FULLBORE

whats involved in turbo'in a st170 engine? i know whats involve in the normal zetecs,but i read that these have steel rods and forged pistons as standard...can you buy turbo pistons for these?and can i do away with the vvt?

vroooom ptssssh

You can buy (get made) any pistons you want!

Why would you want to get rid of the VVT?

crazycage

i wouldnt go back to a st170 turbo engine again thats for sure ,just use a blacktop,im getting far better results now than i was with the st170.

vroooom ptssssh

I cant see why the St170 would be worse than a black top?

Black top standard - 150bhp
St170 - 170bhp? + VVT/stronger rods/crank no?

I think a properly built ST170 turbo would be a very quick engine!

clarke5700

i thort the crank was the same in the st170 as it was the 2.0 black top?

Big Will_

Cranks are the same.

Rods are stronger - 300bhp is about as far as i'd go with them.

Pistons are stronger - but lets not forget they are very high comp in turbo terms!

Head does flow better than a standard blacktop.

Cams are good for big power, exhaust cam will need a tone down for more moderate power.

Big Will_

Oh, and why do you want to remove the VVT? It gives outstanding response if setup correctly!

crazycage

not any more responsive than a black top with the right bits imo ,

ps if i was to build a 500hp zetec then i would think about the st170 with no vvt and some serious porting on the exhaust side .

Big Will_

If the VVT is mapped correctly it can give excellent low end VE and spool a turbo very early...

crazycage

i no that but ive got no spool up probs with my set up it drives like a n/a car !! boost @2k

simon170

I have a turbo ST170 Had it turbo for about 4 years.

Love it bits

Standard bits:
The rods are forged as standard.

The pistons are high pressure cast, stronger than normal but not as good as forged. Plus, as Will pointed out, very high comp.

Mine runs forged internals, Cosworth WRC.

It makes for great engine I think.

vroooom ptssssh

Ah, I couldnt remember if the crank was steel too or not

I wouldnt use std pistons if I was turboing one, it would deffo be low comp forged pistons.

The VVT as stated if setup correctly will be a lot better than an engine without it....FACT

zetaboostboy522bhp

if the silver top head is sorted properly ie cam , pulleys , valve springs , valves , and all the rest of your usual shit then it will do a dyno provern 522bhp( and the same for the blacktop head)so theres no need for the st170 head , oh and still on hydralic followers

rst in breaking

iTrader: (2)

who done your head paul? i was speaking to ian about doing mine whilst its off

simon170

I dont know if its the VVT, or the fact its a small turbo, or that the comp is 8.8:1, but...

mine comes on boost like banshee! Even at 1500rpm its starting to pull.

RS Grant

iTrader: (1)

If you dont mind me asking mate, what sort of costs are involved in building a car to your spec??


Cheers,
Grant

simon170

No I dont mind mate

It was quite pricey and doesnt make a lot of economic sense (but what does in modded cars eh? lol)

Cosworth rods/pistons: Ł1200
Manifold/exhaust: Ł1000
Turbo: Ł800
Intake manifold: Ł500
Omex: 6 or Ł700
Clutch and single flywheel: Ł800
Fuel pump, injectors, breather system, actuator, intercooler, piping, water injection, Mapping, etc (plus other stuff I cant remember lol)

In the end I paid about 7k I think, but that was to have it built so theres labout in there as well.

Makes about 330 at 20psi. The turbo is tiny, fast spooling and incredibly punchy. Its the limiting factor really, but a turbo swap would release loads more power, which the rest of the engine should be able to handle no probelms.

I love the car and would do it all again in a heartbeat

crazycage

my point was that you could save some money as the ports and valves are massive on the inlet side so only the exhaust side needs work .and to all these people standing up the vvt if you havent driven both then there no point in you posting about it . all the extra cost to have it mapped with the vvt is not worth it and that cash could get you loads of trick bits for your build but each to there own.

zetaboostboy522bhp

ian did my head mate , i think he uses cnc heads (nick warple) as he tends to use the best people for the job and sticks with them, not cheap thou fella Ł1000 for the big valve head still using hydralics and a futher Ł350 if you want to use solids
get it done mate as you can wind the boost up at a later date

zetaboostboy522bhp

repost

simon170

I have driven both, there is a noticable difference and it is worth it.

Anyone telling you it costs a fortune to map a VVT engine or takes ages to map, is having you on...

cjwood555

It does depend on how you go about mapping the VVT though - yours uses standard VVT mapping via the ford eecv, with ignition/injection controlled via the omex doesn't it?

if you ditched the factory pcm and mapped the vvt from scratch the it's another variable and another set of load sites, and is actually interdependent with the other two tables as it changes the ve! so it could take a while from scratch....

Garage19

Nick waple and cnc heads/ric woods are two different companies. They can't have both done it.

simon170

Its controlled via oil pressure, not the PCM. The Omex is doing all mapping work.

zetaboostboy522bhp

yeh that was the blokes name , rick woods as i met him at the autosport show a few years ago , i think nick had something to do with harveys engines when we was chatting when my engine was on the dyno, i think thats where i got the name from and got a bit confused ,silly me!

cjwood555

Yes but the oil pressure to the helix in the pulley is regulated by the solenoid which is modulated by the PCM, as standard. Omex 600 does have enough outputs and tables for it to have been mapped in, but I was under the impression from what mr todd said that vvt was left in its factory form?

Either way it bloody works!! Wish i'd gone through with mine....

simon170

I'm not sure there is a solenoid, I thought there was only a sensor to tell the PCM when its activated


Yeah you should have... pussy

Rick

I've got an ST170 turbo engine in the S2. Still running in miles, but the gearbox is now shafted so will have to wait and see how it works out.

XRT_si

iTrader: (2)

Crazycage - You posted not long ago stating how much better the VVT was, how it made the car drive much nicer and that it was well worth the extra mapping. What made you change your mind so much?

Not trying to catch you out or anything just asking as I was keeping my VVT because of what people like you said.


I have got a silvertop bottom end (forged pistons and steel rods) and a ST170 head. Ive uprated the valve springs, and am using a T34.63 and tubular manifold, and was wondering whether to bother keeping the VVT but was planning to. How much more effort/time/money is it to map the VVT too?

crazycage

dont get me wrong when i was running the st170 head and the vvt its good but i wont go down that road again . not trying to be funny but can anyone name one engine that is turbo'd with vvt from the factory?? i cant think of any !! that says a lot on its own.
i would just put a black top head on it and see a easy 350bhp with that turbo mate .

crazycage

so this other car that you drove was it a black top turbo same spec as yours? ie comp ratio manifolds and same turbo?? genuine question

simon170

Yes it was a black top, same turbo, same manifold, same exhaust, the comp ratio was 9.0:1 (mines 8.8:1)

groomers

911 turbo

ar4ibaldo

iTrader: (1)

Not ford but SR20DET has vvt, turboed from the factory.

crazycage

looks like theres a few then ,ether way im happy with mine as it is and if anyone wants to run it thats upto them ,but all the fastest zetec turbos in the uk are are siver and black tops .

crazycage

what was the difference then??

Big Will_

Mitsubishi went single MIVEC VVT on the inlet for the Evo 9 and twin MIVEC for the 10!

There is a reason for it and IF mapped correctly, it works well!

crazycage

i bet it does but i still wouldnt like to pay for the mapping on it tho.
what would msd charge to map one??

simon170

Mine picked up quicker, dispite having slightly lower comp (only .2 lower) than the other Focus. Pulled noticable harder in the lower revs.

XRT_si

iTrader: (2)

Fair enough mate, and a fair point the fact that there's only a handful turbo VVTs made does raise some questions?