Strokercharged95GT 13b-REW Build
#726
Registered
Thread Starter
With the 369, I would be happy with 10 psi by 4,500, 14 psi by 5,000, and 18 psi by 5,500. etc. (kill mode would be 20-22 psi from 6-8k)
#728
Registered
Thread Starter
#730
Registered
Thread Starter
The following users liked this post:
Brettus (03-18-2020)
#732
speaking of transmissions... I would really like to see the ZF8hp put in an rx8... consistency and really a great trans.
#733
Registered
Thread Starter
#734
Registered
Thread Starter
Kinda bored on lock-down. I took my last 3rd gear pull at 24-28 psi.
I took all the raw data in excel and calculated the average time and average mile per hour and took and average at every RPM point from 4000-7800 RPMs in 100 RPM increments from the pull.
I then added as trendline to see exactly where I was making power and where I wasn't.
Some interesting finds. Now none of this takes air resistance as a factor which it definitely would as a car accelerates from 50 to 100 mph, so you have to take that into consideration while analyzing the data.
As I have mentioned in the past, the car feels fast but I have definitely noticed the power dropping off more and more in the upper RPMs as I keep turning up the boost. This is likely due to the compressor efficiency dropping like a rock as I move into the inefficient areas along the 2.7-2.9 PR of the compressor map. It could also be an undersized 3" exhaust.
I think that the data pretty much confirms this. Based on the data, it appears that i'm making peak horsepower around 6,100-6,500 RPMs then the power tails off. Even with wind resistance, you would think this graph would level off as I should be making more power between 7-8k....
I took all the raw data in excel and calculated the average time and average mile per hour and took and average at every RPM point from 4000-7800 RPMs in 100 RPM increments from the pull.
I then added as trendline to see exactly where I was making power and where I wasn't.
Some interesting finds. Now none of this takes air resistance as a factor which it definitely would as a car accelerates from 50 to 100 mph, so you have to take that into consideration while analyzing the data.
As I have mentioned in the past, the car feels fast but I have definitely noticed the power dropping off more and more in the upper RPMs as I keep turning up the boost. This is likely due to the compressor efficiency dropping like a rock as I move into the inefficient areas along the 2.7-2.9 PR of the compressor map. It could also be an undersized 3" exhaust.
I think that the data pretty much confirms this. Based on the data, it appears that i'm making peak horsepower around 6,100-6,500 RPMs then the power tails off. Even with wind resistance, you would think this graph would level off as I should be making more power between 7-8k....
Last edited by strokercharged95gt; 04-03-2020 at 06:31 PM.
#735
Registered
...Some interesting finds. ...have to take that into consideration while analyzing the data.
As I have mentioned in the past, the car feels fast but I have definitely noticed the power dropping off more and more in the upper RPMs as I keep turning up the boost. This is likely due to the compressor efficiency dropping like a rock as I move into the inefficient areas along the 2.7-2.9 PR of the compressor map. It could also be an undersized 3" exhaust.
I think that the data pretty much confirms this. Based on the data, it appears that i'm making peak horsepower around 6,100-6,500 RPMs then the power tails off. Even with wind resistance, you would think this graph would level off as I should be making more power between 7-8k....
As I have mentioned in the past, the car feels fast but I have definitely noticed the power dropping off more and more in the upper RPMs as I keep turning up the boost. This is likely due to the compressor efficiency dropping like a rock as I move into the inefficient areas along the 2.7-2.9 PR of the compressor map. It could also be an undersized 3" exhaust.
I think that the data pretty much confirms this. Based on the data, it appears that i'm making peak horsepower around 6,100-6,500 RPMs then the power tails off. Even with wind resistance, you would think this graph would level off as I should be making more power between 7-8k....
#736
Boosted Kiwi
iTrader: (2)
You should be measuring turbine backpressure IMO . At a guess I'd say the numbers will be getting much higher than what you are predicting on matchbot.
I am running a separate exhaust for WG ..... might be worth considering to get post turbine backpressure down. Have you tried VTA wastegate at this level ?
I am running a separate exhaust for WG ..... might be worth considering to get post turbine backpressure down. Have you tried VTA wastegate at this level ?
Last edited by Brettus; 04-03-2020 at 08:16 PM.
#737
No respecter of malarkey
iTrader: (25)
Well hopefully another exhaust insert didn’t close off like before. Which may have occurred previously due to the fuel injection/harness issue you may have resolved recently. It was a head scratcher then, but kind of all makes sense now, right?
So on one hand you don’t have the modular ecu or emap would be simple. On the other hand, there’s no point putting the larger S369 turbo on there without at least a 4” or larger exhaust. Which we know can make up to 700 whp and also provides the torque curve you were wanting. Since you’re not planning to keep that turbo, not sure I’d bother with doing anything else before getting a larger exhaust system and taking a peak into the exhaust ports.
So on one hand you don’t have the modular ecu or emap would be simple. On the other hand, there’s no point putting the larger S369 turbo on there without at least a 4” or larger exhaust. Which we know can make up to 700 whp and also provides the torque curve you were wanting. Since you’re not planning to keep that turbo, not sure I’d bother with doing anything else before getting a larger exhaust system and taking a peak into the exhaust ports.
#738
Registered
Thread Starter
I agree with everything. Even now with running the open gate which helps the take the back-pressure off the exhaust system, the amount of wastegate gasses moving through the gate is inversely proportional to the boost level.
The more boost I run, the lower the flow through the gate and higher amount that goes through the turbine. I know there are parts of the exhaust that neck down to 2.75" so its not even a true 3". Even if I ran a true 3.5" from down-pipe to exhaust tip, i'm sure that would equal a 50% flow gain.
I would almost certainly do a true 3.5" exhaust with the new turbo. To make a 4" down-pipe fit I wold definitely have to do some metal massaging on the inner frame rail....
The more boost I run, the lower the flow through the gate and higher amount that goes through the turbine. I know there are parts of the exhaust that neck down to 2.75" so its not even a true 3". Even if I ran a true 3.5" from down-pipe to exhaust tip, i'm sure that would equal a 50% flow gain.
I would almost certainly do a true 3.5" exhaust with the new turbo. To make a 4" down-pipe fit I wold definitely have to do some metal massaging on the inner frame rail....
The following users liked this post:
Brettus (04-04-2020)
#741
No respecter of malarkey
iTrader: (25)
In theory, but reality indicates otherwise in both response and output. I have full 3” running NA, lol 😆
I only suggested it because his intention is to move to a larger turbo. 3.5” would be better, but it’d be better still with a 4” DP based on everything I’ve ever seen from people who made the change from 3” to larger. A 3” dump pipe would be fine because it’s short and open, but back to the bumper with mufflers and such is going to add restriction.
I only suggested it because his intention is to move to a larger turbo. 3.5” would be better, but it’d be better still with a 4” DP based on everything I’ve ever seen from people who made the change from 3” to larger. A 3” dump pipe would be fine because it’s short and open, but back to the bumper with mufflers and such is going to add restriction.
#743
No respecter of malarkey
iTrader: (25)
You first
the turbo has to be choking up for sure, but if it was running super lean on one rotor then he might have melted down an exhaust insert on that one rotor again even if only partially
https://www.rx8club.com/rotary-swaps...1/#post4883248
the turbo has to be choking up for sure, but if it was running super lean on one rotor then he might have melted down an exhaust insert on that one rotor again even if only partially
https://www.rx8club.com/rotary-swaps...1/#post4883248
#744
No respecter of malarkey
iTrader: (25)
Last edited by TeamRX8; 04-05-2020 at 02:24 PM.
#745
Registered
Thread Starter
When the exhaust inset collapsed the car made 0 power and the engine made a loud tick noise. Even with power dropping off, I am seeing the highest acceleration numbers under 7,000 RPMs with my latest pulls.
I would go hood dump, but my neighbors would murder me and the HOA wouldn't be too happy. I'm already the "loud car guy" in my neighborhood.
I may be able to massage a 3.5" inch downpipe between the LIM and frame rail with some massaging, but a 4-inch would be impossible without some hacking of the frame rail.
I could run maybe 12-14" of 4" directly off the turbo then neck it down to 3.5" and run it all the way back....
I would go hood dump, but my neighbors would murder me and the HOA wouldn't be too happy. I'm already the "loud car guy" in my neighborhood.
I may be able to massage a 3.5" inch downpipe between the LIM and frame rail with some massaging, but a 4-inch would be impossible without some hacking of the frame rail.
I could run maybe 12-14" of 4" directly off the turbo then neck it down to 3.5" and run it all the way back....
#747
Registered
Thread Starter
I am using the BR10EIX 6801 NGK (same as NGK 6957 BR10EIX SOLID IX). I had to take a socket and lathe it down with a angle grinder to fit it inside of the rotor housing.
Yes adding water will likely rob some horsepower from the engine. Its definitely better to have five 200 cc/min nozzles than one 1000 cc/min nozzle to keep the injectant atomized.
I like the idea of putting as many safeguards on the motor as possible. I am almost 100% certain that my rear secondary injector (1650 cc/min) was not firing for months as I pushed the motor pull after pull at 20+ psi.
Running high amounts of water, methanol, and ethanol likely saved the motor during all this as I rarely documented any knock levels that worried me.
Yes adding water will likely rob some horsepower from the engine. Its definitely better to have five 200 cc/min nozzles than one 1000 cc/min nozzle to keep the injectant atomized.
I like the idea of putting as many safeguards on the motor as possible. I am almost 100% certain that my rear secondary injector (1650 cc/min) was not firing for months as I pushed the motor pull after pull at 20+ psi.
Running high amounts of water, methanol, and ethanol likely saved the motor during all this as I rarely documented any knock levels that worried me.
Last edited by strokercharged95gt; 04-13-2020 at 07:14 AM.
#749
Registered
Thread Starter
Just a quick update. About 2-3 weeks ago I noticed that my coolant expansion tank was leaking from one of the welds. The tank was a POS and way undersized at like less than a half liter. So I decided to replace with a bigger tank.
In true me fashion, I purchased a $38 china bay coolant tank that is 1.25 liters, welded my old cap and assembly to the top for pressure relief and fabricated a bracket to hold in the perfect place. I am now just waiting on a 8AN orb to 10AN fitting to complete the connect from the tank to the thermostat housing.... About $55 in parts to make this.
Should be up and running by early next week.
In true me fashion, I purchased a $38 china bay coolant tank that is 1.25 liters, welded my old cap and assembly to the top for pressure relief and fabricated a bracket to hold in the perfect place. I am now just waiting on a 8AN orb to 10AN fitting to complete the connect from the tank to the thermostat housing.... About $55 in parts to make this.
Should be up and running by early next week.
The following users liked this post:
MaD666MaX (04-24-2020)
The following users liked this post:
strokercharged95gt (04-24-2020)