Just been on the rollers for the first time....

at Millway in Andover and...228bhp & 270lb/ft. Torque seems good, but it spikes to 270 and then drops off down to about 260 over 250rpm, then slowly starts creaping up again then starts going back down from about 4500rpm. Bhp is alot lower than I expected. Is that normal, why would the bhp be so low??! Peak torque is at 2750rpm and peak bhp is at about 5300 or so revs.

Bearing in mind my car has:

hybrid Turbo
Pace SMIC
Gtec1
Supersprint exhaust
De-cat
K&N panel filter
PRV set to 1.2bar

It's also only holding about 0.6bar boost at redline with it starting to tail off from 4500revs. I should be fitting my greddy at the weekend, how do you think that will affect power/torque as it should hold it better to redline keeping it to about 1.0bar(I hope).

Headly said that it's slightly rich at higher rev's but nothing to worry about, didn't menion a figure though. Not sure if this will still be the case though when the holding of the boost is sorted out?!!

How does this seem to you?! Graph to follow later when I get to a scanner.

By the way, the rolling road is rated to 1000bhp, but they have only got software to map to 350bhp.

Cheers, Mark

heard on modded coupe,uprated fuel pump is essential may help hold the power longer.dont quote me as im learning.

I think the fuel pump and wiring mod will be next on the agenda after I get my greddy installed and got the Pro Alloy FMIC ordered. I think that this might sort out my boosting loss that I've got at the moment, so when that's sorted, I might well not be running rich anymore. Just have to wait and see I suppose!!

I think after that my tuning will stop so I'll get a map done. Until I need a cambelt change, then I'll get some cams whacked in.

was speaking to jbt about the fuel pump mod and he says the standard fuel pump can drop power quite low down the revs such as your 4500.mine seems to peak power at 5900 revs,unsure its had the mod to be honest but from the understanding it could be one of the better next buys especially at around 100 pounds.

the spike is caused by whatever you're using for boost control - the GReddy will sort this out (assuming you want to). The tailing off could be either that your turbo is not up to the job or your boost control device.

Check your other thread. Its your prv.

Ross

http://i160.photobucket.com/albums/t174/Mark_klat/rollingroad.jpg

The dip is the fuelling at 3000rpm. Presumably your running gtech which dumps fuel in at that point.

Although there isnt a boost graph, the torque drops as your boost drops. You'll notice some difference after you hold boost longer.

Ross

I this would be a wet finger in the air, but what would you estimate the gains to be by purely using the Greddy instead of the PRV?!
Your right also, it is using a Gtec1 chip.

Well your only running 0.6 bar redline. That will move to nearer 1.0 bar and i think you'll get nearer 270-280.

Ross

Should be like driving a different car then!! So should that also iron out some of the wiggles the current graph has!?

Is there a rough ratio of what boost relates to in bhp terms?! like losing 0.4bar equates to 30bhp or something so that each 0.1bar is 1bhp or something!? Just wondered really.

Cheers Ross, you've been spot on with your predictions and help, that's very much - top man.

Never really worked it out what the difference in boost affects with regards to bhp. Suppose its gonna be different for each setup. As for the wiggles, the dip will still be there i presume, as your greddy aint going to change that, thats something that a custom map, unichip or live map, will resolve.

The rest of the wiggles *should* even out but you will still get some because the gtech chips fuelling will never be exact.

Just get the greddy fitted and setup for road use to a boost level your happy with and then take back for some more power graphs. I think you'll be pleasantly shocked.

Ross