Max bhp on standard internals?

[Mellow Matt]

What would be the max bhp on standard internals on a turbo mk1 1.8 do you think?

I'm thinking about going down the turbo route, but am a bit concerned about reliability - what's a safe level without modding the internals?

What kind reliability issues do people face with turbo mx5s?

TIA

(Apologies if this has been covered before, search is down!)

[TrophyMax]

I'm no expert on this but I think you'd be safe up to 230-240bhp on standard internals.

I've just bought a '91 1.6 turbo that's been tuned to 265, so it's either got forged bits inside or it's living on borrowed time.

Have a look here, some very knowledgable people about all things forced induction.

[Richyvrlimited]

250ft/lbs is about the limit of the stock rods, so keep below that.

It's not bhp that kills engines it's torque.

As for reliability, it's fine as long as you use quality parts, kimp out and you'll get issues. Note that on track you'll likely experience broken/lost exhaust -turbo studs. Incomel studs will fix the issue, either that or spec V-bands.

[Mellow Matt]

Ta chaps

[VladD]

Mellow Matt said:

Ta chaps

From what I've read, the MX5 engine is based on the 323 turbo engine, so is low compression and over engineered as a NA engine.

[Richyvrlimited]

VladD said:

From what I've read, the MX5 engine is based on the 323 turbo engine, so is low compression and over engineered as a NA engine.

It is. You have oil cooled pistons, a forged crank and low compression to aid you in your quest for decent power.

Shame the rods are so weak or you'd be able to push closer to 300bhp without opening the engine.

Not that the 5speed gearbox would stay together long.

[JQ]

My 1.8 runs 260 bhp without issue, however, I don't know what torque it's running, which is the most relevant issue.