Cold side removal to run N/A
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
When you beat him with the charge pipe off, then he will say "ok, now unplug 5 of your spark plug wires and let's see who's faster". It's never ending with those mustang guys. Then when you beat him while running with no turbo and only 3 cylinders firing.....he will just get pissed and take out the nearest crowd. I guess what I'm saying is, don't do it.
Makes perfect sense.
Really...what's the fun in making your own car slower, just to race a very slow car who might crash into you.
You can run a turbo car with the throttle body open to atmosphere. It will not hurt anything if it's a MAF tune (as long as the IAT sensor is reading actual intake temp). If it's speed density, then your fueling will be off as it will change the VE. Do not try this if it's speed density.
Yeah, this thread is pretty worthless.
Do not demod your setup just to race a guy who's pissy because you have more power than him.
If he moans because you're 'boosted', tell him to man up and put on a power adder or shut up.
Do not demod your setup just to race a guy who's pissy because you have more power than him.
If he moans because you're 'boosted', tell him to man up and put on a power adder or shut up.
the original premise of this thread is nonsense but it is interesting understanding what would happen when running with the cold side open to admosphere...so after reading the stuff in this thread that actually makes sense (freeflowing compressor side = increase in required power to drive compressor) would it not put a huge load on the engine and possibly damage it due to the exhaust backpressure/heat?
this is assuming you didn't hold the wastegate open since there isn't any boost pressure to open it.
or would it just be down on power even compared to na since you're essentially running a choked exhaust and using that power to move a bunch of air through the compressor as opposed to drive the rear wheels
i do agree the derp is strong though
this is assuming you didn't hold the wastegate open since there isn't any boost pressure to open it.
or would it just be down on power even compared to na since you're essentially running a choked exhaust and using that power to move a bunch of air through the compressor as opposed to drive the rear wheels
i do agree the derp is strong though
TECH Junkie
Joined: Jul 2015
Posts: 3,012
Likes: 48
the original premise of this thread is nonsense but it is interesting understanding what would happen when running with the cold side open to admosphere...so after reading the stuff in this thread that actually makes sense (freeflowing compressor side = increase in required power to drive compressor) would it not put a huge load on the engine and possibly damage it due to the exhaust backpressure/heat?
this is assuming you didn't hold the wastegate open since there isn't any boost pressure to open it.
or would it just be down on power even compared to na since you're essentially running a choked exhaust and using that power to move a bunch of air through the compressor as opposed to drive the rear wheels
i do agree the derp is strong though
this is assuming you didn't hold the wastegate open since there isn't any boost pressure to open it.
or would it just be down on power even compared to na since you're essentially running a choked exhaust and using that power to move a bunch of air through the compressor as opposed to drive the rear wheels
i do agree the derp is strong though
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So without the cold side you are getting none of the benefits of boost and all the drawbacks: crappy exhaust flow that is choked by a turbo. (Compared to a long tube header)
Correct. I've seen this done before to verify. Turbo lag without an end. The car will be slow as ****. Probably wouldn't even run a high 13 sec quarter. For you N/A guys, narrow your exhaust tip to 1" run it and see what happens.....
The compressor will/may overspin and damage the turbo. the other guy is trying to fool you into blowing up your turbo (there seems to be alot of trolling in threads these days). Do some research, or use your head. Look at the compressor map for any turbo. The larger the engine you try to feed, the less boost it will make given the same compressor rpm, the farther to the right of the map you will move, right off the edge. having no engine connected to the compressor means the "invisible engine" acts as an infinite sink (it will never build boost because there will never be a restriction, and the compressor will move to max flow position provided there is enough exhaust energy), it could potentially move right off the map to the right and blow into a million pieces.
the only way you can do this is if you wire the wastegate fully open (external gate), blow it open and hold it open with CO2, or disconnect the flapper (internal gate)
Another thread with the same question
https://ls1tech.com/forums/forced-in...up-intake.html
If the turbo is big enough, it might be fine. but its not worth the risk in my opinion. With the gate shut, you can hit any compressor RPM that the engine can provide energy enough to move it to, and that is the risk as there is nothing to stop it or slow it down.
the only way you can do this is if you wire the wastegate fully open (external gate), blow it open and hold it open with CO2, or disconnect the flapper (internal gate)
Another thread with the same question
https://ls1tech.com/forums/forced-in...up-intake.html
If the turbo is big enough, it might be fine. but its not worth the risk in my opinion. With the gate shut, you can hit any compressor RPM that the engine can provide energy enough to move it to, and that is the risk as there is nothing to stop it or slow it down.
Last edited by kingtal0n; Nov 28, 2016 at 02:49 AM.
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
the original premise of this thread is nonsense but it is interesting understanding what would happen when running with the cold side open to admosphere...so after reading the stuff in this thread that actually makes sense (freeflowing compressor side = increase in required power to drive compressor) would it not put a huge load on the engine and possibly damage it due to the exhaust backpressure/heat?
this is assuming you didn't hold the wastegate open since there isn't any boost pressure to open it.
or would it just be down on power even compared to na since you're essentially running a choked exhaust and using that power to move a bunch of air through the compressor as opposed to drive the rear wheels
i do agree the derp is strong though
this is assuming you didn't hold the wastegate open since there isn't any boost pressure to open it.
or would it just be down on power even compared to na since you're essentially running a choked exhaust and using that power to move a bunch of air through the compressor as opposed to drive the rear wheels
i do agree the derp is strong though
Tell your friend he's right. he could beat you on motor, but you will never know because you built a turbo car and it's faster than his. If he wants a fair race tell him to bite the bullet, spend the money and build a car like you did. Leave your car alone
I suppose the findings when running a belt driven centri into free air don't apply to a turbo.
Like I said, when that info was first posted up, I was like, this is stupid as ****, a free flowing blower should take zero power to turn.....when in fact it was just the opposite.
I just can't help but think that if you disconnected the cold side and plugged the cold side outlet on the turbo....it would just spin to the moon and explode from not having a load on it. I'm trying to use the common sense method here and say for sure that a turbo that is flowed into free air will take more power to spin than one that has the outlet blocked........and then if that is right, I'd conclude that letting it free flow would not hurt it as it would theoretically have more load on it than if it were hooked to the motor.
I don't know, I do confuse myself sometimes and will flat out tell everyone, you shouldn't ask me for turbo sizing advise. If the conclusion of testing with blowers is used to generate a theory on how a turbo will act....then I'd be right. Problem is, we only have data on the blower tests........I haven't seen anyone test this with a turbo so it is only a theory and not a conclusion.
Does that make sense?
Like I said, when that info was first posted up, I was like, this is stupid as ****, a free flowing blower should take zero power to turn.....when in fact it was just the opposite.
I just can't help but think that if you disconnected the cold side and plugged the cold side outlet on the turbo....it would just spin to the moon and explode from not having a load on it. I'm trying to use the common sense method here and say for sure that a turbo that is flowed into free air will take more power to spin than one that has the outlet blocked........and then if that is right, I'd conclude that letting it free flow would not hurt it as it would theoretically have more load on it than if it were hooked to the motor.
I don't know, I do confuse myself sometimes and will flat out tell everyone, you shouldn't ask me for turbo sizing advise. If the conclusion of testing with blowers is used to generate a theory on how a turbo will act....then I'd be right. Problem is, we only have data on the blower tests........I haven't seen anyone test this with a turbo so it is only a theory and not a conclusion.
Does that make sense?
I still think the massive exhaust backpressure could blow back through the turbo oil seals and burn the bearings, along with killing any semblance of horsepower. With the divide by zero backpressure ratio, I wouldn't be surprised to see a long pull have exhaust residue blowing out the charge side.
i don't see why it wouldn't...the compressor side doesn't know what is driving it (belt/gears/crank vs exhast flow/pressure) and the power required to move a certain mass/volume of air has to come from somewhere...just not sure what that would equate to on the exhaust side of the turbo with regards to backpressure and exhaust flow rate, i.e. would the turbo spin to the moon or would the exhaust side choke first and limit its rpm?
I actually tried to go find it on the bullet last night and couldn't find it. There is a pretty good thread on the subject over there, but none of my search parameters could produce it. I did save a picture of the chart showing the power needed to drive an F2 blower at particular blower rpm/boost levels, just for reference cause I run an F2. According to that chart, on my quickest pass to date, I was spinning the blower 54,500 rpm and making about 26 lbs of boost and the blower was soaking up 260 horsepower.
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
I still think the massive exhaust backpressure could blow back through the turbo oil seals and burn the bearings, along with killing any semblance of horsepower. With the divide by zero backpressure ratio, I wouldn't be surprised to see a long pull have exhaust residue blowing out the charge side.
It wont. There wont.