going to track tomorrow night I need tuning tips!!!
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imjoesnuffy
I just break stuff!
- Joined
- Sep 13, 2005
- Messages
- 1,541
I would raise the boost a couple psi before messing with the timing and fuel. You have said your O2's were 700-800. What was the lowest you saw them in 3rd gear WOT? It is a delicate balance, 800 is good (maybe the slightest bit rich, 750-780 is where my car runs well) and 700 is very, very bad. Each car is different though. Main thing is just tuning for no knock.
Sounds like you have the car running well at 24 psi :biggrin: . How much boost are you launching with? Try launching with more and see what happens.
meanchicken
gallo vicioso
- Joined
- Oct 6, 2007
- Messages
- 5,254
I've been schooled by a guy who definitely knows his Turbo Buicks that if you're running a stock turbo, stock head gaskets, stock head bolts and stock bottom end and are running more than 20lbs of boost on a frequent basis...you're on borrowed time.
...Even with alky or race gas in the mix...
The stock turbo's efficiency is basically max'd at 20lbs and it has to spin too fast when pressed beyond that. More heat means power loss and also means the bugger will fail sooner rather than later.
Stock head gaskets just are not constructed to take more than 20 lbs, and stock head bolts are typically stretched or weak enough to possibly allow the head to lift if you press boost too high. When a stock head gasket blows, it can frag in such a way as to cause other issues (cam, rod and main bearing faliure) if you continue to drive on it for any amount of time after it's blown.
Stock bottom end is likely to walk a bit at higher RPM under extreme load, and if it moves too much..you donate a motor.
Since boost is actually a resistance/back pressure measurement, more boost does not necessarily mean more power...it just means the air can't over come the restrictions in front of it any faster. That's why bigger turbos, down pipes, inlet tubes,etc. can produce more power at lower boost levels than smaller ones. I think someone else already mentioned there is a point of diminishing returns.
Sure you can crank up the boost on a stock combo until it runs 11's or faster....but for how long before it gets real expensive?
The approach I've decided to take is to keep my boost at 20 or less and tune by playing with fuel first and then timing and then work on my 60's etc.
If I max out what I can do at this level and want more, then it's time to invest in some upgrades (i.e. Bigger turbo, better bottom end, etc.) and preventive measures (i.e. Better head gaskets, bolts etc.) And start upping boost from there.
My goal is to go as quick as I can with what I've got, without compromising reliability too much.
Now I just gotta get my happy @$$ to the track and run this thing.
Does any of the above sound off base?
...Even with alky or race gas in the mix...
The stock turbo's efficiency is basically max'd at 20lbs and it has to spin too fast when pressed beyond that. More heat means power loss and also means the bugger will fail sooner rather than later.
Stock head gaskets just are not constructed to take more than 20 lbs, and stock head bolts are typically stretched or weak enough to possibly allow the head to lift if you press boost too high. When a stock head gasket blows, it can frag in such a way as to cause other issues (cam, rod and main bearing faliure) if you continue to drive on it for any amount of time after it's blown.
Stock bottom end is likely to walk a bit at higher RPM under extreme load, and if it moves too much..you donate a motor.
Since boost is actually a resistance/back pressure measurement, more boost does not necessarily mean more power...it just means the air can't over come the restrictions in front of it any faster. That's why bigger turbos, down pipes, inlet tubes,etc. can produce more power at lower boost levels than smaller ones. I think someone else already mentioned there is a point of diminishing returns.
Sure you can crank up the boost on a stock combo until it runs 11's or faster....but for how long before it gets real expensive?
The approach I've decided to take is to keep my boost at 20 or less and tune by playing with fuel first and then timing and then work on my 60's etc.
If I max out what I can do at this level and want more, then it's time to invest in some upgrades (i.e. Bigger turbo, better bottom end, etc.) and preventive measures (i.e. Better head gaskets, bolts etc.) And start upping boost from there.
My goal is to go as quick as I can with what I've got, without compromising reliability too much.
Now I just gotta get my happy @$$ to the track and run this thing.
Does any of the above sound off base?
getting quicker
another personal best tonight, but only 1/8th mile, ...
1.778 60ft. leaving on 10lbs of boost and not spinning much at all...im wonder what is going on, i should be seeing low 60's on that much boost.
7.98 @ 86.3mph
1st/2cnd timing 28 deg
3rd/4th timing 24 deg
fuel 5.5% on the fat side wot thru all gears
mv = 800ish with zero knock in high gear
22 lbs of boost
took sway bar off, had 6 and 12 lbs of air in airbags, and still i can leave at 10 lbs of boost and a crappy 60ft...and very very little tire spin if any.
is my trans fried?(beleive to be untouched with at most a shift kit)
is my 2 1/4 exhaust smothering it?
dirty intercooler? i haven't checked this yet..
leaks? boost? dunno...just odd to get that poor 60ft with that boost.
opinions?
another personal best tonight, but only 1/8th mile, ...
1.778 60ft. leaving on 10lbs of boost and not spinning much at all...im wonder what is going on, i should be seeing low 60's on that much boost.
7.98 @ 86.3mph
1st/2cnd timing 28 deg
3rd/4th timing 24 deg
fuel 5.5% on the fat side wot thru all gears
mv = 800ish with zero knock in high gear
22 lbs of boost
took sway bar off, had 6 and 12 lbs of air in airbags, and still i can leave at 10 lbs of boost and a crappy 60ft...and very very little tire spin if any.
is my trans fried?(beleive to be untouched with at most a shift kit)
is my 2 1/4 exhaust smothering it?
dirty intercooler? i haven't checked this yet..
leaks? boost? dunno...just odd to get that poor 60ft with that boost.
opinions?
meanchicken
gallo vicioso
- Joined
- Oct 6, 2007
- Messages
- 5,254
If your stock converter is anything like mine...it's too tight and you need to get a new converter with higher stall speed.....3200 seems to be a sweet spot...
Do you have a Direct Scan or similar?
It would give you better visibility to what's going on.
I've heard there is also a way to lock up your stock converter....I'm not sure how tho...
A clogged IC and vac leaks certainly would not help.
Pull the IC and clean it....easy work...and replace all your vacuum lines if they have not been replaced recently. Replace those check valves at your EGR and charcoal canisters and the three way at the fire wall too. If these are blown they can behave like a vacuum leak.
Do you have a Direct Scan or similar?
It would give you better visibility to what's going on.
I've heard there is also a way to lock up your stock converter....I'm not sure how tho...
A clogged IC and vac leaks certainly would not help.
Pull the IC and clean it....easy work...and replace all your vacuum lines if they have not been replaced recently. Replace those check valves at your EGR and charcoal canisters and the three way at the fire wall too. If these are blown they can behave like a vacuum leak.
i have recently replaced all vacuum lines, t's, y's, etc...and that helped fix some other O2 issues i had, leaks, etc..
so not sure whats going on. im looking into with Eric at TT if i can tune my 60 ft's better with his chip or its an actual mechanical failure like trans or too small exhaust...dunno...either way im happy with crappy 60ft and stll getting into 7's. 1/8 mile.:biggrin:
so not sure whats going on. im looking into with Eric at TT if i can tune my 60 ft's better with his chip or its an actual mechanical failure like trans or too small exhaust...dunno...either way im happy with crappy 60ft and stll getting into 7's. 1/8 mile.:biggrin:
