Which is better?

[Wanda]

For a car nutter like myself, to buy a top of the range and remap (standard 150bhp - remap to 170bhp) or do a complete engine swap with a sports model with standard 175bhp and then remap to 205bhp?

Whats my aim you ask? Not really speed, want my car to achieve 0-62 in 8 seconds and be able to do 45mpg and not brake the bank.

A new (second hand) car is around £3500 and engine swap route would cost £2000 for a donor car and £1000 in labor (I hope).

Opinions welcomed.

 

[Lunchmoney]

Opinions welcomed

Ok....

want my car to achieve 0-62 in 8 seconds and be able to do 45mpg...

With great power comes great respons.... Nope, with great power comes shitty mpg.
You are not likely to get a sub 8 second car and still manage 45mpg without it being a new Merc AMG (or M, Abarth and the like, or maybe a fancy electric sports car).

and not brake the bank.

Buying a better car and remapping it will be easier on the wallet than buying a lower spec car and transplanting an engine, unless you can do the work yourself, as the biggest cost will be labour. Estimates appear to range between 12 and 20 man hours to do the job. Plus replacement parts (engine mounts, pipe work, wiring loom, etc) I would think £1000 is under budget.



What car were you thinking of doing this with?

 

[Wanda]

I was thinking either the second generation megane RS diesel or diesel GT

 

[obi_waynne]

The cost of a remap and perhaps a larger turbo will yield your higher power target without the complexity of an engine swap.

Engine swaps are more fun but harder to do and often require a gearbox and lots of other supporting mods.

Personally I'd probably do the larger turbo and remap.

 

[TCJBOLDIE]

Before getting "a larger turbo" I would consider having the existing unit "hi flowed" ( machining the compressor housing to fit a slightly larger and possibly more efficient wheel) plus having a larger diameter MANDREL BENT exhaust system fitted AND THEN have the car remapped on a dyno/rolling road to get the best result AND THEN you will be all .

The "larger turbo" will/may produce more power BUT will have more lag(slower to produce an increase in pressure).

I have done this and know that it works a treat

PS and not BREAK the bank

 

[Wanda]

Silly question, isnt the combination of large turbo and inter cooler going to make the engine pop in no time?

 

[TCJBOLDIE]

Silly question, isnt the combination of large turbo and inter cooler going to make the engine pop in no time?

Not if the maximum boost pressure remains @ the stock factory level BUT the fuel and ignition settings may need a tweak due to different boost inlet air pressure in various rev bands.

 

[obi_waynne]

A bigger turbo extends the power band rather than adding peak power, it can do both but it makes sense to having it push more power from lower down to a higher point in the RPM range.

Diesel engines are generally pretty strong and you are planning to hit 200bhp anyway, this just gives you an easier route to get there than an engine swap. (You might need to uprate the injectors and fuel pump, I don't know what the stock items flow like on that engine.)

 

[thexav]

Nitrous gives a good instant boost if you can be bothered to keep refilling the bottle each time you use it.