Greddy Turbo Kit F.A.Q's. post them here
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dirtyDEE (11-03-2017)
11-02-2017, 08:00 PM
#527
If you have low compression then you have low compression, I don't know what you are asking?
Of course running lean while under boost will kill your engine... if you have to ask that I feel like you didn't have much business boosting this engine.... or any engine...
Of course running lean while under boost will kill your engine... if you have to ask that I feel like you didn't have much business boosting this engine.... or any engine...
Iam just curous to understand what caused it
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RotaryMachineRx (04-12-2018)
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RotaryMachineRx (04-12-2018)
07-08-2018, 12:30 AM
#537
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You guys where right the 2 emanage Blue worked fine about 300mile each. After this both failed and stopped Working on rotor 2. I did a dyno tune with Mazda edit now running 14 psi peak 10psi to redline. Thanks for all the advice you guys gave me !!
Last edited by Miclantragt; 07-08-2018 at 01:42 AM.
07-10-2018, 09:15 PM
#540
Hybrid Greddy Boosted
In case you haven't had too much exposure to turbo rx8s, seeing a drop in boost pressure close to redline indicates excessive backpressure in the turbo manifold. It's pretty common on T25 turbine housings on rx8 motors running more than about 9psi. It's an indicator that your turbo hotside can't flow the exhaust gas being generated, and it means more hot exhaust gas remains in the combustion chamber each cycle (due to high exhaust manifold backpressure), increasing the likelihood of detonation. It's not generally recommended to run this type of setup at more than about 11psi, and at a minimum you need to make sure you have good quality gas and AFRs stay below 12 under boost. I've run my car at 13psi on a T25 turbo for 6-12 months without any noticeable damage, I was lucky, and also understood that the motor may let go at any time. Pretty sure Brettus has run a T25 turbo up to 16psi, but he has tuned a lot of turbo cars and I think he suggested to me that I shouldn't run more than about 11psi if I recall correctly.
A lot of people fail before hitting 14psi, so you've done alright so far. If it were my car I'd wind down the boost to 12psi and enjoy it for a long(er) time. But it's your car and your call. Good luck either way!
Edit: Do you have any details on your turbo spec's, wheel inducer, exducer sizes, etc.?
A lot of people fail before hitting 14psi, so you've done alright so far. If it were my car I'd wind down the boost to 12psi and enjoy it for a long(er) time. But it's your car and your call. Good luck either way!
Edit: Do you have any details on your turbo spec's, wheel inducer, exducer sizes, etc.?
07-11-2018, 04:27 AM
#541
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Well i dont gave the Spec of the turbo since i buyed à used kit freshly rebuilt. My AFR Nevers go over 10.6 under boost and got 25 degree timing retard. The only thing my tuner suggest me it's to mod the intake to take air out or the hood.i did 10 passes at drag strips with no ping at all. The only noticable thing is when the car was colder did way better Time ans each consecutive pass i was loosing .2 sec 1/4 mile every pass.
12-04-2018, 03:37 PM
#542
Registered
What’s the biggest fault in the greddy kit? It seems like it was the software but there’s much better software avail now than when it was released. I see so many failed kits or people get them running and sell
12-04-2018, 03:45 PM
#543
That's because most people think it's just plug and play . It's a really big modification to your engine .............it takes a lot of time/effort/skill/knowledge to get it running correctly and the failures are almost always from people who thought it would be easy.
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Kane (12-10-2018)
12-15-2021, 10:48 AM
#544
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Whilst not wanting to pack this thread out with side discussions, I thought I had to write something for the benefit of others who might read this.
There are several reasons why the standard Greddy T618Z turbo makes less peak power than other turbos, whether Greddy hybrids or complete replacements, but IMO they all come down to higher boost pressures in the other turbos or the Greddy's not being able to maintain that x psi.
As an aside, I have seen a lot of wasted effort in power vs boost discussions because participants have bandied around boost pressures without realising they are different at the manifold and compressor outlet. I have also seen many people use compressor maps with manifold pressure instead of compressor pressure (manifold + pressure losses between turbo and manifold) and think that changing pressure ratio/boost pressure moves any point vertically rather than diagonally (remember, mass air flow is, for our purposes, proportional to boost pressure). It all gets so confusing . . . . .
- Mass air flow has everything to do with boost pressure. Boost pressure, whether at the turbo or MAF, is effectively synonymous with mass air flow in a given system, where mass air flow is proportional to total pressure (boost + ambient), regardless of how that boost is generated. There are some second order effect (for example, a lower efficiency compressor will generate that 12 psi at a higher temperature, which will feed into a lower air density in the engine's chambers/cylinders) but these are small in an efficient charge air system.
- You are conflating pressure losses with flow pressure in a turbo system. Sure, pressure differences indicate the restrictions in a system and they vary with mass air flow/boost pressure, but that has little to do with mass air flow from the turbo for a given system (there may be second order effects from higher temperature/lower density/higher volume/boundary layer effects but, again, these are too small to bother about).
There are several reasons why the standard Greddy T618Z turbo makes less peak power than other turbos, whether Greddy hybrids or complete replacements, but IMO they all come down to higher boost pressures in the other turbos or the Greddy's not being able to maintain that x psi.
As an aside, I have seen a lot of wasted effort in power vs boost discussions because participants have bandied around boost pressures without realising they are different at the manifold and compressor outlet. I have also seen many people use compressor maps with manifold pressure instead of compressor pressure (manifold + pressure losses between turbo and manifold) and think that changing pressure ratio/boost pressure moves any point vertically rather than diagonally (remember, mass air flow is, for our purposes, proportional to boost pressure). It all gets so confusing . . . . .
I started playing recently. I currently have all the accessories of the original T618, the original computer, the original exhaust, and I am preparing to install the oil breathable pot. Now the 217P vortex pressure peak on the horsepower wheel is 0.38 bar, high rotation 0. 2bar
I would like to ask if there are any good suggestions that can be given to me. I am a little confused now, and the funds are relatively tight.
Is it necessary to replace the full exhaust? I don’t want him to be very noisy (it is very noisy). Does the engine need to be a port? Even I don’t even know what viscosity is better for the oil. At present, 5W40 feels a little too sticky. The technician said 30 is fine, but it’s really hot in summer. Other car friends also use 30 for self-priming, so I am worried. . .
I don’t know if you have used ORC clutch
My car currently uses ORC 250 light
When the car is driving, there will be a very strange noise between 3-5 gears and 3000-4000 rpm. After that, it will be gone, and there will be no other times. The technician said that the clutch problem cannot be solved, otherwise it can only be changed. Kind of clutch.
12-17-2021, 02:53 PM
#545
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Hello, I don’t know if you are still playing Turbo RX8
I started playing recently. I currently have all the accessories of the original T618, the original computer, the original exhaust, and I am preparing to install the oil breathable pot. Now the 217P vortex pressure peak on the horsepower wheel is 0.38 bar, high rotation 0. 2bar
I would like to ask if there are any good suggestions that can be given to me. I am a little confused now, and the funds are relatively tight.
Is it necessary to replace the full exhaust? I don’t want him to be very noisy (it is very noisy). Does the engine need to be a port? Even I don’t even know what viscosity is better for the oil. At present, 5W40 feels a little too sticky. The technician said 30 is fine, but it’s really hot in summer. Other car friends also use 30 for self-priming, so I am worried. . .
I don’t know if you have used ORC clutch
My car currently uses ORC 250 light
When the car is driving, there will be a very strange noise between 3-5 gears and 3000-4000 rpm. After that, it will be gone, and there will be no other times. The technician said that the clutch problem cannot be solved, otherwise it can only be changed. Kind of clutch.
I started playing recently. I currently have all the accessories of the original T618, the original computer, the original exhaust, and I am preparing to install the oil breathable pot. Now the 217P vortex pressure peak on the horsepower wheel is 0.38 bar, high rotation 0. 2bar
I would like to ask if there are any good suggestions that can be given to me. I am a little confused now, and the funds are relatively tight.
Is it necessary to replace the full exhaust? I don’t want him to be very noisy (it is very noisy). Does the engine need to be a port? Even I don’t even know what viscosity is better for the oil. At present, 5W40 feels a little too sticky. The technician said 30 is fine, but it’s really hot in summer. Other car friends also use 30 for self-priming, so I am worried. . .
I don’t know if you have used ORC clutch
My car currently uses ORC 250 light
When the car is driving, there will be a very strange noise between 3-5 gears and 3000-4000 rpm. After that, it will be gone, and there will be no other times. The technician said that the clutch problem cannot be solved, otherwise it can only be changed. Kind of clutch.
12-17-2021, 07:59 PM
#546
Registered
If not..., I agree w/ 9krpmrx8.
All the best.
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