rage2

100km/h is 62.5mph
200km/h is 125mph

Tom M'Guinn

Duke,

Nice video. Is your bypass valve working properly? It seems to have a little turkey gobble between shifts, no?

rage2

Some blow off valves sounds like turkey gobble, or compressor surge. My $99 BOV from demon tweeks sounds like turkey gobbling too.

daniel951

rage when u made 450rwhp on 25psi that was on race gas and what turbo? Is it safe enough to run 25psi for a dyno run. I was reading about what danno said and he said it doesn't really matter on how much boost u are running but your a/f ratio must be on.

Duke

Great to see other 100-200 times, Rage the 2.5 litre 25 psi time is simply crazy!
At 12.2 with my current setup I'm very happy. The boost really drops off in the higher rpm's, making the A/F rich in the low 11's.
I guess raising the overall boost to 1.3 bar and being able to keep it up at redline (from current 1.0 bar) will take care of the GT3's

Duke

Tom I have a huge BOV that went's to atm. and it do sounds like turkey gobble.

But the biggest "blow-off-sound" of all time came near finish line at my last auto-x attempt when the turbo to IC pipe blew off
I'm surprised the 16 year old weak stock hose clamp lasted that long!

hosrom_951

Higher fuel grades help in preventing detonation/knocking..........

You can hit 15psi on pump gas and have detonation (bad a/f ratio).

Higher fuel ratings, give more power, since the burn faster (?), you can also hit 25psi on race gas and still get detonation......

So, basically, if you can get the a/f ratios correct at 25psi, you'd be safe. The a/f ratio is what makes runnin rich (bad for piston rings) and running lean (detonation occuring, but depends on the loads, boost etc) so, yes.......you can get 25psi boost on pump gas IF you'r a/f ratios are correct

Fuel is cheap as hell here in Dubai. We have the 'Special' and 'Super' fuel grades. The Special is 96 octane, while super is 98 octane, both are unleaded. On my stock car and BMW 328is, i ALWAYS use the Super 98 octane (costs $1.35/Gallon here ).

hosrom_951

Duke, why don't you get a diverter valve instead?

Duke

I'm afraid that's not correct. And if someone knows that on this forum it's Rage since he's been running probably higher boost than anyone here and tuned his car by himself.
Timing is also extremely important when starting to run very high boost levels.

Duke

Why should I?
Most bypass valves don't flow nearly as much as the big BOV's and it's working very well.
Personally I think this whole thing that the circulating air would help the compressor wheel spin is extremely overrated.

hosrom_951

Doesn't higher fuel grade help control in detonation and a/f ratios?

BOV make our car's run rich, even with MAF's. Not a whole lot rich, just like ~0.2 richer (like 12.2:1~12.1:1 a/f as an example).

Duke

Yes higher fuel grade helps, but the A/F-ratio doesn't change.

If the BOV works correctly it can never affect the A/F-ratio. Except at instant throttle lift off (when it vents) when using MAF or AFM.
But... I run MAP so this doens't apply in my application.

You have either run a BOV that isn't sealing or a bypass valve designed to run in closed loop in open mode.

porshhhh951

once again all this deverter valve better than bov because you dont run rich for .4 sec's inbetween shift's is pretty stupid.

I have been runing my dumped to atmosphere for over a year and a half now and it's not a big deal trust me.

One of the most overrated ideal's on the board's. I would be much more worried about my air/fuel ratio while I was in gear ...accelerating under high load and boost condition's.

hosrom_951

as i mentioned, it effects AFM and MAF...........MAPS are ok.......

So what you are saying is that you could never hit 25psi on 'normal' gas......?

Konstantin

you mean 100 to 200 right?
0-200 would be too fast ;-)

Konstantin