What makes more power, 1 degree of timing or 1 PSI of boost?

[86BGN]

If you ran 24 degrees of timing at 22 PSI would it make more power than say 22 degrees of timing at 24 PSI?

 

[VadersV6]

High boost and high timing make the most power. But your question leaves other things on the table. Its really not an easy question to answer since there are so many variables. If you run high timing and you're detonating, youre not making a whole lot of power. Run as much boost and timing as you can without detonation. If you want a stronger low end curve and good gas mileage, run a little higher compression, cam with little overlap, lower boost and more timing, but for more overall power, more boost and less timing. I prefer to run alky injection and run alot of both. I can run 27 degrees of timing on 23psi with alky. When I tell mustang guys this, they almost **** their pants. With high compression (late model stangs have 10:1), you're forced to run very low timing. Its typical for them to run 12-14 degrees total timing on only 12psi or so. These "archaic" old technology engines are awesome for what they ar. I dont know anywhere else that you can throw so much boost and timing on a stock bottom and, and have it hold together...well, maybe a supra, but I dont have 50,000 bucks laying around.

 

[NM Tom]

All engines are different. Some motors seem to handle timing better than others. I'm currently running 28* in 1,2 and 25* in 3,4 with 26# boost with no knock. I run 101 unleaded all the time. I would say to put your turbo in it's max efficiency range and then start turning up the timing till you see knock. But to answer your question, it all depends on your combo and tune. Clear as mud!

 

[Marc87GN]

High boost and high timing make the most power. But your question leaves other things on the table. Its really not an easy question to answer since there are so many variables. If you run high timing and you're detonating, youre not making a whole lot of power. Run as much boost and timing as you can without detonation. If you want a stronger low end curve and good gas mileage, run a little higher compression, cam with little overlap, lower boost and more timing, but for more overall power, more boost and less timing. I prefer to run alky injection and run alot of both. I can run 27 degrees of timing on 23psi with alky. When I tell mustang guys this, they almost **** their pants. With high compression (late model stangs have 10:1), you're forced to run very low timing. Its typical for them to run 12-14 degrees total timing on only 12psi or so. These "archaic" old technology engines are awesome for what they ar. I dont know anywhere else that you can throw so much boost and timing on a stock bottom and, and have it hold together...well, maybe a supra, but I dont have 50,000 bucks laying around.

Before I bought my GN, I owned 99 GT that had a big ITS T-76 under the hood for 3 years. The CR ratios are actually 9:1(I think 9.4:1 for 01+), which was great for FI & the Cobras had 9.85:1. you might be thinking of LS1s with the the 10:1 CR, but they make 450-500 rwhp at 8 psi. The great thing was, I didnt need to run much boost at all to make the car fly. 12-13 psi and I trapped 121 mph with an automatic as well. 17 psi and it ran 10s all summer long this was all still on pump gas mind you with no alky. The other advantage to cubes, this was all done on a 3200 stall converter. Full boost by 3400 rpms. I only ran 17 degrees total timing, but the car ran 10s so who really cared.

From a lowend standpoint, my GN seems to launch harder than I would have ever thought at such heavy weight. My 99 GT loved low timing and higher boost, but having the cubes allowed for a bigger turbo with no lag issues to deal with or run 3800 stall to spool it. Turbo buicks I'm still learning, but I have a fairly strong background on 4.6 mustangs and how to make them fly.

 

[Marc87GN]

If you ran 24 degrees of timing at 22 PSI would it make more power than say 22 degrees of timing at 24 PSI?

Sorry for the other post. It's an interesting question and like what was already said, it depends on alot of factors and your setup. I'm able to run 21 psi on 93 Octane with zero knock at 17 degrees of timing. Of course, I would be faster with much more timing, but it's not really possible on straight 93 octane without knock. So I wonder if the car would be faster at 16 psi and 23 + degrees of timing?

 

[buickturbo-t]

For some reason my car hates timing, I have to take it all out or I get tones of KR. My Dads car on the other hand loves it, he runs lots of timing and boost. I was always told that one pound of boost equals 10 HP. I don't think you can see that with one degree of timing.

 

[VadersV6]

Sorry for the other post. It's an interesting question and like what was already said, it depends on alot of factors and your setup. I'm able to run 21 psi on 93 Octane with zero knock at 17 degrees of timing. Of course, I would be faster with much more timing, but it's not really possible on straight 93 octane without knock. So I wonder if the car would be faster at 16 psi and 23 + degrees of timing?

Given they were modular motors, I thought the GT's also had 9.85 like my cobra. Thats what i meant by 10:1..I just rounded it off. I made 500rwhp with my 99 cobra with 11.5psi and an intercooled Novi 1000 on only 14 degrees timing. Well, the 500rwhp thing was a guess. I made 483rwhp with an 80mm LMAF, and I later went to a 90LMAF and an AFM power pipe. Id say 500 was very possible. I had a mail order JMS chip, and I made 470 with that, and my A/F was at 10.5:1. I went to Danny Swanson and paid him big $$$ to lose 22rwhp. I walked in with 470 on a safe tune and walked out 500 bucks poorer and with 448rwhp. 500 bucks for a crappy tune. (he said he did good and fixed my A/F. It was safe before) I was pretty pissed that he didnt even offer a discount after making me lose power for no justifiable reason. Sean Ellis tuned mine for free (political thing) , and he got me the 483 number. Danny also tuned Lou Czarnota's lightning. I think he gained 10rwhp for over 500 bucks. I probably could have run more timing but I didnt want to push it, given the car was my daily driver and I didnt have the kind of money it takes to build a cobra shortblock.
We probably used to see each other on corral, and maybe blueovalnews. My handle over there was 32VHEMIJR.

 

[Mike Licht]

it is not a complete question unless you also figure octane in, the answer on 89 octane is different than on 116
Mike

 

[blackstallion]

You must also consider which size turbo you have i know that for sure to o fast with a stock turbo you need high timing its all done by 22 lbs.

 

[86BGN]

it is not a complete question unless you also figure octane in, the answer on 89 octane is different than on 116
Mike

Thanks for all of the replies! Say you take all of the variables out like knock, octane and turbo efficiency. There is no strait answer? Say I could run either as high as I want (within reason), which would you benefit more from? Like Buickturbo-T posted, I have always heard that 1 PSI of boost is worth 10 HP. That makes me wonder why guys are running so much timing and not more boost. Unless the turbo they are running is at its peak anyway?

 

[Razor]

Boost is more forgiving than timing. If the compressor is in its efficiency range, I would always add more boost before I added timing. If adding boost the motor stopped picking up..then at that point add timing.

You'll be faster at 25 PSI boost and 15 degree's timing than 15 PSI and 25 degree's timing.

As far as splitting hairs over 1 PSI/1 degree... fugedaboutit.

 

[Marc87GN]

[QUOTE My handle over there was 32VHEMIJR.[/QUOTE]

That handle looks familiar and I'm sure I have seen it before. I was Marc99GT or Turbo99GT. I had the silver turbo automatic that MM&FF was kind enough to put on the cover and in the 04/02 issue because I ran 10s on the bone stock longblock. Job Spetter Jr. tuned the DFI and the car would fly on pump gas. I did end up breaking 3 pistons after 6 months of abuse, but dropped a fully built engine in 6 months before I sold it.

Funny how we both ended up here. I think these cars are awesome and remember being 17 in my senior year(1988- damn I'm getting old) and my friends mother came to school to pick him up in a new 87 GN. The rest is history and I have wanted one ever since.

I definitely subscribe to the high boost low timing comments and as mentioned, having the right turbo is key with that approach. 21 psi from my PT6152 and no knock in 3rd gear at 17 degrees and the car feels real good especially when the converter(Raptor 9/12) locks.

 

[Louie L.]

We did some testing on a dyno with my car several years ago to test this theory.Boost will make more power than timing., it did in our case.The octane requirement has to be met no matter what.

 

[Mike Licht]

well then why don't we run -10 timing and 50 PSI?
Mike

 

[Ormand]

well then why don't we run -10 timing and 50 PSI?

Because it won't work? For a given engine/fuel combination, there will be a MAX boost that can be run without detonation. That boost will flow the most air/fuel through the engine, and will make the most power. If you did a graph of boost/timing/power, in 3D, there would be a kind of dome, where power was maxed out, and increasing boost or spark advance would cause detonation. Lowering boost or spark advance would lower power, and provide more margin against detonation. When you are near the top of the dome, lowering timing a little won't cost much power, but raising it will quickly cause things to break. Getting the max advance possible is risky- it's better to leave a couple of horsepower on the table than to run so close to the detonation point that any slip will cause a big "BOOM".
If you are ten psi away from the max, adding timing won't do much for you- not nearly as much as adding that boost. Getting the timing right for the boost helps to get the engine into its most efficient set up. Getting the max boost helps to get the most power.

 

[Marc87GN]

Because it won't work? For a given engine/fuel combination, there will be a MAX boost that can be run without detonation. That boost will flow the most air/fuel through the engine, and will make the most power. If you did a graph of boost/timing/power, in 3D, there would be a kind of dome, where power was maxed out, and increasing boost or spark advance would cause detonation. Lowering boost or spark advance would lower power, and provide more margin against detonation. When you are near the top of the dome, lowering timing a little won't cost much power, but raising it will quickly cause things to break. Getting the max advance possible is risky- it's better to leave a couple of horsepower on the table than to run so close to the detonation point that any slip will cause a big "BOOM".
If you are ten psi away from the max, adding timing won't do much for you- not nearly as much as adding that boost. Getting the timing right for the boost helps to get the engine into its most efficient set up. Getting the max boost helps to get the most power.

I think he was being facetious.

 

[John Wilde]

Ken Duttweiler uses conservative timing and moderate to crazy boost.
He has been dynoing these motors for around 20 years, so what does he know?

 

[VadersV6]

That handle looks familiar and I'm sure I have seen it before. I was Marc99GT or Turbo99GT. I had the silver turbo automatic that MM&FF was kind enough to put on the cover and in the 04/02 issue because I ran 10s on the bone stock longblock. Job Spetter Jr. tuned the DFI and the car would fly on pump gas. I did end up breaking 3 pistons after 6 months of abuse, but dropped a fully built engine in 6 months before I sold it.

Funny how we both ended up here. I think these cars are awesome and remember being 17 in my senior year(1988- damn I'm getting old) and my friends mother came to school to pick him up in a new 87 GN. The rest is history and I have wanted one ever since.

I definitely subscribe to the high boost low timing comments and as mentioned, having the right turbo is key with that approach. 21 psi from my PT6152 and no knock in 3rd gear at 17 degrees and the car feels real good especially when the converter(Raptor 9/12) locks.

That makes 2 of us who were 17 in 1988...yeah getting old sucks! In 86, my Godfather took me for a ride in his 86 turbo T that was all modded to hell by duttweiler (a friend of his). That car ruined me for life. he went on to a record setting N/A regal built by duttweiler, so he lost interest in the street car. he offered it to me for 5500 bucks, which was a steal considering the $5000 stereo, the entire drivetrain was built like crazy...aluminum heads and all that (whats funny was the stock fuel pump and injectors), and a very modified suspension...that car could handle better than any vette of the day. Too bad I didnt have 5500 bucks!

 

[John Wilde]

That makes 2 of us who were 17 in 1988...yeah getting old sucks! In 86, my Godfather took me for a ride in his 86 turbo T that was all modded to hell by duttweiler (a friend of his). That car ruined me for life. he went on to a record setting N/A regal built by duttweiler, so he lost interest in the street car. he offered it to me for 5500 bucks, which was a steal considering the $5000 stereo, the entire drivetrain was built like crazy...aluminum heads and all that (whats funny was the stock fuel pump and injectors), and a very modified suspension...that car could handle better than any vette of the day. Too bad I didnt have 5500 bucks!

This story is both cool and sucks at the same time.
You needed that car!