Mean Machine.

[Tahrey1043]

ninety - FOUR!

christ mate the G40's only supposed to have 108, stock! and a boggo 1.3 SPi about 69 (a GT, perhaps 72, but focussed at higher revs = more power)

i'd pension the astra off immediately, recon the 1.0 and get an induction kit myself, if it truly comes almost within 10% of the effect of giving it MPi and a supercharger... even if it only does that for the torque not the HP, that's cool..

and yours is unchipped as well, right, on a regular zorst? chip it, give it a 4-2-1, freeflow and decat, and see what happens...

and i would have thought that the spi torque should hold fairly flat from around 2200 to 3300 at least, rather than being so... spiky... even if it cannonballs on down from there on out!

[Gareth_GT_Hatch]

you read it wrong its 84, unless were talking about torque in which case I have no idea where 94 came from...

[hayesey]

Gaz, what's the compression ratio of your engine?

[Karl_CLCoupe]

you read it wrong its 84, unless were talking about torque in which case I have no idea where 94 came from...

94 was the torque for mine, bit confusing with 3 topics in one topic .

Karl.

[Krupa]

G40s have 113lbs/ft torque as standard.
Mk5 GTI has 111lbs/ft
Mk4/5 16v has 93lbs/ft
GT 73lbs/ft

Done quite a bit of reading about this while looking for engine conversions.

Mine's got all smooth curves on my powergraph, which I'm very happy about, however I do seem to have 10lbs/ft torque less than a mildly modded 1.3 CL which is bizarre!

[amstrange1]

But look at your torque curve Alex, then compare it to Karl's. Yours is much flatter I think from memory?

[Tahrey1043]

i personally dont trust the sharp peak on that graph, it looks very dodgy compared to what the Butt Dyno says... Karl, do you get a massive kick in the pants at around 2500 that's half gone away barely 1500rpm later? (and has less than half the effect at 1500?)

funny to get the 108 lbft i just divided the official G40 Nm into the official 1 litre Nm and multiplied by the 1 litre lbft I knew it was 113hp, but 113lbft as well?

fishaly speakin' the CL's supposed to have it's at-least-200rpm-broad torque peak in the lower-mid 3000s (should still be rising, 2500 thru 3000, even if shallowly) and should still have a good 57.5lbft out of the 69 - or almost 85% - by 5000rpm... by the dyno figures, there isnt even 80% torque "left" at 4250rpm!

wonder if its a backpressure problem... maybe the exhaust is a bit blocked (knackered cat?)

[Gareth_GT_Hatch]

its only 9.5:1 paul so it could do with going up a wee bit. Theres a couple of ways I can improve that situation, none of which I plan to do in the near future...

[amstrange1]

i personally dont trust the sharp peak on that graph, it looks very dodgy compared to what the Butt Dyno says...

But, with all due respect, what do you know? I've had AAV CL, G40 and GT engines in my car and the CL always runs out of puff - due to its peaky torque curve. It's why it won't rev like mad, whereas a GT or a G40 is worth revving to at least 6k - their torque doesn't drop off so sharply.

[Karl_CLCoupe]

... Karl, do you get a massive kick in the pants at around 2500 that's half gone away barely 1500rpm later? (and has less than half the effect at 1500?)...

Might explain why it doesn't take much to get wheelspin in the dry, laden with another 2 people onboard, But I suspect I might need to look at the pricier end of the market for tyres when these ones are spent.

Karl.

[Tahrey1043]

bollock all mate, i can tell you that, but i know when i drive the spi thats sitting on my drive it doesnt go like crazy at 2500rpm but begin wheezing by 4k...! (or have trouble accelerating almost as strongly from 1500 in the same gear). There's still a bit more power available at 4500 than there is at 3500... it may not be worth taking it to 6000, but a little over 5500 certainly doesnt hurt the performance. GT's worth taking pretty much to the limiter, and certainly by the graphs!

ps edited the 'original' post while you were typing that

karl umm yeah... budget tyres will do that... especially if you put any weight in the back its not difficult to spin even a CLs wheels if you give it some welly!

[amstrange1]

I've compared a GT and a 1.0 AAU pretty much back to back - the SPI engines definately feel torquier off the line, but just don't rev anywhere near as freely. They're positively asthmatic in comparison. I used to thrash the t**s off my AAV, but there was little point in taking it beyond 5500 - whereas the GT will reward you for taking it beyond there.

[amstrange1]

karl umm yeah... budget tyres will do that... especially if you put any weight in the back its not difficult to spin even a CLs wheels if you give it some welly!

Ha! Budget tyres suck major ass. Mind you, on stock 145/80 R13 Michellins I used to be able to do an impressive wheelspin demo in my then stock AAV. Having a good handbrake helped...

[nuttinnew]

My graph has that dip in it also.


For comparison;

1.3 spi mk4

65 (45) bhp @ 4611rpm
approx 94lb ft at about 2800rpm

The biggest pain in the ass with this car is the gearing; GT gearing with very much non-gt power delivery. A total load of annoying toss, I hate it. I was expecting it to be more like a mk3 CL tbh which I could live with as I only want to plod along and keep the revs down on the motorway but what happens? At any reasonable speed on the m-way it revs too high for the delivery characteristics which really psses me off. I will get round to trying a GT cam to see if it makes it more sensible but tbh I think it really needs a more suitable box and that really fcks me off






(and breathe....)

[Krupa]

Ah so that was your Apricot Mk4 on the rollers then nuttinnew?

Near silent when idle, but a screamer when revved hard!

This is my graph, to be honest I can't imagine the rollers were far wrong as that's a fair graphic representation of what my car feels like to drive:



Oh for a steeper curve and triple figures... patience is a virtue.