Jag V6 in MX5

[feef]

With all these significant increases in power from engine swaps, whether it's a Jag V6 or an LS[n], what do folk do to retain the torsional stiffness from the PPF? Adding stiffening arms to the bulkhead and inner wings, and some subframe stuff is fair enough, but the rest of the chassis is left to handle, not only an increase in power, but quite a rise in torque without a PPF to assist it

Or is some form of PPF installed as part of the build?

I think it's the sort of thing that, over time and with fatigue/stressing from the increased torque might have some detrimental effects, but I'm wondering how much

Any thoughts?

[Oldandslow]

Don't worry, be happy.

PPF usually considered way over the top. Ladder braces can fill the void.

[feef]

Oldandslow said:

Don't worry, be happy.

PPF usually considered way over the top. Ladder braces can fill the void.

I like over-the-top, it suits my engineering style

[Gilhooligan]

feef said:

Oldandslow said:

Don't worry, be happy.

PPF usually considered way over the top. Ladder braces can fill the void.

I like over-the-top, it suits my
engineering style

Same. There's other engine swap builds that have managed to retain the PPF. V6 mx5 does sound like an epic car though. Good effort OP.

[dxg]

Gilhooligan said:

feef said:

Oldandslow said:

Don't worry, be happy.

PPF usually considered way over the top. Ladder braces can fill the void.

I like over-the-top, it suits my
engineering style

Same. There's other engine swap builds that have managed to retain the PPF. V6 mx5 does sound like an epic car though. Good effort OP.

https://www.youtube.com/watch?v=dmffKP1grL4

[StangGT]

Any update on this at all?

[Flying Phil]

Just catching up on this and am feeling puzzled - what is a /the PPF? (I've done engine swaps in other cars with an added roll cage or big reinforcement in the sills)

[feef]

Flying Phil said:

Just catching up on this and am feeling puzzled - what is a /the PPF? (I've done engine swaps in other cars with an added roll cage or big reinforcement in the sills)

PPF : Power Plant Frame

it's this girder that connects the engine/gearbox to the diff to help reduce forces being transmitted to the chassis

[Audipardonner]

oilburner said:

Hi Tracker Jack. Glad you liked the MXV6. The plan is to be able provide a kit of parts to enable people like yourself to build one just like it. Everything you need to do the conversion in a weekend including a plug and play ECU. You'll just need to source yourself an engine of which there are plenty. Watch this space!

Hi, Did you ever get any further with this? I'm toying with putting a Jag V6 manual in my MX5 but also considering the V8, although I understand a manual box with these is difficult/impossible and/or bloody expensive!

[Audipardonner]

feef said:

With all these significant increases in power from engine swaps, whether it's a Jag V6 or an LS[n], what do folk do to retain the torsional stiffness from the PPF? Adding stiffening arms to the bulkhead and inner wings, and some subframe stuff is fair enough, but the rest of the chassis is left to handle, not only an increase in power, but quite a rise in torque without a PPF to assist it

Or is some form of PPF installed as part of the build?

I think it's the sort of thing that, over time and with fatigue/stressing from the increased torque might have some detrimental effects, but I'm wondering how much

Any thoughts?

I don't believe the 'PPF' (power plant frame) contributes any significant torsional strength to the overall chassis/body unit. It is simply there as a convenient way to fix the engine/gearbox and front suspension units together with the rear axle and suspension to maintain alignment before the body is dropped on top, temporarily providing a rather weak sort of rolling chassis during production. It may provide some longitudinal bracing between the gearbox and differential but its design means it is bound to flex. The torsional stiffness of the MX5 is provided entirely by the bodyshell. Of course, useful improvements to torsional resistance can always be provided by adding frames or strengthening the sills and bulkheads.

[OSR]

As an alternative you could put a Mazda V6 in.
Check out http://crapengineering.weebly.com/
They do sound awesome with a V6 in and a decent exhaust.

[VladD]

...or a Honda V6.

http://www.superfastmiatas.com/JV6%20Miata%20Kit.h...

[VladD]

Paddy_N_Murphy said:

VladD said:

...or a Honda V6.

http://www.superfastmiatas.com/JV6%20Miata%20Kit.h...

That, sounds like the job !

Sourcing an engine in the UK could be tricky.

[SmilerFTM]

VladD said:

Sourcing an engine in the UK could be tricky.

I'd imagine you could get one easy enough from the US and ship it over.

[Oldandslow]

What engine is in these?
http://www.pistonheads.com/classifieds/used-cars/h...

[VladD]

Oldandslow said:

What engine is in these?
http://www.pistonheads.com/classifieds/used-cars/h...

Thaat would do it I'd imagine.

[AndrewEH1]

Is this the car?

https://www.youtube.com/watch?v=1RM7qfje__U

[feef]

not THAT bad considering the work that goes into it.

I'm waiting to get my welder back from being repaired/serviced so I can get on with my V8 build.

[sjg]

Found this via that carthrottle video - looks great.

For comparison, if you called Flyin Miata and bought all the parts for a LS conversion (minus engine/box) it would be about $15k. I imagine a LS is rather more expensive to get your hands on than a Jaguar 3.0 too, it's not like we have scrapyards full of GM V8 cars to get them from.

[feef]

sjg said:

Found this via that carthrottle video - looks great.

For comparison, if you called Flyin Miata and bought all the parts for a LS conversion (minus engine/box) it would be about $15k. I imagine a LS is rather more expensive to get your hands on than a Jaguar 3.0 too, it's not like we have scrapyards full of GM V8 cars to get them from.

You don't 'need' to go down the LS route tho.

So far I've spent:

1UZ engine (4.0 quad cam V8): £350
Toyota W58 gearbox : £300
gearbox conversion kit : £700
Subframe : £300

Exhaust system : £TBA
I already have a standaone ECU and 1UZ loom so the bulk of the components are there for under £2k.

The more valuable component of that £6k price tag is the time spent and experience gained in making it all fit and work together. Something I'm happy doing, and will fabricate brackets and whatnot, but not everyone has the ability or tooling to make such parts so a plug-and-play solution is worth looking at.

If you were to buy a machine-shop worth of tools to fabricate the parts you need, you'd need more than £6k, and that's before you factor in the time spent dropping the engine in, out, in out, and waving it all about while you work out what goes where.