Zetecs and induction, ECUs etc.
Discussion
Well I have just bough an unfinished Dax Rush. (I built one before about 10 years ago).
I have decided to go the Zetec route for a number of reasons and I should be happy with the 170 ish torquey bhp that they are meant to give.
However that means I have to sort out induction, engine management and fuelling. My engine doesn't have any of the original Ford inlet manifold/fuel injection/ecu.
Looking around the best/expensive route would be to go for jenvey throttle bodies and either OMEX or Emerald ECU. Job done sorted and about 2k lighter out of the wallet.
However the cheapskate route seems to be to re-use bike engine throttle bodies and then use Megasquirt ECU (or even OMEX).
200 quid for a bespoke manifold, 200 quid for the throttle bodies, 700 quid for the ECU. Say 1100 pounds all in.
Does anyone know if the bike route has any big downsides? Is it as good as the Jenvey route?
I have decided to go the Zetec route for a number of reasons and I should be happy with the 170 ish torquey bhp that they are meant to give.
However that means I have to sort out induction, engine management and fuelling. My engine doesn't have any of the original Ford inlet manifold/fuel injection/ecu.
Looking around the best/expensive route would be to go for jenvey throttle bodies and either OMEX or Emerald ECU. Job done sorted and about 2k lighter out of the wallet.
However the cheapskate route seems to be to re-use bike engine throttle bodies and then use Megasquirt ECU (or even OMEX).
200 quid for a bespoke manifold, 200 quid for the throttle bodies, 700 quid for the ECU. Say 1100 pounds all in.
Does anyone know if the bike route has any big downsides? Is it as good as the Jenvey route?
The bike route does have seem to have some downsides from my experience, this is mostly to do with light throttle openings and the difference in the way bike engine work compared with car engines. Now I'm no expert but my understanding is that bike engines generate less inlet vacuum than car engines and that the initial throttle openings on a bike are faster than a car throttle body to compensate for this. In that case it makes it less smooth than using a car setup.
Having said all of that I have had my car mapped to a level of refinement that I have been happy with for that last few years, wide throttle openings are no problem but it can still be a bit snatchy about town. I have a 2 litre Zetec with Suzuki GSXR600 TB's. I will however fit a car set to my next build if I choose a car engine.
The big upside is the cost, my inlet manifold only cost £50 because I had most of it made by homers at work and the bodies were only £80 back in 2008, I just couldn't manage the extra ~£1000 at that stage in the build before.
So, most of the time it's fine, the saving in cost is significant but if I had the cash spare I would have car bodies on another build.
Keith.
Having said all of that I have had my car mapped to a level of refinement that I have been happy with for that last few years, wide throttle openings are no problem but it can still be a bit snatchy about town. I have a 2 litre Zetec with Suzuki GSXR600 TB's. I will however fit a car set to my next build if I choose a car engine.
The big upside is the cost, my inlet manifold only cost £50 because I had most of it made by homers at work and the bodies were only £80 back in 2008, I just couldn't manage the extra ~£1000 at that stage in the build before.
So, most of the time it's fine, the saving in cost is significant but if I had the cash spare I would have car bodies on another build.
Keith.
I have R1 bike carbs(£100) with a megajolt ecu kit(£170) and a bogg bros inlet(£250) on a brand new blacktop zetec engine(£700).When i drove the car for the first time i also noticed the accelerator pedal responce to the lightest touch.I removed the accelerator pedal and refabricated it by moving the pivot point further up the pedal.Now its alot more drivable around town.....job done!
Also have GSXR 600 TBs on an otherwise stock silvertop 2l Zetec and agree that they can be tricky to get right. Probably the biggest single thing that will help is if you are able to define the TPS vs. load sites in your ECU. Bascially, it was going lean just as the throttle was touched. If you can expand the scale a lot at the bottom, you should be able to map it fine. I found a problem on mine at the very bottom, just as the throttle was touched - the change in air for a tiny movement was significant, particularly on stock cams as they suck so well, but the ECU just wasn't seeing the change due to the fixed realtionship between TPS number and map. As a test, we put a newer ECU on that allowed this to be changed and that sorted it easily. It was a while ago, but I think we set it up so the first few loads sites were only 1 or 2% apart - a very expanded lower range.
In the end, we did the best we could and it was pretty good, but did have a habit of popping and banging a bit at times. A bit later, I changed to a taller diff. to better suit our use of the car and this had the side effect of shifting the normal driving rev/throttle point so the problem is now pretty much a thing of the past.
Other than that, very happy with the results. Just shy of 170bhp on rollers I trust to be accurate.
Interestingly, I first has these exact same TBs and ECU on a Xflow motor - 11:1 CR, big valve head, lumpy cam (so poor vacuum) and it never showed the problem, so it's worth noting that they are very sensitive to vacuum as has been said.
In the end, we did the best we could and it was pretty good, but did have a habit of popping and banging a bit at times. A bit later, I changed to a taller diff. to better suit our use of the car and this had the side effect of shifting the normal driving rev/throttle point so the problem is now pretty much a thing of the past.
Other than that, very happy with the results. Just shy of 170bhp on rollers I trust to be accurate.
Interestingly, I first has these exact same TBs and ECU on a Xflow motor - 11:1 CR, big valve head, lumpy cam (so poor vacuum) and it never showed the problem, so it's worth noting that they are very sensitive to vacuum as has been said.
CorseChris said:
Also have GSXR 600 TBs on an otherwise stock silvertop 2l Zetec and agree that they can be tricky to get right. Probably the biggest single thing that will help is if you are able to define the TPS vs. load sites in your ECU. Bascially, it was going lean just as the throttle was touched. If you can expand the scale a lot at the bottom, you should be able to map it fine. I found a problem on mine at the very bottom, just as the throttle was touched - the change in air for a tiny movement was significant, particularly on stock cams as they suck so well, but the ECU just wasn't seeing the change due to the fixed realtionship between TPS number and map. As a test, we put a newer ECU on that allowed this to be changed and that sorted it easily. It was a while ago, but I think we set it up so the first few loads sites were only 1 or 2% apart - a very expanded lower range.
In the end, we did the best we could and it was pretty good, but did have a habit of popping and banging a bit at times. A bit later, I changed to a taller diff. to better suit our use of the car and this had the side effect of shifting the normal driving rev/throttle point so the problem is now pretty much a thing of the past.
Other than that, very happy with the results. Just shy of 170bhp on rollers I trust to be accurate.
Interestingly, I first has these exact same TBs and ECU on a Xflow motor - 11:1 CR, big valve head, lumpy cam (so poor vacuum) and it never showed the problem, so it's worth noting that they are very sensitive to vacuum as has been said.
What ECU did you use?In the end, we did the best we could and it was pretty good, but did have a habit of popping and banging a bit at times. A bit later, I changed to a taller diff. to better suit our use of the car and this had the side effect of shifting the normal driving rev/throttle point so the problem is now pretty much a thing of the past.
Other than that, very happy with the results. Just shy of 170bhp on rollers I trust to be accurate.
Interestingly, I first has these exact same TBs and ECU on a Xflow motor - 11:1 CR, big valve head, lumpy cam (so poor vacuum) and it never showed the problem, so it's worth noting that they are very sensitive to vacuum as has been said.
An old Emerald M3D. We tried a current model at the time (a K3 IIRC) that allowed user config of TPS to load site and it worked a treat. The current K6 ECU allows this as well.
As it is though, with the old M3D it's running now, but with the taller diff, it works fine, and as I said, it worked perfectly well with the Xflow due to that having a lumpy cam. Never experienced the problem at all as the idle opening was so much bigger.
I used the old ECU as it was one I had lying about, and had no need for the fancy features offered by the later versions. It kind of grew - the Xfow was orignally running dizzy and carbs. Phase one was to convert to 3D ignition, then phase two was to fit the GSXR TBs. When I did the Xflow to Zetec engine swap I simply moved the TBs and ECU to the Zetec.
I'd imagine pretty much any ECU you buy now will support user setup of TPS/load so you should be able to get it nicely sorted by a combination of careful setup/mapping and a sensible throttle linkage to slow down the rate a bit at the bottom. A simple snail type setup on the cable should work well.
As it is though, with the old M3D it's running now, but with the taller diff, it works fine, and as I said, it worked perfectly well with the Xflow due to that having a lumpy cam. Never experienced the problem at all as the idle opening was so much bigger.
I used the old ECU as it was one I had lying about, and had no need for the fancy features offered by the later versions. It kind of grew - the Xfow was orignally running dizzy and carbs. Phase one was to convert to 3D ignition, then phase two was to fit the GSXR TBs. When I did the Xflow to Zetec engine swap I simply moved the TBs and ECU to the Zetec.
I'd imagine pretty much any ECU you buy now will support user setup of TPS/load so you should be able to get it nicely sorted by a combination of careful setup/mapping and a sensible throttle linkage to slow down the rate a bit at the bottom. A simple snail type setup on the cable should work well.
silverian535 said:
GBS do an inlet plenum that comes in about 10 bhp shy of ITBs and not too expensive. You use the original throttle body and ecu of your choice.
This does look pretty interesting if it will fit in the dax. I spoke to them this Morning and they also sell Jenvey and Emerald so don't have a major axe to grind. They reckon that they get around 160 bhp out of a zebec with their plenum which is 10 - 15 less than on throttle bodies but still loads more than the original inlet manifold and ECU. He also said that the torque curve was a lot flatter with more low down torque than with throttle bodies but a quicker drop off higher up the rev range. They also have emerald base maps for the zetec / plenum.It looks a good option to me so I may go up there and see what sort of package deal they would do emerald and plenum.
If you're handy with a welder and can make up an inlet Man'f to suit - Lotus esprit bodies can be had for around £50 for a pair [well thats what i paid for mine 'New' from a 'Lotus' parts fair.]
Ecu is expensive - especially if you want the car rollered during setup - I used DW at emerald, but then you know that you've maxed out your engines potential. Mega squirt etc are more DIY for the setup.
Having said all that then TB's & ECU is the way to go IMO.
Good Luck
Ecu is expensive - especially if you want the car rollered during setup - I used DW at emerald, but then you know that you've maxed out your engines potential. Mega squirt etc are more DIY for the setup.
Having said all that then TB's & ECU is the way to go IMO.
Good Luck
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