Discussion
Wan't a few ideas for my car, a 1.6 fiesta zetec s.
1.6 16v, full exhaust including 4-2-1 manifold a decat, decent panel filter.
What's the most cost effective way of more power? Cams, throttle bodies, forced induction?
I understand throttle bodies can be bodged on RELATIVELY easy, bike carbs+manifold+fuel rail+management?
Cams have been done to death, but a certain type of which have been proven to boost power by about 35-40% with the modifications i've already done.
Turbo's have been done, but can only be ran on minimal boost, as substantial boost equals large explosion.
Any ideas? And how easy is it to realistically fit throttle bodies? I've heard bogg brothers can make a manifold up, but what kind of TB's? Bike ones? What size? Jenveys are out of the question unfortunately because of the stupidly high price tag.
Also, management? Omex is silly expensive, and far more complex for what I would need, any cheaper, more basic systems out there?
Lots of questions I know, hopefully somebody knows their stuff.
1.6 16v, full exhaust including 4-2-1 manifold a decat, decent panel filter.
What's the most cost effective way of more power? Cams, throttle bodies, forced induction?
I understand throttle bodies can be bodged on RELATIVELY easy, bike carbs+manifold+fuel rail+management?
Cams have been done to death, but a certain type of which have been proven to boost power by about 35-40% with the modifications i've already done.
Turbo's have been done, but can only be ran on minimal boost, as substantial boost equals large explosion.
Any ideas? And how easy is it to realistically fit throttle bodies? I've heard bogg brothers can make a manifold up, but what kind of TB's? Bike ones? What size? Jenveys are out of the question unfortunately because of the stupidly high price tag.
Also, management? Omex is silly expensive, and far more complex for what I would need, any cheaper, more basic systems out there?
Lots of questions I know, hopefully somebody knows their stuff.
So what exactly is the question ???
There are lots of random points of info in your post, with little real knowledge as to how each will perform.
If you want power, and dont use forced induction, then you will throw thousands at it, for little gain.
If you use forced induction, you can throw thousands at it, and at least get some results.
If you want a fast car, sell the 1.6, and buy a fast car to start with.
There are lots of random points of info in your post, with little real knowledge as to how each will perform.
If you want power, and dont use forced induction, then you will throw thousands at it, for little gain.
If you use forced induction, you can throw thousands at it, and at least get some results.
If you want a fast car, sell the 1.6, and buy a fast car to start with.
Fitting a turbo to an NA car can be a costly exercise. Cams is easy and cheap(ish). Throttle bodies is again quite easy but can be pricey. And then there is the ECU required - I thought omex was quite a reasonable cost? If you want to go cheaper then you need megasquirt but you need some level of intelligence (not saying you are thick) to get it working properly. plus if the car is quite new you'd need sequential injection for emissions.
IMO I'd stick a couple of cams in it to start with.
IMO I'd stick a couple of cams in it to start with.
James998 said:
What's the most cost effective way of more power? Cams, throttle bodies, forced induction?
Buy a faster car is unfortuntely the most cost effective way.James998 said:
I understand throttle bodies can be bodged on RELATIVELY easy, bike carbs+manifold+fuel rail+management?
How did you come to the conclusion installing ITBs was easy?James998 said:
Cams have been done to death, but a certain type of which have been proven to boost power by about 35-40% with the modifications i've already done.
35-40% from cams? Crikey, please let me know more, I have the same engine, if this is so I must get some!James998 said:
Turbo's have been done, but can only be ran on minimal boost, as substantial boost equals large explosion.
Not worth it for this engine.James998 said:
Any ideas? And how easy is it to realistically fit throttle bodies? I've heard bogg brothers can make a manifold up, but what kind of TB's? Bike ones? What size? Jenveys are out of the question unfortunately because of the stupidly high price tag.
If you insist on getting ITBs I would think 40mm would be about right. I'm not sure on the benefits of bike throttles over anything else.davebell1984 said:
It all comes down to how much money you have to spend, we all want supercharger kits, throttle bodies etc
Cams are the single best thing you can do for the money.
Turbo kits are expensive and unless you go low comression are just there for show imo!!
Turbo kits if properly installed and tuned, will give the best potential hp per £££ available.Cams are the single best thing you can do for the money.
Turbo kits are expensive and unless you go low comression are just there for show imo!!
High compression isnt a problem, unless you dont know what you are doing. Good gains can easily be had.
Edited by stevieturbo on Thursday 19th June 22:07
Its easy to say "buy a faster car in the first place", but this is not for everybody and tuning is fun (if you're prepared to learn something that is!).
On any lightly modified factory N/A engine, the best place to start is generally the cylinder head. Port castings out of the factory are usualy poor, so even a port tidy-up can give reasonable gains. If you're handy and do the research, this can easily be done in the garrage/shed. Alternatively, you can get the head flowed properly for around £400ish depending on the level of work undertaken. The higher the cfm, the more time involved so the higher the cost.
Another good thing to do whilst the head is off, is to look at increasing the engines static compression ratio. This can be done on most engines with a skim (nice and cheap). However, a bit of research is required on this to avoid a valve-to-head interface (not good).
Both of the above will give a decent overall gain, and the car will still be nice to drive (lumpy cams are generally not nice for a daily). Coupled with a re-map, you should see very decent gains.
Another area to explore is cam-timing. You'll be needing to do a fair bit of research on that one though
Edit:
Forgot to say; before doing any of the above, I can't stress enough that chassis improvements (i.e. brakes and sus) will actually make the car both quicker and safer. Most OE brake set-ups are pish given the existing performance, adding extra power into the equation can make things scary (and irrasponsible).
On any lightly modified factory N/A engine, the best place to start is generally the cylinder head. Port castings out of the factory are usualy poor, so even a port tidy-up can give reasonable gains. If you're handy and do the research, this can easily be done in the garrage/shed. Alternatively, you can get the head flowed properly for around £400ish depending on the level of work undertaken. The higher the cfm, the more time involved so the higher the cost.
Another good thing to do whilst the head is off, is to look at increasing the engines static compression ratio. This can be done on most engines with a skim (nice and cheap). However, a bit of research is required on this to avoid a valve-to-head interface (not good).
Both of the above will give a decent overall gain, and the car will still be nice to drive (lumpy cams are generally not nice for a daily). Coupled with a re-map, you should see very decent gains.
Another area to explore is cam-timing. You'll be needing to do a fair bit of research on that one though
Edit:
Forgot to say; before doing any of the above, I can't stress enough that chassis improvements (i.e. brakes and sus) will actually make the car both quicker and safer. Most OE brake set-ups are pish given the existing performance, adding extra power into the equation can make things scary (and irrasponsible).
Edited by Richair on Friday 20th June 12:59
I have to agree with Kozy & StevieTurbo.
Buying a faster car is the easiest and most cost effective solution given the starting point is a 1.6 Fiesta. You can get an Impreza WRX wagon for less than £2k now, and that's a lot of performance for very little cash. £2k doesn't go far when it comes to car tuning, even if it is fun.
If you must tune the car you have, then make use of the Ford parts bin to keep costs down - a 2 litre zetec + appropriate ECU should bolt straight in if Ford have done their design work correctly.
You will need much more than a "simple" aftermarket engine management system if you want the car to be well mannered on the road. Think again if you think you can cope with a barely disguised race car for commuting!! (If it's a fun only car, then you'll be OK)
Increasing the static CR is not something to be done on a whim. If you aren't careful, you'll probably make good midrange gains, but then be so knock limited at high speed and high load that it will make the excercise completely pointless. This should be combined with the wilder cams - then the dynamic CR is somewhat reduced which compensates to some degree.
Be careful - Ford spend a lot of money maximising power, fuel efficiency, drivability and low emissions (CO,NOx,CO2 etc) from their engines. All you can really do is trade these off against each other.
Buying a faster car is the easiest and most cost effective solution given the starting point is a 1.6 Fiesta. You can get an Impreza WRX wagon for less than £2k now, and that's a lot of performance for very little cash. £2k doesn't go far when it comes to car tuning, even if it is fun.
If you must tune the car you have, then make use of the Ford parts bin to keep costs down - a 2 litre zetec + appropriate ECU should bolt straight in if Ford have done their design work correctly.
You will need much more than a "simple" aftermarket engine management system if you want the car to be well mannered on the road. Think again if you think you can cope with a barely disguised race car for commuting!! (If it's a fun only car, then you'll be OK)
Increasing the static CR is not something to be done on a whim. If you aren't careful, you'll probably make good midrange gains, but then be so knock limited at high speed and high load that it will make the excercise completely pointless. This should be combined with the wilder cams - then the dynamic CR is somewhat reduced which compensates to some degree.
Be careful - Ford spend a lot of money maximising power, fuel efficiency, drivability and low emissions (CO,NOx,CO2 etc) from their engines. All you can really do is trade these off against each other.
dnb said:
Increasing the static CR is not something to be done on a whim. If you aren't careful, you'll probably make good midrange gains, but then be so knock limited at high speed and high load that it will make the excercise completely pointless. This should be combined with the wilder cams - then the dynamic CR is somewhat reduced which compensates to some degree.
Sorry mate, but thats complete haddock 
Provided you do your homework and stay well within the limits of pump fuel, then an increase in CR should give good gains throughout on a modern engine. Most 'efficient' engines with half decent OE management should be able to take upto 11.5:1 on 99Ron. Obviously this is not the case for all though... However, a quick google turned up that the Zetec-s has an 11:1 static CR from stock so fairly high already.Higher lift cams will actually increase an engines dynamic CR higher in the rev-range and this is how the power increase is made. However, lower down in the rev range port velocities will be lower with some possible reversion; which is why power is lost in this area.
If you can afford the insurance and running costs of a quicker car, then great
Sometimes its best to stick with what you have and do some playing around. To do it properly though, read, read and do some more reading. Sometimes is boring and way to geeky, but its fun! 
The easyest way will probably be an engine swap for something bigger + mods on the new engine if the budget alows.
If you want to get a substanital power increase from your stock engine then your are going to end up spending lots of money
There is no point in increasing the CR, changing cams etc unless you can tune it properly, this will mean buying expensive management and paying out for expensive time on a dyno with a tuner.
Its easy(ish) to bolt on some ITB's but its difficult to choose the right ones and expensive to get them set up properly.
I know its not for everybody but NOS might be an option. Probably the cheapest way to get extra power. With a propperly set up controler and sensible size jets you shouldnt cause any damage. But you will have to pay out to keep the bottle full which isnt cheap if you use it all the time.
How much money do you realistically have to spend?
If its more than a few thousand then you might have more fun buying an older second car or a kit car and building something more extreme.
You may also need an uprated clutch and gearbox.
I dont know anything about tuning fiestas so I cant help with specific advise, the most important thing is to do your research.. and then do even more research before you waste money buying the wrong parts.
If you want to get a substanital power increase from your stock engine then your are going to end up spending lots of money
There is no point in increasing the CR, changing cams etc unless you can tune it properly, this will mean buying expensive management and paying out for expensive time on a dyno with a tuner.
Its easy(ish) to bolt on some ITB's but its difficult to choose the right ones and expensive to get them set up properly.
I know its not for everybody but NOS might be an option. Probably the cheapest way to get extra power. With a propperly set up controler and sensible size jets you shouldnt cause any damage. But you will have to pay out to keep the bottle full which isnt cheap if you use it all the time.
How much money do you realistically have to spend?
If its more than a few thousand then you might have more fun buying an older second car or a kit car and building something more extreme.
You may also need an uprated clutch and gearbox.
I dont know anything about tuning fiestas so I cant help with specific advise, the most important thing is to do your research.. and then do even more research before you waste money buying the wrong parts.
Richair said:
However, a quick google turned up that the Zetec-s has an 11:1 static CR from stock so fairly high already.
Didn't think that one out very well did you?BTW I run a 11:1 CR + wild cammed Rover v8 as my daily driver. It's a little different to standard...
Richair said:
Higher lift cams will actually increase an engines dynamic CR higher in the rev-range and this is how the power increase is made. However, lower down in the rev range port velocities will be lower with some possible reversion; which is why power is lost in this area.
Errr how? The valves spend more time in a cycle open by definition. So you always lose out at the start of the cycle, no matter what speed. Remember what the definition of DCR is... It is nothing to do with cylinder pressures as you describe! (Sorry - I'm a geek too.)Richair said:
If you can afford the insurance and running costs of a quicker car, then great Sometimes its best to stick with what you have and do some playing around. To do it properly though, read, read and do some more reading. Sometimes is boring and way to geeky, but its fun!
If you declare the mods, then the faster but standard car may be more cost effective. Unfortunately insurance companies don't really like modded cars. For instance my TVR, when it was standard, was much cheaper than my Impreza to insure, and to make a Fiesta into a quick car, there will be a lot of mods needed to the whole drivetrain. Not declaring mods is not an option - I know first hand how thorough insurance assessors can be. Sometimes its best to stick with what you have and do some playing around. To do it properly though, read, read and do some more reading. Sometimes is boring and way to geeky, but its fun! I agree about needing to do a lot of reading though.
Oh oh, a geek off 
Higher lift/longer duration cams will increase the volumetric efficiency (VE) of an engine (providing they're correctly speced of course!), i.e. increasing its ability to 'completely' fill the cylinders with charge. So, the higher the VE, the higher the dynamic CR (more charge in the cylinders being compressed the same amount). Otherwise where does the additional power come from..? (laws of physics).
Regardless of what happens in the start of the cycle in the port (lower intial port velocity), overall throughought the cycle more charge will enter the cyclinders.
This is all assuming that the cams are correctly specced for an engine though; too often I see people fiting high lift cams to a stock head
Probably a little off topic now though
Higher lift/longer duration cams will increase the volumetric efficiency (VE) of an engine (providing they're correctly speced of course!), i.e. increasing its ability to 'completely' fill the cylinders with charge. So, the higher the VE, the higher the dynamic CR (more charge in the cylinders being compressed the same amount). Otherwise where does the additional power come from..? (laws of physics).
Regardless of what happens in the start of the cycle in the port (lower intial port velocity), overall throughought the cycle more charge will enter the cyclinders.
This is all assuming that the cams are correctly specced for an engine though; too often I see people fiting high lift cams to a stock head
Probably a little off topic now though
Let's try to avoid the geek-off. It'll only frighten people!! You're end result is correct, but your reasoning is missing a few steps:
Some definitions:
The standard compression ratio assumes the cylinder is sealed at the bottom of the stroke, and that the volume compressed is the actual cylinder volume.
However, the intake valve always closes after BDC, which loses us some charge at low speeds. Only the percentage of the stroke after intake valve closure is compressed. This is defined as the dynamic compression ratio, and it is fixed for the engine at build time.
Extra power from a wild cam comes simply from having more time to fill the cylinder plus any pulse tuning effects, ram effects etc - valves are held open longer. This is, of course, happening in the intake stroke, so compression is irrelevent. Yes, you do get an increase in VE, but the DCR cannot change because it is defined at engine build time.
The cost of this extra time to fill cylinders is that there is less "time" in the compression cycle because the inlet valve closes later allowing charge to escape out of the inlet port until the valve closes. Thus a wild cam always lowers DCR. Not too much of a problem at high rpm, since the wild cam has hopefully allowed you to get even more than what you lose into the cylinder in the first place.
The obvious solution is to increase the static CR to compensate for the loss in DCR and make the car behave better at low RPM.
Some definitions:
The standard compression ratio assumes the cylinder is sealed at the bottom of the stroke, and that the volume compressed is the actual cylinder volume.
However, the intake valve always closes after BDC, which loses us some charge at low speeds. Only the percentage of the stroke after intake valve closure is compressed. This is defined as the dynamic compression ratio, and it is fixed for the engine at build time.
Extra power from a wild cam comes simply from having more time to fill the cylinder plus any pulse tuning effects, ram effects etc - valves are held open longer. This is, of course, happening in the intake stroke, so compression is irrelevent. Yes, you do get an increase in VE, but the DCR cannot change because it is defined at engine build time.
The cost of this extra time to fill cylinders is that there is less "time" in the compression cycle because the inlet valve closes later allowing charge to escape out of the inlet port until the valve closes. Thus a wild cam always lowers DCR. Not too much of a problem at high rpm, since the wild cam has hopefully allowed you to get even more than what you lose into the cylinder in the first place.
The obvious solution is to increase the static CR to compensate for the loss in DCR and make the car behave better at low RPM.
2.0 Zetec from a Mondeo. Cheap and gives an instant 130bhp.
http://www.fiestaturbo.com/forums/viewtopic.php?t=...
(Not the same mark fiesta as you but I guess it still applies)
http://www.fiestaturbo.com/forums/viewtopic.php?t=...
(Not the same mark fiesta as you but I guess it still applies)
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