Subscribing to this thread so I can share these details with my tuner when it happens.
Stew's Sonic
- Thread starter Stew
- Start date
Subscribing to this thread so I can share these details with my tuner when it happens.
ScarabEpic22
Member
Stew- Those Bosch injectors are rated for 42lb/hr at 3Bar (43.5psi [common Ford pressure]) while GM uses 4Bar (58psi). Since GM uses a higher base pressure, these injectors are actually larger than 42lb/hr and in a GM vehicle are 47lb/hr.
I know everyone's hot and heavy on these Bosch injectors, but can someone please explain why to me? From what I've gathered, they're popular because it's what Trifecta can easily tune for. With HPTuners/EFILive, we have a LOT more (and IMHO, potentially better) injectors available because we can calibrate the tables ourselves. Questions like what is the spray pattern like on the Bosch 42lb/hr? How close is this to the stock spray pattern so wall wetting and evaporation factors are accounted for?
I know everyone's hot and heavy on these Bosch injectors, but can someone please explain why to me? From what I've gathered, they're popular because it's what Trifecta can easily tune for. With HPTuners/EFILive, we have a LOT more (and IMHO, potentially better) injectors available because we can calibrate the tables ourselves. Questions like what is the spray pattern like on the Bosch 42lb/hr? How close is this to the stock spray pattern so wall wetting and evaporation factors are accounted for?
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Stew
Sedans Rule!
Erik - Thank you for chiming in! I'll admit that choosing these injectors was largely based on other users success with them (ok it was entirely based on that!), and because others are using them there is data in our Sonic forum for them. I guess that's how defacto standards get started, lol.
When I was looking for documentation on the OEM and Bosch injectors I did find a little bit of data about spray patterns on the Bosch units but nothing on the OEM injectors. So I think the only way to know for sure would be to consult an injector tuning company.
I also saw some websites selling the Bosch injectors that had the lb/hr data you posted but there's also the other data saying 42 @ 39.15, I'm on my way out the door now but later I'll check the calculations using all the different numbers and see what the differences are.
No matter what though this is interesting stuff! Stay tuned...
When I was looking for documentation on the OEM and Bosch injectors I did find a little bit of data about spray patterns on the Bosch units but nothing on the OEM injectors. So I think the only way to know for sure would be to consult an injector tuning company.
I also saw some websites selling the Bosch injectors that had the lb/hr data you posted but there's also the other data saying 42 @ 39.15, I'm on my way out the door now but later I'll check the calculations using all the different numbers and see what the differences are.
No matter what though this is interesting stuff! Stay tuned...
Stew
Sedans Rule!
I'm officially running the Green Giants, woot.
The Ultragauge came in Friday, I got it set up for the car and got the fuel trims as the big gauges on the first page. Had to work all day Saturday at a clients installing new workstations which kinda sucked on a nice Saturday but that gave me two 45 minute drives on the freeway to monitor trims, on the way there and on the way home. As I was sort of expecting, they were pretty much right on but more importantly I could see how they responded to different driving conditions.
Got the injectors in this morning which takes about 15 to 20 minutes if you're taking your time, not much to call out about installing them except maybe one thing. As others have mentioned, the retaining clips don't work on the 42 lb injectors which isn't a big deal because the fuel rail keeps them in, BUT I don't think those clips are so much for retaining the injectors, I believe they are there to keep the injectors clocked correctly.
Without the clips the injectors can rotate around so you want to make sure to line them up as best possible to keep the injector squirt holes (surely there must be a more technical name) pointing towards the intake valves and not the intake port walls.
On to the tuning...
I decided to pick a mid point percent increase of all the various 'percent this' and 'lb/hr that' numbers that are out there and raised the values in the table by 35%. It fired right up and seemed to be running ok. I drove around a little and it was trimming about 20% to 22% negative, meaning it was running rich and it was reducing the injector on-time 20% to 22%.
Alright, pull back in the driveway and lower the percent increase from 35% down to 30% and go back out for a spin. Now I was running even richer and it was trimming 25% or higher, sigh. Pull back in the driveway and put my thinking cap on. I really should just leave it on all the time.
By reducing the amount I increased the injector table, I was getting the numbers closer to stock. If I hadn't changed the injector table at all and simply put in the larger injectors it would be running WAY to rich; eureka, I was adjusting the wrong way.
Re-flash with increased injector values to 45%, and this time go up and down the freeway for a few miles to give the trims a chance to settle, better but still a tad rich. Again to 60%, now it's a little lean, down to 58% and hit the freeway.
Bingo, it is now trimming almost exactly as it was with the OEM injectors. For my car with the SAB, stock exhaust and ported intake manifold I raised the values in the Flow Rate vs Pressure table 58% and it is perfect.
I don't mind sharing this with the forum because you should NEVER simply plug in someone else's data into your tune unless you like living dangerously. Had I done that with the other users data I would not be running right.
I want to say one more thing, HPT is so awesome! I love having the ability and control to adjust anything I want, any time of the day, immediately. If you are on the fence about how to tune, seriously consider HPT!
The Ultragauge came in Friday, I got it set up for the car and got the fuel trims as the big gauges on the first page. Had to work all day Saturday at a clients installing new workstations which kinda sucked on a nice Saturday but that gave me two 45 minute drives on the freeway to monitor trims, on the way there and on the way home. As I was sort of expecting, they were pretty much right on but more importantly I could see how they responded to different driving conditions.
Got the injectors in this morning which takes about 15 to 20 minutes if you're taking your time, not much to call out about installing them except maybe one thing. As others have mentioned, the retaining clips don't work on the 42 lb injectors which isn't a big deal because the fuel rail keeps them in, BUT I don't think those clips are so much for retaining the injectors, I believe they are there to keep the injectors clocked correctly.
Without the clips the injectors can rotate around so you want to make sure to line them up as best possible to keep the injector squirt holes (surely there must be a more technical name) pointing towards the intake valves and not the intake port walls.
On to the tuning...
I decided to pick a mid point percent increase of all the various 'percent this' and 'lb/hr that' numbers that are out there and raised the values in the table by 35%. It fired right up and seemed to be running ok. I drove around a little and it was trimming about 20% to 22% negative, meaning it was running rich and it was reducing the injector on-time 20% to 22%.
Alright, pull back in the driveway and lower the percent increase from 35% down to 30% and go back out for a spin. Now I was running even richer and it was trimming 25% or higher, sigh. Pull back in the driveway and put my thinking cap on. I really should just leave it on all the time.
By reducing the amount I increased the injector table, I was getting the numbers closer to stock. If I hadn't changed the injector table at all and simply put in the larger injectors it would be running WAY to rich; eureka, I was adjusting the wrong way.
Re-flash with increased injector values to 45%, and this time go up and down the freeway for a few miles to give the trims a chance to settle, better but still a tad rich. Again to 60%, now it's a little lean, down to 58% and hit the freeway.
Bingo, it is now trimming almost exactly as it was with the OEM injectors. For my car with the SAB, stock exhaust and ported intake manifold I raised the values in the Flow Rate vs Pressure table 58% and it is perfect.
I don't mind sharing this with the forum because you should NEVER simply plug in someone else's data into your tune unless you like living dangerously. Had I done that with the other users data I would not be running right.
I want to say one more thing, HPT is so awesome! I love having the ability and control to adjust anything I want, any time of the day, immediately. If you are on the fence about how to tune, seriously consider HPT!
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This is interesting to me because my 2013 rpm limiter steps in @6,500
ScarabEpic22
Member
Im looking at my tune now, 7k and 6900 are the breakpoints for the SD<->MAF failover point. Betting that's what it is...
GM put the limiter in about 5 places, have to change ALL of them otherwise the fun patrol will step in!:banana:
FWIW, my 13 RS is set to 6500rpms as the low end limiter. It barely revs over 6k stock because of the way the Commanded TQ table requests a HUGE drop in TQ from 6000->6500rpms.
Erik,
I altered the RPM vs gear tables to allow 7K in first, and 6,800 in second, and from 3rd on is 6,500.
The gap between gears in the non-RSs is horrible for performance, and this things rolls the tires over hard before you ever get rolling in 1st. Giving myself some room in first makes a big difference in acceleration. Not sure how bad the drop between gears is with the RSs.
I altered the RPM vs gear tables to allow 7K in first, and 6,800 in second, and from 3rd on is 6,500.
The gap between gears in the non-RSs is horrible for performance, and this things rolls the tires over hard before you ever get rolling in 1st. Giving myself some room in first makes a big difference in acceleration. Not sure how bad the drop between gears is with the RSs.
ScarabEpic22
Member
Mmmmm 7k in 1st.
opcorn: I'd be interested in playing with this, 1st in the RS is so steep half the time in traffic I'm only in it for a second or two before shifting. Wonder what it'll do for longevity, this is my DD and it's going to stay that way for at least 3 years.One of these days Ill break my GoPro out and can take a video of the RPM drop. It's not as significant as the non-RS, but it's still pretty large from 1->2. The rest of the gears are much better, heck 5->6 is only about a 500rpm drop at 50mph.
Stew- Sorry for the thread hijack!
They actually go right on there. I'll get a picture of mine. There was something a little bit different about installing them, but they went right on with the injectors pointed in the right direction.
Stew
Sedans Rule!
Mmmmm 7k in 1st.
One of these days Ill break my GoPro out and can take a video of the RPM drop. It's not as significant as the non-RS, but it's still pretty large from 1->2. The rest of the gears are much better, heck 5->6 is only about a 500rpm drop at 50mph.
Stew- Sorry for the thread hijack!
No worries! I'll tell ya what, I still need to hook up with an RS owner so I can take a bunch of pics of the rear discs to help me plan my OEM rear disc conversion, help me out with that and we'll call it good!
Stew
Sedans Rule!
I'd definitely be interested to see what you did. I bet if you rotated them 90* from stock the clips would work. The groove in the injector does not go around the entire circumference on the Bosch units like it does on the OEMs. Plus, the OEM injectors have that post sticking out the side which locks their position in the clips. So with the clips on the post-less Bosch injectors they could still rotate, I think!
Sorry.. Phone being goofy. Give me some time.
Stew
Sedans Rule!
Yep, not a prob.
Also, I'd like to thank MPFab for providing some helpful data for my injector install. I did not want to mention him by name at first, or post his data because I asked for my own personal use, but now that the injectors are in, thank you!
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ScarabEpic22
Member
No worries! I'll tell ya what, I still need to hook up with an RS owner so I can take a bunch of pics of the rear discs to help me plan my OEM rear disc conversion, help me out with that and we'll call it good!
Lol we talked about this last summer and life happened, next time John and I meet up to install some parts Ill let you know so you can come down and hang out.
Stew
Sedans Rule!
Clips in place.
As I was looking at this picture another thought popped in my head. I bet another purpose for these clips is to keep the injectors at a known height.
Without the clips not only are the injectors able to rotate in place, mind you they are in there pretty snug so it's not like they're going to be vibrating around on their own, but also without the clips you have some up/down play as well.
If you don't have the injectors in the correct up/down location you could have the spray cone less than ideal. The spray cone widens as it gets further from the injector, if the injector isn't at the correct height then the spray cone isn't positioned correct either.
Looks like I'll be putting those on in the near future.
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calmb4dastorm
New member
So I've just spent the last few min reading your thread and most of the info is way over my head. lol. Your process is super interesting tho. If I grow any balls to try something a know very very little about, I may give HPT a try instead of trifecta. Subscribing for sure. Keep up the great work!
Stew
Sedans Rule!
Thank you! Yeah it's been interesting and fun, this has been a learning process for me, that's for sure, first time tuning a modern car using a software package for me.
