3800 lets talk about boost

[xierxior]

I've been walking on the wild side and if you read my sig you should have a better idea of whats going on

lets say you used a fuel that had a very high octane rating 100+ and lets say you threw a 3.2" pulley on a car that didn't have enough supporting mods and lets say it hit 15psi and 18 degrees WOT timing and didn't knock... lets also say this car waxed a subaru sti.

now one must ponder.. exactly how much boost can the 3.8 take (if it doesn't knock) ? *looks at 3.1" h34r:

Click to read more...

 

[phat_ridegt]

well boost is boost regardless if its turbo, m90, or csc...there are people running 20+ on stock motors...i think zoom ran 30 on his twin charged car...that was supposed to be a stock bottom end...id say if there's no knock, i dont think you will ever get TOO much the motor cnt handle with a gen 3

 

[xierxior]

alright I'm going to assume there's no power above 13psi tho on a m90 hmm? from what I read air starts to push back up and tries to get past the rotors?

 

[imported_1fastGTP]

thats why you start to PnP the S/C along with the TB to get more out of it.

 

[Sinister Drag Designs]

Originally posted by 1fastGTP@May 23 2006, 11:16 PM
thats why you start to PnP the S/C along with the TB to get more out of it.

[snapback]127260[/snapback]​

well you wont get more boost form those justa slightly cooler charge
15-16psi-LIM gaskets blow....20-21psi head gaskets blow

tho ron vogal is getting like 15-16.5 psi out of his setup, and his stuff by todays standards is a little less efficant(of course ron makes it work like a dream)
the map sensor only goes to 14.7 tho also, i run 14 psi daily and 15-16 on the highway if i feel frisky,
that is high boost for your mods, i was only at like 12-12.5 with 3.25 and 17* of timing.

above 13 psi i would get some valve train work to open up some airflow

 

[xierxior]

eh it has nothing to do with the motor my catalyc is clogged.. you can actually go well over 20psi its called a three bar map sensor

 

[Sinister Drag Designs]

im aware of the 3bar i will getting mine soon i hope, dont like bouncing off the limit of mine.

yeah i would get a high-flow cat(no cat is so annoying)

 

[M@]

Originally posted by phat_ridegt@May 23 2006, 09:26 PM
well boost is boost regardless if its turbo, m90, or csc...there are people running 20+ on stock motors...i think zoom ran 30 on his twin charged car...that was supposed to be a stock bottom end...id say if there's no knock, i dont think you will ever get TOO much the motor cnt handle with a gen 3

[snapback]127248[/snapback]​

BAD INFO POLICE

boost is not boost regardless. 10 psi from a G3 M90 is in NO way equivalent to 10 psi from a T70. The turbo or CSC will have a MUCH higher CFM at a given boost, which results in a MUCH higher air/fuel density in the conbustion chamber, resulting in higher cylinder pressures. On the same note, high boost from an M90 will not be a very dense fluid, but will have an extremely low viscoscity, which means it is MUCH easier for the working fluid to find a weakness, and a way out, usually head gaskets. This is why you see fewer high boost turbo cars blowing HG's while M90s on much lower boost blow them constantly.

BTW, the twin charged car DID blow the head gaskets while it was running 9s, and that was WITH 2 extra head bolts they added to try to prevent that from happening. To their credit however, it did hold up better with those extra bolts than without....MUCH better in fact.

Anywho, if you are knock free, you are lilkely ok at your mod level. You really don't have the mods to break parts due to cylinder pressure alone, so I don't think it's a worry, but its really probably not making hardly any power over the bigger pulley, just a little more torque. The only issue is that if you DID run into knock with that much boost, you have substantial cylinder pressure to pop pistons on 1-2* of KR, not the safest setup, ya know?

MT

 

[Sinister Drag Designs]

hes pretty much dead on...

 

[sr71_rgl]

Originally posted by phat_ridegt@May 23 2006, 08:26 PM
well boost is boost regardless if its turbo, m90, or csc...

[snapback]127248[/snapback]​

Totally wrong...the boost coming from a non intercooled M90 is A LOT hotter than boost coming from a CSC or turbo.

 

[phat_ridegt]

but if he can run 15psi from an m90, non intercooled with 0kr, (not likely) it could be considered 'safe' for the motor....i cant speak for turbo's or csc's, but out of an m90, seems like an ic'd 13psi is the way to go...at least on my end

 

[Sinister Drag Designs]

pushing and m90 that far is chopping its efficency in half, switch power- adders if you want higher boost, lots of people run decent times pushing it to the limits, but then how long are you letting the car cool after?how long will the blower last spinning that much... with turbos and 2k novis, 15psi is just where you start to have some fun

 

[phat_ridegt]

x2 agreed

but it CAN be done with an m90. cool time should be around an hour...at the track, for both the trans and the motor...

 

[imported_Ron Vogel]

Boost only helps to a point, after that it's just a waste of energy. If you can't get the air in/out, there's no point to it. You can create tons of boost in a sealed container...hell, my aircompressor can develop over 100 psi, but it's not making more than 2hp.

A cooler/denser charge has more potential for explosive force, but even at that you can only do so much with it. Doing dyno sims a lot, I found the difference between 15 and 45 psi of boost only increases power by about 50hp. Not really worth the time. If you can do 10 psi with stratsipheric (sp?) static compression...well that makes tons of power.

Stock heads+15:1+15psi+260 degrees @.050lift=800-900ish HP. No one makes a cam tat big yet as far as I know, and the aggressive ramp rates needed call for triple springs and solid lifters, with stud girdles or shaft rockers, but it can be done. I found a few combos that should check out around 1000hp.

Just have to find a good way to put down more than 450-500hp to the ground at this point.

 

[M@]

Originally posted by Ron Vogel@May 27 2006, 07:09 PM
Boost only helps to a point, after that it's just a waste of energy. If you can't get the air in/out, there's no point to it. You can create tons of boost in a sealed container...hell, my aircompressor can develop over 100 psi, but it's not making more than 2hp.

A cooler/denser charge has more potential for explosive force, but even at that you can only do so much with it. Doing dyno sims a lot, I found the difference between 15 and 45 psi of boost only increases power by about 50hp. Not really worth the time. If you can do 10 psi with stratsipheric (sp?) static compression...well that makes tons of power.

Stock heads+15:1+15psi+260 degrees @.050lift=800-900ish HP. No one makes a cam tat big yet as far as I know, and the aggressive ramp rates needed call for triple springs and solid lifters, with stud girdles or shaft rockers, but it can be done. I found a few combos that should check out around 1000hp.

Just have to find a good way to put down more than 450-500hp to the ground at this point.

[snapback]127720[/snapback]​

You don't sleep much, do you Ron?? :lolsign: