you want to do it properly, yet you want a 9:1 compression ratio? Do you have a vast quantity of race fuel in your shed?

 

i also heard that the secret spec cams quite often refers to an inlet cam from one zetec engine eg 2ltr and an exhaust cam from another eg 1.8ltr

 

the 9:1 isnt that high!

Also the omex will be mapped using the knock sensor capability and also using the wide band lambda control functions so will be fulling correctly and knock wont be an issue.

Also it will be running optimax at all time anyways!

red16 - yeah i have heard of people swapping and changing cams to try to get a better match between engines but its not something that i would like to do by trial and error really unless soemone could give me good proof that the aftermarket cams are of a similar profile. Then it would prob be cheaer to but the aftermarket ones anyways.....

 

What you think will happen and what will happen are two very different things, as you will surely find out in your experimentation! Testing is good though...


As far as cams go, the previous comments are fine. The standard 2L cams are 'too hot' for say a 300bhp engine, but work fine. They'll give you a perfectly flat torque curve from 2500 upwards, depending on turbo choice. Although I doubt you'll be making 300bhp reliably on that CR

 

do you know who mitsi fq is? i think you need a chat with him bud. my mate got a dynoed 330hp 340lbs tq on 2.0 cams in his 2.1 16v so how much power are you expecting from your 9-1? boost and cooling?

 

What turbo and boost was he running for 330bhp? I'm guessing a t34 and 20psi?

 

If you are building a zetec with 9:1 cr you will want to go for some long duration cams!

 

yes t34 and i think .48 not sure on boost mate.

 

And piss away all the power ... the 'merican way!!!

 

i am only after 300 but with scope for more at a later date if the urge takes me....

Cooling is done by radtec front mount, water cooling by custom full width rad, oil cooling will be aided by setrab 10 row oil cooler (am looking to mount it in fog light hole in front bumper) and other fog light for either number plate or duct to custom airbox housing induction cone to prevent heat soak.

Boost will be left to see what is safe during mapping but as for the 9:1 CR, have a look at alot of the newer engine and what power they are producing on pump fuel with higher CR's than that with forced induction through decent mapping and a host of sensors such as knock and wideband.

needforspeed - no dont know who mitsy FQ is hence didnt say anything more about his reply as it sounded like the normal sarcasm that can be found from some members when a question is asked. hence my reply....

Mitsy - sorry if i sounded flippant towards you, drop me a pm please mate so we can chat bit bout which is best for the blacktop.

 

Without sounding sarcastic, a shonky old zetec doesn't suddenly gain 10 years development because you bolt a wideband lambda and knock sensor to it. And a shonky Omex ECU isn't exactly state of the art when it comes to engine control, especially not when you intend to live on the very fine edge of what the engine is capable of. Good luck with your project though

 

no i appreciate what your saying, omex and a zetec isnt cutting edge stuff but the basic principle for the modern very high compression in comparison to the days of cvh and a chip is quite simple, good mapping, knock and lambda capabilitys. But on the other hand 9:1 isnt exactly high compression and if it doesnt work it can always be lowered for not that much money considering.

On the upside to 9:1 it will offer better off boost drving and also better fuel economy off boost.

On the up side tho for a 2.5k build (with all of those parts except the clutch, turbo and flywheel as they were from a previous project) plus mapping its not going to be a bad learning experiance if it does fail in spectacular fashion.

 

No matter how many sensors you have, with the sort of spec engine it looks like you are building you will run into det at a fairly low boost level on pump fuel.

 

The efficiency difference between say 8:1 and 9:1 is about 3% so you're not really going to gain any 'off-boost driveability' - that's just an old wives tale.

All I will say is if you haven't purchased the parts yet (as it's blatently an internet spec - off the shelf crap from America, where they mainly run superchargers and low boost levels), is have a bit of a think about it. They have drawings over there with JE, CP, Arias etc. for proper low-comp pistons and can sell you those.. From experience, anything over 8:1 isn't going to make a genuine 300bhp on pump fuel - you WILL get unavoidable det before that point and it doesn't matter how much you think you can drown the engine in fuel, it'll still be there!

I'm just trying to save you a lot of money and heartache..

 

My engine:

8.8:1 CR
20psi
standard cams (ST170)
Cosworth WRC rods and pistons

oh and "Shonky" Omex710

310bhp on a tiny GT28R.

No det issues and plenty of scope for more power.

XRSI, call Ian Howell he wrote the book on Zetec Turbos and is very helpful.

 

yeah the pistons were from america which if needs be can always be sold on providing i dont split one in half!

EDITED :- oh and i do agree off bost drivability is to an extent an old wives tale but there is some truth behind it.. if the car is that lumpy then off bost its horrible to drive then its off boost drviability is next to zero, higher compression is better off boost but its a balancing act between alot of factors as you will no doubt agree.

Even 1% is an improvement, albit a very small one and as for drowning it in fuel - as im sure your aware that it's almost as bad as det for the insides of an engine as it will eat the bores and rings rather than the crown of the piston or the head around the valves.

There has tho been good reports in the uk from the exact pistons i am using one fiesta running them in a ZVH (with loads of zoo parts) is running over 300 with nos as well so will just have to wait and see if the gamble pays off.

Like i said its a complete ZT for 2.5k so it aint going to set the world alight in terms of performance or cutting edge developments and if it doesnt make 300bhp then $hit happens and just run it for 18 months and change bit then if i still have it.

 

could you run 9-1 with octane boost to try and pervent det?

 

yeah an octain booster could be used to suppress the onset of knock to a certain extent but it would be very imprecise to gain a precise required octain rating due to the amounts you add is oftern basically guess work hence the suggestion of race fuel as it is more precise and a better blend of fuels than pump fuel and a booster.

 

As above there is really only one proven guy to contact regarding zetec heads/specs.

Ian Howell.

He is away on holiday at present but on his return in a weekish give him a call and discuss what you are wanting.

Please remember however the whole engine package has to work together...
i.e bottom end -head -turbo..

 

Sounds good. For info what size ex housing are you running on the 28 and what ign advance are you running at peak torque?

 

way offtopic but what safe power can I expect from this..

silvertop zetec rebuilt new seals ect
LET pistons
rover inlet
hybrid t34
tubular exhaust manifold
7.4:1
Not bought management yet but I think im going with gotech pro x

ive allways thought it would be pretty low like 250bhp but never asked as im not that bothered tbh lol

 

.42 comp
I think its .64 ex housing (going by the Garrett website). I did look when it came out a while back but couldnt find a number stamped on it.

I'll have to ask my mapper about the ignition, as I dont have Omex software to look on the ECU. Will ask him tomorrow.

My 28R...

 

Luke - yeah will try ian in a weeks time it gives me chance to strip down the gearbox and fit the new bellhousing to it so i can use the focus RS one still after swapping from the cvh idea to the zetec turbo.

also gives me chance to strip the head down and clean it all up before speaking to ian about the choice of cams and then valve make and size.

 

Excellant mate, glad to hear you have a proper box going into.

Ian will most certainly help you mate, but dont push to far with regard to getting all the information you may need, as he has worked and invested time and money into those....

Facts, figures and specs.
Some things you know you can purchase elsewhere cheaper, you have to see through this and purchase whats tested and in the end built for you.

Just look at all Ians engine specs from past years and there is not a single sole running a zetec in the UK that i can think of that has bettered these cars.

 

If you forgot to mention uprated valve springs, then the engine will technically make up to about 330bhp.. however it's up to you if you wish to gamble your standard rods at that level.. I've never heard of standard rods breaking on a well-mapped/built spec at 300bhp, but it's still a gamble.

If however you haven't uprated the valve springs, then you won't be seeing 200bhp!

 

As Garage19 said, run silly came with huge amounts of overlap and you can run a higher static compression ratio - the dynamic compression ratio will end up being the same (it has to, if it wasn't it a) wouldn't make the same power or b) it'd explode).

Ian Howell is unlikely to spec such a high compression ratio, i've not seen him do anything above about 7.8:1.

 

Mine runs higher

 

Was that at your request? What cams? How much overlap do you have?

People look at stuff like CR's as a black/white thing.. Anyway, probably best to stop hijacking this thread.. The advice for the thread starter to speak to a qualified tuner is probably best as they can discuss the whole spec rather than the theory behind individual components.

 

if you look on microcat the parts numbers for the focus RS cams and standard 2.0 blacktop cams are the same.

you can get cams developed for forced induction zetecs from america.

i thought piper made F.I. zetec cams aswell?

 

Overlap will increase the amount of hot exhaust gases in the mixture and isn't exactly healthy for high comp turbo engines.

 

I know who he is
clearly my offer of help was not appreciated

 

Unfortunately you cannot compete with the infamous 'internet spec'