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Back when I was JB4, I was able to cut 3.9s RWD.

An AWD car should be able to cut better, probably like a 3.7 on the street. It'll take some practice with footbraking off the line, but it's doable.

Here's the JB4 custom map 6 I had back then - this is full send and only recommended if you know you've got good 93, are watching temps and timing etc, and make if you've got a full turbo back exhasut setup.

RPM 1500-7000, interval 500 +3 +3.5 +4 +5 +8 +8 +7 +7 +7 +5 +3 +0

This is on a RS400, for a SS/Luxe add 5psi to all of those.
3.9s on a JB4 is pretty impressive regardless of drivetrain.

So you had traction issues holding you back?
I've seen plenty of RWD JB4s who deadhook no issues, but also aren't running 3.9s.
 

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I think there's a lot of misconceptions about the boost profile on a RS400.

It's 14psi peak, not flat, and even then the car doesn't always request 14psi. For example, my RS400 I noticed that according to the JB4 logs, it never requested more than 13ish psi.

The highest overall boost request was +8psi resulting in a max boost of 21psi. This is still less than a lot of other tuners run on stock turbos early on in the rev range. I usually tune cars to 18-19 nowadays, but there's some guys who want that extra torque and we'll still push them to 21 on request.

Here's 3 data logs with 3 similar JB4 profiles I tested on a dyno that day, one was from Jay who ran an 11.9 on JB4

 

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The highest overall boost request was +8psi resulting in a max boost of 21psi. This is still less than a lot of other tuners run on stock turbos early on in the rev range. I usually tune cars to 18-19 nowadays, but there's some guys who want that extra torque and we'll still push them to 21 on request.
Well, to be fair, it seems that the stock turbos on an RS can barely handle the factory tune of 14 psi, whether or not they even hit that peak number.
 

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Back when I was JB4, I was able to cut 3.9s RWD.

An AWD car should be able to cut better, probably like a 3.7 on the street. It'll take some practice with footbraking off the line, but it's doable.

Here's the JB4 custom map 6 I had back then - this is full send and only recommended if you know you've got good 93, are watching temps and timing etc, and make if you've got a full turbo back exhasut setup.

RPM 1500-7000, interval 500 +3 +3.5 +4 +5 +8 +8 +7 +7 +7 +5 +3 +0

This is on a RS400, for a SS/Luxe add 5psi to all of those.
Do you happen to have a Dragy of this? Would love to see it as I'm assuming you weren't using the JB4 app for 0 to 60 time.
 

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I didn't even consider the RS models but yeah maybe the gearing and more aggressive base tune could help get it done. My AWD sport could only cut 1.9 60ft and the tires wouldn't even spin at that point. I'm not sure I've seen a AWD JB4 car go any faster than a high 1.8 60ft.
Back when I was JB4, I was able to cut 3.9s RWD.

An AWD car should be able to cut better, probably like a 3.7 on the street. It'll take some practice with footbraking off the line, but it's doable.

Here's the JB4 custom map 6 I had back then - this is full send and only recommended if you know you've got good 93, are watching temps and timing etc, and make if you've got a full turbo back exhasut setup.

RPM 1500-7000, interval 500 +3 +3.5 +4 +5 +8 +8 +7 +7 +7 +5 +3 +0

This is on a RS400, for a SS/Luxe add 5psi to all of those.
 
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Here's the JB4 custom map 6 I had back then - this is full send and only recommended if you know you've got good 93, are watching temps and timing etc, and make if you've got a full turbo back exhasut setup.

RPM 1500-7000, interval 500 +3 +3.5 +4 +5 +8 +8 +7 +7 +7 +5 +3 +0

This is on a RS400, for a SS/Luxe add 5psi to all of those.
Don't think this is possible to run even close to safely on an RS with pump gas. If you did it on high E content fuel you would also likely be running dangerous AFR if still on stock fuel pumps. JB4 probably limited you to 20psi as failsafe unless you raised it. Even that is too much on just pump gas.

JB4 maxes out at +9 so not possible to add 5 to those numbers...probably a very good thing! Not a responsible recommendation IMHO.
 

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I think "Boxy" may have some experience with tuning Qs :)
 

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All due respect Blackhawk (you have done some amazing things with your car) JB4 is limited in what it can do. Maybe he cracked the code somehow and turned it into a precise tuning instrument? But, what you do with your own car is one thing...advising someone to add +13 is not a responsible thing to do.
 

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My comment wasn't specifically directed at you although directly under yours. Just wasn't sure if people realized Boxy was Racebox, that does carry some weight.

But yeah I wouldn't run +13 on a JB4 but have no concerns running it on an ecutek tune. Peak boost is just exactly that but I could see someone thinking they can target hitting +13 across the whole rpm range in a JB4. JB4 is pretty dangerous in that regard in the wrong hands
All due respect Blackhawk (you have done some amazing things with your car) JB4 is limited in what it can do. Maybe he cracked the code somehow and turned it into a precise tuning instrument? But, what you do with your own car is one thing...advising someone to add +13 is not a responsible thing to do.
 
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My comment wasn't specifically directed at you although directly under yours. Just wasn't sure if people realized Boxy was Racebox, that does carry some weight.
Oh wow! I had not idea it was Racebox! I thought in that interview he had with BoostinMotion he said he did some crazy stuff with JB4 prior to learning how to tune the platform and starting Racebox.
 

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I could be wrong but I think it is :)

Oh wow! I had not idea it was Racebox! I thought in that interview he had with BoostinMotion he said he did some crazy stuff with JB4 prior to learning how to tune the platform and starting Racebox.
 

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Boxy is Hussain Boxwalla from Racebox.
 

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Boxy is Hussain Boxwalla from Racebox.
If it is Hussain, then he has the same problem as Wayne Gretzky trying to coach. It does not work telling much lower (discipline specific) IQ/Skillset people "Just go do it how I did it"!
 

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If it is Hussain, then he has the same problem as Wayne Gretzky trying to coach. It does not work telling much lower (discipline specific) IQ/Skillset people "Just go do it how I did it"!
I'd love to see the Dragy.
 

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Well, to be fair, it seems that the stock turbos on an RS can barely handle the factory tune of 14 psi, whether or not they even hit that peak number.
True, but also true of literally everything else on the VR30. We literally had a bone stock car come in yesterday because he developed a crack in the casting at the back of the block. Quality control is a huge issue on these cars, so if you're going to mod your car, I wouldn't really base decisions off the fact that stock turbos blow at stock levels. PS2s also blow brand new from factory without even doing a pull. It's just the way this platform is.

Do you happen to have a Dragy of this? Would love to see it as I'm assuming you weren't using the JB4 app for 0 to 60 time.
I used to, but that was like 4 phones ago so I don't have it anymore. I swear I had posted it somewhere but I guess not. You'll have to take my internet word for it, don't really have a reason to lie.

I didn't even consider the RS models but yeah maybe the gearing and more aggressive base tune could help get it done. My AWD sport could only cut 1.9 60ft and the tires wouldn't even spin at that point. I'm not sure I've seen a AWD JB4 car go any faster than a high 1.8 60ft.
I did it at the track on an 1/8 mile pass, it would have never done it on the street.

Don't think this is possible to run even close to safely on an RS with pump gas. If you did it on high E content fuel you would also likely be running dangerous AFR if still on stock fuel pumps. JB4 probably limited you to 20psi as failsafe unless you raised it. Even that is too much on just pump gas.

JB4 maxes out at +9 so not possible to add 5 to those numbers...probably a very good thing! Not a responsible recommendation IMHO.
All of these things I agree with, lol. Which is why I said "this is full send and only recommended if you know you've got good 93, are watching temps and timing etc, and make if you've got a full turbo back exhasut setup."

I added a disclaimer, but this is a forum and people probably won't read it. Then again, OP asked what was possible with a JB4, not what was possible with safety and running it like that back to back for 100k miles or anything. I assume people can use their own discretion (although my customer base has repeatedly proven to me that this is not true, lol).

I think "Boxy" may have some experience with tuning Qs :)
1127 VR30s as of my latest count today :D

All due respect Blackhawk (you have done some amazing things with your car) JB4 is limited in what it can do. Maybe he cracked the code somehow and turned it into a precise tuning instrument? But, what you do with your own car is one thing...advising someone to add +13 is not a responsible thing to do.
Nah, no code cracking. I also mentioned in a follow up comment that not all VR30s target/make the same boost stock even from RS to RS or Luxe to Luxe. For example, mine targeted 13 peak and I added 8, so 21psi. I'm just repeating myself here, but you get the point (I hope). Not really about responsibility, this is an open internet forum and the thread is discussing what is possible. I understand your concern, but that's why I offered up the disclaimers and extra info. This was advice meant for people who understand JB4 and how to read their own logs, which I assume OP is able to do.

I'll re-iterate though since this got more attention than I thought it would (I guess the forums are pretty active these days!), 21psi peak on JB4 93 is generally NOT safe and should only be done if you are certain your gas quality is good and have taken logs to confirm timing is not being pulled (stair stepping).

Oh wow! I had not idea it was Racebox! I thought in that interview he had with BoostinMotion he said he did some crazy stuff with JB4 prior to learning how to tune the platform and starting Racebox.
I could be wrong but I think it is :)
Unless I'm confusing him with another member (entirely possible) I believe he is AMS tuned so it's not Hussain.
It is I! I was never AMS tuned, lol. JB4 and then my own sauce.

If it is Hussain, then he has the same problem as Wayne Gretzky trying to coach. It does not work telling much lower (discipline specific) IQ/Skillset people "Just go do it how I did it"!
Indeed. That post was intended for disciplined people experienced in looking at their JB4 logs, as I initially said as well lol.

I'd love to see the Dragy.
Unfortunately I don't have it :( Sorry to disappoint. I just scoured all my posts on FB but there's too many to go all the way back and FB's search function sucks.

I DID find Colby's post of his best JB4 time though, showing sub 4 0-60 (invalid but slope on 0-60 is rarely accurate on dragy, you'll see valid 1/4 mile times with an invalid 0-60 at the start). Attached slip from Colby Conaway who also holds the stock block PS2 record at like 10.3x, so driver mod is required to get good times on JB4 lol.
 

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I DID find Colby's post of his best JB4 time though, showing sub 4 0-60 (invalid but slope on 0-60 is rarely accurate on dragy, you'll see valid 1/4 mile times with an invalid 0-60 at the start). Attached slip from Colby Conaway who also holds the stock block PS2 record at like 10.3x, so driver mod is required to get good times on JB4 lol.
Thanks for the info. Was Colby or your car an RS? Reason I ask is looking at my Dragy vs the 1 you posted, that pic hits peak G almost right at launch lamost like launch control, but all JB4 pics I've seen show the delayed peak G because of throttle response/torque limits of the stock tune. I would assume this would be the case regardless whether it's RWD or AWD assuming no tire spin, but the RS has different torque tables so that could help explain it.
Ps....love the technical dicussion!
 

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Wow Boxy - great to see a stand up guy coming back here and clarifying and commenting on everything said! No wonder your work is widely praised here - both the service and the results!
 
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