Area under the HP curve

[Scholzey]

i was thinking of pushing my current setup to its limited and i think i'll be faced with a shifting point situation.

my valves get a littly noisy at 20psi at 8000rpm. so to go faster i was thinking of finding the limit of boost vs rpm for the valves getting noisy and the also the limit of pump fuel.

so if i do this i'll be having a boost curve that peaks at about 6000rpm and tapers down as pump fuel limit and valve noise come into play down to 20psi upto 8500rpm.

now the problem with this is that it might end up haveing a hp curve that basically sits at 340hp from 5500~6000 to 8500rpm(at the moment its about 290 upto 337). so i was thinking to have the best torque at the wheels curve, with a completely flat hp curve, would i shift as early as i can so that i fall down to the start of the flat curve, even though the hp curve pre shift would still be heading flat.

reducing drive train losses and such, and then just run 4th gear out to 8500rpm crossing the line.

let me know! also reducing max rpm would be awesome, i want this engine to last!

oh, as a side side note. could clutch fluid level cause mis shifts? i seemed to all of the sudden got crunches in 3rd and 4th after i hadnt drivent the car for a few weeks.

[TODA AU]

Change your fuel pump & injectors & retune.

[turbotegs]

Change your fuel pump & injectors & retune.

fuel pump and injectors will be a long way from being maxed out!

i'd be looking into why your valves are getting noisy at 8000rpm and rev it harder, your valve train setup should be safe (and quiet) to 9000 all day regardless of the boost!

[TODA AU]

fuel pump and injectors will be a long way from being maxed out!
Maybe, but it's a big call seeing he mentioned the fuel pump running out of puff & we don't know the injector size...

Ageeed on the valve noise, but it's likely detonation.

[turbotegs]

Maybe, but it's a big call seeing he mentioned the fuel pump running out of puff & we don't know the injector size...

he hasn't said that the fuel pump is running out of puff, he said about finding the limit of "pump fuel". the way it was worded is a bit confusing! as for injector sizes in his spec list for the car it's listed as having 750cc injectors.

i was probably a bit reckless in saying that the fuel pump and injectors will be a "long way" from being maxed out, but providing the fuel pump is a genuine walbro the fuel system should support more power yet!

[82911]

If it is detonation..... and it is audible at 8000rpm..... then it isn't going to last long.

[Scholzey]

yes limit of adding boost vs removing ignition timing on pump fuel was what i was talking about. on bp ultimate.

went back for the retune and since my car has been sitting around for a while, my tyres are hard and we couldnt get it to grip on the dyno even when we put the ramp rate to 150, he likes to tune at about a ramp rate of around 90.

so i have to get some new tyres then up my boost, although we did try to expand the maps a bit with what timing an efficent setup should be able to hold, and it started to ping on 24psi 150 ramp rate spin run. so it looks like my setup is running out of puff anyway.

apparantly my springs should be good to 9000rpm, since im only using acura gsr cams. and skunk2 tuner series springs and titanium retainers.

about having enough fuel, in 22psi column and 8500rpm, hondata says estimated injector duty cycle 99%

on quarter mile drag run data logs, the highest injecter duty cycle ive seen is around 86% that was 2.35bar 8500rpm crossing the line in 4th

injecters are rc 750cc with stock fuel reg and walbro 255 fuel pump