What do you think

[ray_von]

Any comments,preferably sensible ones, welcome.

[bigdods]

My standard 450 does 259BHP but the torque doesnt drop off until about 5200RPM (IIRC not having the print out in front of me). If thats a 400 its bloody marvellous. a 450 and its looking weak at the top end on the torque curve, although peak torque looks high, not the standard Cam I guess. If its a 500 you need to remove the potato thats stuck up your exhaust pipe....

Edited to add: Of course depending which RR you go to the results could vary. Can . Worms. Open

Edited by bigdods on Friday 7th September 15:58

Edited by bigdods on Friday 7th September 16:00

[The AJP Griff]

LOADS of torque,compared to peak hp.Give it some more air,ie allow it to breathe more through the inlet.

[ray_von]

frazer guest said:

What model chim is your Ray, and what have you done to it?

V8d 500 with MC1 cam

[bigdods]

FOrgot to say - my post figures are the calculated fly figures, not at the wheels. Am I correct in assuming this graph is at the wheels ? if so its looking good BUT the torque shouldnt drop off so early.

[ray_von]

Fly figures

[softtop]

BHP looks reasonable.

[v8 racing]

Before all the b@@@@@@@ starts about the bhp!!, which is about what a standard 500 gives out, i think that graph is very good for the spec of the engine espiecially the torque lower down in the rev range

[ray_von]

Cheers Rob, I was going to e-mail it to you but you've saved me the bother. As long as you say it's good that's good enough for me!!

[CaptiV8ted]

In the interest of comparison and the fact that the print outs are easily compared, here is my dyno chart from when I fitted my V8D stealth cam a few months back. 'Tis a 500, with precats removed, otherwise standard. It would appear that the MC1 and the stealth do exactly what hey say on the tin!

[ray_von]

I know all engines and rolling roads are different but going off what's been said in the past that's a high figure you've got. Would I see much of a gain with pre-cats out?
Also what else can be done to boost the figure without spending another load of money?

[CaptiV8ted]

Ray,

From what I know, removing precats is not worth an awful lot. I believe it's worth about 7 horses if the cats come out and non reverse cones are welded in. I think mine were removed for a manifold repair (quite common I hear). I don't have the cones.

A good std 5.0 litre engine should put out about 275 hp. With the stealth, V8D advised me that it would be worth about 20 hp, but move the torque slightly up the range, which is eactly what has happened. I did consider an MC1, but was advised I would lose top end to gain more lower down torque. Your cam has about 12 lbs more than mine and lower down.

The H303 can quite easily top 300 hp, but you'll lose stacks of torque low down. From what V8D said, I think the figures are about right.

[spend]

Can't say I've ever understood the attraction of low down torque unless you want to pull a caravan AFIK there is only SH who openly admits to having a towbar on his shed

Dave

[ray_von]

Ehh??

[The AJP Griff]

spend said:

Can't say I've ever understood the attraction of low down torque unless you want to pull a caravan AFIK there is only SH who openly admits to having a towbar on his shed

Dave

[s5tuart]

Can anyone tell me, in words of one syllable preferably, what is the difference between torque and BHP?

[The AJP Griff]

s5tuart said:

Can anyone tell me, in words of one syllable preferably, what is the difference between torque and BHP?

http://www.pistonheads.com/gassing/topic.asp?h=0&t=360417&hw=+%2Btorque%2Fbhp Torque is the only 'true' value,and BHP is calculated from the torque figure.The best analogy for me is that torque is the power of an engine to move a load,and the BHP is how fast it can move it.

[Slikk]

Power dictates how fast you hit the wall. Torque dictates how far you go through it.

[LordGrover]

Slikk said:

Power dictates how fast you hit the wall. Torque dictates how far you go through it.

I like that.

[radzoule]

If you wanted to make a 500 engine (in a RR classic) as torquey as possible what mods/cam would be best? I believe cropping trumpets etc is to release BHP rather than torque?