247BHP Not bad for a 400

[Matt_]

Still have a bit to do but my Chim had it's first session on the rollers this afternoon.

247BHP at 5300RPM, was quite pleased with that. Spec is fairly mild. JE 218 Cam, lots of new bits, gas flowed heads, mild CR increase, different trumpets, no pre-cats.

Could do with a mapping session though as I had to raise the fuel pressure to get the AFR right at high revs but it's a touch rich through the mid range now. Also suspect a failing ignition amp as it looked to have a bit of a misfire occasionaly.

Still a good clean 200bhp at the wheels. Pleased with that.

Best Regards
Matt

[GreenV8S]

Peak power at 5300 is a bit low for that cam in a 400 I'd have thought? The power figures are exceptionally high too - what rolling road was it measured on?

[Graham]

tis good for a 4ltr, most standard cars i've seen pull about 160-180 at the wheels so 200 at the wheels for a tweeked car is bad...

My modded 5ltr pulled 274 at the wheels at 5950 rpm... yesterday

>> Edited by Graham on Thursday 25th May 17:05

[Matt_]

CBR's rollers. Their not exactly modern though, it's going on a DD rolling road shortly so I'll be sure to post the results from that.

I suspect the RPM recorded on the rollers may be a bit off, unless it's rev-limited to 5800RPM?

Matt

[Sharky500]

Graham said:

My modded 5ltr pulled 274 at the wheels at 5950 rpm... yesterday

Think you may mean at the flywheel, no? Otherwise 274 would translate to approx about 340bhp at the fly!

[chassis 33]

If this is the engine i think he's on about, its 274 at the wheels. I've seen the car go..past me 3times...it's ****ing quick, the cheeky bastard so the rumours are true...

Regards
Iain

[cre]

274 at the flywheel????

I wouldnt get myself out of bed in the mornings for that!!!



Jamie

[trackcar]

Sharky500 said:

Graham said: My modded 5ltr pulled 274 at the wheels at 5950 rpm... yesterday Think you may mean at the flywheel, no? Otherwise 274 would translate to approx about 340bhp at the fly!

Seeing as they race in a class with a limit of 350bhp you can bet your last cherry bakewell that they're as close to 350bhp as they can get. 274bhp at the wheels sounds just about perfect

[v8 racing]

I just dont get these rolling road figures at all!!! the 4.0 is basicaly claiming a 25% transmision loss is this about right joolz? 240 at the flywheel to be honest sounds about on the money for the bits its got, but one of the engines i built for a griff made 315 bhp at the wheels which at the 25% would make it around the 400 bhp mark, ps it was a big motor, but they only claimed a 10%loss??

[jellison]

All this roller stuff id nonsese - best way is just suss one cars power vs another is to do a 1/2 mile starting start drag with speed gun at he end (mile tooo far and too dangerous if something fails).