And the turbocharger doesn't use less energy, in fact it uses more.
I would like to hear the logic to this. being that a turbo utilizes some waste energy in the form of heat to opperate, that would lead me to believe that it is more efficient because the heat(along with exhaust pressure) is doing some useful work. whereas a supercharger is letting the heat go to atmosphere and turning the compressor with the engine's power alone.
notice I have said nothing about "free energy". yes a turbo does require power to operate, more then a supercharger though, I can't see that happening.
------------------ we're in desperate need of a little more religion to nurse your god-like point of view...
Going back to the original question, selection of pistons and camshaft would depend on whether you run it naturally aspirated or boosted. Once you make that determination, the rest of the puzzle pieces will start falling into place.
Originally posted by ericjon262: I would like to hear the logic to this. being that a turbo utilizes some waste energy in the form of heat to opperate, that would lead me to believe that it is more efficient because the heat(along with exhaust pressure) is doing some useful work. whereas a supercharger is letting the heat go to atmosphere and turning the compressor with the engine's power alone.
notice I have said nothing about "free energy". yes a turbo does require power to operate, more then a supercharger though, I can't see that happening.
I wasn't comparing it to a supercharger. I was saying when you decrease restriction, you increase flow, and the turbocharger then takes more energy to run. But it's efficiency doesn't change unless you move it off it's AE island. The engine will in all likelihood make more power, and increase more than the added exhaust restriction costs it, but it's efficiency doesn't change, and it's dillusional to think it operates like Louie says.
If you reduce intake restriction, it will actually take less energy to spool up the turbo. You'll also get more flow at any given boost level (or conversely, it will take less boost to achieve a certain amount of flow).
[This message has been edited by Blacktree (edited 01-20-2014).]
I wasn't comparing it to a supercharger. I was saying when you decrease restriction, you increase flow, and the turbocharger then takes more energy to run. But it's efficiency doesn't change unless you move it off it's AE island. The engine will in all likelihood make more power, and increase more than the added exhaust restriction costs it, but it's efficiency doesn't change, and it's dillusional to think it operates like Louie says.
not really, because the turbo is just a air pump, so if you decrease the restriction, you decrease the mount of force required to move the same amount of air, thus decreasing the energy required.
now if you're saying a turbo is a restriction in the exhaust that takes power to operate, then that would in fact be true.
Just search "Dennis LaGrua turbo". Would you like to purchase a rebuilt 3.4 dropout with a turbo and a 4T60? I might be going another route now that it's complete.
$1000+ just in parts to see 200hp ....maybe. No thanks. There are dyno tests on Youtube of people getting 327-335 HP and 397- 450 ft lbs of torque with the 3.4L . Look at the videos.
http://www.youtube.com/watch?v=C6UpoCnGPEY The last one is a video from Shaun Hammitt. If you can get passed the disparaging remarks Shaun makes in the video he makes some incredible horsepower and torque with his 3.4L. Like 367 RWHP and 456 ft lbs of torque.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Powerlog manifold, Northstar TB, LS1 MAF, 3" Flotech Afterburner Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 09-01-2012).]
"
OK just read this out of one of Dennis's threads.... am i missing something... those are great numbers and it was on stock internals. i don't doubt that the motor has a very short life ahead of it but bring it down to 250 rwhp and you have a SCREAMING fast fiero that should last if its driven moderately. I've had 800hp camaros and supras... so I'm not trying to get a 10sec fiero but anything in the 13's or 14's is still a fun ride for a street car.
I'm not claiming anything just thinking wow proof is in that video that it can be done. now just how to do it???? lol
$1000+ just in parts to see 200hp ....maybe. No thanks. There are dyno tests on Youtube of people getting 327-335 HP and 397- 450 ft lbs of torque with the 3.4L . Look at the videos.
http://www.youtube.com/watch?v=C6UpoCnGPEY The last one is a video from Shaun Hammitt. If you can get passed the disparaging remarks Shaun makes in the video he makes some incredible horsepower and torque with his 3.4L. Like 367 RWHP and 456 ft lbs of torque.
$1000+ just in parts to see 200hp ....maybe. No thanks. There are dyno tests on Youtube of people getting 327-335 HP and 397- 450 ft lbs of torque with the 3.4L . Look at the videos.
http://www.youtube.com/watch?v=C6UpoCnGPEY The last one is a video from Shaun Hammitt. If you can get passed the disparaging remarks Shaun makes in the video he makes some incredible horsepower and torque with his 3.4L. Like 367 RWHP and 456 ft lbs of torque.
looks to me like double the stock crank hp seems possible on 10psi seeing as how these dyno runs are more than that with hp readings at the wheels.
ok this car was supposed to be for my daughter thus the paint job.... she changed her mine as to what she wanted so i put a funner motor in it and had a little fun with it. remember I'm a newbie to wrenching so be nice lol
Please tell me this, if my turbo hits 10psi and holds steady almost instantly at wide open throttle and my boost gauge measures boost from the upper plenum how would a wider neck at the TB really make a difference?
If your top end is restrictive enough you could push 20 psi into the plenum but with an unrestrictive top end that same amount of air might be 10 psi instead. Higher boost creates more heat. Heat = bad. More prone to detonation and less efficient.
I added a turbo, 272 cam, custom chip, and larger injectors (Ford 19 lb IIRC) to mine and am quite happy with the result.
Nelson
what type of turbo setup are you running, and whats the numbers on boost? most are running about 8-12lbs with a stock setup. what is your opinion with the 272 being used with the turbo? depending on the turbo setup you have, I can imagine if you arent making boost at idle, everything should be fine with the 272's overlap.
not really, because the turbo is just a air pump, so if you decrease the restriction, you decrease the mount of force required to move the same amount of air, thus decreasing the energy required.
now if you're saying a turbo is a restriction in the exhaust that takes power to operate, then that would in fact be true.
You're right, if you're moving the same amount of air. But you're not. Decreasing the restriction means more flow at the same boost levels. And turbochargers are regulated by a set boost pressure via the waste gate. So you'd still be making 10psi, but your CFM would of course increase, thereby increasing energy required. But the added CFM will most certainly result in more power of course.
what type of turbo setup are you running, and whats the numbers on boost? most are running about 8-12lbs with a stock setup. what is your opinion with the 272 being used with the turbo? depending on the turbo setup you have, I can imagine if you arent making boost at idle, everything should be fine with the 272's overlap.
This was done about five years ago so I have to go back in the memory for some information wrt this build. I am making very little boost at idle speeds and my mechanical boost gauge reads somewhere around 7-8 psi at more normal rpm. The 272 has worked well for me and I am using a Mitsubishi turbo (GSP T3 KKR480 T480 TURBO RB25 RB25det SKYLINE SILVIA ) at this time. I really do not have very many photos of the build but have a couple of the completed installation if anyone is interested.
Nelson
[This message has been edited by hnthomps (edited 01-23-2014).]
thats awesome to hear thank you for sharing. do you have a build thread, pictures, videos???? anything
Most of what I have is final product photos and modifications to the engine made afterwards to correct some warmer air induction issues. I also have a custom fuel chip provided by Jeremy (Fiero Factory owner) that was necessary to correct the original running rich issue. This was originally a Dennis LaGrua "turbo" kit from a number of years ago and has been modified several times since then. Let me know if you want some specific photos and I may be able to help out.
Nelson
[This message has been edited by hnthomps (edited 01-23-2014).]
What exactly are you guys talking about "making boost at idol"? Your turbo is spooling up at idol?
Its because there are two guys using a 272 cam with a turbo. a 272 cam has valve overlap to help the 60* motors make more power at the higher rpm, because as we all know no matter what between a 2.8 and 3.4 they both fall flat on thier face after 5500rpm since the intake is so restrictive. BUT they are also using a turbo.
so I was wondering how the motors run at idle with the turbo, thinking that if they dont create any boost at idle would be understandable, because im imagining that if the turbo was making pressure, it would interfere with the idle since the cam has overlap.
Its because there are two guys using a 272 cam with a turbo. a 272 cam has valve overlap to help the 60* motors make more power at the higher rpm, because as we all know no matter what between a 2.8 and 3.4 they both fall flat on thier face after 5500rpm since the intake is so restrictive. BUT they are also using a turbo.
so I was wondering how the motors run at idle with the turbo, thinking that if they dont create any boost at idle would be understandable, because im imagining that if the turbo was making pressure, it would interfere with the idle since the cam has overlap.
Well, being I'm one of the 3.4 272 Turbo owners I can tell you that it idols steady at about 900 RPM's (in drive) and the VAC sits around 10.0 @ idol. And lastly, it still falls flat on its face at 5500 or so.
[This message has been edited by JCircs (edited 01-23-2014).]
Well, being I'm one of the 3.4 272 Turbo owners I can tell you that it idols steady at about 900 RPM's (in drive) and the VAC sits around 10.0 @ idol. And lastly, it still falls flat on its face at 5500 or so.
Dang...
well, at least we know that the turbo doesnt interefere enough at idle then.
If the turbo is spooling at idle, a) your blow-off/recirculating valve would be venting the boost, and b) that would mean that the turbo is WAAAYY too small for the engine and would be choking it most likely by low to mid-range rpms.
It's normal for a turbo to spin while the engine idles but it is definitely not normal for it to be producing boost.
The blow off valve is vacuum actuated, so no, it wouldn't. And if you could even find a turbo small enough that it made boost at idle, it would choke the engine as soon as you touched the throttle. Not mid rpm, but like 1400 if that. This entire thread sickens me.
The blow off valve is vacuum actuated, so no, it wouldn't. And if you could even find a turbo small enough that it made boost at idle, it would choke the engine as soon as you touched the throttle. Not mid rpm, but like 1400 if that. This entire thread sickens me.
wow Robert i couldn't disagree more. Not trying to attack your opinion but bro these kind of threads aren't just for the gurus to debate... this stuff offers great material for guys like me who are not inherently mechanically inclined to read and research for our own knowledge bank. I've learned a lot about that 3.4l motor from starting this thread and about turbos. I've also had some really nice guys send me pm's and offer some great advice along with some awesome links to builds and reading material.
anyway thats just my thoughts on threads like this... debate breeds ideas and solutions
The blow off valve is vacuum actuated, so no, it wouldn't. And if you could even find a turbo small enough that it made boost at idle, it would choke the engine as soon as you touched the throttle. Not mid rpm, but like 1400 if that. This entire thread sickens me.
Yes, it would (blow-off valve would vent). Anytime the throttle plate is closed, the plenum is under vacuum, which would actuate the BOV. I also have real world experience... we put a pre-TB supercharger on my friends truck and the BOV would always be whistling at idle (throttle closed). The sound was really annoying, but you get my point... SC pushing air, but vacuum in the plenum opening the BOV.
