detonation
Thread Starter
Teching In
Joined: Dec 2002
Posts: 4
Likes: 0
From: United Kingdom
detonation Hi Guys,
LS1 engine running a Vortech supercharger @ 7psi boost.At WOT from 5-6000 rpm detonation occaisionally.I have increased PE v RPM by 5% with no effect.What table and cells in Edit do I change to reduce advance? if this is the answer.
Runnuing 28lb injectors.Are they to small?Also at max RPM ie 6450 KR comes in @ 8-9Deg.Only see KR thro rest of rev range @ about 3-4Deg.
A lot of questions but here in the UK not a lot of people to ask on these engines.
Thanks
LS1 engine running a Vortech supercharger @ 7psi boost.At WOT from 5-6000 rpm detonation occaisionally.I have increased PE v RPM by 5% with no effect.What table and cells in Edit do I change to reduce advance? if this is the answer.
Runnuing 28lb injectors.Are they to small?Also at max RPM ie 6450 KR comes in @ 8-9Deg.Only see KR thro rest of rev range @ about 3-4Deg.
A lot of questions but here in the UK not a lot of people to ask on these engines.
Thanks
Re: detonation You are most likely topping out your injectors. You need to get larger injectors.
Using 28 lb injectors on your setup is pushing it. At WOT above 6000 rpms they have to be FULL open in order to add enough fuel, and depending on your setup (specifically, your brake specific fuel consuption) may or may not be enough fuel to keep you at a proper a/f ratio. If you car goes too lean it will detonate and show up as KR as you have been seeing.
Other possibilities, aside form a poor a/f ratio. Your timing may be too high for your setup, your octane too low, or you intercooler to shitty. Any one of these will cause you to see KR once boost comes into play.
Here is what I would try:
Put in some race gas (110 octane). If the KR goes away then you know that you may be able to pull timing to fix the problem.
If the KR doesn't go away, then you have dreaded false KR on a blower setup. However, on the bright side, this won't blow up your car, unlike the real KR will. To fix this you are going to have to either have to find what is causing the false KR (nearly impossible sometimes) or use some method to ignore the KR at these points.
Cheers,
Kevin
Using 28 lb injectors on your setup is pushing it. At WOT above 6000 rpms they have to be FULL open in order to add enough fuel, and depending on your setup (specifically, your brake specific fuel consuption) may or may not be enough fuel to keep you at a proper a/f ratio. If you car goes too lean it will detonate and show up as KR as you have been seeing.
Other possibilities, aside form a poor a/f ratio. Your timing may be too high for your setup, your octane too low, or you intercooler to shitty. Any one of these will cause you to see KR once boost comes into play.
Here is what I would try:
Put in some race gas (110 octane). If the KR goes away then you know that you may be able to pull timing to fix the problem.
If the KR doesn't go away, then you have dreaded false KR on a blower setup. However, on the bright side, this won't blow up your car, unlike the real KR will. To fix this you are going to have to either have to find what is causing the false KR (nearly impossible sometimes) or use some method to ignore the KR at these points.
Cheers,
Kevin
Thread Starter
Teching In
Joined: Dec 2002
Posts: 4
Likes: 0
From: United Kingdom
Re: detonation Hello Kevin,
Many thanks for your advise.I am of the opinion as well that the injectors are too small.I think 34 to 36 lbs are in the right ball park. Would you agree?I will try this first and then progress down the other route you suggested.
Cheers,
Brian
Many thanks for your advise.I am of the opinion as well that the injectors are too small.I think 34 to 36 lbs are in the right ball park. Would you agree?I will try this first and then progress down the other route you suggested.
Cheers,
Brian
