Greddy Turbo Installed - Details Inside!!!!
01-21-2005, 04:05 PM
#901
RX8 and a Truk....
Originally Posted by twospoons_
A little side note on the crank hp. Since RB had an engine dyno the numbers should be pretty accurate. Secondly, if the rx8 had 25% drive chain loss then it would open up for some nice aftermarket parts to reduce parasitic loss. Since it's down to "only" 15% it makes me sleep better at night at least.
01-21-2005, 04:11 PM
#902
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Originally Posted by RX-Nut
Is there a way to fix this... or do you think Greddy would release new maps? I for one would probably not know how to tune it to minimize the backfire so I would rely on Greddy. Is backfire a bad thing, other than sounding ugly?
01-21-2005, 04:11 PM
#903
Originally Posted by PoLaK
Over and under hummmmm
i'll say 210 for Jeff untuned
and 235 for John using the greddy map.
i'll say 210 for Jeff untuned
and 235 for John using the greddy map.
Still wrong, though...:p
Jon and I will both post up once he gets back home to NJ.
Give it 'till 9pm or so.
Last edited by MazdaManiac; 01-21-2005 at 04:15 PM.
01-21-2005, 04:12 PM
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Originally Posted by dmp
I contend, similiar sized turbos, similar boost, a lower displacement engine will make LESS power.
The important factor isn't the displacement of said motor, it's the output of said motor.
My 2.0L Mazda motor doesn't respond to boost as well as most 1.8L Acura motors. Why? Because the Acura motor has more output to begin with.
Within reason, if you run 7.5psi on any given motor, you'll almost always get between a 40% and 60% hp gain, regardless of the displacement.
01-21-2005, 04:17 PM
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Originally Posted by MazdaManiac
Cheater!
Still wrong, though...:p
Jon and I will both post up once he gets back home to NJ.
Give it 'till 9pm or so.
Still wrong, though...:p
Jon and I will both post up once he gets back home to NJ.
Give it 'till 9pm or so.
01-21-2005, 04:18 PM
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Originally Posted by dmp
I compare them because they are two engines I have, or have owned. I don't know much about the volumetric efficiency of either - but I'm pretty certain in my belief re: similar turbos/similiar boost/ higher displacement engine will make more power. Again - I doubt I could 'prove it' but I think I'm right. We'll see, maybe, when the dyno's are published.
01-21-2005, 04:19 PM
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Originally Posted by dmp
but I'm pretty certain in my belief re: similar turbos/similiar boost/ higher displacement engine will make more power. Again - I doubt I could 'prove it' but I think I'm right. We'll see, maybe, when the dyno's are published.
It all comes down to how much control you have with your fuel and how rich or lean you're willing to run. I think that will be the biggest difference between Jon and Jeff...unless Jon tossed the GReddy map and started from scratch. Then I'd say they'll be within few hp of each other.
01-21-2005, 04:21 PM
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Originally Posted by 2ks2k
Nope displacemnt isn't an issue...an S2000 (I4 2.0l) makes about 300whp @ 7psi...which is an increase of about 100hp (they put 190 to 200hp stock). I think tuning is the biggest issue. I've seen anywhere from 300hp (with VAFC) to 330hp (Greddy Emanage).
01-21-2005, 04:25 PM
#912
RX8 and a Truk....
Originally Posted by 2ks2k
Nope displacemnt isn't an issue...an S2000 (I4 2.0l) makes about 300whp @ 7psi...which is an increase of about 100hp (they put 190 to 200hp stock). I think tuning is the biggest issue. I've seen anywhere from 300hp (with VAFC) to 330hp (Greddy Emanage).
It all comes down to how much control you have with your fuel and how rich or lean you're willing to run. I think that will be the biggest difference between Jon and Jeff...unless Jon tossed the GReddy map and started from scratch. Then I'd say they'll be within few hp of each other.
It all comes down to how much control you have with your fuel and how rich or lean you're willing to run. I think that will be the biggest difference between Jon and Jeff...unless Jon tossed the GReddy map and started from scratch. Then I'd say they'll be within few hp of each other.
Right - the point was, all other things equal, a td04 on a 2.5@ 7psi will likely produce less power than a T3/T4. I've seen the same mazda v6 I had make 300whp on 8psi - with a BIG hair-drier; compared to my ~250.
Again - given similiar-sized turbos, ICs, etc, the larger displacement an engine will make more power. Thus, I was suspecting the ~7psi on the GReddy turbo system won't make as much power, psi-for-psi, as 7psi on my Mazda V6 made.
We'll find out soon enough.
One huge assumption I'm making: I'm assuming the GReddy-supplied turbo is about the same specs as my T3Super60 was.
I really love s2k's, btw...if i didn't need a four seater, I'd have one.
Last edited by dmp; 01-21-2005 at 04:28 PM.
01-21-2005, 04:50 PM
#913
RX8 and a Truk....
Originally Posted by Kooldino
Within reason, if you run 7.5psi on any given motor, you'll almost always get between a 40% and 60% hp gain, regardless of the displacement.
That suggests if the RX8 really DOES have 238hp - 7.5psi should neat at least 330hp...or 280+whp at the wheels. I hope that's the case! If they stop stringing us along, we'll know! :p :p :p
01-21-2005, 04:55 PM
#914
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Im going with 250-260 for Jon
270-280 for Jeff. Gotta go with the homemade brew! That and the maps, larger turbo, yadda. AND YES LARGER TURBO DOES MATTER!!! Compressing 1 ft^3 of air in a small turbo to 7 psi IS NOT THE SAME as 1.4 ft^3 of air compressed at 7 psi by a large turbo.
270-280 for Jeff. Gotta go with the homemade brew! That and the maps, larger turbo, yadda. AND YES LARGER TURBO DOES MATTER!!! Compressing 1 ft^3 of air in a small turbo to 7 psi IS NOT THE SAME as 1.4 ft^3 of air compressed at 7 psi by a large turbo.
01-21-2005, 05:00 PM
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Originally Posted by Richard Paul
Now I will tell you again why you can't tell hp gain from pressure.
Go to the first few pages of the axial flow thread or search for the plots produced by Turbine_pwr.
Here he shows you the mass flow for different efficencys.
I'll give you a simple equation to show what gets into the engine, it's called: density ratio. As opposed to pressure ratio which is what you guys are using.
P2/P1 = Pr
Pr x T1/T2 = density ratio or the actual amount of additional mass entering the engine.
Temps are in degree R, or absolut F. Or ambiant plus 460.
Given a Pr of 1.5 which is roughly 7.5psi. Then given an efficency of 65% we can calculate the temp rise.
Pr to the power of .283-1 gives the y factor
So 1.5 ^.283-1=.1215
this times the tempR at std cond=520F
=63 F at 100 % eff.
divide by eff so 63/.65=97 temp rise
so 520 + 97=617 therefore 520/617=.84
.84x1.5=1.26
so if you want to use your 14.7 std times 1.26 you now have18.6
or 18.6-14.7=3.88psi worth of air.
So you really are getting 3.88 if it were a perfect world that is what you would need to produce to get the same results.
So use your 3.88 times whatever power you had to start with and you will be closer.
The question is how much does the ren produce? And what is the real eff of the turbo. As that is a big part of the equation.
If It is what I said and you were getting say 170 WHP mult it by 1.388=235 WHP
Lets see how close that number is. I'm betting a bit less because i think the eff is less due to heat transfer from the turbine side. Which is never figured into the compressor maps.
Next I'll tell you why you might get more then the math says you will. But I have to go to work so save it for later. Or you can go back and study the math provided at the start of my thread.
Go to the first few pages of the axial flow thread or search for the plots produced by Turbine_pwr.
Here he shows you the mass flow for different efficencys.
I'll give you a simple equation to show what gets into the engine, it's called: density ratio. As opposed to pressure ratio which is what you guys are using.
P2/P1 = Pr
Pr x T1/T2 = density ratio or the actual amount of additional mass entering the engine.
Temps are in degree R, or absolut F. Or ambiant plus 460.
Given a Pr of 1.5 which is roughly 7.5psi. Then given an efficency of 65% we can calculate the temp rise.
Pr to the power of .283-1 gives the y factor
So 1.5 ^.283-1=.1215
this times the tempR at std cond=520F
=63 F at 100 % eff.
divide by eff so 63/.65=97 temp rise
so 520 + 97=617 therefore 520/617=.84
.84x1.5=1.26
so if you want to use your 14.7 std times 1.26 you now have18.6
or 18.6-14.7=3.88psi worth of air.
So you really are getting 3.88 if it were a perfect world that is what you would need to produce to get the same results.
So use your 3.88 times whatever power you had to start with and you will be closer.
The question is how much does the ren produce? And what is the real eff of the turbo. As that is a big part of the equation.
If It is what I said and you were getting say 170 WHP mult it by 1.388=235 WHP
Lets see how close that number is. I'm betting a bit less because i think the eff is less due to heat transfer from the turbine side. Which is never figured into the compressor maps.
Next I'll tell you why you might get more then the math says you will. But I have to go to work so save it for later. Or you can go back and study the math provided at the start of my thread.
If you have 1 cubic inch of air at 60f under 7psi it is possible to determine the
density. And the density of air molecules increases with the psi. As long as we keep stuffing air inside our little box it doesn't matter if we use PSI or density as PSI is a function of density. Higher the pressure is the same as higher density.
According to the data provided by turbine_pwr the change in temp is almost linear depending on boost which leads me to believe that a statistical approach to calculating hps from psi is valid.
Arrest me if i'm wrong. I'm just trying to understand this.
01-21-2005, 05:05 PM
#916
Your under arrest. Look at the equation again, you have to add the temp rise or heat to the factor.
Once more, (I know I've said this before) ...............Wait a minuite, where did I explain the experament box recently. I'm going to look for it, Might be in Hymees thread. I'll get back to you.
Once more, (I know I've said this before) ...............Wait a minuite, where did I explain the experament box recently. I'm going to look for it, Might be in Hymees thread. I'll get back to you.
01-21-2005, 05:06 PM
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Originally Posted by AvatarQAZ
Im going with 250-260 for Jon
270-280 for Jeff. Gotta go with the homemade brew! That and the maps, larger turbo, yadda. AND YES LARGER TURBO DOES MATTER!!! Compressing 1 ft^3 of air in a small turbo to 7 psi IS NOT THE SAME as 1.4 ft^3 of air compressed at 7 psi by a large turbo.
270-280 for Jeff. Gotta go with the homemade brew! That and the maps, larger turbo, yadda. AND YES LARGER TURBO DOES MATTER!!! Compressing 1 ft^3 of air in a small turbo to 7 psi IS NOT THE SAME as 1.4 ft^3 of air compressed at 7 psi by a large turbo.
Take one big box. Take 20 balloons and fill them with air. You drop 10 balloons inside the box and squeeze the lid shut. The pressure on the walls inside the box is now 2 psi. Drop 10 more and squeeze the lid shut. The pressure is now 4 psi. There are 20 balloons in the box.
Drop 20 balloons inside the box and shut it. The pressure is 4 psi. The amount of balloons is the same.
01-21-2005, 05:11 PM
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Originally Posted by Richard Paul
Your under arrest. Look at the equation again, you have to add the temp rise or heat to the factor.
Once more, (I know I've said this before) ...............Wait a minuite, where did I explain the experament box recently. I'm going to look for it, Might be in Hymees thread. I'll get back to you.
Once more, (I know I've said this before) ...............Wait a minuite, where did I explain the experament box recently. I'm going to look for it, Might be in Hymees thread. I'll get back to you.
01-21-2005, 05:13 PM
#919
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I am not disputing that 20 balloons in a small box is still 20 balloons in a small box. Proportion it though. Lets say box A has a housing size of 20 balloons maximum. Box B can hold 40 balloons maximum.
Box B and A, when at maximum pressure, are 7.5 psi. When you open the boxes, 20 balloons come out at the same rate from box A as box B's 40 balloons. Is there 'more balloons' per cubic whatever? Maybe, but not that much if any at all. But, there is more airspace for compression and for more air, period. More volume of air at 7.5 psi rushing into your engine with Box B v. Box A
Box B and A, when at maximum pressure, are 7.5 psi. When you open the boxes, 20 balloons come out at the same rate from box A as box B's 40 balloons. Is there 'more balloons' per cubic whatever? Maybe, but not that much if any at all. But, there is more airspace for compression and for more air, period. More volume of air at 7.5 psi rushing into your engine with Box B v. Box A
01-21-2005, 05:14 PM
#920
Twospoons, go to post 973 in my axial flow thread. This explains it and gives you a lab experiment example. See I knew I went through this before.
I'm going to the post office now to mail some shifters, when I comeback I expect you will have had an awakening.
I'm going to the post office now to mail some shifters, when I comeback I expect you will have had an awakening.
01-21-2005, 05:16 PM
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Originally Posted by AvatarQAZ
I am not disputing that 20 balloons in a small box is still 20 balloons in a small box. Proportion it though. Lets say box A has a housing size of 20 balloons maximum. Box B can hold 40 balloons maximum.
Box B and A, when at maximum pressure, are 7.5 psi. When you open the boxes, 20 balloons come out at the same rate from box A as box B's 40 balloons. Is there 'more balloons' per cubic whatever? Maybe, but not that much if any at all. But, there is more airspace for compression and for more air, period. More volume of air at 7.5 psi rushing into your engine with Box B v. Box A
Box B and A, when at maximum pressure, are 7.5 psi. When you open the boxes, 20 balloons come out at the same rate from box A as box B's 40 balloons. Is there 'more balloons' per cubic whatever? Maybe, but not that much if any at all. But, there is more airspace for compression and for more air, period. More volume of air at 7.5 psi rushing into your engine with Box B v. Box A
01-21-2005, 05:25 PM
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Originally Posted by twospoons_
Which again leads me to my first question. If the size of the tubing going to the intake is the same it doesn't matter what kind of turbo you have if the pressure and the temp. is the same.
01-21-2005, 05:26 PM
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Originally Posted by Richard Paul
Twospoons, go to post 973 in my axial flow thread. This explains it and gives you a lab experiment example. See I knew I went through this before.
I'm going to the post office now to mail some shifters, when I comeback I expect you will have had an awakening.
I'm going to the post office now to mail some shifters, when I comeback I expect you will have had an awakening.
IF you have a 2" tubing. The temp. of the air inside the tube is 60F. The pressure is 7PSI. This pressure is created with my hand pump.
Prove that there will be more air molecules inside this tube if you add a bigger turbo which produces 7PSI and the air temp. is still 60F inside the tube.
Or again, prove that more air molecules will flow out of the end of this tube.
The only benefits I can see of a bigger turbo are that it can create more pressure. If you want to keep the PSI the same and have more air flow you need to increase the size of the tubes going from the turbo all the way to the intake. Then again I would assume that the size of the intake is fixed so when you have 7 PSI in a large tube going to the intake it narrows down and you actually increase the pressure going in through the intake.
Heck, give us some dyno numbers!!!!!!!!! This is torture. I'm trying to play semi intelligent just to get the time to pass.
Last edited by twospoons_; 01-21-2005 at 05:28 PM.
01-21-2005, 05:28 PM
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Originally Posted by twospoons_
...the more you pressurize the air the hotter it will get and the less air molecules you will be able to fit inside the same space. My point was, if the air temperature of the compressed air is the same it should have the same amount of air molecules if it has the same PSI, which again leads to the air having the same density.
01-21-2005, 05:49 PM
#925
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Originally Posted by dmp
That suggests if the RX8 really DOES have 238hp - 7.5psi should neat at least 330hp...or 280+whp at the wheels. I hope that's the case! If they stop stringing us along, we'll know! :p :p :p
I'm talking WHP.
So 40%-60% added to ~170whp = 238-272 whp.