Big Bhp or Feel for Seven style kit car?

[gav2612]

Struggling to best know what to do guys, so looking for opinions. Due to late night drunken ebay bidding, I picked up a really nice little Sylva striker Kit Car a couple of months back for a good price. I've had a history of fairly quick road cars (TVR 5.0, 911, M3, currently have a Z4M as well) but my last few cars haven't really scared the sh**t out of me like 300bhp plus cars used to. I kinda like that feeling, so high BHP per ton is the way to go. I'd not trust myself on a Bike, so a quick seven style car will hopefully be the answer. It'll be used almost exclusively on the track, but will MOT it for the odd time I might want to take it on the road

For those of you who don't know the sylva, its a seven style lightweight road/track car and has won the kit car championships a few times in years gone by so is a great handling little car. It came with a tuned 1700 crossflow which i've now removed and sold, type 9 gearbox and english live axle.

Id thought of a Duratec 2.0 engine from a fiesta ST150 as a swap. These can be easily tuned to just under 200 bhp with throttle bodies and standalone management, but after that cost lots of money to make much more power. I like the idea of keeping it NA and the engine is relatively light probably only adding 20- 30kgs over the weight of the crossflow that came out of it. All the bits are available off the shelf for mating it to the type9 box and its been done plenty of times before.
Downsides:
If 200 bhp isnt enough then I'll need deep pockets for a turbo or supercharger conversion
Not sure how the type 9 gearbox will stand up to the abuse from the extra power so may also need a rebuild
Throttle bodies and standalone management aren't cheap to buy new
Build costs probably going to be over £3k by the time I get it in the car


My dilema is i've also got a supercharged mx5 track car as well, which will one way or another need to be sold as 4 cars is just too many(5 including my wife's!)
I've looked into it, and the mx5 engine and box will fit into the Sylva chassis with a bit of negotiation. I also have an FM2 turbo kit in the garage which I was going to fit to the MX5 and which will easily push out over 250bhp and would be mental fun in such a lightweight car as the sylva (circa 450bhp per ton)
The MX5 engine and box is very strong and many are running with that kind of power on standard internals. It is a heavy lump though and will be adding around 75kgs over the crossflow or 45kgs over the duratec to the overall weight once the turbo and other bits are connected. I'm pretty sure that would be plenty of power to scare the S**t out of me, but the turbo and supporting parts can easily make 300bhp with forged internals for not ridiculous money if I want more! As I have all the bits including aftermarket ECU etc, costs would be relatively low, and I reckon I could get decent money for the rest of the car by stripping it and selling on as its got a load of upgraded parts fitted.

Downsides:
Weight
Lots of fabrication to get it fit(quite enjoy the challenge so could be fun too)
Turbo'd so wont have the same sound and feel as a high revving NA on ITB's
Hassle of stripping the MX5

Which way would you go??

[gav2612]

Thanks guys, already looked at the s2000 as an option. There's a great YouTube video of a guy one in a striker. In a word it's awesome, however I don't think I'd get much change out of £6k with the crazy Second hand value of the engine and box and fitting issues. Also if it did go pop, I'd be another £2.5k just to get an engine replacement. The 2.0 duratec can be had for under £500 in St form or less in standard mondeo form. I looked at the ztec as well, and it would be an easier fit with it mating straight to my current bell housing and exhaust on the same side. The ST170 focus would be the one to go for, cheap as chips and goes well. However, they apparently are a struggle to get much over 170- 180hp out of without spending bigger money and the are quite a bit heavier than the duratec. Thought about bike engine, but the hassle of putting a reverse gear in and getting it all set up put me off.

Edited by gav2612 on Thursday 26th November 14:26

[gav2612]

Thanks Everyone for the comments. As much as id love 500bhp per ton upwards, I think I might be kidding myself on at my level of driving abilty and how much fun it'll actually be on track trying to get that sort of power round a corner. My "quick" cars up until now have had well over 300bhp, but have been heavy mostly heavy german cars like the M3. My Chimera 5.0 is probably the highest power to weight ive owned and they realistically make just under 300bhp(not the factory quoted 340!) and weigh just over a ton.

For ease of conversion and driving experience I think Im now leaning towards the duratec 2.0 engine. I'd use bike throttle bodies and megasuirt to run it which should give me around 180 or so BHP and can easily add cams in the future to take it to just over the 200 bhp mark. That should give me caterham r400 power to weight for under £6k all done.
The MK3 Mx5 gearbox also bolts straight up to the 2.0 duratec although at a 10 degree angle and I might look at that with a custom prop to ensure I dont have a gearbox blown to bits on my first trackday(The weak point would then be the english diff) The transmission tunnel in mine is tight, but from measuring up for the MK1 Mx5 box, I reckoned other than a bit of fettling to the pasenger side at the entry to the tunnel, it would fit.

Long term if I do decide that its not enough power, there are supercharger kits available that will push up to 300bhp on the duratec, but thats when the big spend comes in on uprated internals.

Next choice if I am going down that route is whether to try and sell the MX5 as is or to strip for parts. With a supposed built engine, genuine JRSC supercharger, 16" rota alloys, LSD, Alloy Rad, Oil cooler, etc etc its got probably over £4k in parts resale. Not sure what ill get for it as is. Its got no MOT and on
sorn as ive been trailering it to the track for the last year.

and BERW, your car must be absolutely mental!!

Edited by gav2612 on Thursday 26th November 10:48

[gav2612]

Ok Decision made, its going to be a duratec!
Having read all your feedback, I realise this little car is all about the feel, balance and revs. A big high torque turbo lump up front isn't going to be the same fun. Rewinding back a few years, I had a bog standard 1.8 mx5 with open diff for my first dedicated track car. Quick it was not, but had great fun in it which is what its all about.

I've measured up the tunnel and reckon I can get a MK3 Mx5 box in there at a push. This will bolt straight up to the Duratec. Although the thread on the Type 9 was very interesting and it looks like it may well stand up to 200bhp, I just don't like the gearbox that much. Apparently the mx5 box will cant over at 10 degrees if fitted to the ford duratec as the mazda engine sits over at an angle. Will look into a fabricated shifter to get the gearstick nearer upright and may fit the engine at a two or 3 degree angle to reduce the angle down a bit. If I cant make it fit, I'll make do with the type 9 meantime. Looking to do it without spending a fortune, I was considering Bike throttle bodies and megasquirt. Anyone have any advice on this? Whilst I realise drivability and ultimate power may be a bit down on other solutions, I can have the fueling and ignition up and running this way for under £700 as opposed to over £2k for Jenvey and Omex combination. I've done basic tuning before with MS and have someone local who can map it on a RR

[gav2612]

ugg10 said:

Sorry, bit late to the discussion but for the road my view is that around 180hp/140ftlbs and rev to 8k with a tad under 600kg on 185/195 tyres is the sweet spot (diff around the 4:1 mark). This would be plenty quick enough and still be able to use 80% of the performance on the road if required.

So if I were to build another kit, I would go for a Zetec SE 1.7 with cams, HD springs, rod bolts and ITBs (185hp and very light) in a Raw Stiker with a close ratio type 9 (SPC Tracsport semi helical?) or if funds allow an elite sequential.

Just my 2p's worth.

Thanks Ugg, Just about where I have got to. My Striker(Sylva not raw so live real axle) will end up around 180-200bhp with the duratec engine and around 550kgs(the live axle makes it lighter It's on 195 tyres at the moment. Im toying with a Mk3 Mx5 box and custom prop to go with the duratec engine rather than a new bellhousing on the type 9. Costs will not be too dissimilar once I sell the type 9 and I much prefer the Mx5 gearbox. Should save some money in the long run too in gearbox rebuilds.

I found a Mk3 box cheap in a scrappies which should be here this week. Will try it to see if it'll physically fit in the tunnel then work out fabricating mounts if it does. the Duratec engine in the Mx5 sits at a 10 degree angle towards the drivers side, so I'd need to work round that either by mounting the engine at the 10 degree angle and getting a different sump or alternatively, as im tight for space under the bonnet, I thought about mounting the engine at a 3 or 4 degree cant (which would leave the gearbox 6 or 7 degrees tilted towards the passenger side) and then fabricate a bend in the bottom of the gear shift lever to have it sit upright. Thoughts on that?

[gav2612]

ugg10 said:

Sorry, bit late to the discussion but for the road my view is that around 180hp/140ftlbs and rev to 8k with a tad under 600kg on 185/195 tyres is the sweet spot (diff around the 4:1 mark). This would be plenty quick enough and still be able to use 80% of the performance on the road if required.

So if I were to build another kit, I would go for a Zetec SE 1.7 with cams, HD springs, rod bolts and ITBs (185hp and very light) in a Raw Stiker with a close ratio type 9 (SPC Tracsport semi helical?) or if funds allow an elite sequential.

Just my 2p's worth.

Thanks Ugg, Just about where I have got to. My Striker(Sylva not raw so live real axle) will end up around 180-200bhp with the duratec engine and around 550kgs(the live axle makes it lighter It's on 195 tyres at the moment. Im toying with a Mk3 Mx5 box and custom prop to go with the duratec engine rather than a new bellhousing on the type 9. Costs will not be too dissimilar once I sell the type 9 and I much prefer the Mx5 gearbox. Should save some money in the long run too in gearbox rebuilds.

I found a Mk3 box cheap in a scrappies which should be here this week. Will try it to see if it'll physically fit in the tunnel then work out fabricating mounts if it does. the Duratec engine in the Mx5 sits at a 10 degree angle towards the drivers side, so I'd need to work round that either by mounting the engine at the 10 degree angle and getting a different sump or alternatively, as im tight for space under the bonnet, I thought about mounting the engine at a 3 or 4 degree cant (which would leave the gearbox 6 or 7 degrees tilted towards the passenger side) and then fabricate a bend in the bottom of the gear shift lever to have it sit upright. Thoughts on that?