Got Over 400kw Atw?

[SimonR32]

Shootout 6f and strapped down as per normal and wasn't leaving the rear roller but regardless all the little improvements should've help so the strip should show something..

The graph you posted clearly show Shoot_4

[Ryan1200]

^^

Your big valves helping or hurting?

Are you using pods or an air box?

Apexi pods and hurting spool helping top end. Before the latest mods it's a pretty normal figure 400kw on 98 for a nicely built 26 with stock valves always thought something may have been holding it back considering the amount of head work iv had done.

"Clearly" shoot 4??

[Piggaz]

Apexi pods and hurting spool helping top end.

I want to test this back to back. Considering the RP car made 449 on 20psi on -5's with a airbox, at what point does it become a restriction?

[Ryan1200]

Iv been considering returning to stock airbox to till I noticed one of my plastic turbo to afm pipes completely chewed up by a hungry possum in the shed wasn't fn happy.. If I get time in the next few months I'll return it to stock and re test id prefer the stock look.

[Piggaz]

That will be an interesting result .

I also noticed 1 mm OS valves on the inlet and 2 mm on the exhaust. What was the reason for that?

[Ryan1200]

Built the engine back in 2004 and didn't know any better at the time looking back its definately an over kill for such small turbos but oh well..

[Piggaz]

It's obviously working.

Reason I ask is that I have 1.5 OS IN and EX going in my new head.

[Ryan1200]

Went 2 & 1 to bring the ratio of inlet to exhaust closer together..

[bigmikespec]

Unless you are opening the ports to 90% of the valve head ratio don't bother with bigger than +1.0mm exhaust valves. The bigger valve head can also hurt flow in a small bore. Moreso a problem on intake though.

[black bnr32]

Yep close about 4300 on pump but I think around 3800 on e85. I still believe my +2mm Exhuast valves effect spool a bit... Not only was it a smallish outlet on the manifolds but there could have been a nasty square edge in the mix aswell I really should've matched it up earlier but got lazy...

hot damn. your spool is comparatively very good, imo. what cams? dumps? boost control info? timing?

[Ryan1200]

The graph you posted clearly show Shoot_4

Sorry actually missed that on the bottom left the shoot 4 is what the dyno is currently set in and the 6f in the details is what the run was done in.

[Ryan1200]

hot damn. your spool is comparatively very good, imo. what cams? dumps? boost control info? timing?

260 10.2mm 270 inlet 10.2 tomei cams exhaust. Ces dumps with long wastegate pipes. Blitz I-colour.

[GASCO123]

How do you work that out exactly?

You - 175km/h @ 7000rpm (4th)

RPMGTR - 230km/h @ 8000rpm (4th)

You are doing 150km/h @ 6k, 175km/h @ 7k... So roughly 200km/h you are 8k

Meaning yours is the shorter ratio... So of course yours appears more responsive.

Ben's dyno using 5th, mines 4th gear.

Ben's getting 28.7 km/1000rpm. Std is 33.5 5th and 25.5 4th. Half way between.

Ben tends to use 5th gear as it give less gear box loss, 5th is 1:1 ratio.

Unusual he starts the dyno at 3000 rpm

[jangles]

Ben's dyno using 5th, mines 4th gear.

Ben's getting 28.7 km/1000rpm. Std is 33.5 5th and 25.5 4th. Half way between.

Ben tends to use 5th gear as it give less gear box loss, 5th is 1:1 ratio.

Unusual he starts the dyno at 3000 rpm

isnt the idea to run the dyno in 1:1?

[GTR_JOEY]

Depending which gear you run it will give u a higher/lower torque readout...

Hp should still be the same yea?

Though I guess depending what gear the car is in it will effect how much load is on the engine causing the curve to move left/right relative to load

[rob82]

Depending which gear you run it will give u a higher/lower torque readout...

Hp should still be the same yea?

Though I guess depending what gear the car is in it will effect how much load is on the engine causing the curve to move left/right relative to load

No gear ratio will only change the tractive effort or the actual load through the load cell. In a perfect world the gear ratio shouldn't make a difference in measured hp or only be slightly different due to the differing thrust loading through the gearbox.

In reality even the good dynos show a slight difference between say 3rd and 4th gear probly due to unaccounted for acceleration rates.

The ramp rate is really the only thing that should influence how a turbocharged cars power delivery is plotted. Slower ramp rate gives the turbocharger longer to spool hence moving the graph to the left.

[GASCO123]

No gear ratio will only change the tractive effort or the actual load through the load cell. In a perfect world the gear ratio shouldn't make a difference in measured hp or only be slightly different due to the differing thrust loading through the gearbox.

In reality even the good dynos show a slight difference between say 3rd and 4th gear probly due to unaccounted for acceleration rates.

The ramp rate is really the only thing that should influence how a turbocharged cars power delivery is plotted. Slower ramp rate gives the turbocharger longer to spool hence moving the graph to the left.

In my opinion, exactly.

Dyno's are set up to give a fixed road speed increase with time, e.g. 12 kph/sec.

If you use a taller gear the dyno stills holds the wheel speed to 12 kph/sec, giving the dyno sweep longer time from start to red line.

This then gives the turbo's more time to spool. Should give a quicker spool up , not by time but by road speed, which is what the reads.

I prefer dyno runs in rpm not road speed. This shows what the motor is doing more acurately than the unknown gearing of the car.

People on this thread do not even knowin what gear Ben's run was done.To me it seems 5th with a 4.1:1 diff. Only way to get 230 kph at 8000rpm.

He does use 4th sometimes,and 5th soetimes. He tuned my R32 GTR many years ago, great job too.

[GASCO123]

isnt the idea to run the dyno in 1:1?

Yep, until you run out of dyno allowable road speed

[ezy_09s]

Ben's dyno using 5th, mines 4th gear.

Ben's getting 28.7 km/1000rpm. Std is 33.5 5th and 25.5 4th. Half way between.

Ben tends to use 5th gear as it give less gear box loss, 5th is 1:1 ratio.

Unusual he starts the dyno at 3000 rpm

Since when is 5th gear 1:1 ratio ?

4th is 1:1 , 5th is 0.752

[XKLABA]

Since when is 5th gear 1:1 ratio ?

4th is 1:1 , 5th is 0.752

In the R34 GTR with a six speed 5th is 1:1 with a 3.545:1 final, that is assuming the R34 the motor is in is a GTR