mx5cartalk.com

i wonder should i change superchargers?
saw an ad for an mp62 4th gen sc...$1700
currently enjoying 140kw/360nm... on 98 nb 1800...mp45 with small nose pulley
how much extra urge do you get with the mp62 ?
what add ons would be needed to change it over...ie different connecter?
thanks for your opinion/experience
enjoy

I recon the mp62 is a bit small for a v8?.... :grin: can't help with the technicals except probably need a retuned. Still stock rods?

Sent from my GT-I9100 using Tapatalk 2

selling the v8 . keeping the supercharged mixxy
mixxy has adaptronic, 380cc inj .
5 or 6 psi now...which seems low to me given the numbers the turbo people are putting out
i reckon the 62 is an easyish swap
but what do you get for the 2k investment

It gets you a manifold, a brand new GT2560r and a dump pipe. So around 280 rwhp on your current exhaust but only 250 on the rods.

Dann

mhj wrote:5 or 6 psi now...which seems low to me given the numbers the turbo people are putting out

That seems low full stop.

I've got an M45 (the sister charger to the MP45) with a 15% reduction pulley and got nearly 12 psi (easily 11psi by about 2500 all the way through to 5000 where it slowly dropped away as I hit 7000 to around 9 psi).

The only thing the MP62 gives you is the avoidance of that drop off as the RPM increases... so you keep the boost steady all the way to the redline (and beyond).

Maybe you should check the belt (for slippage), the pipe work (for boost leaks), or the pulley (to confirm it really is a reduction and spinning the charger more).

G

360nm? that 120nm more than my charged NC. what mods do you have?

Torque numbers on chassis numbers are all bull sh*t.

Dann

deanb90 wrote:360nm? that 120nm more than my charged NC. what mods do you have?

Means nothing, it's wheel torque. Too many variables to compare torque figures at the wheels,

Woz

wozzah1975 wrote:

deanb90 wrote:360nm? that 120nm more than my charged NC. what mods do you have?

Means nothing, it's wheel torque. Too many variables to compare torque figures at the wheels,

Woz

thanks for the responces
mania dyno....dunno the details ...just the numbers...
as for the boost ...i thought it would be better to0 but i note from the us site that seems to be what you get with the 1.8...boost is better for 1.6
regardless...what i would love to knpow is....should i bother?
does it feel substantial at bum level
has anyone done it on a 1.8 and so speak from experencce?

Boost isnt better in the 1.6, its higher because the head flows less, the head is more of a restriction, so less air just flows in unimpeded, it gets backed up, builds pressure, and is read as boost.

Dann

NitroDann wrote:Boost isnt better in the 1.6, its higher because the head flows less, the head is more of a restriction, so less air just flows in unimpeded, it gets backed up, builds pressure, and is read as boost.

Dann

yeah, but double...?? is the 1.6 head really that bad that I'd be seeing twice the boost he's got just due to the head? I think not.

g

Its REALLY crap. REALLY.

Is there a crank pulley size difference? Thats the only other factor.

Dann

You also get more boost on a 1.6 versus a 1.8 when using the same supercharger / pulley because the supercharger will only flow a certain amount of air given its pulley system. If it flows a set amount of air on a 1.8 engine, then it makes sense that it will give more boost on a 1.6 engine, albeit only 1 or 2 psi because your set amount of air is filling a smaller engine.

Actually, how does head flow make any difference. The charger should be filling the intake when exhaust is closed, so the only reason you see positive boost is due to the minimal overlap between intake and exhaust valves (cams). The head just can't account for any real measurable boost difference as that's like saying too many bends in an IC will account for 3-4 psi boost.... And it doesn't.

Cylinder size yes, as that is volumetric capacity that does impact the boost pressure at 4000x per minute. So taken to extremes, on a 5.0L V8 you'd only see a small psi due to the massive volumetric difference.

But head flow? Really?

G

Would it be possible for his timing to be aways out and boost is just going straight out the exhaust??