+1 :smile:
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Prospeed rdx injectors & ecu rom tune kit
- Thread starter Prospeed
- Start date
+1 :smile:
How much is the kit if I already have a socketed ECU?
It would be cool to include the OEM injector in the comparison as well to see what spray pattern and cone angle Honda’s engineers chose when the intake manifold and cylinder head were designed. If the RDX injector has the same pattern but just atomizes the fuel better, it sounds like a winner! It’s too bad the RDX injector has a higher flow rate than stock, in my opinion, since that means you cannot use it with the chip you currently have in your PGM-FI. And I don’t know who can do a custom tune for me over here in Europe.
To be fair, there are still two variables being changed at the same time – more modern injectors plus a custom-tuned chip. To see how much the injectors alone bring, it would be good to install them in a car that has already gotten a custom tune from you. You could do a before dyno (OEM injectors, OEM chip), a halfway dyno (OEM injectors, custom-tuned chip), and an after dyno (RDX injectors/custom-tuned chip). That would quantify how much of a gain you can get with custom tuning alone and how much more you can get with custom tuning plus more modern injectors. But it would require more dyno time…
Personally, I’m glad our NSXs don’t have Direct Injection (DI). I’ve read about too many problems you can get with carbon fouling the tiny holes in the nozzles when you place the injector in the combustion chamber itself. I’m sure the problems will be worked out over time so that only the benefits remain. With direct injection engines, the evaporating fuel only cools the combustion chamber, not the intake system as well, allowing you to make more power. From a cold start, direct injection engines don’t have to worry about droplets of fuel condensing along the walls of the intake tract. Until the problems are worked out though, I’m glad our NSX has good old reliable indirect fuel injection. Like Formula 1 cars are still using in 2012.
It seems to me that the injectors are mounted at very different angles in SoS’s ITB setup than in the stock intake manifold. For that reason, the spray pattern of the OEM injectors may not be ideal in your ITB setup. With the OEM pattern you may end up spraying the fuel at the wall of the ITBs instead of down the backs of the intake valves. If your current injectors spray the fuel at an angle, I’d try to find replacements that atomize the fuel better while still spraying the fuel at the correct angle. 2¢
- Joined
- 28 May 2011
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- 184
sup fellas, i just got the rdx injectors installed by brian (prospeed) a few weeks ago along with ecu rom. all i can say is this is a must to get for the budget. i am only running intake and exhaust, no headers at all..and the powerband felt so much better thru redline. i had my redline to be extended to 8100rpm and i am telling you, you can still feel the power!!!
this is a "must" have for people who is going to n/a route. i wish i had individual throttle bodies but i am going to get headers soon, get it dynoed by prospeed. props to brian's knowledge and effort to make this happen. dont hesitate guys, you will never be disappointed.
p.s. i also had the car smogged (cali rules) and it passed like a charm!
i will posts the numbers when i can.
brian, i guess i'll see you nextweek.......lol !!!:wink:
this is a "must" have for people who is going to n/a route. i wish i had individual throttle bodies but i am going to get headers soon, get it dynoed by prospeed. props to brian's knowledge and effort to make this happen. dont hesitate guys, you will never be disappointed.
p.s. i also had the car smogged (cali rules) and it passed like a charm!
i will posts the numbers when i can.
brian, i guess i'll see you nextweek.......lol !!!:wink:
Has anyone seen this video? Is more always better? Or do we max out the benefits at 750cc for a stock motor? I think this guy was running a turbo and I am going to guess that if you are NA, you can't get enough air in to the combustion chamber to match that much fuel.
http://www.youtube.com/watch?v=9OR_QHPm-9w&feature=youtube_gdata_player
http://www.youtube.com/watch?v=9OR_QHPm-9w&feature=youtube_gdata_player
2000 is WAY too big for an NA application.
ID725s should be fine for the biggest of NA applications.
ID725s should be fine for the biggest of NA applications.
It would be cool to include the OEM injector in the comparison as well to see what spray pattern and cone angle Honda’s engineers chose when the intake manifold and cylinder head were designed. If the RDX injector has the same pattern but just atomizes the fuel better, it sounds like a winner! It’s too bad the RDX injector has a higher flow rate than stock, in my opinion, since that means you cannot use it with the chip you currently have in your PGM-FI. And I don’t know who can do a custom tune for me over here in Europe.
The spray pattern I showed in the pic is essentially the same as the OEM injector... This is another pic I found on the internet of the OEM 240cc injector
The purpose of our RDX Spec rom is to offer a chip which you can use with the RDX injectors. Cherylmejia hasn't dynoed his car yet and is running the 410cc injectors... he also recently passed emissions here as well.
To be fair, there are still two variables being changed at the same time – more modern injectors plus a custom-tuned chip. To see how much the injectors alone bring, it would be good to install them in a car that has already gotten a custom tune from you. You could do a before dyno (OEM injectors, OEM chip), a halfway dyno (OEM injectors, custom-tuned chip), and an after dyno (RDX injectors/custom-tuned chip). That would quantify how much of a gain you can get with custom tuning alone and how much more you can get with custom tuning plus more modern injectors. But it would require more dyno time…
Yes, If you read again what I wrote I said the comparison is between ONLY the rdx injectors AND ecu rom tune. =) If you look at the first dyno graph on the first page you can see that we did just that...
91 NSX 5 SPEED with K&N filter,Comptech Headers,Stock cat and muffler.
Dynapak Dyno
We tested the OEM ecu vs. a Stage 3 rom tune vs. RDX Spec Program and here is the results.
-The dotted green line is the OEM ecu with stock factory 240cc injectors
-The fine green line is the Prospeed ROM tune program with stock factory injectors
- The blue line is the Tuned Prospeed RDX Spec tune with Factory Acura RDX 410cc injectors
We noticed a whopping 37 ft lbs of torque increase at 4200 rpm over stock and over 16 whp on top in VTEC. A combination of a superior injector and a properly tuned ECU really helps the NSX run safer AFR with an ideal idle and part throttle drivability.
Personally, I’m glad our NSXs don’t have Direct Injection (DI). I’ve read about too many problems you can get with carbon fouling the tiny holes in the nozzles when you place the injector in the combustion chamber itself. I’m sure the problems will be worked out over time so that only the benefits remain. With direct injection engines, the evaporating fuel only cools the combustion chamber, not the intake system as well, allowing you to make more power. From a cold start, direct injection engines don’t have to worry about droplets of fuel condensing along the walls of the intake tract. Until the problems are worked out though, I’m glad our NSX has good old reliable indirect fuel injection. Like Formula 1 cars are still using in 2012.
I have no problems with Direct Injection... There is a place for it and more and more manufacturers are going this direction. Honda plans to do this in the new NSX as well. In racing applications such as Formula 1 having the injectors suspended over the individual throttle body is great for racing but not for a street car IMO. I would love to see DAN run a dual stage injector set up like Bisi's drag car =)
It seems to me that the injectors are mounted at very different angles in SoS’s ITB setup than in the stock intake manifold. For that reason, the spray pattern of the OEM injectors may not be ideal in your ITB setup. With the OEM pattern you may end up spraying the fuel at the wall of the ITBs instead of down the backs of the intake valves. If your current injectors spray the fuel at an angle, I’d try to find replacements that atomize the fuel better while still spraying the fuel at the correct angle. 2¢
I agree that is why he plans to run the RDX injectors which do atomize fuel better. We'll see the results soon =)
Thanks man... can't wait to see the smog #'s.
Thanks bud... hopefully people realize what a great product this is!
More isn't always better that's for sure.
Correct!
That picture also looks promising! If the OEM NSX injectors and the OEM RDX injectors have the same cone width and angle (if any) at which the fuel is sprayed out – great.
If I understand it correctly, a “Stage 4” chip is custom-tuned for a specific engine on a dyno (requiring the car to be local) whereas the Stage 1, 2, and 3 chips do not require the car to be local. So the most apples-to-apples comparison would be a “Stage 4” chip with the OEM injectors vs. a “Stage 4” chip with the RDX injectors.
I agree that when the kinks are worked out, placing the injectors directly in the combustion chambers will be only good. But as long as there still are kinks, I like the tried and true port fuel injection we have in NSXs. Maybe with updated injectors, though. Those RDX injectors do look good from what I’ve read so far. Are you planning a skiing holiday in the Alps during which you could maybe do a custom dyno tune?:smile:
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- Joined
- 19 August 2008
- Messages
- 330
No, the "stage 4" does not require you to be on a dyno. Its simply a tune that compensates for the new RDX injectors, where the previous tunes were made for OEM NSX injectors.
Hi Brian,
How it's going? So excited on this new mod, please check your PM.
-Henry
How it's going? So excited on this new mod, please check your PM.
-Henry
greenberet: If it helps any, a couple of tidbits:
1. There's a video of the RDX spray pattern on page one of this thread. Sorry, no angle measurements, but RC Engineering said themselves that the RDX spray pattern was better than: (1) OEM Honda 240s and (2) their own 440 cc injector.
2. Tony Palo from Injector Dynamics told me that their 725 injector has a 5 degree (total) spray pattern, while their 1000 and 2000 injectors have a 25 degree total spray pattern. I asked about the "straightness" of the 725, and here was his reply:
"We've found this to work better in almost every application we've tested because it prevents wall wetting from the injector spraying on the port walls.
Think about it, the port isn't that wide. By the time the spray gets near the valves, a 5º spray angle is about 1-1.5" wide."
As to Prospeed's Stage 4 for you, should you decide to go with the RDX, I would just ask Brian to wait until he dials in an ECU with mods that are nearly identical to yours. I don't think aftermarket Header/Exhaust combo A is going to be that much more efficient than aftermarket Header/Exhaust combo B where it will tremendously effect the scavenging of the cylinders and thereby the AFRs.
1. There's a video of the RDX spray pattern on page one of this thread. Sorry, no angle measurements, but RC Engineering said themselves that the RDX spray pattern was better than: (1) OEM Honda 240s and (2) their own 440 cc injector.
2. Tony Palo from Injector Dynamics told me that their 725 injector has a 5 degree (total) spray pattern, while their 1000 and 2000 injectors have a 25 degree total spray pattern. I asked about the "straightness" of the 725, and here was his reply:
"We've found this to work better in almost every application we've tested because it prevents wall wetting from the injector spraying on the port walls.
Think about it, the port isn't that wide. By the time the spray gets near the valves, a 5º spray angle is about 1-1.5" wide."
As to Prospeed's Stage 4 for you, should you decide to go with the RDX, I would just ask Brian to wait until he dials in an ECU with mods that are nearly identical to yours. I don't think aftermarket Header/Exhaust combo A is going to be that much more efficient than aftermarket Header/Exhaust combo B where it will tremendously effect the scavenging of the cylinders and thereby the AFRs.
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L_RAO: thanks and it does help.
It makes sense that you want the injector spraying down the back of the intake valves and not wetting the walls, if possible. However, since NSXs have two intake valves per cylinder, you need a pretty wide fuel cone to spray both valves from edge to edge. If the injectors are about 130 mm from the valves, it looks like you’d need about a 30° fuel cone to fully hit them since the valves are about 73 mm wide in total. With a 25° fuel cone, you won’t hit the entire surface area of the valves (theoretically), but you’ll get pretty close. With a 5° fuel cone, it looks like you’ll mainly be spraying at the center divider.
Note: picture from JGE Racing Engines
I’d guess a 5° fuel cone is great for engines with only one intake valve per cylinder – see the Corvette LS3 intake port below - because then you can focus on that one valve while barely hitting the walls.
With two intake valves per cylinder, I’d guess that a “split stream” spray pattern would be good and barring that, a wide cone.
The “Factory Honda 240cc” injector pictured in post #84 looks like it sprays a 25° fuel cone without angling it off to one side. Looking at NSX intake ports, it would make sense to mount an injector with that kind of geometry in our engines. If that “Factory Honda 240cc” spray pattern is what our OEM NSX injectors have and the RDX injectors have the same spray pattern, great.
It makes sense that you want the injector spraying down the back of the intake valves and not wetting the walls, if possible. However, since NSXs have two intake valves per cylinder, you need a pretty wide fuel cone to spray both valves from edge to edge. If the injectors are about 130 mm from the valves, it looks like you’d need about a 30° fuel cone to fully hit them since the valves are about 73 mm wide in total. With a 25° fuel cone, you won’t hit the entire surface area of the valves (theoretically), but you’ll get pretty close. With a 5° fuel cone, it looks like you’ll mainly be spraying at the center divider.
Note: picture from JGE Racing Engines
I’d guess a 5° fuel cone is great for engines with only one intake valve per cylinder – see the Corvette LS3 intake port below - because then you can focus on that one valve while barely hitting the walls.
With two intake valves per cylinder, I’d guess that a “split stream” spray pattern would be good and barring that, a wide cone.
The “Factory Honda 240cc” injector pictured in post #84 looks like it sprays a 25° fuel cone without angling it off to one side. Looking at NSX intake ports, it would make sense to mount an injector with that kind of geometry in our engines. If that “Factory Honda 240cc” spray pattern is what our OEM NSX injectors have and the RDX injectors have the same spray pattern, great.
Brian - quick question regarding the rom chip. Is it a general set of tables for I/H/E/RDX setup or are you taking learned values from the stock ecu rom we send you and augmenting those for the higher flow etc? I'm just wondering since I only have H/E right now, but would likely do a K&N Filter at the same time as installing the injectors etc - but by this time I would have the RDX chip back from you. If that's the case it would have no data for the marginally higher intake flow, would it?
Interested to know what the best process would be in terms of order of tasks.
Interested to know what the best process would be in terms of order of tasks.
- Joined
- 22 December 2005
- Messages
- 209
don't want to sound like that guy in here, but is anyone actually a fuel injector expert?
No more or less than anyone here is a "C30A expert" I imagine. Depends what you consider 'expert' - someone familiar with it? The person who designed it? Just people experimenting and theorizing, doing some great research and practical testing it seems. =)
What's a fuel injectors expert?
I get paid to fix people.
However, I have consulted with the following "injector experts": RC Engineering, Injector Dynamics, Deastchwerks, and FIC during the course of this project.
I get paid to fix people.
However, I have consulted with the following "injector experts": RC Engineering, Injector Dynamics, Deastchwerks, and FIC during the course of this project.
- Joined
- 22 December 2005
- Messages
- 209
I mean. It has a power gain obviously, so why is everyone arguing over if its good or not?
I work at a place that designs and manufactures FI and O2 sensors... well gasoline systems, so intakes, injectors, throttle bodies, and o2 sensors... but im no expert, i just know how to test on a computer, lol
I work at a place that designs and manufactures FI and O2 sensors... well gasoline systems, so intakes, injectors, throttle bodies, and o2 sensors... but im no expert, i just know how to test on a computer, lol
Honestly the K&N Filter will not affect the AFR enough to make it worth a tune... you are still using the stock airbox. If it was a intake pipe with a filter than that will come into play. The ecu tables are tuned and fuel and ignition optimized for the addition of mods. You can get the injectors and ecu rom tune with or without the K&N drop in filter.
I am not an expert however I have been using and testing injectors of all styles and sizes for over a decade. I've consulted with Bisi & RC engineering and they know their stuff when it comes to injectors!
I dunno if people are arguing but they want to know more and understand why it's one of the best bang for the buck mods for the NSX! =)
I am in, money paid, cant wait, it will go very nicely with my sick new Messiah.
Brian thanks for the prompt replies to my requests looking forward to receiving the goods.
Cheers
Cam
Brian thanks for the prompt replies to my requests looking forward to receiving the goods.
Cheers
Cam
New injectors that atomize the fuel better than 20 year old injectors do sound great. However, if I’m spending the money on new injectors and a new chip for my PGM-FI, I’d like to do it once and do it right. I don’t want to find out in six months that another injector would have been clearly better, if only I had done the research.
Dude, if you work at a place that has insight into intakes, injectors, etc., could you ask an expert what kind of spray pattern and volume he thinks would be best for an NSX’s engine? (two 35 or 36 mm intake valves per cylinder, one injector per cylinder pointed pretty much straight at the valves and mounted about 130 mm away, 50 psi fuel pressure, naturally aspirated engine with 270 or 290 crank hp in stock form that spins to 8000 rpm)
Dude, if you work at a place that has insight into intakes, injectors, etc., could you ask an expert what kind of spray pattern and volume he thinks would be best for an NSX’s engine? (two 35 or 36 mm intake valves per cylinder, one injector per cylinder pointed pretty much straight at the valves and mounted about 130 mm away, 50 psi fuel pressure, naturally aspirated engine with 270 or 290 crank hp in stock form that spins to 8000 rpm)
Don't you also need the dimensions, volume, compression and material parameters of the combustion chamber?
L_RAO: thanks and it does help.
It makes sense that you want the injector spraying down the back of the intake valves and not wetting the walls, if possible. However, since NSXs have two intake valves per cylinder, you need a pretty wide fuel cone to spray both valves from edge to edge. If the injectors are about 130 mm from the valves, it looks like you’d need about a 30° fuel cone to fully hit them since the valves are about 73 mm wide in total. With a 25° fuel cone, you won’t hit the entire surface area of the valves (theoretically), but you’ll get pretty close. With a 5° fuel cone, it looks like you’ll mainly be spraying at the center divider.
Note: picture from JGE Racing Engines
I’d guess a 5° fuel cone is great for engines with only one intake valve per cylinder – see the Corvette LS3 intake port below - because then you can focus on that one valve while barely hitting the walls.
With two intake valves per cylinder, I’d guess that a “split stream” spray pattern would be good and barring that, a wide cone.
The “Factory Honda 240cc” injector pictured in post #84 looks like it sprays a 25° fuel cone without angling it off to one side. Looking at NSX intake ports, it would make sense to mount an injector with that kind of geometry in our engines. If that “Factory Honda 240cc” spray pattern is what our OEM NSX injectors have and the RDX injectors have the same spray pattern, great.
I took a closer look at the RDX injector and you can see it was designed for a similar port design as the NSX or B-Series head. It was designed for a K-series had which has some similarities as far are port size and valve dimension to the older Honda heads. In the pic you can see the vectoring of the holes and they go right and left... This should give us close to a 25 degree to 30 degrees.
In the video I posted earlier on the first page if you look carefully as the injector slows down you can see it is separated.
<iframe width="420" height="315" src="http://www.youtube.com/embed/bmy8bZHugRA" frameborder="0" allowfullscreen></iframe>
I personally feel the ID725cc injector is superior to the RDX injector but not by much... Again we will test this with L_RAO to see how much better they really are and if they are worth the extra money...What makes the RDX injector so special is the price... Most equivalent/better injectors out there cost twice as much.
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- 22 December 2005
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- 209
I will talk to someone. I work at Bosch Anderson, but I deal with TCU, ECU, ESP, and ABS. does someone have the official intake/cylinder dimensions and angles? and stock fuel injector stats vs. the new one. Ill just give them everything and get an opinion. Also, if the injectors are Bosch or if you guys need any Bosch parts, I can order for you at a pretty nice discount usually, and it ships direct to you... I do this same thing on L4P, so why not do it for you guys to and save a few $$$.
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