I've my rolling road tomorrow, thought it'd be a bit of fun to take guesses on what power it'll make.

ST170 engine,
GSX-R 750 throttle bodies on ST manifold,
VVT pluged in, No Cat
Vernier pulley on Exhaust cam.
Omex 500 ecu,

I'll be happy with anything over 180. assuming it doesn't blow up

ATB Dan.

153 bhp at the WHEELS though

150 BHP

why don't you have a vernier on the inlet cam?

195 brake at the flywheel

163bhp at the wheels.

210 bhp down the pub

quote:

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Originally posted by Mark Allanson
210 bhp down the pub

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ooooooh, at least 10
er, dunno really, for an st170, i'd say 160bhp engine or wheels, dunno, say wheels

quote:

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Originally posted by omega0684
why don't you have a vernier on the inlet cam?

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If its a down hill dyno then 160+ at the wheels... otherwise about 154.282721bhp

quote:

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Originally posted by Mark Allanson
210 bhp down the pub

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215 down the pub after the second pint.

315 after the fourth....

165 At the wheels

15-20% losses on a rwd car through transmission.

I reckon 150-155bhp at the wheels or 180-185 at the flywheel.

i tell evryone my xflow is 1100cc and 60bhp lol
when its 1700cc on twin 40s and around 135bhp lol
better fun that way.

Ive got a 1.3 badge im putting on the back of mine......

quote:

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Originally posted by MakeEverything
Ive got a 1.3 badge im putting on the back of mine......

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Well back with 180 in the stable. Didn't play with the exhaust cam and he thinks the exhaust collector could realise a few more ponies.

All in all very nice to drive, going to fix the dip in torque and play with cam after a cheeky cam regrind and i've seen what it's like to live with.

ATB Dan.



rolling road 05/08/10

[Edited on 6/8/10 by scutter]

Hi Dan

Is the dip in the power around the VVT kicking in?

Is it flowing enough air and what was the AFR map like?

Looking at it again, sort that dip out and I think it will make more power, it is struggling to revover from that dip at 4000 / 4500 rpm its all over by 6500.

Almost looks like its bad fueling before it comes on boost

The VVT does kick in at 4000, I'm ashamed to say but todays run was to get me on the road and was mostly limited by money.

From what i can remember, the afr went very rich at that point, down to 12.5. It did have serveral dips in it.

ATB Dan.

So it sounds like it was cam timing or a lack of air then, it should have been able to use the fuel?

Did they swing the cam / Cams

No, he wanted me to drive it for a few weeks then taking it back with any issues, strangley it does feel flatter (if that make sence) than the old engine.

ATB Dan.

I can understand that, because I bet you dont take it much past 5500 on normal use, and looking at the graph its gone flat at 4000 onwards.

Needs a good tune really. So difficult with rolling roads though, do you have a AFR gauge in the car, if so I would give it a go myself on the runway till you feel its improved. Just watch it does not go lean.

12.5 AFR is where peak power will be anyway. It may have gone richer or leaner than that to give the dip in the power curve.

Without the AFR plot alongside the power and torque curves its difficult to comment on what could cause it to drop off at 4000rpm

My intial thoughts are that the VVT isn't being modulted as it is in the ST, so the angle changes from 85 to 145 degrees after TDC in one hit.

Just more time mapping around that point i feel.

I'm going to lower the shift point myself to 3250 and see if it feels better.

ATB Dan.

Hi Dan,

Like yourself I was unable to get a progressive control of vvc with ms and had to operate it in a switched mode. I was concerned that changing directly from 0% to 100% vvc might give me a hole in the middle of the curve, fortunately with the 'k' it was fairly easy to fit some 'stops' (actually just spacing washers) in the hydraulic actuator to limit the range to roughly 25% - 75%. This seems to have worked pretty well and has given me a reasonably even curve with little hole in the mid range. I've no idea how the Ford vvt is actuated and whether this 'limiting' is possible, but may be worth looking into.

When I had mine on a rolling road I got them to do a power run with the vvc locked off, and another with it locked on. This helps with a couple of things :-

a) you should be seeing two very different graph shapes, indicating that the vvt is operating correctly. If they look the same then there's obviously a problem.

b) Assuming you have these two different graphs, you can overlay them and the crossover point gives the correct rpm to operate the vvt switch. It was suprisingly high with my setup, something like 5000prm. Mine being a 'k' though we're not comparing like with like here obviously.

I agree with James re: the AFR gauge, you really do need to know what's happening to fueling, certainly during the setup phase but I ended up leaving mine in as a permament fixture. I just feel that it gives an early warning if something goes wrong with the fueling for whatever reason, and allows you to tweek out those annoying little hiccups/flatspots that you invariably seem to end up with.

Looking promising though, 180bhp isn't too shabby for what is probably just a 'rough tune' at this stage.

Geoff.

After seeing 210 down the pub I was gonna guess 700 in my dreams