Quench on turbo engines
10-14-2013, 08:28 AM
#22
Quench becomes more important when the engine is used on the street and spends lots of time out of boost. If you're going for peak power and reliability in boost, keep the piston in the hole. Most drag cars that push the limits of power per displacement (like the old 1200+ HP 4 cylinder hot rod cars) keep the pistons in the hole because quench creates hot spots, which can be really bad at high boost when the dynamic compression is already through the roof even with low static.
Basically it comes down to intended purpose.
Basically it comes down to intended purpose.
I run .040 quench on my flap tops with e50 and 10:1 static
10-15-2013, 01:35 PM
#26
Not to hijack the OP's thread, but could you elaborate. I am with the user in that my quench is at .038 static compression is 9.4:1 and dynamic is at 7.96:1. Based on the info gathered so far, it looks like good numbers, but this was mostly acquired from N/A precedents. Why wouldn't they apply to a boosted engine also. Assuming the compressor is in it's efficient operating range, and you're not running extreme IAT's what is to be considered.
10-15-2013, 02:36 PM
#27
tight quench on an na angine will reduce the large tuning window but the normal thickness of pistons and such means even when "hot" it does not break as much stuff as a high HP NA or Nitrous motor will. The minimal gains say from .035 to .050 in hp advantage are not worth the smaller tunning window in most cases. Tight quench should be saved for limited power adder class racing IMHO. You just don't need to speed up the flame travel on PA cars. you normally are trying to slow it dwon with colder fuel.
10-15-2013, 09:59 PM
#28
Not to hijack the OP's thread, but could you elaborate. I am with the user in that my quench is at .038 static compression is 9.4:1 and dynamic is at 7.96:1. Based on the info gathered so far, it looks like good numbers, but this was mostly acquired from N/A precedents. Why wouldn't they apply to a boosted engine also. Assuming the compressor is in it's efficient operating range, and you're not running extreme IAT's what is to be considered.
I can't stress enough how important this is, but you have to read your plugs when they're fresh and brand new, no to very limited idle time and shut it off at the stripe or on a back road somewhere.
Once you do this and learn your car and your tune up you won't have to read plugs that often. It's part of pushing the edge. Still should do it even if you're not "pushing it" though.
tight quench on an na angine will reduce the large tuning window but the normal thickness of pistons and such means even when "hot" it does not break as much stuff as a high HP NA or Nitrous motor will. The minimal gains say from .035 to .050 in hp advantage are not worth the smaller tunning window in most cases. Tight quench should be saved for limited power adder class racing IMHO. You just don't need to speed up the flame travel on PA cars. you normally are trying to slow it dwon with colder fuel.
I'd love to have an A2W, but I don't think it's feasible to get what I want due to cost.
Last edited by Sales@Tick; 10-15-2013 at 11:08 PM.
