Looking for info on NC with 2.5 L conversions

Dre · Postby **Dre** » Sat Dec 27, 2014 3:33 pm

I would prefer a bigger engine over a turbo conversion but cost wise it seems like they'd be on par.

Would you like the response of an NA or the ability to wind up the boost for a jump in power? Reliability is a factor but you can get lots of torque + power from a 2L turbo. That's something to debate.

rascal · Postby **rascal** » Sat Dec 27, 2014 7:26 pm

Dre wrote:I would prefer a bigger engine over a turbo conversion but cost wise it seems like they'd be on par.

Would you like the response of an NA or the ability to wind up the boost for a jump in power? Reliability is a factor but you can get lots of torque + power from a 2L turbo. That's something to debate.

Lots of torque and power can be nice, but the heat and drivetrain issues that can come with it aren't so nice.
I'd take a 2.5 conversion over a 2.0 turbo any day of the week, buts thats jmho.

sailaholic · Postby **sailaholic** » Sat Dec 27, 2014 8:53 pm

Turbo on a right hand drive NC is pretty tricky due to the steering column and exhaust manifold being on the same side i believe.

magenb · Postby **magenb** » Mon Dec 29, 2014 2:40 pm

Dre wrote:I would prefer a bigger engine over a turbo conversion but cost wise it seems like they'd be on par.

I've only seen 1 turbo kit that will fit a RHD correctly, but the cost to simply land it in Australia is more than the 2.5L conversion completely installed and tuned.

Happy to look at other options if any one has any

but it sounds like the 2.5 is the best bang for buck at the moment.

JBT · Postby **JBT** » Mon Dec 29, 2014 2:44 pm

Supercharge the 2.0 litre.
http://store.automotiveplus.com.au/

Danny · Postby **Danny** » Tue Dec 30, 2014 8:42 am

Is there space to run the piping and fit the turbo on the passenger side? Like Porsche did on the 944t. Worked well for them. Modern engine management got their turbo response to be as good as current turbo cars too.

Craig · Postby **Craig** » Tue Dec 30, 2014 8:55 am

JBT wrote:Supercharge the 2.0 litre.
http://store.automotiveplus.com.au/

That seems like the best idea! :mrgreen:

magenb · Postby **magenb** » Tue Dec 30, 2014 10:59 am

JBT wrote:Supercharge the 2.0 litre.
http://store.automotiveplus.com.au/

Yep looked at that one as well, the Kraftwerks is about $2k cheaper and is a DIY kit, with no cutting or drilling. SC was my second option until I learned about the 2.5 conversion.

The problem is I can find, stock acceleration times (0-60/100, 1/4 mile), Turbo times, SC times, but no 2.5L times.

From what I've been able to see, Turbo and 2.5l are great for Daily (which mine is) but the SC can be an annoyance due to the noise and have heat issues, which is not really a problem for dailies that have short distances, but I'm looking at a 3+hr round trip each day.

Regie · Postby **Regie** » Tue Dec 30, 2014 1:09 pm

If you are going for the 2.5, while the engine is out id go for some aftermarket cams also (just something to factor in cost wise)

Would you install yourself or get it done by someone else?

magenb · Postby **magenb** » Tue Dec 30, 2014 1:54 pm

Regie wrote:If you are going for the 2.5, while the engine is out id go for some aftermarket cams also (just something to factor in cost wise)

Would you install yourself or get it done by someone else?

I've only talked to Decker's about installing it cost wise, but I wouldn't mind taking time off work to install it myself, I was planning on doing that for the SC kit anyway. Just need to work out what tools I might be missing.

Charlie Brown · Postby **Charlie Brown** » Wed Jan 07, 2015 11:55 am

magenb wrote:I can find more dyno sheets than I can poke a stick at, but I would like to find out how much difference this conversion make to acceleration (0-100, 1/4 mile etc), does any one have any info one this? I would really like to see how much difference it makes with just standard cams and exhaust if possible.

I'm in holiday mode, so haven't been looking at posts for the last few weeks.

Sorry I too can't give you real life numbers but can say that flat out, through the gears, on a level road, there isn't a hell of a lot of difference, maybe one car length to 100kph against a modded 2.0. Throw in a hill climb and be in fifth in the 2.5 where the 2.0 is in third and you'll pull away easily.

Torque is the big thing with the 2.5, with headers it's around 240 - 250rwNm compared to around 160 - 170 for the stock car. Power is up from 91rwkW to 127rwkW, so you do notice the difference but it won't worry most of the hot hatches going round. It does do very low 1:09's at Wakefield and there aren't many NA road cars doing less than that.

At a guess I'd say a 0 - 100 time would be between 7.2 and 7.5, 400 meters in the mid 14's but that's running a 4.1 diff.

Compared to a S/C 2.0, the 2.5 would be quicker to 80, about the same or a fraction less to 100 and then the S/C would blow it away.

If you're a Club member, I'm hoping to make the Club day at Avon Dam on Australia Day, you can take it for a run and see what you think.

magenb · Postby **magenb** » Mon Jan 12, 2015 8:18 am

Charlie Brown wrote:At a guess I'd say a 0 - 100 time would be between 7.2 and 7.5, 400 meters in the mid 14's but that's running a 4.1 diff.

I found some 0-60mph times for stock setups, Mazda 3 2.5L - ~7.5s, Mazda 6 2.5L ~7.9s and NC Miata's around ~6.8s.

rascal · Postby **rascal** » Mon Jan 12, 2015 9:42 am

magenb wrote:I found some 0-60mph times for stock setups, Mazda 3 2.5L - ~7.5s, Mazda 6 2.5L ~7.9s and NC Miata's around ~6.8s.

Mazda 3 and 6 are totally different configurations to an NC rendering the above 0-60 comparison irrelevant.
You could only use the 0-60 times as a comparison if they were in the same type of vehicle.

bruce · Postby **bruce** » Mon Jan 12, 2015 1:09 pm

Waste of effort if I t is to be used for a 3 hour commute each day.
The conversion would need fettling, so I wouldn't trust it initially for a commute.

magenb · Postby **magenb** » Mon Jan 12, 2015 2:26 pm

rascal wrote:
magenb wrote:I found some 0-60mph times for stock setups, Mazda 3 2.5L - ~7.5s, Mazda 6 2.5L ~7.9s and NC Miata's around ~6.8s.

Mazda 3 and 6 are totally different configurations to an NC rendering the above 0-60 comparison irrelevant.
You could only use the 0-60 times as a comparison if they were in the same type of vehicle.

its the closest I could get to the setup, but yeah there's 200+KG difference as well as gear ratio etc.

It also seem that Aus delivered cars have a different diff and there also seems to be some differences in how the 0-60 tests are done to our 0-100.