Turbo HP vs Boost & What fuel do I run??

[TimSoltys]

Hello all. I just joined and am hoping someone can help answer questions about Turbo's sleds.

I just purchases a 2003 Yamaha RX-1 with a CPR Simmons Turbo and after cooler. The motor is pretty much stock except for a head gasket spacer to lower the compression. Here are some of the spec's on it. My questions are:

What kind of HP can expect to make at various boost

I have spoken to different dealers and am confused on the fuel to run. I have been told everything from just premium to 50% race fuel. Does anybody have the right information??

Tip up 169 tunnel Lightweight
Mointain Mod lightweight seat
Under tunnel exhaust
Lightweigth rear suspension kit
8" rear chrome, rubber idlers star or 5 spoke
Lightweight front end suspension
CR racing rear gas rack
Chrome rear bumper
162 x 15 camoplast track
8 in handlebar risers with FLY handlebars
Light weight hood and windsheild
Tunnel, rear suspension, front suspension are all powder coated black, coolant rails on tunnel are chrome
All rivets are polished chrome on the black tunnel
CPR simmons turbo kit and aftercooler, at 10 # boost = 265 HP at 18 # boost = 320 HP

 

[dooryder]

where are they?

 

[Mongrol]

Horse power increases on a pressurized engine are linear. Easiest way to approximate is as follows. If normal atmostpheric pressure where you normally operate is 15 lbs per sq. in. (normal sea level) and your boost pressure is 5 lbs, you are making 33 1/3 % increase over your rated base HP. 7 lbs boost would be 50%. To be totally accurate, other things such as cam, etc, have to be considered but this way will be pretty close. Normally, pipes don't add to the performance on a boosted engine.

 

[raustincat]

Horse power increases on a pressurized engine is lineage. Easiest way to approximate is as follows. If normal atmostpheric pressure where you normally operate is 15 lbs per sq. in. (normal sea level) and your boost pressure is 5 lbs, you are making 33 1/3 % increase over your rated base HP. 7 lbs boost would be 50%. To be totally accurate, other things such as cam, etc, have to be considered but this way will be pretty close. Normally, pipes don't add to the performance on a boosted engine.

Thanks, mangrol

i didn't know that was the "basic" way to figure that out... not to shabby!

 

[new24stroke]

i have a Alpine front mount with the head shim and I can run 12psi on premuim fuel.After that i can eithier run 50/50 or avgas to 15 psi.Then from 15-20 psi striaght race.Hope this helps

 

[shawnmcgr]

Search for "boostcalculator" on the totalyamaha site. Fairly handy excel spreadsheet. I'd post it here for you but it comes up as invalid file type.

 

[Modman]

......I have spoken to different dealers and am confused on the fuel to run. I have been told everything from just premium to 50% race fuel. Does anybody have the right information??
........at 10 # boost = 265 HP at 18 # boost = 320 HP

Best to call the turbo kit manufacturer and see what they recommend, it is their kit. You might be a shade high at 320 at 18 lbs boost (maybe closer to 300-305?) but depends on more than just boost levels (timing, etc) so that is probably in the ballpark. Find a dyno and actually dyno that thing, actual verification will determine what the motor output is at certain boost levels, this will be the only way to really determine. From what I have seen in the past, actual field based consumer numbers are generally lower than manufacturers specs just due to fuel consumption values, timing and various motor tweaks from kit development to production runs. Give a call to Neil at Neil's Power Pipes in Edmonton or Ralph at Split Second in Valleyview, either of them can hook you up with the dyno.

 

[Mongrol]

Don't know if this helps or pertains to sleds, but on my race boat running 28 lbs boost, I used 110 to 130 octane aviation gas and water injection with a 50/50 water/alcohol mix.

 

[Turbo68]

i have been running a turbo apex for three years. Do not run av gas it is to dry. You will have engine problems sooner or later. Run at least 50/50 vp racing fuel C12. You can run C11 it is a bit cheaper. YOu also want to side on the the higher side of the mix to be safe especially if you venture into the 18 pounds of boost range. A barrell of C12 will run you somewhere around 600 dollars depending on where you buy it. I have seen it as low as 590 and as high as 750. There is no better sled than a 4 stroke turbo for power and reliability. Dont let any double lunger tell you different. I have towed to many of them off the hill for them to argue. Have a good one.