Kev83

Right all, im on the verge of investing of a stage 3 cylinder head complete with newman cam, vernier pulley and solid lifters. what kind of gains can i expect to see on my FRST, if any?? Current spec is:

Stage 2 T3 Hybrid Turbo Conversion
Scorpion Exhaust
Airtec Single Pass front mount Intercooler

Car's not chipped so still running 9psi of boost.

Any advice would be much appreciated

Christian and Beccy

iTrader: (14)

IMO, no gain at that level.

bigchez

I'm no expert but I would expect you haven't reachered the limit of the standard stuff @ 9 psi, so going that far is prob a waste.

Kev83

cheers christian mate. It would however be worth while at a higher boost level would it not??? so say 195 chip with the relavant supporting mods (chip, injectors, pump etc). Would this see close to 200bhp??

cheers fella

Stu @ Claims Care Centre

iTrader: (1)

you will start seeing a gain at around 18+psi

Kev83

cheers chez mate, im asking the question as the oppurtunity has arose to pick the head and cam up for a bargain and i plan a 195 chip with the relevant supporting mods mate.

if they will see some kind of benefit with those mods then i'll be raiding the piggy bank at the end of the month to see what coppers i have left lol

Christian and Beccy

iTrader: (14)

I think it's a waste of time for under (genuine) 250bhp, will probably be detrimental to torque.

foreigneRS

9 psi of boost with a more efficient head (if indeed that combination is more efficient, which it won't necessarily be at all engine speeds) will be more air than with a standard head, so providing it fuels correctly you should see a gain

joffy

iTrader: (1)

not if there is something else that is a limiting factor?? isnt it like breathing through a piece of pipe, the bigger the pipe the easier to breathe, but there comes a point where the pipe makes no difference how massive the pipe is as its your throat that becomes the limiting factor??

Kev83

cheers for the advice people. Maybe the head would be overkill, but the cam must surely make a difference. For the money its going to cost, i think i will go ahead with it, but not have it fitted until im ready for the rest of the parts

Garage19

As nick has said 9psi of boost with those mods will probably be alot more air. Remember boost pressure is a measure of restriction.

If on an off the shelf your engine will probably be fueling dangerously lean at the top end.

For people that say there will be no improvement ask your self this. If a ported head and cam makes more power on a n/a engine why shouldn't it with 0.6 more atmos pressure?

Christian and Beccy

iTrader: (14)

Doug, I'm speaking from actually experience, not science.

If I was going to spec a 250bhp CVH, it probably wouldn't have a big valve head. If you ask me, from my own experiences, many engines can run double their factory power before needing a big valve/ported head. That's a very general statistic, but a rough rule of thumb.

Also, Chaz, you're in for fun with CVH cams.

Kev83

good point. I was under the impression that it would make a difference, but maybe only a marginal one at the current state of tune. My intention as it stands would be to have the head fitted at the same time as the MSD 195 conversion so there is a sizeable difference in performance from its current state.

That way any fueling issues can be addressed by stuart at the time

Kev83

guess there a bit of a mare then christian mate. Are the newman cams a good choice fella??

Christian and Beccy

iTrader: (14)

Also, based on that theory, would a larger plenum and tubular exhaust manifold benefit at this level?

Again, the answer is no. Not only would it not benefit, but in my opinion it would affect the torque characteristics negatively.

As said before, this is based on real experience.

Christian and Beccy

iTrader: (14)

They are the best of whats available, but the CVH camshaft design is fundamentally flawed and no-one has truly answered it, because there really is no answer.

With solids though, if the clearances alter, the cam will probably self-destruct. Simple as.

Rick

In my experience, decent heads make a huge difference on a CVH. I had massive gains at only 11psi, and the boost threshold was also lowered. It's the best mod you can make to a CVH, and with a stage 2 hybrid makes for a very punchy 250hp engine. There are no downsides when done properly, and the gains only get bigger when you use more boost and a bigger turbo.

Rick.

Christian and Beccy

iTrader: (14)

OK, I'll leave it to the experts then. But they day a Stage 2 T3 makes 250bhp......

Not in a million years on a 1600CVH.

Kev83

good to get some varie opionins and experiences. I suppose fundamentally its down the man actually mapping the car as everybody has a different prefrences.

Cheers guys much appreciated

pani_k

iTrader: (1)

I'm no expert on FRSTs but from my days on fiestaturbo.com (first forum I joined and stuck with for a long time), as Christian said, the big valve head isn't really all too necessary until you really start pushing the boundaries of what it is capable of. If I was you mate, I'd go with the chip and you should be fine! Also if you haven't already I think the done thing is also a -31 actuator (I'm sure Christian can correct if I'm wrong)

foreigneRS

probably would benefit, but is it worth the cost for the size of the benefit? same with the head. it's usually cheaper per unit power increase to tune with other means first (more boost typically), but if you get the parts for a cheap price then it's more likely to be worth doing.

Christian and Beccy

iTrader: (14)

But my point is that by porting the head and increasing the size of the valves, it's possible to take away the punchiness of a low/moderately powered car and for no top-end gain.

Kev83

got the head, cam, solid lifters and vernier for £300. so for the money i cant grumble really!!

Rick

C, proper head and you can ring the neck out of a 55 trim T3 with a 0.36 back end for 240hp, 250 maybe pushing it. Think Oranoco had 250hp from his Stage 2?

Your choke point here is the exhaust back pressure, the inlet can easily flow the air. Anything you can do to derestrict the exhaust side, eg porting the head and a longer duration cam is going to boost your chances of making the figures.

Remember back in the Day your car and Dave E's/RW's old one? They made the same power, you on 20+psi, him under a bar on the same turbo - the main difference was that car had a peoper head on it.

Rick

foreigneRS

i would agree if the turbo is at the limit and cannot flow any more. i don't have the experience that you do, but i reckon that my initial statement that if he keeps the same 9 psi boost figure, which that turbo should be more than capable of, he will gain at the top end.

pani_k

iTrader: (1)

Well all you can do now is get a before and after RR and see what's what really!

Kev83

sounds like a good plan pani mate. To make the results as fair as they can be, i'll use the same dyno for both power runs. Suppose it will give a definitive answer to the question.

I'll see which tuners will undertake the job and if they are happy to do a before and after power run to see the benefits (if any) of adding the head and cam

If any tuners are reading this........

foreigneRS

christian is reading it. he works at APT

karl norris is the man to ask

Kev83

Karl is only up the road from me, so will have a word with him tomorrow. Obviously the rolling road side of things will have to be done somewhere else. maybe john nobles altho he hasnt got a dyno dynamics set of rollers.....i'll see what i can sort

Would use APT, but they are a tad too far from me

bigchez

Bit of a mission maybe but Reyland in brum has dyno dynamics now...

Karl and Martin is a pretty good combo to have on your motor.

Kev83

sounds good chez. will try and arrange something tomorrow. Be good to see what results i get

Kev83

bit of an update to those who are interested. I have spoken with NMS today and disscussed about changing the head over for the new stage 3 head and cam. Got to speak to Karl tomorrow to finalise a few things but basiclly im going to carry out the test as follows:

Run the car in its current state of tune on the rollers (who's rollers im yet to negotiate)

Take the car to NMS for fitment of the head, and dialing in of the cam. Fueling will be checked to make sure not running lean.

Car taken back to the same rolling road for re-run to see what gains (if any) have been made

I will also be replacing the headstuds for ARP ones and using an uprated headgasket, but these shouldnt make any difference to the results

cheers

foreigneRS

did karl say if he would expect to see any gains?

JamboRS

of course its gonna see gains,but it will make losses also

foreigneRS

care to elaborate?

marky_g

think your money would be better spent else wear mate maybe management change and more boost.

also listed to tuners mate Christians cvh is mental you dont get there without making a few mistakes. Thats my 2 pence worth

Kev83

mark mate, i paid £300 for it, so small change really. I bought it looking at a bigger picture to be honest but interested to see whether any gains are to be had at stock boost levels.

It may turn out to be a complete waste of time, but at least people will have some graphs and experience to relate to infront of them. Im not doubting what christian has said as he's obviously very knowledgeable with the CVH engine and has had past experience. Im doing it purely to post some graphs to see all the effects of the head and cam

Kev83

Spoke with karl at length this afternoon and have decided not to go ahead with the test. There is, however a reason behind this!!!

All shall be revealed soon

Garage19

Because you are buying one of his heads?

Christian and Beccy

iTrader: (14)

Chas, you also need to forget everything you learnt about tuning Evo's, because tuning CVH's is very different. Starting with head bolts.