engine conversion, ideas and advice.

[MattDon]

ha i love the esprit v8, but not the reliability problems. The reason for looking at a smart roadster was that theyre fun even at legal speeds or so is the theory, and theyre cheap to run. the NA was more for sound but the v8 sounds awsome even with a pair of turbos, but i also like the sound of 3 cylinders engines and theyre alot cheaper to run. im still torn but im leaning to a light roadster as a bit of a toy at around £3500 until i can get enought for the evora, saw my first +2 S at below £40k today, but the my12 cars sound amazing and have a better gear change. Wish list.... Evora S +2 in velvet red with ivory leather, gloss black wheels, premium and tech pack.... mmmmmmm nice!
wondered about a carrera 4 s convertible as a steping stone but starting at 30k for the post (terrible engine problem) 05 model, i could get a launch 09 evora.

i'll give you midlife crisis, im 33, people these days have no respect for their elders.

the family wouldnt see me for dust if i had a V8 lol.

[surfboardfiller]

I'm 38 and looking forward to affording a mid life crisis! I'll let you know how it goes

The V8 is fine if the liners have been done and most have under warranty.

Will you really be happy with a smart? You should test drive one and an Elise back to back.

[MattDon]

your profile says 32, i thought you were a little older than me. Ha ha, yeh keep me posted, the way things are im going to be 80 before i can afford a midlife crisis.

i thought the gearbox was a weak spot also?

i have driven an elise and i just couldnt get comfy, ive sat in a smart and felt a little better but im yet to drive one, think id be more tempted by the VX220 turbo, but its not about going fast.... honest.

[surfboardfiller]

Ha ha, fooled you! I just put 1980 on my birthday as it was a nice round number, I don't like giving personal data away on my profile.
The Elise with Probax seats feel a lot better but the handling and feedback is unmatched.
The Gearbox in the Esprit V8 is the same as the S4 so they detuned the power down from 500 Bhp to 350, but you can get a kit that solves that problem and then tune away if you need to, but it's still very quick with 350 bhp and you should be fine.
Where people normally run into problems is when they tune the engines and it stresses the input shaft.

[bratboy_y2k]

From what I understand the kit that makes the Esprit gearbox stronger than a wet noodle is NLA. I have a buddy who could build it but hasn't had much motivation. I know that drivers would break the box when accelerating in 5th.

[Fredjohn]

As an alternative to the Isuzu 1.8 + turbo, have you thought about a flat 4 Subaru boxer 2.0L? Don't know if it would fit, but it can be breathed on a lot (to say the least), there is a 6 speed box option and WRX seem to go pretty fast with a distinctive sound. Parts are pretty common too.

You may even manage to shoehorn in the Subaru 3.0L flat 6, which also has considerable tuning potential, but ain't bad in std n/a "Spec B" format....245bhp. Again with 6 speed box.

[surfboardfiller]

There's a race team that offered a race upgrade to the esprit/Renault box too. Not much use to us as they are based in the USA.
I'd expect to be able to buy an Esprit with this already done, that's what I'd look for to start with, like an Elan with an AP brake upgrade.

The Boxer Engine is fitted in line for 4WD with the gear box in the tunnel, the Elan engine bay is not just shallow its very short due to it being front wheel drive and there being a big box chassis in front of the bulk head under the scuttle where you want the gear box to go.

It's one thing finding an engine that fits in the hole, and a completely different thing finding one that doesn't ruin the cars brilliant handling or exceptional divetrain and doesn't cost a fortune to engineer into the car.

That's what makes bratboy's Isuzu conversion the only sensible alternative so far. Although not as practical here in Britain with so few engines available.

[ashm]

You could perhaps squeeze in the engine from a Mazda RX-8, since they're reputedly very compact. I once saw an article where someone successfully swapped an RX-7 engine into a 924 (I think,or maybe 944...).
Seriously hard work to fabricate all the necessary bits and find a gearbox that'll work though.

If I ever build a kit car, I'm going to go hunting for an engine from one of these:
www.motorweek.org/reviews/two_wheelin/bmw_k_1600_gtl
Wouldn't want to try and hack one into an Elan though.

I'd suggest just go out for a blast and forget about the niggles!
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[abmunro]

Wankel engines guzzle petrol.

I had a RX7 Turbo 2 Convertible

[MattDon]

and oil do they not? or is that just the older ones.

Ok was watching topgear on dave the other day and there was BMW 330, which had twin turbos.... one was a smaller for low end and a larger one for top end, and i wondered if this would work for us... or two smaller turbos? then i had the thought, i noticed phil sold a supercharger and i gather one could be run of an AC pulley and ive also heard of engines using superchargers and turbo's together.... is this a totaly crazy idea? cant help but think that has legs.

[ashm]

I suspect you could just use the existing Garrett turbo conversion kit (LGM) and a gt2554r - that's a ball bearing turbo and it's claimed it'll spin up faster than the stock unit. Our existing turbo's pretty dinky, I doubt you'd be able to source one suitably tiny as a "stage 1" for low revs.

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PS. yep, Wankel engines burn oil by design and get through a lot of fuel, although not _that_ much if you consider that apparently you can squeeze 400bhp out of a 1.3l lump weighing a little over 100kg. As I see it that's the tradeoff for the huge power to weight ratio.

[MattDon]

it was always my intention to run the gt2554 on my lgm conversion but was convinced that there wouldnt be that much difference between that and the larger turbo so went for bigger of the two, after hearing what other people have said im talking to a couple of turbo places asking if it would be possible to modify my turbo or if id be better off giving up on it and getting a gt2554.

So do two small turbos acumulate at the topend, meaning if the gt2554 is rated to 220hp would two cope with 440hp or do they run out of oomph? or is one bigger and one smaller the way to go?

[surfboardfiller]

2 small ones or you will be constantly spooling up, there isn't much point in adding weight and complexity with a bigger turbo, as you are back in the realm of custom fabrication and continual test development.
The point of 2 turbos is so you get half the lag to start and then whist that is delivering power the 2nd one starts to spool up. You will improve the characteristics of delivery but on a 1.6 L engine there isn't much power driving the turbos to start and you are doubling the weight of the system.

I think if a bigger Turbo suited the Elan then Lotus would have fitted one already.
The bigger the Turbo the more power you will lose at the bottom end and probably end up running out of revs before the 'upgrade' pays back.
It's a bit too american for me, bigger is not always better. You also have the rest of the engine to consider when adding more pressure and more air to the system.

The standard IHI turbo can deliver more pressure without adding any lag, so why change it? Just let it deliver more pressure if that's what you want, unless of course your waste gate never opens on boost?

[abmunro]

My graph with bigger LGM Turbo


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[MattDon]

wow 267.5hp is not to be sniffed at but the lag looks huge, it doesnt even begin to kick in until 4000rpm. i wonder if the gt2554r will be ok at the top end as its rated to 270hp, always thought the elan would do with a few more rpm but im understand its not that simple. even if the N/A does have a higher limit.

[norman lovie]

i,ve got a 25 series VVT garrett sitting in my shed - It's on my long term project list of things to do, lovely bit of engineering
i,ve not tried to work with one of these before, but know a few projects which were successful in using big turbo's with variable vanes ( typically Holset's) to achieve earlier spool with a big turbo - but they all have a lot of hassle getting the system to work across all driving conditions without including an independent ECU to manage the vane control - which is black magic territory

the other main issue is temp. - it's only relatively recently that we're seeing VV technology in petrol engines ( Porsche ) - diesel is well proven - they say it shouldn't be done, however, the diesel holset's VV do seem to survive in petrol engines

see http://www.youtube.com/watch?v=kGGpZLidkQI

[MattDon]

yeh i did a little research on these lastnight, and decided it was too complex. along with the turbo'd and superchagred option much like this

[abmunro]

wow 267.5hp is not to be sniffed at but the lag looks huge, it doesnt even begin to kick in until 4000rpm. i wonder if the gt2554r will be ok at the top end as its rated to 270hp, always thought the elan would do with a few more rpm but im understand its not that simple. even if the N/A does have a higher limit.

My reason for wanting more CC's

[MattDon]

yeh id seen your posts, are you saying the gt2554 wouldnt suit your needs better? and be cheaper than trying to increase you capacity?

[abmunro]

yeh id seen your posts, are you saying the gt2554 wouldnt suit your needs better? and be cheaper than trying to increase you capacity?

More capacity = More power

I already have turbo installed.

I have a short engine stood and I also have complete engine incuding all ancillaries with only 8 miles on it.

Tony