Advantages to bigger turbo on pump gas?

[GNVAIR]

Addendum to some of the previous remarks:
From camshaft theory that goes for any engine...
Back in the good old days, guys realized that changing camshaft duration could change the power band and help to increase power. The down side was always a loss of cylinder pressure.
To make up for it, they would increase the compression ratio.
One of the biggest mistakes I remember watching guys do was to take a stock, low compression engine and add a long duration cam to it. The car would be an utter dog with no power. The main reason was the fact that the long duration cam kept the valves open longer and decreased cylinder pressure.
Then there were the guys that heard the romantic benefits of 11:1 compression or 12:1 compression.
They would rebuild their 350 Chevy with those pop up pistons PAW and others advertised and then they would install a stock or very short duration cam. The result was an engine that made way too much cylinder pressure and would ping itself to death on pump gas.
A properly chosen combo of parts would give satisfactory performance on a given octane of fuel.
I have a friend who was quite adept at this and built himself an 11:1 compression 302 Ford with a fairly long duration cam that he tuned to run on 87 octane. The thing was an animal that would go 12.60's @112 on the radials. The 2 key factors were the aluminum heads and the camshaft he picked out.
Manufacturers have know for years the benefit of aluminum.
Besides the weight savings, it helps pull heat out of the combustion chamber and it allows running more advance. I really do think they are beneficial on a Buick V6 as they would be on any other engine.
I also think that the pipe dreams of running ridiculous amounts of boost on pump gas is achievable if you take into consideration the camshaft theory I posed. You can take a long duration cam and kill your cylinder pressure and make up for it with boost.
But the fact also remains that it IS cylinder pressure that makes power. To me, it is just a matter of how much power you want to make. I personally am building a mild engine that I plan on running fairly high boost on pump gas and alky. Yes, I know its a gamble.......then again just about anything you do with these cars is a gamble. But it is a risk I am willing to take.
Ok, off my box now.

 

[Joe 1320]

Engines are nothing more than air pumps. The more flow (not pressure) in and out, the more power. IMHO, there is more gain to be made in the intercooler effeciency, intake flow, heads and exhaust than simple turbo size and flow. If you can't get the air in and out of the engine, more force won't make it happen.

 

[RealFastV6]

How many people have posted here with data to support what I said? If you think a puny stock turbo is efficient at 19psi... I'll send you at my expense a 2" silicone hose thats been drilled out for your MAT sensor to go between the stock intercooler and stock turbo. Log MAT, BOOST, and A/F with TurboLink or the SpeedPro Software, and post the results.

(Your MAT sensor runs out at 250 though I think right? In which case it probably wont read high enough for the stock turbo at 18psi).

Whos in?

 

[The Radius Kid]

Interesting post Lee.The 218 seems to come on about 300-3200 rpm and pulls like an animal there to 5000+.The aluminum heads do of course reduce detonation tendencies,however they still need the bigger turbo to do the dirty.I still don't think a stock turbo can move the kind of air mass it will take to produce that H/P level.Feel free to mount the soapbox any time.At least you're thinking when you talk.
Now the 218 becomes "active" or efficient at a higher rpm.
Most of the cams available[<208 duration],tend to have better low end characteristics,with the turbo carrying the power in the higher rpm's.Lonnie Diers posted about this on another thread a while back.He saw successively better times and higher mph's as the cam durations got longer.
Could it be that the longer durations got the Intake/Exhaust interface or event moving more efficiently,scaveging the cylinders better?This would lower residual heat in the cylinders and left over exhaust gases that would hurt power production because of residual exhaust contamination of the incoming intake charge.This would tend to put you closer to the "Crossover Point" of the turbo/engine operation.
Explaination[for those reading who don't know]:Crossover Point-the point at which exhaust back pressure equals intake inlet pressure,Effectively Allowing 100% Scavenging.Or something along those lines.
Maybe JD Estill can chime in here.
You around JD?

 

[azgn]

whatever happened to the original question here? The fellow wants to know if a turbo upgrade will help him on pump gas....he didn't mention a thing about some exotic combo of GN1's, long duration cams, big ass front mounts, etc

I still maintain when using pump gas, money will be better spent reducing knock potential (alky) rather than upgrading the turbo....

of course, building an entire combo around a certain fuel will definitely add to the performance potential.....that same combo will always run better on race gas (or higher octane/lower charge temp) when tuned for the different fuel


I am impressed with the power some guys seem to be making on pump gas.....we can only get 91 octane oxygenated crap here...I suspect some good 94 octane stuff would help a bunch!

 

[GNVAIR]

My point on the cylinder pressure, as others was to point that the amount of octane required is solely dependent on the entire combo of parts. IMHO opinion, there is no benefit to buying a bigger, larger, prettier, turbo and running it at a lower boost level IF you dont have the parts to back it up. By doing so, you are pissing in the wind to be quite blunt. I am sure there are a few people that have gone very fast on pump gas, but they have an exclusive and elusive combo of parts that no one as of yet has posted or verified.

 

[strikeeagle]

Well Woody, I can tell you Sunoco 94 sux since they started dosing it with ethanol.

Yes, we've got to get the recipes for these ultraquick cars running minimal parts and 92 octane documented because once they are, I'm going to pull all of the (apparently) stupid stuff (e.g. 52, V-2, 009's, 9/11, C16) off my GN and see if I can make it go faster...

 

[fubar2.5]

Without going into a lot of rhetoric at this time I think some of you guys are looking at this backwards.I don't do things to my car to make the boost guage go higher I try to make it go lower because the guage is reading what is NOT going through the engine so anything you do to make it more efficient down stream is a good thing.
As far as a big turbo making more power yes it will up to a te45a or t64e Street turbo for the same reason an upgraded intercooler works.
BTW I like the bumblebee theory the ark theory and the pyramids_It can't be done but there they are.