12-06-2002, 10:27 PM
Quote:Originally posted by Ross L:Actually, it BLOWS
5 psi sucks! There's my contribution,,,
12-06-2002, 11:08 PM
I agree that we need to leave the word boost out of this. There comes a point where the T3 no longer is able to efficiently produce the cfm necessary to supply a higher horsepower engine. The point is, most (probably > 70%) of those import tuners do not utilize the airflow that a T3 can effeciently supply. What is the point of adding a larger wheel and housing if you do not need the extra airflow they can produce? I would love to understand how putting a larger wheel on a turbo will not cause more lag, all things being equal. To me, it is like 2 identical cars, one with 4.56 rear and the other with 2.56 rear...the 4.56 takes less torque to get started, but runs out of steam earlier. Which gear you choose depends on your needs, not what sounds best or is the "in" gear. Is a hybrid capable of producing more power...definitely. My point is if you do not even come close to needing the extra airflow, you are hurting yourself more than you are helping.
Sorry for the rant...I just can't understand the purchase of a hybrid to produce 200 or less hp. At some point, bigger wheels have to cause more harm than good. If not, maybe I really am confused.
Galen
Sorry for the rant...I just can't understand the purchase of a hybrid to produce 200 or less hp. At some point, bigger wheels have to cause more harm than good. If not, maybe I really am confused.
Galen
12-07-2002, 12:18 AM
B16 or B18 or B20 with a 16 valve V-Tec can flow a lot of air. A hybrid is perfect for that application. More flow at the low rpm's wich contributes big time with higher compression. But has to be limited at about 9pounds with intercooler. Compression ratio is the effiecincy of the motor to turn kinetic energy to machanical energy. Words from the insider... using double factory headgaskets are working great.
12-07-2002, 04:17 PM
It seems this has gotten way off the subject :offtopic: . Correct me if Im wrong but a hybrid is merely a T3 exhaust housing with a T4 inlet housing. The benefit is obviously the faster spool up than a T4 with the ability to flow more air than a T3.
Now on the subject of a larger turbo flowing more air at a given psi over a smaller one on the same engine. This does not compute. Boost is directly indicative to a restriction in the intake and doesnt really have much to do with CFM. You may benefit from a larger compressor if the smaller one in question is near its efficiency peak. But this would also come with the afformentioned slower spool time.
On the subject of higher compression. The higher your compression the more you are going to benefit from extra airflow. The downside to this is detination and difficulty tuning. You can run 11 or 12:1 with 15-20 psi of boost but you better have all your cards right. Top fuel and funny car engines run huge amounts of boost and have incredible amounts of compression.
But in the real world of stock electronics or even limitations on ability to tune aftermarket electronics, less efficient combustion chambers and such this just isnt possible for most. So most tend to take the easier road and run less compression to take advantage of more combustible oxygen.
Now on the subject of a larger turbo flowing more air at a given psi over a smaller one on the same engine. This does not compute. Boost is directly indicative to a restriction in the intake and doesnt really have much to do with CFM. You may benefit from a larger compressor if the smaller one in question is near its efficiency peak. But this would also come with the afformentioned slower spool time.
On the subject of higher compression. The higher your compression the more you are going to benefit from extra airflow. The downside to this is detination and difficulty tuning. You can run 11 or 12:1 with 15-20 psi of boost but you better have all your cards right. Top fuel and funny car engines run huge amounts of boost and have incredible amounts of compression.
But in the real world of stock electronics or even limitations on ability to tune aftermarket electronics, less efficient combustion chambers and such this just isnt possible for most. So most tend to take the easier road and run less compression to take advantage of more combustible oxygen.
89 Mustang LX notch, 87 TC engine, 5 spd, LA3, Big VAM, Front mount, 3" exhaust, 8.8 w/ 3.73 gears, gutted with recaros.
91 LX hatch 5.0 turbo
91 LX hatch 5.0 turbo
12-07-2002, 04:35 PM
I did want to hit on boost with variable valve timing. This concept interests me. Would it be safe to assume that when the engine is in lower rpms and the airflow velocity and heat levels are higher than say a regular engine with the same airflow capabilities spool up time is quicker? And then once it gets up on its cams this boost is sustained by the more airflow and heat that would be generated at the higher rpms?
Thus the boost level stays close to the same level but airflow is greatly increased. I would think that in some cases the boost level could even drop from a substantial increase in the airflow capabilities of the engine once it does get up on its cams.
This isnt how it worked on the 96 cobra I put a supercharger on. When the secondary ports in the intake {IMCAs} open up the boost didnt seem to drop or even slow down. But in some way it must have, if even just a small amount. :dunno:
Thus the boost level stays close to the same level but airflow is greatly increased. I would think that in some cases the boost level could even drop from a substantial increase in the airflow capabilities of the engine once it does get up on its cams.
This isnt how it worked on the 96 cobra I put a supercharger on. When the secondary ports in the intake {IMCAs} open up the boost didnt seem to drop or even slow down. But in some way it must have, if even just a small amount. :dunno:
89 Mustang LX notch, 87 TC engine, 5 spd, LA3, Big VAM, Front mount, 3" exhaust, 8.8 w/ 3.73 gears, gutted with recaros.
91 LX hatch 5.0 turbo
91 LX hatch 5.0 turbo
12-07-2002, 04:49 PM
Thats what I thought.......Ya a t4 can flow mroe air....but....if they both make 5 psi..something is giving back pressure to make a measurable pressure...right? so....if a t4 is pushing alot of air..and is pushing ar into this engine....and..the engine can take all of it obviously...then you get back pressure...or boost? correct?...now if a t-3...its spinning faster to achieve the same volume...but...the backpressure in the intake...still leaves us with 5 psi.....right...so...the t-3 has to spin faster..to make the same 5spi......but...which one gets there faster? Thats how I'm seeing it...because...you dont have boost if you take your turbo to throttle body ose of do you? you jsut have cfm.....thats how I see it...I'm cnfident I'm right but who knows? :dunno: 
WTT 94 V8 T5 trans for 87-93 V8 T5
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12-07-2002, 05:01 PM
this might be redundant but vtech engines pass alot of air so the reason for a big turbo is not psi its overall air volume,5 psi in a 1 cube box is the same as 5 psi in a 10 cube box but it takes more flow to fill a 10 cube box.
who cares about hondas anyway.
who cares about hondas anyway.
12-08-2002, 03:37 AM
what im saying...is that the t3 will jsut spool that much higher..till it flows that much air..itll still amke the same boost....flow the same amont of air..jsut spin faster...and spool faster right? this of course asuming the engine isnt out of the turbos effiecny range.....and im SURE its not.....oh well..who cares.....
WTT 94 V8 T5 trans for 87-93 V8 T5
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