Dyno RWHP

[007 VXR]

Since my last dyno run i have changed my clutch from a LS7 to a ACT.
Would this effect rwhp in anyway ?
Also now run 35 profile tyres not 30s .

[Granby]

Nope

[S800VXR]

007 VXR said:

Since my last dyno run i have changed my clutch from a LS7 to a ACT.
Would this effect rwhp in anyway ?
Also now run 35 profile tyres not 30s .

Tyre profile likely to reduce the power level slightly as your turning a larger dia wheel basically but atmo could also effect the power given!

[007 VXR]

what if the ACT has a lighter fly wheel ?

[S800VXR]

007 VXR said:

what if the ACT has a lighter fly wheel ?

Pickup response will be better but I doubt you will notice any difference from that or tyre profile TBH.

[anonymous-user]

Nope, same engine and transmission so same power.

[007 VXR]

so my back to back results will be ok

[stevieturbo]

007 VXR said:

so my back to back results will be ok

Well...given weather, fuel, tyres, bonnet up/down, direction of the wind, height of the sun in the sky and general life variations...

Other than that the back to many days apart different days, weather etc...back results will be ok LOL

Question is...does it go faster though ? That's the important one.

[007 VXR]

stevieturbo said:

Question is...does it go faster though ? That's the important one.

cars at the fish now, so dont now. But i could feel the improvment last time going from 498 to 535 so we will see in a couple of weeks

[MyM8V8]

007 VXR said:

Since my last dyno run i have changed my clutch from a LS7 to a ACT.
Would this effect rwhp in anyway ?
Also now run 35 profile tyres not 30s .

Anything that allows the engine to respond better (like lightening rotating components) will help performance.

You will notice that throttle response is now an instant blip rather than winding up that super heavy LS7 unit. Engine decel' is better too. You'll love it.

[007 VXR]

MyM8V8 said:

Anything that allows the engine to respond better (like lightening rotating components) will help performance.

You will notice that throttle response is now an instant blip rather than winding up that super heavy LS7 unit. Engine decel' is better too. You'll love it.

engine decel is alot slower imho, but revs better

[Jupp318]

In the old drag racing days we used to have an Air Density gauge. It took Pressure, Relative humidy & Temperature into account. If the gauge went up we richened up the mixture... etc etc. We always noted what the gauge read for a pass as well as tyre pressures +

[MyM8V8]

007 VXR said:

engine decel is alot slower imho, but revs better

Must be in the tune then, because with less weight/momentum, it should slow down quicker as well. Especially against an LS7 flywheel.

You have got the ACT lightweight twin plate and f/wheel as well???

[007 VXR]

MyM8V8 said:

Must be in the tune then, because with less weight/momentum, it should slow down quicker as well. Especially against an LS7 flywheel.

You have got the ACT lightweight twin plate and f/wheel as well???

yes act fitted.
once it was installed noticed when liffting of throttle that engine braking was almost nil. So not a remap thing. Also noise from gear box area was a lot quieter..

[MyM8V8]

007 VXR said:

yes act fitted.
once it was installed noticed when liffting of throttle that engine braking was almost nil. So not a remap thing. Also noise from gear box area was a lot quieter..

Mark, engine braking should be a lot better.

[007 VXR]

MyM8V8 said:

007 VXR said:

yes act fitted.
once it was installed noticed when liffting of throttle that engine braking was almost nil. So not a remap thing. Also noise from gear box area was a lot quieter..

Mark, engine braking should be a lot better.

Dont know then ? But its is very noticeably less on mine ...

[stevieturbo]

007 VXR said:

Dont know then ? But its is very noticeably less on mine ...

Must be something with the mapping holding the rpm's up or something.

[M11 MFP]

stevieturbo said:

007 VXR said:

Dont know then ? But its is very noticeably less on mine ...

Must be something with the mapping holding the rpm's up or something.

Perhaps Roger found an old Sprag clutch lying about and kept the ACT.

[007 VXR]

M11 MFP said:

stevieturbo said:

007 VXR said:

Dont know then ? But its is very noticeably less on mine ...

Must be something with the mapping holding the rpm's up or something.

Perhaps Roger found an old Sprag clutch lying about and kept the ACT.

Roger did not fit it, Stick100 did..

Old LS7 would engine brake like mad, but not the ACT on the same Map..

[stigmundfreud]

Jupp318 said:

In the old drag racing days we used to have an Air Density gauge. It took Pressure, Relative humidy & Temperature into account. If the gauge went up we richened up the mixture... etc etc. We always noted what the gauge read for a pass as well as tyre pressures +

yep we have maf's now that do the same shizzle though Richard wont admit it, they're good really