Going on the rollers for the first time.....

Should I increase or decrease tyre pressures or anything? I've not been on a rolling road before so I just wondered what the process is and what to expect?! I'm going to Millway in Andover. I'm hoping to get 250+bhp, but the main reason is to getting the fuelling checked out. If the fuelling is out, what can be done to correct it?

Currently got Pace SMIC, Hybrid Turbo, Gtec1, K&N filter, Supersprint exhaust with de-cat, PRV set to 1.2bar. What bhp/torque do you reckon?!

275ish i reckon!

You should wait until you get your greddy in mate and get it set up at the same time, as for for the fuelling being out all you can do is fit oa FPR or get some form of specialist tunes map for your can with a live map or unichip.

I should be getting my pro alloy FMIC in the next month or two aswell, so I'll probably get back on the rolling road after that and get the Greddy set up properly then if I haven't got it sorted already.

I'll see how it goes I suppose. Probably have to be a uprated fuel pump and wiring mod after that and then maybe a 3.8fpr before I go for a chip/map of some description.

My understanding is that setting up a boost controller on the rollers is a bad idea, as real world driving conditions will see you getting different results.

yeah i found that too i have to say.. overboosting on hills and stuff...

still it would be good for a ballpark when he wil be there anyways, and i know that its often hard unless the middle of the nite, to do 4th gear 140mph runs to get it set up

Is it a 4th gear setting up thing then or will 3rd do?

Better in 4th as more load is on the engine in 4th?

Ross

Bear in mind that Millway's roller don't really read over 280 bhp (unless they've changed them), so that'll be the max figure you'll get!

270 bhp is my guess

I've had this too with a few RRs, seem to get at least .1bar more on the road. Although, on a recent run on a MAHA dyno, the boost on the rollers was the same as on the road

i guessed on this... did i not? ? ?

260bhp and 270lb/ft.

Ross

228bhp & 270lb/ft. Torque seems good, but it spikes to 270 and then drops off down to about 260, then slowly starts creaping up again then starts gong 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?!

Well, it seems a bit lame to me, to be honest. You should be running anything up to 50 bhp more than that. The weak point of your system is, I would have said, the Pace SMIC, but I doubt this is causing your problems.

You say the boost starts tailing off from 4,500 rpm - describe what it tails off to, and when. 0.6 bar at redline is lower than I would expect. Having said that, 1.0 bar at redline is a lot, bearing in mind you have an SMIC. Although did I read you were going to get a PA FMIC fitted ?

Its the prv mark. End of. I guessed the torque because i knew it would spike but obviously your prv is tailing off quicker than i expected.

Ross

I doubt it’s only the PRV – I reckon you’ve got a boost leak! See if the greddy fixes it – if not then you have a hose that is probably split – with the split opening up under boost.

yeah man i would say its a boost leak too.. surely a hybrid should be fit to hold 1.1bar at the readline?

I reckon u give the car a good check over, make sure all ur jub. clips etc are tight!

Guys im talking from experience here. I think i still have my graph to prove it aswell. The spring in the prv doesnt hold up very well at high revs and you end up with the boost trailing off. This is why his power is so low.

Had a look for the graph and i cant find it.

Ross

ahh makes sence like.. are all prvs the same?

Mostly. Some are stronger than others. You notice it more if you try to run more boost midrange.

Ross

I've checked for boost leaks before and I don't appear to have anything obvious. So you'd say the torque is normal, but bhp is low. Is the torque likely to go down if the bhp goes up with the Greddy?!

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

No. The torque will stay the same as long as the boost level remains the same at midrange. The greddy will hold the boost higher up the rev range allowing more power to be extracted at high revs releasing the extra bhp.

Ross

Sure its not bhp at the wheels?

Well the torque isnt at the wheels!!!

Ross