Safe boost levels?

[kev-yorks]

What boost levels is every one running at? There seems to be this unwritten rule in this country that you can only run a max boost level in the region off 1.2bar/18psi on pump fuel in a rotary. Yet our friends in Aus and the states don\'t seem to have any bother with much higher settings on pump fuel. Is it a case that no ones the bottle to try it or is there something peculiar about UK fuel that stops us doing the same? :confused:
Kevin

[stuart wizy]

my profec b controler boost nob will be turned fully clockwise  when i get my fc running mate :3gears-rh
if i can get enough fuel in that is !!!!!!!!!!

[Brett]

I think it really comes down to how long you want to wait between rebuilds!
I was running 1bar all day long.

[stuart wizy]

i wouldnt do this with an fd though,  to much money tied up in them to risk it i think personally anyway.
you can pic fcs up dirt cheap now for projects, theres an fc without engine and box for 30 quid on ebay at the moment with 1 day left, theres blown motors knocking about cheap everywhere, get a rebuild vid and have a go :yes
gt45 rolling bearing turbos from the states are selling for 600 dollars

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1,1&item=8038902922&sspagename=STRK%3AMEWA%3AIT

[kev-yorks]

Hoping one of the builders may come in on this one.

i wouldnt do this with an fd though, to much money tied up in them to risk it

Thats what i\'m thinking is the real reason nothing technical just a reluctance to push the envelope. guess i\'ll just have to crank up the boost a bit more on the 3 rotor and give it a try.
Kevin

[bnaellis]

Maybe in Aus but not in U.S.A
Most of the guy\'s in U.S run 15,16 psi on pump fuel. Any running higher than that run water injection. I run 1.4 bar on pump fuel and water injection. I don\'t run more boost than that (1) because my duty cycle is 92% & (2) I just about can go in a straight line at 1.4 bar so anything higher will and i\'ll just be drifting.

[stuart wizy]

most mildly tuned fds are kickin 250rwhp to 300rwhp anway, thats plenty for road use and safe at low boost.
its all down to how far u wanna go past that

[stuart wizy]

what tyres you running at the back with that set up then?

[bnaellis]

what tyres you running at the back with that set up then?

Mickey Thompson drag radials.
Probably due to me running tyre pressure not ideal for the road too.

[stuart wizy]

and it still spins the wheels with them on :3gears-lh
what they like when you warm them up for grip?
and what power did the motor give at 1.3 bar mate?

[kev-yorks]

Maybe in Aus but not in U.S.A
Most of the guy\'s in U.S run 15,16 psi on pump fuel. Any running higher than that run water injection. I run 1.4 bar on pump fuel and water injection. I don\'t run more boost than that (1) because my duty cycle is 92% & (2) I just about can go in a straight line at 1.4 bar so anything higher will and i\'ll just be drifting.

Thats the difference between the Cosmo and Fd Brian whilst it may not corner as well the backends set up to take the power better certainly with the sport version. Now i\'ve got some dry roads to play with there\'s still full traction with 16psi of boost and i\'ve no issues with duty cycles. As its already insane i may as well turn it up a bit more no point in half measures. I was hoping to get a bit of a tech discussion going see if we can all learn the probs with higher boost levels if anyone out theres done it yet.
Stu not sure if the tyre size question was for me or Brian mines on 265\'s at the rear
Kevin

[bnaellis]

and it still spins the wheels with them on :3gears-lh
what they like when you warm them up for grip?
and what power did the motor give at 1.3 bar mate?

If warmed up properly by doing a good brunout then they are very sticky.
Don\'t know how much power at 1.4 bar as it was mapped on the road, not a dyno.

[stuart wizy]

ived played with a couple of  5 turbos and run almost 25 psi !!!! in a crappy little 1400! and rebuilt a s13 200sx that was quite high powered
rotarys are a different story, theres a scary myth by a lot of people about rotarys over here and not many people know exactly how they work and how to go about tuning them, ie fueling timing etc compared to piston engines, diy lads that is.

[bnaellis]

Thats the difference between the Cosmo and Fd Brian whilst it may not corner as well the backends set up to take the power better certainly with the sport version. Now i\'ve got some dry roads to play with there\'s still full traction with 16psi of boost and i\'ve no issues with duty cycles. As its already insane i may as well turn it up a bit more no point in half measures. I was hoping to get a bit of a tech discussion going see if we can all learn the probs with higher boost levels if anyone out theres done it yet.
Stu not sure if the tyre size question was for me or Brian mines on 265\'s at the rear
Kevin

Running high boost say 20+psi, you will have higher combustion temps. When the spark plugs ignite the air/fuel mixture, ideally we want a controlled burn. Running higher boost increase both charge temps & combustion temps, and also increases pressure in the rotor chamber. This combination can lead to uncontrolled burn, where you have two flame fronts colliding, which results in detonation due to the excessive heat and pressure. So if someone doesn\'t have an appropriate setup to run high boost, the detonation and a rebuild will be likely. An example would be someone running an inadequate intercooler for instance, they could never run at higher boost levels as safe as someone with a decent intercooler setup.
Tuning obviously plays a big part also, so limitations of running high boost boils down to both an individuals setup and also the knowledge to tune such a setup. The ones who have knowledge tend to run higher boost on pump fuel reliably do the ones who don\'t either don\'t or blow up trying.
Water is very good at absorbing heat and reducing cylinder pressure, as well as being free, so is ideal for when running higher boost and minimising the risks of detonation even with normal pump fuel.

[kev-yorks]

rotarys are a different story, theres a scary myth by a lot of people about rotarys over here and not many people know exactly how they work and how to go about tuning them, ie fueling timing etc compared to piston engines, diy lads that is.

Thats why i put up this post Stu try and dispel a few rumors and get some info out for the DIY tuners.
Kevin