Bhp Levels

[vickiw106 1]

I have just had my 205 rally car on the rolling road

 

The spec is

 

1.9 standard bottom end

Big valve head

grp a piper cam

Ported and polished head

Dellorto twin 40s

Magnex 4 branch manifold

 

It’s producing 145bhp at the flywheel

 

I personally thought I would get a bit more bhp

 

I’m interested if anyone thinks that this is good or bad

 

Thanks

[dirtdog 4]

how much LB-FT?

[vickiw106 1]

how much LB-FT?

 

 

sorry for being stupid

 

what do mean by this

Edited December 7, 2008 by vickiw106

[projectpug 0]

Seems vey low for this spec. Have the webers been jetted correctly? Could be many reasons for the low figure but you should be good for 150 + .

Whos big valve head? Personally you need weber 45's with that sprec.

Any chance of posting up a graph, it could be the operator wasn't revving it high enough.

[oli-pug 6 2 Cars]

I'd say you'd be better off with weber 45's, who built the head too?

 

Dirtdog means what's the torque figure

[vickiw106 1]

.

Whos big valve head? Personally you need weber 45's with that sprec.

Any chance of posting up a graph, it could be the operator wasn't revving it high enough.

 

 

dont know whos valve head it is brought it second hand.

 

the rr people did say that is could do with 45.

 

i will try and get the graph posted

 

it was producing 145bhp at 5792 revs and it looks like it was still climing ( so it maybe more bhp)

[projectpug 0]

Hi,

 

If you can post a graph even if its a link to photobucket , that will be a great help.

Any information on your carbs configuration ie chokes and main jet sizing.

Ignoring the rolling road figure you have how does it feel to you to drive? Any significant dips in power or surges?

What fuel? i take it you are using a minimum of super unleaded and that the ignition has been played with on the rollers to optimise hp/torque?

[Miles 331 1 Cars]

If it was still climbing why stop, But as said the heads are easy to loose flow to a S/H unknown one is iffy to say the least

[vickiw106 1]

Hi,

 

If you can post a graph even if its a link to photobucket , that will be a great help.

Any information on your carbs configuration ie chokes and main jet sizing.

Ignoring the rolling road figure you have how does it feel to you to drive? Any significant dips in power or surges?

What fuel? i take it you are using a minimum of super unleaded and that the ignition has been played with on the rollers to optimise hp/torque?

 

 

on the road is seems supurb no dips in power or anything and it pulls like hell but that could be down to the gearing i am running.

 

the ingnition was adgjusted on the rollers

 

dont get me wrong i was happy the the job the the rolling road company did, as they increased the power by 30bhp and it does run good

 

i was just expecting a little more bhp out of a 1900 as there are 1600 running more power

[vickiw106 1]

how much LB-FT?

 

 

the maximum lbft it has is 140 @ 5000 revs but when the bhp is at 145 the lbft drops to 130

 

i will try and get the graph posted later today.

[DrSarty 90 1 Cars]

the maximum lbft it has is 140 @ 5000 revs but when the bhp is at 145 the lbft drops to 130

 

i will try and get the graph posted later today.

 

I believe that's some good torque, as an Mi16 (std) makes 133lbft max, and I believe torque and driveability is where it's at.

 

I wouldn't get hung-up on horse power Vic, as it's just a figure to sell cars or bits for them. In effect it doesn't even exist; it's just a marketing tool.

 

Your torque and how it drives and makes you feel is key.

Edited December 7, 2008 by DrSarty

[andy0075 9 1 Cars]

Hi vickiw106!

 

As DrSarty said, the torque is the important value which accelerates your car !

And 140 lbft is really god ! My 8V with 45 Weber produces 130 lbft at 4100rpm and

150hp at 6400rpm. The engine setup is similar to yours.

 

Andy

[weejimmy 1]

erm what ???? torque is irelivent bhp is what wins races.

torque is for motorway overtaking in 5th, for all other situations drop a gear. ( but lets not go there )

but i would say that power is around what i would expect on that set up.

its very hard to get more power from a 8v gti as they are very good stock,

[saveloy 8]

erm what ???? torque is irelivent bhp is what wins races.

torque is for motorway overtaking in 5th, for all other situations drop a gear. ( but lets not go there )

but i would say that power is around what i would expect on that set up.

its very hard to get more power from a 8v gti as they are very good stock,

 

 

Torque versus weight = Acceleration.

Power versus aerodynamics = Top speed.

[dirtdog 4]

BHP is for pub banter. Torque is what makes me grin.

 

I've seen 1900cc 8vs running up to 177bhp (Someone from here I am assuming?)

[Moz_Goodwood 0]

bhp for show...... torque for dough

 

thats why ive gone for a turbo engine over the mi 16 as turbo's throw lots of torque into the mix

[boombang 2]

erm what ???? torque is irelivent bhp is what wins races.

 

As BHP is a figure derived from torque, RPM and a constant, how the hell can torque be irrelivant?

[weejimmy 1]

thats exactly why.

because all torque is, is bhp at a certin revs

so bhp is the power of an engine, torque is where on the rev range the power is.

torque = bhp x 5252 divided by rpm

so low torque means you need to rev it more. which is fine, so imo torque figgures dosent mater much, its bhp that wins races,

[DrSarty 90 1 Cars]

thats exactly why.

because all torque is, is bhp at a certin revs

so bhp is the power of an engine, torque is where on the rev range the power is.

torque = bhp x 5252 divided by rpm

so low torque means you need to rev it more. which is fine, so imo torque figgures dosent mater much, its bhp that wins races,

 

With all due respect Jimmy, and as you've already started with immense attitude, torque is ALL an engine produces, a rotational moment.

 

BHP is a product of torque combined with RPM, i.e. it's throwing in the factor of time, it is NOT the other way round. Without torque, there is zero way in which to calculate BHP, which I say again, is a product of torque, not the other way round.

[weejimmy 1]

hey sorry didnt mean to come accross with an atitude.

 

for me its bhp that counts but for many others its torque, thats fair enough

[DrSarty 90 1 Cars]

hey sorry didnt mean to come accross with an atitude.

 

for me its bhp that counts but for many others its torque, thats fair enough

 

Ok then. What we are saying is that BHP simply doesn't exist without torque, i.e. it's another way of explaining the same thing.

 

Think: the simplest function and component of an engine, whether it be rotary or traditional 'piston in bore' internal combustion engines, is to ROTATE a crank. That manner of force is a 'moment'.

 

Two typical units of measure are used, pound/foot (lb-ft) and Newton/metre, i.e. one imperial one metric, but ultimately describing a rotational force described as a mass wanting to act at right angles to a fulcrum or pivot. This is all an engine produces, a crank shaft rotation. Everything else an engine produces such as extra heat caused by friction and sound is effectively energy wasted, similar to a typical light bulb, which should produce light, spending most of its time producing heat = highly inefficient.

 

Sorry for the lecture, but BHP is just a tool to package up torque, by relating it to RPM which makes it more tangible, sexy and saleable. That's my humble opinion anyway.

 

If you prefer the sexiness of BHP, then that's fine. But all you're really liking is torque and a rate at which it is produced, aka, where it is in the rev range. But again that is subjective, because an engine could produce the same peak BHP at two different RPMs, i.e. a lower torque figure at high RPMs, or a higher torque figure at lower RPMs. Those are both in BHP terms equally high, but totally different in terms of driveability.

Edited December 7, 2008 by DrSarty

[vickiw106 1]

bloody hell where did all this come from

 

all i wanted to know if my engine was performing or not

 

thanks for everyone's input

 

after looking at what everyone has said i am happy with my engine

 

ps i will still try and get the graph on later

 

ta

[Anulfo 22]

If its a full on group A cam you have im assuming the head is more heavily modified than just the big valves???Otherwise your head might not last too long.

[GLPoomobile 958]

I don't think any of our heads are likely to last long with the way this topic is going. But it keep it up chaps, you've given me a laugh

 

And Rich, please cease your incorrect use of aka

Edited December 7, 2008 by GLPoomobile

[welshpug 1,661]

BHP is for pub banter. Torque is what makes me grin.

 

I've seen 1900cc 8vs running up to 177bhp (Someone from here I am assuming?)

 

That's chris penrose, 309pug