Safe boost level on 93 with 49?

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Point is when your limited on octane you get creative with the tuning.
Example running it richer affords more boost, doesn't mean it makes more power.
Typical tuning is start on low timing and adjust your air fuel to optimize power. From there add boost, add timing, adjust air fuel and watch for knock. Encounter knock then play with the variables.. Buy once you start getting knock the bulk of the power you where going to make is made already.
Seat of the pants tuning to watch a needle arbitrarily go up is just that.


Good stuff. I still keep mine around 15-18psi in the Winter w/out alky but I have to take timing out to even run that. And I just have the 93 timing in the my chip and I run a CAS V4. I wouldn't try to run it all out with low timing and high boost. I just do what I have to do to eliminate knock. I'm sure I could add timing in the warmer months when I do spray and get a few ponies out of it, but I just leave the 93 timing tables set and run as much boost as me TE44 can make. My heavy car with my heavy rear in it goes 120 in 1320 so I figure I'll leave those last 20rwhp on the line as my margin. At least my local lets me slide to 11.0 now that NHRA made that rule about going 10.99 or slower w/out a cage but it's supposed to be in a 2005 or newer car. The 11.49 or slower previous cutoff is what kept me from searching for more hp anyway. I'll finish the new motor someday THEN go get kicked off for good and I'll have to start the whole tuning process all over again. Why do we do this?
 
Awesome info. Ive always been curious as to does a Turbo Regal make more power with low timing/more boost or vice versa? and I guess I am pretty limited as to what I can do without a wideband huh?
 
Point is when your limited on octane you get creative with the tuning.
Example running it richer affords more boost, doesn't mean it makes more power.
Typical tuning is start on low timing and adjust your air fuel to optimize power. From there add boost, add timing, adjust air fuel and watch for knock. Encounter knock then play with the variables.. Buy once you start getting knock the bulk of the power you where going to make is made already.
Seat of the pants tuning to watch a needle arbitrarily go up is just that.
I'm actually a bit on the lean side. Mt TT chip is 20/18 and I get no knock unless I'm well over a 100 mph. 2.1 is the highest KR recorded on my scanmaster. The only adverse affect so far is burning the tires off when the boost hits. My car gets squirrely and almost sideways at times. I'm about to see if some wider tires will help with that issue.
 
Awesome info. Ive always been curious as to does a Turbo Regal make more power with low timing/more boost or vice versa? and I guess I am pretty limited as to what I can do without a wideband huh?
Not that I know but I remember reading here that the rule of thumb is smaller turbos, stock/49/44 like more boost less timing .. Larger turbos like more timing less boost .. Something like that
 
I'm actually a bit on the lean side. Mt TT chip is 20/18 and I get no knock unless I'm well over a 100 mph. 2.1 is the highest KR recorded on my scanmaster. The only adverse affect so far is burning the tires off when the boost hits. My car gets squirrely and almost sideways at times. I'm about to see if some wider tires will help with that issue.


HR or Hellwig bar will keep it straight...
 
It seems like most DOHC 4 bangers don't run a lot of timing. I don't think they need as much with better combustion chambers and a more centered plug. It takes a little longer to get things lit in our engines! My car feels better with more boost and less timing so that's how I run it in the Winter when I turn the alky off.

Seems to me like timing is super important and not sure enough of us fully understand just why (me for one).
Joel
 
Seems to me like timing is super important and not sure enough of us fully understand just why (me for one).
Joel


Essentially you need to light the mixture before top dead center so the mixture ignites and starts to make real pressure to force the piston down right after TDC, about 10*. How big the bore is, placement of the plug, temps in the chamber, timing of the intake and exhaust valve events and overlap, and NUMEROUS other things I'm not mentioning all have an effect on overall cylinder pressure and best mean torque. More timing doesn't make more power all the time, less timing doesn't always take power away, etc. Finding the magic combo for your combo and engine is the trick. That's why getting a lot of advice here is a good start, but you won't know what is best for your or any car until you start testing it at the track or some other controlled environment. This is why Jason White can go 8's on a 109 block at 150+mph and others struggle. He's found the combo that produces mass flow, creates best mean torque over a broad rpm band, and he's figured out the chassis pretty well too apparently, but he didn't get there by not testing and recording data for HIS car and not just what others told him would and wouldn't work.

The journey is the best part. As far making power though, and engine is an air pump, the more you can flow through it in any given amount of time is what will limit your hp. When you flow a certain amount of air, you need exactly the right amount of fuel to light the fire that produces the most efficient combustion under that certain operating condition. The fire needs to be lit soon enough to offer efficient combustion on downward thrust on the piston but not too soon that cylinder pressure gets too high before piston reaches TDC and thus causes knock. Again numerous other factors affect the details of this operation but just imagine the piston operation in slow motion. This is why race gas needs more timing, it's harder to light and takes longer to get going.
 
Here's a good one showing the spark plug lighting early (advance) and how long it takes the mixture to really get going.

 
I guess I have figured out the magic combo for my car. These engines are so picky what works for me most likely won't work for someone else.
 
I guess I have figured out the magic combo for my car. These engines are so picky what works for me most likely won't work for someone else.

where's the timeslip

your sig
"87 T daily driving 20lbs of boost on pump gas 0 knock, TA-60, 50lb inj, RJC Power Plate, boost controller and biggie oil filter, PTE slic, PTE 70mm plenum, Accufab 70mm tb, Tin Man cold air, TT 5.7 chip, Casper's hot wired Walbro 340, Casper's volt booster, Hooker cat back, BGC 3" downpipe and elbow, Bilstein shocks, Scanmaster 2.1, AEM WB02.
"

you have a huge SLIC , power plate and probably running 17 degrees ..no magic there
short bursts are one thing ..will the tune hold for 1/4mile, hot day , back to back pulls

op has higher compression pistons , cam and a stock IC , as they say your results may vary but one has to expect that his combo (this is his thread) wont be able to push 93 as far as your combo

murphster runs alky and 93 but on his street car he tried to see (for shits and giggle) how far he could go on just 93
with champ irons, diamond pistons, 206 roller, 60 turbo and a cottons FMIC ...the no knock tune as i recall was 20psi at 15 degrees for a 1/4 mile pass at 11.5
 
No the car is not proven in the 1/4 mile or been ran at a track
It's runs daily in 100+ north Texas temps
I have ran sustained 20 psi runs (street drag racing) and not just bursts
Tune has held for 6 months
Timing dunno TT chip 5.7 with 20/18 timing
 
Essentially you need to light the mixture before top dead center so the mixture ignites and starts to make real pressure to force the piston down right after TDC, about 10*. How big the bore is, placement of the plug, temps in the chamber, timing of the intake and exhaust valve events and overlap, and NUMEROUS other things I'm not mentioning all have an effect on overall cylinder pressure and best mean torque. More timing doesn't make more power all the time, less timing doesn't always take power away, etc. Finding the magic combo for your combo and engine is the trick. That's why getting a lot of advice here is a good start, but you won't know what is best for your or any car until you start testing it at the track or some other controlled environment. This is why Jason White can go 8's on a 109 block at 150+mph and others struggle. He's found the combo that produces mass flow, creates best mean torque over a broad rpm band, and he's figured out the chassis pretty well too apparently, but he didn't get there by not testing and recording data for HIS car and not just what others told him would and wouldn't work.

The journey is the best part. As far making power though, and engine is an air pump, the more you can flow through it in any given amount of time is what will limit your hp. When you flow a certain amount of air, you need exactly the right amount of fuel to light the fire that produces the most efficient combustion under that certain operating condition. The fire needs to be lit soon enough to offer efficient combustion on downward thrust on the piston but not too soon that cylinder pressure gets too high before piston reaches TDC and thus causes knock. Again numerous other factors affect the details of this operation but just imagine the piston operation in slow motion. This is why race gas needs more timing, it's harder to light and takes longer to get going.

Funny we4mMateo, where you at the track last night? A turbo-T guy was there and was working through some kinks in his 11 second plus / minus T. He mentioned that he was running some race fuel last night and felt it had changed things and the car was not performing as well as he hoped, I wonder if he took timing into account?
Joel
 
Funny we4mMateo, where you at the track last night? A turbo-T guy was there and was working through some kinks in his 11 second plus / minus T. He mentioned that he was running some race fuel last night and felt it had changed things and the car was not performing as well as he hoped, I wonder if he took timing into account?
Joel


I wish I was at the track last night! I don't mix in race gas into my tune. I'm a straight pump and alcoholic!
 
Variables are all over this one.
Aftermarket Boost gauge accuracy... Lines leaking? whats the MAP showing? Most cars have a discrepancy between the two.
Timing.... Low or high
Weather... cold or hot
Fuel.. lean or rich
Combo.... look at what I just wrote.
The general consensus is 93 octane, low timing, bla bla... is around 17 psi with a good running GN.
Some claim higher and some claim lower. Fact is... Too many variables.
I highly recommend getting your drink on at ALKYCONTROL!!!
 
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