Modern v6 into 1990 tvr s2, standalone ecu or carbs??

[bobbybo]

Hi all

Could use a bit of help please

Looking at fitting a Ford ‘cyclone’ 3.7 v6 used in Ford Mustang and others (similar to duratec) into a 1990 tvr s2.

Car currently has cologne 2.9 v6, has a disi & a Ford basic EFI system

The 3.7 v6 has ti vct, twin independent variable cams , good 300bhp. I’m looking at the option of an ignition only ecu for £500 ish and a 500cfm approx carb to run it. It’s a summer Sunday car so carbs although not perfect would be acceptable for me for a few years. I would lose 10-15% power in some rev ranges but as it’s a light car it’s not end of world. After I get engine and gearbox swapped in and running I could move to ecu on future years.

The aftermarket ecu option is superior in all ways but I’m trying to figure out the costs of buying, fitting including any wiring and works, tuning, trailering it around and all the add ins, is it going to be out of budget? Anyone any rough ideas on what costs I’m looking at for the ecu option? Emerald or something similar I’m guessing..

[GreenV8S]

I assume you'll need to meet the pre cat emission standards applicable to the original car and engine, but you should confirm that.

An EFI based system can be made to behave better than most carb setups. The expertise to make a new engine run well on carbs might be hard to find, whereas the expertise to set up an EFI system is readily available, and it's a practical DIY task if you're willing to get your hands dirty.

[stevieturbo]

bobbybo said:

Hi all

Could use a bit of help please

Looking at fitting a Ford ‘cyclone’ 3.7 v6 used in Ford Mustang and others (similar to duratec) into a 1990 tvr s2.

Car currently has cologne 2.9 v6, has a disi & a Ford basic EFI system

The 3.7 v6 has ti vct, twin independent variable cams , good 300bhp. I’m looking at the option of an ignition only ecu for £500 ish and a 500cfm approx carb to run it. It’s a summer Sunday car so carbs although not perfect would be acceptable for me for a few years. I would lose 10-15% power in some rev ranges but as it’s a light car it’s not end of world. After I get engine and gearbox swapped in and running I could move to ecu on future years.

The aftermarket ecu option is superior in all ways but I’m trying to figure out the costs of buying, fitting including any wiring and works, tuning, trailering it around and all the add ins, is it going to be out of budget? Anyone any rough ideas on what costs I’m looking at for the ecu option? Emerald or something similar I’m guessing..

So if it has VVT, it is a somewhat recent engine already with fuel injection and ecu etc ? And you cannot use the factory ecu ?

Aftermarket ecu is only superior, if it is a good ecu and done right.

No idea if anything will be out of budget, as you don't state a budget.

If it is a half modern engine, are carb manifolds available to go that route ?

I would think that given the VVT, to run it all properly, you're unlikely to be buying any bare ecu for under £1k, plus wiring, plus fitting, plus any sensors needed ( if not already present with the engine ), plus whatever labour to fit it all.

You could easily be into 2, 3, 4k. Just depends how experienced the people are doing such a conversion, and how much setup time.

[gazza285]

stevieturbo said:

So if it has VVT, it is a somewhat recent engine already with fuel injection and ecu etc ? And you cannot use the factory ecu ?

Aftermarket ecu is only superior, if it is a good ecu and done right.

No idea if anything will be out of budget, as you don't state a budget.

If it is a half modern engine, are carb manifolds available to go that route ?

I would think that given the VVT, to run it all properly, you're unlikely to be buying any bare ecu for under £1k, plus wiring, plus fitting, plus any sensors needed ( if not already present with the engine ), plus whatever labour to fit it all.

You could easily be into 2, 3, 4k. Just depends how experienced the people are doing such a conversion, and how much setup time.

Looking at the VVT setup in that engine, it’s not a system that gets to a set rpm and a solenoid opens, it is a constantly varying timing setup, I’d be surprised if there’s many aftermarket ECU systems with the capability to run such a setup on injectors, let along carbs.

Best of luck OP, but there’s got to be easier ways to get more power than using that engine on carbs, if that is even possible.

What’s wrong with tuning the engine you have? Easy enough to upgrade that, or to stick a carb on. Plenty of go fast goodies available from Burton Power.

[bobbybo]

Thanks for the answer

The 3-4K was what I was thinking

Car is pre cat emissions, new engine is a pest with electronics according to others that swapped it, doable but not cheap or easy.

I don’t have a budget for the project, but others have started similar to this and build thread on year 3, I’m aware of getting ‘lost’ on this type of project if that makes sense. The time the car is off the road is part of it. The strategy was to get it done in stages , over time rather than one big bite. Carbs seem to be despised in the UK forums now, interesting a lot of our US cousins still use them happily.

I think the new engine and transmission with associated work is plenty for ‘stage one’ , use a carb and then spend another 3k or so on ecu in future if needed. If I thought 2k would get an aftermarket ecu wired & running I would go with that, but 4K & the time, maybe wait👍

[gazza285]

I honestly do not know of an engine management system that would run VVT and carbs. Why would you not use injection?

[SlimJim16v]

Why not use a duratec? Aftermarket parts to get it working are available as it's being put into MX5. There's a build thread on here.

[bobbybo]

The 3.7 v6 has more power than duratec, hence that choice

I can use ecu, but it’s 4K, versus £1000 for ignition only and carb.

Given the whole engine swap has a lot of costs & time involved I wanted to go cheap first for a few years then possible e I in future. No doubt ecu is better. Just the 4K , on top of the 4-5k for the swap mounts up…

Ignition only is just a trigger wheel thing, microjolt, or others do them ready to go..

Thanks for all replies, much appreciated 🙏

[gazza285]

Are you planning on not using the variable valve timing then?

[rev-erend]

I'm pretty sure people on here have put the coswirth v6 from the Scorpio into the s2 with great results.

[bobbybo]

Yes the cosworth gives an extra hp from 170 to 190, apparently it’s not much difference from those that went down that path.

Also there is stuff to tune the 2.9 cologne engine , 3.5k stroker to 3.5 conversion plus 2.5k for head work to let it breathe enough, but that’s a lot of pennies..

The Vvt being off will drop a bit of mid range but still a dramatic boost from 170hp to say 270hp..(300hp with Vvt) ..

[dhutch]

What manifold are you going to use to mount the carb(s)?

I have a 2l blacktop on cars with megajolt+edis, moved over from a 1900 cvh, but I also have an Omex 600 and Jenveys in a box waiting for me to fit them.
Do not underestimate the amount of faff getting a nice set up with the carb manifold, linkages etc. I did and it was painfull!

[bobbybo]

I’m planning on making up a manifold , owned a plumbing business previously so I think it’s doable, or adapt one to fit. At least I can do the work as opposed to farming it all out at god knows what price..

What snags did you hit when doing the blacktop mega jolt & carbs..?

[gazza285]

One other thought, you are replacing a pushrod engine with an overhead cam, and then putting a carburettor on top, will this fit under the bonnet?

[stevieturbo]

gazza285 said:

Looking at the VVT setup in that engine, it’s not a system that gets to a set rpm and a solenoid opens, it is a constantly varying timing setup, I’d be surprised if there’s many aftermarket ECU systems with the capability to run such a setup on injectors, let along carbs.

Best of luck OP, but there’s got to be easier ways to get more power than using that engine on carbs, if that is even possible.

What’s wrong with tuning the engine you have? Easy enough to upgrade that, or to stick a carb on. Plenty of go fast goodies available from Burton Power.

Bog standard, plenty of ecu's to do it and have been for 20 years at least. ( I've done plenty of Subarus with it, latest ones have full 4 cam VVT, whether that's deemed worth it or not )

[stevieturbo]

bobbybo said:

The 3.7 v6 has more power than duratec, hence that choice

I can use ecu, but it’s 4K, versus £1000 for ignition only and carb.

Given the whole engine swap has a lot of costs & time involved I wanted to go cheap first for a few years then possible e I in future. No doubt ecu is better. Just the 4K , on top of the 4-5k for the swap mounts up…

Ignition only is just a trigger wheel thing, microjolt, or others do them ready to go..

Thanks for all replies, much appreciated ??

Your engine should already have all triggers needed, and sensors etc. It should have a fully viable injection system on it.

TBH reverting to carbs and ignition only, is a really bizarre notion when the engine has everything already there to run fuel injection. You just need wiring and an ecu.

And as mentioned, should already the factory ecu available so it just needs some wiring to make it work ? Which whilst wiring is tedious, would be an instantly running engine that does not need tuned.

[gazza285]

stevieturbo said:

gazza285 said:

Looking at the VVT setup in that engine, it’s not a system that gets to a set rpm and a solenoid opens, it is a constantly varying timing setup, I’d be surprised if there’s many aftermarket ECU systems with the capability to run such a setup on injectors, let along carbs.

Best of luck OP, but there’s got to be easier ways to get more power than using that engine on carbs, if that is even possible.

What’s wrong with tuning the engine you have? Easy enough to upgrade that, or to stick a carb on. Plenty of go fast goodies available from Burton Power.

Bog standard, plenty of ecu's to do it and have been for 20 years at least. ( I've done plenty of Subarus with it, latest ones have full 4 cam VVT, whether that's deemed worth it or not )

I have to admit my knowledge of such things is twenty years out of date, I’ve been poking around the internet as this topic has got me intrigued, and I see now that stand alone ECUs have the capacity to run such things.

I’m still curious as to why the OP would want to run with a carb though, it seems like a lot of work in the name of simplifying things, with a much poorer outcome.

[stevieturbo]

gazza285 said:

I have to admit my knowledge of such things is twenty years out of date, I’ve been poking around the internet as this topic has got me intrigued, and I see now that stand alone ECUs have the capacity to run such things.

I’m still curious as to why the OP would want to run with a carb though, it seems like a lot of work in the name of simplifying things, with a much poorer outcome.

They can do much much more. OEM ecu's can be very good too and really in a case like this, probably not a lot of reason not to just use one.

But a carb would be a downgrade for sure, if manifolds etc even exist for that

[dhutch]

gazza285 said:

.... it seems like a lot of work in the name of simplifying things....

Yeah I think that is where I am with it.

I did in effect do that with the blacktop Zetec I put in the kitcar, but its a simpler engine, much more similar the the one it was replacing (cvh) as its a iteration of the same base design. And even then, the amount of time and to and fro'ing I put into getting the carb linkage to work at the slightly different pitch of the alternative inlet manifold what proberbly on a part with the faff of setting up a swirl pot and hp fuel pump and just fitting the Jenveys.

All of this is in a Westfield where you dont have room for the factory inlet setup so the throttle bodies are the same pattern as the carbs, so will use the same manifold etc if and when I go to the ITBs. If you can fit the oem factory inlet manifold and injectors, no brainer in my book. Probably with an aftermarket ecu unless using the factory OEM ecu outside of the car is well documented, because the cost of the aftermarket ECU is likely less than the cost of the time and effort getting the OEM one to work, but I havent looked into any of it in detail and am unfamiliar with the engine in question here.

[CrutyRammers]

bobbybo said:

The 3.7 v6 has more power than duratec, hence that choice

I can use ecu, but it’s 4K, versus £1000 for ignition only and carb.

Given the whole engine swap has a lot of costs & time involved I wanted to go cheap first for a few years then possible e I in future. No doubt ecu is better. Just the 4K , on top of the 4-5k for the swap mounts up…

Ignition only is just a trigger wheel thing, microjolt, or others do them ready to go..

Thanks for all replies, much appreciated ??

Where are you getting 4k from for an ECU?
Emeralds are less than a grand, for example and would do all of that stuff.