MX5 with Lexus 1UZ Quad Cam V8 conversion

[dom1102]

I’ve just bought an MX5 / Lexus V8 1UZ conversion last weekend from an exotic vehicle dealer in Essex who took it in PX . I have zero history on the build, there’s a post from a previous owner (Biggzy) on the Driftworks forum in 2018 (https://www.driftworks.com/forum/threads/v8-mazda-mx5-using-lexus-1uz.268393/) re selling it due to a baby on the way. I have posted a reply there but I’m not holding out for a response. Actually I’ve nicked the pics from the post as I haven’t even photographed it yet. It’s looking a bit tidier now than it did back in 2018 (not difficult) the awful spoiler in has gone and the black wide arches are now body colour and extend all the way down to the sills(??). The rear bumper is now straight and it has much nicer wheels and it sports anodised green wheel nuts! It has also had the suspension and brakes sorted. Be great if anyone can help fill in the blanks so to speak! Needless to say it absolutely flies!!

Edited by dom1102 on Wednesday 3rd July 15:50

[yellowstreak]

I can't help you but I want to know more about this car and see some pictures! The lexus engine was near 400 bhp? It must be frightening!

[anonymous-user]

It looks terrible, but I'll do you a favour and swap it with my 2007 Avensis.

[feef]

'custom subframe' would suggest an item from Clare at CrapEngineering

https://crapengineering.weebly.com

I've got an MX5 and a 1UZ waiting to go in. (time pressures have stalled the project for far longer than I care to think) and I got my subframe from her.

I don't know this build, but I've been through most of the options in terms of what's needed so I may not be able to shed any light on this particular car, but happy to offer what knowledge I've got

[dom1102]

feef said:

'custom subframe' would suggest an item from Clare at CrapEngineering

https://crapengineering.weebly.com

I've got an MX5 and a 1UZ waiting to go in. (time pressures have stalled the project for far longer than I care to think) and I got my subframe from her.

I don't know this build, but I've been through most of the options in terms of what's needed so I may not be able to shed any light on this particular car, but happy to offer what knowledge I've got

Thanks Feef, I had assumed the same Re Claire’s subframes. I’ll hopefully be getting a bit more amongst the car this weekend and will have a better look at how it is screwed together. I have to say there is a surprising amount of space under the bonnet considering it was designed to house a 4 pot. Saying that it does have an exhaust blow at one of the manifolds so that could be interesting! At the moment it’s having an mot courtesy of the guys I bought it from and I know that there are a few bits and pieces that need sorting before they pass it. I’ll update on that later.

[feef]

dom1102 said:

feef said:

'custom subframe' would suggest an item from Clare at CrapEngineering

https://crapengineering.weebly.com

I've got an MX5 and a 1UZ waiting to go in. (time pressures have stalled the project for far longer than I care to think) and I got my subframe from her.

I don't know this build, but I've been through most of the options in terms of what's needed so I may not be able to shed any light on this particular car, but happy to offer what knowledge I've got

Thanks Feef, I had assumed the same Re Claire’s subframes. I’ll hopefully be getting a bit more amongst the car this weekend and will have a better look at how it is screwed together. I have to say there is a surprising amount of space under the bonnet considering it was designed to house a 4 pot. Saying that it does have an exhaust blow at one of the manifolds so that could be interesting! At the moment it’s having an mot courtesy of the guys I bought it from and I know that there are a few bits and pieces that need sorting before they pass it. I’ll update on that later.

The engine bay space is fine for length and width, but tight for height. This is why the 1UZ (and LS) engines are suitable as they aren't too tall: quite a few overhand cam V8s are just too tall.

Even so, those I've seen with the stock subframe have often had to either pop the bonnet at the bulkhead, or cut away the supports under (or even through) the bonnet for additional clearance. With Claire's subframe, it can sit lower and keep the bonnet flush.

I chose the 1UZ as options for routing the intake are more flexible. The LS seem to all have the intake 'snout' out the front which means removal of the bonnet catch and the fix I've seen is usually race clips at the corners. As I want to keep mine looking as stock as possible.

(as an aside, if you get any photos of the engine mounts and rear cross member on your subframe, that would be appreciated and useful)

[dom1102]

Here’s some pics of her in all her lovely greenness...

[dom1102]

[dom1102]

[feef]

Looking tidy.


I see you're in Essex... if you're ever up near St Neots in Cambs on a Sunday morning, we have an informal PH meet there, would be cool to see it in the flesh

[dom1102]

Might take you up on that Feef, got some tidying up to do first though. Had her up on a ramp today, a few pics of the oily/rusty bits! I’m thinking a new set of front and rear suspension arms/poly bushes, suggestions welcome..?

[dom1102]

[dom1102]

[dom1102]

[feef]

Is that big box the sump?

if so, I'm hoping to do something a little more elegant when I get to that point on mine :/


The stock bushes aren't too bad. I'd be tempted to just renew rather than polybush. Those I know who have put polys in have commented that the ride is less comfortable, but the improvements in handling aren't necessarily worth it in comparison.

I fitted some Tein S.Tech lowering springs to mine which drop it by only 35mm, but it has made a difference, even with the stock bushes, and doesn't affect comfort as they are progressively wound.

Edit : posted this before I saw you had coilovers

[dom1102]

[dom1102]

Yeah that’s the sump, it’s a bit ugly!!

[dom1102]

Know what you mean re the comfort lost on Poly’s however it’s making so much power that you can literally feel the movement and flex in the suspension as you open her up! I’ve seen some cool looking aftermarket suspension arms, any idea where to get them?

[feef]

The ones I'm keen to get my hands on are the tubular ones from V8 roadsters in the states. I've not seen anyone do them here. I spoke to them a couple of years ago to see if they were interested in having them made here under licence to save on duty and whatnot, but they weren't keen.

I'm in two minds to fabricate my own and see what happens. T45 Chromoloy would be a nice metal to use for something like that to keep the unsprung weight down

https://v8roadsters.com/product/tubular-control-ar...

[designforlife]

For a mk2 MX5, that's very clean underneath!!