Single Turbo RX-7's Questions about all aspects of single turbo setups.

hybri turbos

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Old Oct 4, 2004 | 06:27 PM
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hybri turbos

Could anyone advise me whats the pros and cons going hybrid turbo. i wouldnt choose to go full T04 because thats what im running right now and i hate the lag.

car will be running with haltech....

does a hybrid turbo have anything to do with blowing up an engine?.....pls advise thanks
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Old Oct 4, 2004 | 06:47 PM
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I have a BNR Stage 3 which is capable of 350 rwhp. Yes it can blow your engine as can any turbo if you are not set up for it. Seeing as you are running a TO4E I would probably say you would be set up for a hybrid already. Personally I think the hybrid spools up almost as fast as a stocker. I see full boost around 3800 rpms.
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Old Oct 4, 2004 | 08:04 PM
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hybrid you are running more intake but still stock exhaust, thast why its has such quick spool. some people like hybrids for this reason but its not good for your car running alot in but not the same amount out.
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Old Oct 4, 2004 | 08:19 PM
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Explain please as this is the 1st I have ever heard of this, maybe we should invite bryan from BNR in on this discussion.
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Old Oct 4, 2004 | 11:03 PM
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yea explain more pls../.... so the extra back pressure will cause more stress and engine blowing up?
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Old Oct 5, 2004 | 12:04 AM
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Backpressure is bad in general, but I think it can be useful in FI applications. There are lots of things that can cause more stress on the engine. What kind of hybrid turbocharger are you thinking about? There's tons.
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Old Oct 5, 2004 | 12:09 AM
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Reversion.

Send a PM to BDC about it. He will tell you all there is about why hybrids aren't at the top of his suggestions.

The BNR hybrid's have their turbine wheels clipped. It helps with exhaust flow, somewhat balancing the extra compressor side of things.
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Old Oct 5, 2004 | 12:47 AM
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Hello all.

Here is my opinion on hybrids. They are bang for the buck, no fabrication required, 100% bolt up turbos that will pass inspection, and will not cost you an arm and a leg. Yes a full T04 would be the best way to go for achieving overall HP, but for someone with a mildly modded car can achieve the most out of a hybrid. I have many customers dynoing over 330 RWHP on hybrid set ups. Not everyone is out to make over 400 RWHP, but there are some that do. My opinion is once you get over 16 psi and 400 RWHP, your car starts to be on the verge of unreliable. Most people say that rotaries are unreliable even without a turbo! lol, so go figure!!!
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Old Oct 5, 2004 | 12:48 AM
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Sorry. I am logged under Steve Kans Screen name. Sorry Steveo. This is Bryan from BNR .
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Old Oct 5, 2004 | 04:08 AM
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Originally Posted by Infini IV
Reversion.

Send a PM to BDC about it. He will tell you all there is about why hybrids aren't at the top of his suggestions.

The BNR hybrid's have their turbine wheels clipped. It helps with exhaust flow, somewhat balancing the extra compressor side of things.
What the hell does reversion have anything to do with this???


-Ted
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Old Oct 5, 2004 | 04:27 AM
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Originally Posted by RETed
What the hell does reversion have anything to do with this???

-Ted
Just going by what was said by BDC over here:
http://www.teamfc3s.org/forum/showth...threadid=17566
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Old Oct 5, 2004 | 07:11 AM
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Well I dont know everything about turbos but I have plenty of good flow with the ported manifold and RB Turbo back exhaust. My BNR turbo is awsome and I did not have to F around with fabricating much other than my FMIC and 2.5" piping and I could buy the 2.5" TB inlet off Ebay. So all in all it was real nice to achieve the power I have with minimal fabricating. I agree for a street RX especially with stock internals that 400rwhp is really pushing the ol reliabilty envelope.
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Old Oct 5, 2004 | 07:51 AM
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Originally Posted by Infini IV
Just going by what was said by BDC over here:
http://www.teamfc3s.org/forum/showth...threadid=17566
Look at the date stamp - it was over a year ago.

It sounds like BDC was talking about excessive backpressure through the turbine section.
Funny how a lot of people CLAIM this is so, but I've never seen hard numbers to back their claims.
It sounds more like excessive exhaust gas backpressure.

Exhaust gases already normally shoot back up into the intake due to the overlap of the exhaust and intake (port) timing.
The EGR valve also does this by design.
I can't see how increasing the exhaust gas backpressure by a little is going to affect power output of the engine significantly.
A lot of port jobs increase overlap, so I guess you can argue with all those guys about this "reversion" effect on power...

I find it funny that BDC is bitching about this reversion of exhaust gases into the intake charge, but yet he's pushing his turbo bridgeports...


-Ted
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Old Oct 5, 2004 | 03:30 PM
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Alright here is the turbo that is being spoken about here;
S5 Turbine Manifold Machined to fit a slightly larger clipped t04 turbine wheel
Air Research T04B Compressor manifold with a 60-1 V-Trim compressor wheel.
It has a Coolant cooled center section
It has a ported wastegate right to the edge (anymore and it would leak exhaust gases)
This turbo is comparative to the stage 4 from BNR.
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Old Oct 5, 2004 | 03:57 PM
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hey jeff , yea thats the hybrid im talking about.....

can anyone give me any info if that will harm my engine , i will be running a haltech e6k , with that turbo , with a med or large NPR i/c.... harm my engine as in causing it to blow up..

im shooting for 250-280whp nothing more than that......i want to keep my engine which is at 92psi on each rotor now to last me another 2 years......so i would just like to push 8psi daily driven and 13-15 psi on the race course....

or should i opt for the T04e with 0.84 a/r side with the same mods above? all on stock ports... pls let me know what u guys think i should go with?

in terms of engine stress and damage....

thanks....putting a new setup is confusing........
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Old Oct 5, 2004 | 04:17 PM
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In my opinion this Turbo (Hyrbid) explained above would be perfect for your wants. if tunned properly and setup it done properly should have no engine damage.
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Old Oct 5, 2004 | 05:22 PM
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what do u mean tuned properly? and what kind of setup are we talking about here?
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Old Oct 5, 2004 | 05:22 PM
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Originally Posted by RETed
Look at the date stamp - it was over a year ago.

It sounds like BDC was talking about excessive backpressure through the turbine section.
Funny how a lot of people CLAIM this is so, but I've never seen hard numbers to back their claims.
It sounds more like excessive exhaust gas backpressure.

Exhaust gases already normally shoot back up into the intake due to the overlap of the exhaust and intake (port) timing.
The EGR valve also does this by design.
I can't see how increasing the exhaust gas backpressure by a little is going to affect power output of the engine significantly.
A lot of port jobs increase overlap, so I guess you can argue with all those guys about this "reversion" effect on power...

I find it funny that BDC is bitching about this reversion of exhaust gases into the intake charge, but yet he's pushing his turbo bridgeports...


-Ted
Maybe I had this all wrong, but would an increase in backpressure cause exhaust gasses to shoot back in through the exhaust ports? I figure if there is enough of a restriction, the exhaust gasses will have nowhere to go. With that in mind, I was thinking that if the engine is pushing all that exhaust out, and it has nowhere to physically go, then it either has to go back through the exhaust ports or place a great strain on the turbine wheel (or force an exhaust leak at the flanges/gaskets).
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Old Oct 5, 2004 | 05:29 PM
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Originally Posted by jreynish
Alright here is the turbo that is being spoken about here;
S5 Turbine Manifold Machined to fit a slightly larger clipped t04 turbine wheel
Air Research T04B Compressor manifold with a 60-1 V-Trim compressor wheel.
It has a Coolant cooled center section
It has a ported wastegate right to the edge (anymore and it would leak exhaust gases)
This turbo is comparative to the stage 4 from BNR.
Hmm, that's wierd. The compressor wheel is either a 60-1 wheel or a V-trim wheel. They are two completely different wheels. The V-trim wheel is very popular, actually. It is capable of a good solid 300rwhp at just under 15psi boost on a ported motor. This wheel is probably closer in size to a BNR stage 1 or stage 2. The stage 3 and 4 wheels used by BNR are the 60-1 wheels. These wheels should be capable of flowing enough air to support 400rwhp... However, I have not seen anyone dyno 400rwhp on a 60-1 hybrid as of yet.
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Old Oct 5, 2004 | 07:59 PM
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ok......anyone can clear up which turbo is better?.......
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Old Oct 5, 2004 | 10:51 PM
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Originally Posted by Infini IV
Maybe I had this all wrong, but would an increase in backpressure cause exhaust gasses to shoot back in through the exhaust ports? I figure if there is enough of a restriction, the exhaust gasses will have nowhere to go. With that in mind, I was thinking that if the engine is pushing all that exhaust out, and it has nowhere to physically go, then it either has to go back through the exhaust ports or place a great strain on the turbine wheel (or force an exhaust leak at the flanges/gaskets).
The rule of thumb on exhaust gas pressure versus (intake) boost is 2:1, if I remember correctly.
So if the turbo is making 10psi, try to keep the exhaust gas pressure under 20psi.

Yes, excessive exhaust gas pressure will cause exhaust gases not to flow out the exhaust port and eventually end up back into the intake charge.
BUT, the rotary engine already does this normally.
This is also a natural EGR effect, and it's almost impossible to eliminate.
This is due to the high overlap that the rotary engine design (prior to the MSP-RE) has.

So, my question is...I'd like to here objective data on the significant increase of exhaust gases leaking back into the intake charge due to an "overly restrictive" turbine section???

I think BDC is pulling **** out of his *** on the thread posted.
Why?
Cause BDC also likes to push his turbo bridge ports...
Bridge ports significantly increase overlap.
Increases in overlap induces more exhaust gases to leak into the intake charge.
If BDC is so worried about exhaust gas dilution back into the intake charge, then why is he pushing turbo BP's so hard?
This sounds like a contradiction to me...

Very big hybrids have been proven to make significant power.
I've seen them break 350hp to the wheels on a DynoJet.
If there is a downside to them, it is minimal.
BDC likes to push full turbo upgrades; he does not like hybrids.
BDC is not the end-all authority on this subject - don't be fooled.
BDC was against FCD's on stock ECU's due to the FCD's supposedly affect on fuel delivery - well, we've been claiming the stock boost sensor does not affect fuel delivery.
Guess what, it's been proven through disassembly of the stock ECU code that the boost sensor does not significantly affect fuel delivery when the turbo goes into boost.
BDC was wrong on that point.
BDC does not like stock ECU's; he pushes stand-alone ECU's for making more power.

A lot of the stuff BDC pushes have merit, but he has a nasty habit of knocking on these so-called "band aid" upgrades.
I claim these so-called "band aid" upgrades have their place for owners, cause we're not all made of money to pay for the best components.

I guess what it comes down to is...
If you can afford a full turbo upgrade, go for it.
If you can't, a hybrid turbo is a viable option for an upgrade, regardless of what BDC is saying.


-Ted
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Old Oct 5, 2004 | 11:12 PM
  #22  
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hmm.......alrighty thanks a lot.....

but no matter what i still want a haltech anyway......the turbo thing comes second and third comes choosing an i/c
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Old Oct 5, 2004 | 11:13 PM
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more contribution would definately help......
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Old Oct 5, 2004 | 11:55 PM
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Originally Posted by RETed
The rule of thumb on exhaust gas pressure versus (intake) boost is 2:1, if I remember correctly.
So if the turbo is making 10psi, try to keep the exhaust gas pressure under 20psi.

Yes, excessive exhaust gas pressure will cause exhaust gases not to flow out the exhaust port and eventually end up back into the intake charge.
BUT, the rotary engine already does this normally.
This is also a natural EGR effect, and it's almost impossible to eliminate.
This is due to the high overlap that the rotary engine design (prior to the MSP-RE) has.

So, my question is...I'd like to here objective data on the significant increase of exhaust gases leaking back into the intake charge due to an "overly restrictive" turbine section???

I think BDC is pulling **** out of his *** on the thread posted.
Why?
Cause BDC also likes to push his turbo bridge ports...
Bridge ports significantly increase overlap.
Increases in overlap induces more exhaust gases to leak into the intake charge.
If BDC is so worried about exhaust gas dilution back into the intake charge, then why is he pushing turbo BP's so hard?
This sounds like a contradiction to me...

Very big hybrids have been proven to make significant power.
I've seen them break 350hp to the wheels on a DynoJet.
If there is a downside to them, it is minimal.
BDC likes to push full turbo upgrades; he does not like hybrids.
BDC is not the end-all authority on this subject - don't be fooled.
BDC was against FCD's on stock ECU's due to the FCD's supposedly affect on fuel delivery - well, we've been claiming the stock boost sensor does not affect fuel delivery.
Guess what, it's been proven through disassembly of the stock ECU code that the boost sensor does not significantly affect fuel delivery when the turbo goes into boost.
BDC was wrong on that point.
BDC does not like stock ECU's; he pushes stand-alone ECU's for making more power.

A lot of the stuff BDC pushes have merit, but he has a nasty habit of knocking on these so-called "band aid" upgrades.
I claim these so-called "band aid" upgrades have their place for owners, cause we're not all made of money to pay for the best components.

I guess what it comes down to is...
If you can afford a full turbo upgrade, go for it.
If you can't, a hybrid turbo is a viable option for an upgrade, regardless of what BDC is saying.

-Ted
Which is why I think it makes sense to find a setup that will minimize exhaust gas pressure. Really, what good does exhaust pressure (and "reversion") have? Nothing, correct? Perhaps I'm missing something, but if you can increase the velocity at which exhaust gas exits the engine and gets through the turbo, then you will have a much more efficient setup than one which has more exhaust gas pressure held up between the engine and the turbo.

Now since FC_mania is setup with a full T4 system already, why not keep the setup and maybe just switch to a smaller T04E to get the same response as a hybrid?
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Old Oct 6, 2004 | 01:56 AM
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Originally Posted by Infini IV
Which is why I think it makes sense to find a setup that will minimize exhaust gas pressure.
Yes, that's the million dollar question.
I think there's going to be an explosion of data popping up soon, as owner figure out how to plumb in a pressure gauge to measure exhaust gas pressure.

Really, what good does exhaust pressure (and "reversion") have? Nothing, correct?
Yep, that was my point.
It is something you really cannot totally eliminate, so you basically live with it.
It seems kinda silly to bring up this point, cause it's really a non-issue, as you have concluded.


Perhaps I'm missing something, but if you can increase the velocity at which exhaust gas exits the engine and gets through the turbo, then you will have a much more efficient setup than one which has more exhaust gas pressure held up between the engine and the turbo.
Yes, it's one way to get better performance from the turbo.

Now since FC_mania is setup with a full T4 system already, why not keep the setup and maybe just switch to a smaller T04E to get the same response as a hybrid?
Now, this is the trick.
Dropping down turbine A/R will increase reponse and decrease drag, but it also chokes the engine.
The whole black-magic aura about turbo sizing hasn't really been freely discussed, especially with some of the top tuners of 13B's.
It's all about sizing the turbine A/R.
Too small, and you lose top-end power.
Too large, and you induce too much lag.
There is an "ideal" turbine A/R which gives you best power response across the entire RPM band and yet keep lag in check.
Add porting to the entire mess, and that's adds another dimension which changes everything.
Now you know the million dollar question.
Do you know what the answer is?


-Ted
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