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Reds in P1, Blues in P2, and Yellows in aux. All new from five-O Motorsports. Even with the E85 mix I have not needed more injector yet. I am getting close though so I will just leave it be for now and enjoy it until I blow the engine. It's nice to just have a boosted 8 and to not be dicking with it,
Just saying that if there's a straight forward conventional way, and a less straight forward way where I might learn something, I'll typically take that more difficult path.
The idea of putting the largest injectors into the P1 position came about while chatting with Brett. We were spit balling the best location to put these shiny new Bosch injectors I had just purchased. The P1s provide a nice location closest to the intake ports, and since the P1s come on again at higher loads/RPM (unsure of the trigger for this), the theory is that the larger injectors would address the additional fuel requirements at high load/rpm. There was never any guarantee it was going to work, but since it only cost me some time I thought I'd give it a go. It may still work, but I didn't have enough of the variables identified before I started, so I was always going to fail in spite of my persistence. From this experience I've learned that at a bare minimum you'll need a tune that's dialed in very well (9k on the money), AND you need at least one of the following: accurate scaling value, and/or accurate latency table...I didn't have any of these...lesson learned.
I think that yellow injectors in all positions would be the most reliable injector upgrade, as latency tables and scaling are known. This doesn't provide a huge upgrade in fuel flow though.
Yellow P1s and blue P2s and Secondaries would be my next choice for a "known quantity" solution. The latency tables need to be relatively accurate in the P1 position, so the yellows should go there. Blues in P2 and Secondary could get away with using yellow latency tables, as you're typically using the blues with high load. Inaccuracy from using yellow latency tables for blue injectors would possibly be noticed at high rpms and low load, though it's unlikely this would be very severe, or cause any engine damage due to the low load.
As a side note, I'm not that convinced that the ID1k latency table is particularly accurate. It's very expensive to do the testing to find a single latency value for an injector, let alone a whole table, so I think that table is a best guess on their part. Not that it really matters so long as these injectors aren't used in the P1 position.
Latency figures apparently change when an injector is uncapped, so uncapped injectors probably shouldn't be used in the P1 position unless the tuner has the patience to dial in the latencies (which is a PITA, but possible with a good starting tune and accurate scaling value). Since uncapped are mostly used in P2 and Secondary positions, inaccurate latency figures doesn't seem to be an issue.
Last edited by JimmyBlack; 04-04-2016 at 01:38 AM.
Injector scaling is easy. The number in atr is the actual flow at the cars fuel pressure. 58 psi.
Just take the flow rates your injectors come with a 43.5 psi. Then go online and find a flow calculator. I like deatchwerks. Punch in the flow. Old fuel pres and new pres. Then volia. You have the correct injector scaling number.
The calculator is handy to get into the ball park to get the engine running, but tuning the engine will give us the accurate value.
My Bosch injectors are quoted to flow 980 at 3 bar, but on the flow bench at the local shop they come out at 906cc/min. So using the flow calculator with the initial flow of 906 at 3 bar (4 bar absolute), this give a flow rate of 1013cc/min at 4 bar (5 bar absolute). But from my testing so far I believe it'll end up closer to 1003cc/min.
The scaling figure we put into the tune is arbitrary anyway, but while it may not match flow bench numbers, at least it should translate across different rx8s so we should all be able to use the same scaling value for a specific injector.
As a side note, I'm not that convinced that the ID1k latency table is particularly accurate. It's very expensive to do the testing to find a single latency value for an injector, let alone a whole table, so I think that table is a best guess on their part. Not that it really matters so long as these injectors aren't used in the P1 position.
Check out this video, its a tour of the Injector Dynamics facility, gives a good insight into their manufacturing processes, as well as testing procedures.
Yeah, I know it's not absolute, but it gets you into the ballpark.under boost that number will fall off also. I'm using the ve table to adjust for that fall off.
Yeah, I know it's not absolute, but it gets you into the ballpark.under boost that number will fall off also. I'm using the ve table to adjust for that fall off.
Still Mc'Lovin my ID 1000's! Latency table provided by ID has been great. At $240/pair they cost just a little more than Denso yellows but with no guesswork... That to me is worth it's weight in engine blocks and hours spent sorting out unknown injectors
...As a side note, I'm not that convinced that the ID1k latency table is particularly accurate. It's very expensive to do the testing to find a single latency value for an injector, let alone a whole table, so I think that table is a best guess on their part. Not that it really matters so long as these injectors aren't used in the P1 position.
I'm not going to say they are "accurate" but they have worked well for me
Honestly, I have my doubts about alot of things being "accurate". What matters most is whether or not you are getting the results you are after. I personally prefer to have accurate inputs, but I've come to my own conclusion that we will chase our tails on this. My philosophy for the last couple of years is to get things in to the ball park accuracy-wise then tune for results. Maybe I am wrong, but I am happy with my results...
Edit: For clarity's sake I am not meaning to imply the ID latency table is not accurate, just that I am not equipped to debate the subject. But personal experience has been 100% positive.
I have watched too many guys (including myself) screw with things endlessly and just never have a well running car. That is why you have to have a goal and stick to it and resist temptation to start that chase.
Quick update. Bosch EV14s are now dialed in to a point that I'm happy with.
I've latched up a new external wastegate that holds pressure to 9psi, and since my tune is looking good I've increased boost to 11.5psi.
Performance of the new turbo as compared to the smaller old turbo is quite disappointing. The new turbo is spooling slower than expected, flowing less air at target boost than the old turbo and suffering worse boost taper at high RPM. I suspect there's a boost or exhaust leak causing some inefficiency with the turbo.
Some good news - I tightened up the WG actuator arm over the weekend and the spool improved significantly. I had previously installed it with no tension on the arm as I was concerned that the WG actuator spring was too strong. As there was no tension on the wastegate flap, it was always cracked slightly open and this had a very big affect on spool up. Those experiencing unexpected lag with iWG turbo setups should make sure there is tension on the WG actuator arm pulling the WG firmly shut.
After sorting this out, the lag issue is practically gone, with the car now only slightly laggier than the old turbo, with more zoom at the top end. By comparison, previous turbo flowed a max of 330g/sec on the MAF, and the new turbo flows 356g/sec at same boost pressure (11-12psi), with a max load of 204%. If anyone with a Greddy setup (e.g. BNR turbo) has logs at similar pressure I'd be interested to see a comparison with these figures.
Later this week I'll record the exhaust back pressure and chart it against the old turbo for comparison.
I'm reasonably happy at this point, bearing in mind that this is an interim stage between the existing Greddy manifold and a new custom T3 manifold.
As a learning exercise I'm thinking about getting an external WG welded onto my Greddy manifold to see how much extra top end this will give me before I go to the full custom T3 manifold.
I can't wait for the next step - I have a stainless manifold flange, T3 turbine housing and external wastegate sitting on the garage bench, and I look at them longingly every time I walk past.
Having said that, I'm pretty sure I can hold off for at least a month while I still remember how much of a pain the current turbo was to (re-re-re-)install...and it's really good being able to beat on the car knowing it has a reasonable tune on it once again.
Last edited by JimmyBlack; 06-06-2016 at 10:06 PM.
I was in Fiji until yesterday, but when I saw Brett's post and flew home so I could reply with this:
So I've now dialed my current tune for the new turbo to use the same MAF calibration curve as the old turbo tune, and used the VE to get AFRs accurate. This may have resulted in some tumble weeds, but I did this so that I can accurately compare MAF sensor readings from old turbo logs against new turbo logs.
At first glance it looks like the new turbo wheels are not performing as well as the old ones. However, according to my logs I'm pushing more air than the previous turbo at the same PSI (as expected with the better efficiency from the new compressor wheel). More intake airflow means the engine is pushing more exhaust gas out. I'm thinking that the additional Exhaust gas is increasing the back pressure due to the very restrictive T25 turbine housing. It's gotta go.
Conclusions:
1. Comparing back pressure ratio between turbos that use different wheels while using the same housings, manifold and exhaust only provides a ball park indicator between turbos, as demonstrated independently by Brettus on his turbo setup and me on my turbo setup.
2. Measuring back pressure ratio while keeping the same compressor and turbine wheels gives useful results that help to identify restrictions in the turbo piping setup (compressor inlet piping, charge piping, exhaust manifold, turbine housing and exhaust).
3. Logging MAF sensor output to get an intake airflow reading is an excellent method of measuring performance improvements between turbos, so long as your MAF calibration scale and turbo inlet piping has not been altered between logs...dyno sessions also work.
Interesting results . Perhaps i could do a run at 10psi to make the comparison of the same compressor wheel on a much larger turbine housing.
We're using different turbine wheel size and design, so not sure how much of a comparison that'd give us.
I'm going to pull the turbo over the next few weeks and do a bit of porting work on the flow path from Greddy manifold through the spacer into the turbine housing. It's a bit rough, and I think I can improve performance by a few percent once I smooth it out. Also, the Greddy intake pipe immediately after the MAF pipe, that runs down across the front of the pulleys is pretty rough where it necks down to the smaller pipe diameter, so I'll clean that up at the same time. I'm interested to see if turbine housing porting is a complete waste of time or not.
After that I'll be moving onto fabricating the new manifold, because a few weeks ago I purchased this:
We're using different turbine wheel size and design, so not sure how much of a comparison that'd give us.
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55/65 vs 62/68 not actually that much bigger
Originally Posted by JimmyBlack
I'm going to pull the turbo over the next few weeks and do a bit of porting work on the flow path from Greddy manifold through the spacer into the turbine housing. It's a bit rough, and I think I can improve performance by a few percent once I smooth it out. Also, the Greddy intake pipe immediately after the MAF pipe, that runs down across the front of the pulleys is pretty rough where it necks down to the smaller pipe diameter, so I'll clean that up at the same time. I'm interested to see if turbine housing porting is a complete waste of time or not.
My guess is ............. a 1-2 % is all you get . IMO , the only way to get a significant improvement using existing components is to route the wastegate externally.
The inside of the T25 spacer that sits between the mani and turbine housing has about a 3mm lip from memory - the inside dimensions are way bigger than the mani and turbo flanges, so there's got to be a fair amount of turbulence when it's going full noise. I may also be able to improve flow to iWG. The T25 housing is a throw away item once the new T3 goes on, so I'm not too bothered if I muff it up completely. No doubt I'll learn something from it either way.
While the turbo is off I'll weld up the final location for the new T3 engine and turbo flanges, joining them together with steel rods to hold them in their final position. I can continue sorting out the runner path for the new manifold while it's off the car as I'm using the 8 as my DD.
While the turbo is off I may also check out how easy it'll be to add an eWG while the Greddy manifold is off, as I already have the eWG and welder. I've been searching, but haven't yet found any results posted from people that have installed an eWG on a Greddy. There's a thread with one guy that did this, but he never posted any description of before and after results.
May seem like a lot of fecking about, but for me it's all about the journey.
Ordered stainless pipe for a new twin scroll T3 manifold this week. I've decided on 1.5" diameter Schedule 40 304L for the primaries. 6 week lead time on the short radius elbows, because this is NZ.
04-03-2016, 11:18 PM
