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Its off my list, but that has to do with the fact that I want to drive a V8 car. For me the car is pretty much done at this point so I can save money at a faster rate
The big tb made more power on my cars from 3000 and above. No change to below 3k. One is stock long block and one has bvh and cam
Most of the gain in the data logs was over 6000
I also had gains in boost/hp by tuning the TB to open more than 81 degrees
if your running the stock intake tube there nooooo wayyyyyy you utilized that throttlebody to its full potential. The oem intake hose is puny. Im running a FULL 3in custom made intake. I actually asked an ebay seller to make it for me and he did very cheap.i wanted a complete 3in internal diameter because I planned on matching it to that larger tbody buuuuut yaaaaaa...which makes me wonder , I wonder if running a 2 1/4 or 2 1/2 inch internal diameter intake might actually add power. I wonder if my intake is over kill , along with my fully ported sneedspeed manifold. I bet I pick up power going smaller intake and smaller intake manifold.
how did you log that it made more power ?? It showed a huge drop of air velocity with my setup and I was running a sprintex with 62mm pulley , bvh , cam and every other bolt on. So I thought for suuuuuuuuure the larger tbody would help but was disappointed. I then asked adriancl to adjust tune to accommodate for it and he explained to me after looking at my logs the reason why it was causing a powerloss and no tuning could have fixed it. Yea , It felt like it diiiiiiid pull a little harder 5-6kish rpm to 7300rpm but that's it. As much as it lost befor that absolutely DID NOT make up for what it gained on after.
the TB blade adriancl explained to me should only open a set degree because after that it goes past full open and then start closing towards opposite end..optimal tb spot I forget what degree it was buy it has the blade perfectly centered in the housing at wot , it's just not going to get any better either by adding or taking away degrees of opening.. though I think stock tune it doesn't open fully centered but I may be wrong.. I just remember on all my older v8 cars I'd 2x check throttle linkage and make sure my throttleblade was set perfectly.. I HATE drive by wire , how dumb.. and just think , they're going all electric brakes where the brake feedback is electrically controlled....geez NO THANK YOU
Last edited by MiniManAdam; Dec 14, 2021 at 10:47 PM.
if your running the stock intake tube there nooooo wayyyyyy you utilized that throttlebody to its full potential. The oem intake hose is puny. Im running a FULL 3in custom made intake. I actually asked an ebay seller to make it for me and he did very cheap.i wanted a complete 3in internal diameter because I planned on matching it to that larger tbody buuuuut yaaaaaa...which makes me wonder , I wonder if running a 2 1/4 or 2 1/2 inch internal diameter intake might actually add power. I wonder if my intake is over kill , along with my fully ported sneedspeed manifold. I bet I pick up power going smaller intake and smaller intake manifold.
how did you log that it made more power ?? It showed a huge drop of air velocity with my setup and I was running a sprintex with 62mm pulley , bvh , cam and every other bolt on. So I thought for suuuuuuuuure the larger tbody would help but was disappointed.
In red above -
Anything "before" the throttle body is just ambient air, in pressure. Other than ugly bends and or other restrictions in the factory inlet tubing, you should find no gains or drops in air velocity through the throttle body. Notice that most race cars have no inlet tubing (drag racing), and large inlet tubes (road racing), before the throttle body.
The rest of the inlet tract size (throttle body to super charger) will be affected by the square inches of the ducting.
Thanks for the info guys, I was also thinking about trying a larger throttle body in my JCW. I guess I'll save my time and money for something else, maybe that the EPA (California !) doesn't care about !.
Some false info above the stock intake tube from the throttle body to the air filter is not a restriction. The The throttle body surface area is the most restricting part of the intake you have to account for the throttle plate itself and how much volume it takes up That's why the gains are so good when you install the big throttle body. I did before and after virtual dinos and data logs the gains were significant anyone that says otherwise probably did not do datalog testing. The next most restrictive part of the intake is the plastic to connecting to the supercharger.
By far the cheapest way to get a little more air into the supercharger is the $50 throttle body for me the second deep way is to increase the throttle plate opening from 81° to 90°. The stock to limit it to 81°. It kind of goes back to my first point that throttle body is by far the most restrictive point even when it's fully open at 81°
I should also note the big throttle body gave me an extra pound of boost. Modifying the ECU limit for the throttle body gave me another half pound so a total of one extra pound of booze you do the math on how much horsepower that is
I posted logs showing the boost increase in the first post
Interesting info on the tb blade angle. I always thought that 81° in the logs meant it was fully open, ie. that the sensor angle isn't 1:1 with the blade angle.
it's a software limit, the siemens software has code & tables for "overboost" that opens the throttle plate more but it was never enabled. I found a way to enable it.
the biggest difference on a stock car with just a pully and the big TB the power wont drop off so bad over 6500. The increase in boost at high rpm is almost like adding a mild cam, the car will pull to redline.
I had to add fuel in my open loop map to account for the extra air, it was lean..
YES, please let us know. an 81° throttle opening is a bad thing. I see no reason (other than an (EPA, rpm limiter) that the OEM throttle body to be limited to such a low opening angle.
I did it with winols, I have access to the full damos & siemens documents. it was quite a bit of trial and error modifying the tables in the tune this is the part of the code that led me on to the discovery "Boost for TPS opening to 90° in case of high gear engaged (to be used for R53 power limitation); Typical value: for debug ; O cm2 before 0.75 and 10 cm2 after"
I can do it for others if they have a facelift ecu and MPPS cable... one of my 750 tb's goes to 89 the other to 87. These cheap TBs are knockoffs I'm sure so they cant all get to 90. I keep increasing till it causes a limp error and then back off a degree. I have not tested a stock TB as I see no value in them at this point, first mod I do is junk it and put on a big one
it's a software limit, the siemens software has code & tables for "overboost" that opens the throttle plate more but it was never enabled. I found a way to enable it.
the biggest difference on a stock car with just a pully and the big TB the power wont drop off so bad over 6500. The increase in boost at high rpm is almost like adding a mild cam, the car will pull to redline.
I had to add fuel in my open loop map to account for the extra air, it was lean..
Seems like they left a lot on the table then. Will need to check if that is editable with Bytetronik. I've seen a lot of tables there with max TB opening set to 81 (or 82) degrees. I remember this was discussed at Bytetronik forums a few years back, but then it was concluded that's just the max physical opening angle. Maybe that is the case with the stock TB.
But all the the R53 dyno sheets I've seen have the power curve going up all the way to about 7000rpm where the (stock) limiter is. Did yours start dropping off at 6500?
every R53 I've been in had power drop off on top, the stock RPM limit is 6750 up that to 7500 and you feel it drop off more as it does not flow well up there. There is a soft RPM throttle body cut 200 rpm below whatever you set the redline to (you'll see it start to close TB in log), that's why these cars do not kick you in the ***** when they hit redline, unlike say a subaru... the big tb & limit increase makes a big difference over 6000, feels much more like a PH2/dominator cam for a lot less money. This is assuming you have supporting mods that need the air, like a pulley, intake, header, exhaust.
I dyno'ed my stock head/ph2 cam car a couple years ago, power peaked at 6500, with the cam it does not drop off so sudden.
There's a simple strategy I use to verify changes. use a data logger that captures AFR and do pulls on flat ground 3rd gear to redline. Roll into the throttle.. Feed the log into virtual dyno to compare pulls, you can use it for run to run comparisons of your own car to see changes. the second part of this is the AFR, adding air makes it leaner so to target the same AFR your going to add fuel. Obviously it's making more power, I had to add fuel on every car I did this on.
fwiw I tune my cars to 11.4 from 5k to redline
the last time I looked at bytronik it did not have all the tables that need to be modified they also miss label and incorrectly describe some of the tables
every R53 I've been in had power drop off on top, the stock RPM limit is 6750 up that to 7500 and you feel it drop off more as it does not flow well up there. There is a soft RPM throttle body cut 200 rpm below whatever you set the redline to (you'll see it start to close TB in log), that's why these cars do not kick you in the ***** when they hit redline, unlike say a subaru... the big tb & limit increase makes a big difference over 6000, feels much more like a PH2/dominator cam for a lot less money. This is assuming you have supporting mods that need the air, like a pulley, intake, header, exhaust.
I dyno'ed my stock head/ph2 cam car a couple years ago, power peaked at 6500, with the cam it does not drop off so sudden.
There's a simple strategy I use to verify changes. use a data logger that captures AFR and do pulls on flat ground 3rd gear to redline. Roll into the throttle.. Feed the log into virtual dyno to compare pulls, you can use it for run to run comparisons of your own car to see changes. the second part of this is the AFR, adding air makes it leaner so to target the same AFR your going to add fuel. Obviously it's making more power, I had to add fuel on every car I did this on.
fwiw I tune my cars to 11.4 from 5k to redline
the last time I looked at bytronik it did not have all the tables that need to be modified they also miss label and incorrectly describe some of the tables
If power is dropping at 6500rpm then I'd say there's something wrong with it. Stock limiter is at 6950rpm, and the soft limiter you mention starts kicking in at 50-100rpm below it (it doesn't seem to be consistent) in my logs. I see this in my logs with stock limiter, and I see the same when I raise the limiter. Your car isn't automatic is it? They have different tunes and limiters.
I am familiar with Virtual Dyno. Getting comparable runs can be difficult tho, as I don't own a private runway. Anyway, the first proper 3rd gear wot log that I took back in 2014 with stock limiter is showing peak power at 6872rpm in Virtual Dyno. That's where the TB started closing. The only engine mod back then was a -17% pulley, and I was doing AFR tuning for E85. I aim for about 12.0 - 12.2 with it.
You're right about Bytetronik table labels and descriptions, they're good guesses at best. They have been promising an update with correct descriptions for over 4 years now I think. Obviously they have moved on from the R53 to more profitable platforms...
I've had 10-12 r53's in for work including the three I own, all of them have a power drop at top
if you lower the sampled data you can get more data points in most loggers and catch the RPM the soft limit starts at there is a consistent throttle close I'll see if I can find what the parameter is and how it works in the siemens docs
I prefer the soft limit just account for it in your tune.. The injector cutout on most cars is horrible, when our toyota 86 hits the rev limit it's like hitting the brakes, rpm will drop down well below the limiter it's so dumb
I spent some time in the docs today, the ETC aka throttle control appears to have a time function when nearing the limit. I"ll have to test to see if the cut RPM changes based on gear, typically I only log in 3rd gear, 4th gear is out of the question until I do another trackday
The Bytetronik dongle is actually getting more data points in logs than any generic OBD2 logger than I've seen, so I don't think that's the issue with me seeing variance in the soft limiter.
I bought another cheap big TB too, will be playing around with them to see how far they open up to. My car is in winter hibernation and due for some maintenance work (and rust fixes...) so can't do any testing before early April probably. Hoping to put it in action at Nordschleife in May.
I'm gonna be working my big tbody. Past I tried it I lost too much down low far to justify using it BUT I was on a stock sc and other things then. I'm curious to see if this is going to help my 21lb max psi peak abit sooner in the rpm..
I plan on actually tapping the throttlebody to install tge vacuum line on it because idk if it effected my car last time or not but i feel like i may have messed up vacuum routing . Though it didnt cause a vacuum leak i have a feeling my tmap was not getting accurate reading because of my T's in my vacuum lines then ( I've fixed ALL vacuum routing and lines since) so I'm hoping trying this a 2nd time will net me better results.
If you had a drop in low rpm power it was not from the bigger tb. Logs would show if you needed more fuel at low rpm high load. I alter my pedal table so the car is easier to modulate power on track, you could do this too it's effectively keeping the throttle plate closed more at low rpm/pedal input
I already had a custom intake tube made that's 3in all the way through so it should fit onto the throttlebody just fine..like I mentioned before last time I tried this mod I had far far less engine modifications and I'm pretty sure whwre I tapped in for vacuum wasn't rite, my car just never felt like it was making enough power downlow to run it then.
so a bunch of mods and 6lb more of boost I'm hoping that it will now benefit my setup running a larger tbody. Then , so I know FOR SURE my cars vacuum routing is correct I drilled and tapped the throttlebody to accept the vacuum line that goes to our stock throttlebody.... won't be about a month until I get around to this modification but I will chime in again with my results the 2nd go around .
If you had a drop in low rpm power it was not from the bigger tb. Logs would show if you needed more fuel at low rpm high load. I alter my pedal table so the car is easier to modulate power on track, you could do this too it's effectively keeping the throttle plate closed more at low rpm/pedal input
you may be correct. It may have been too lean. I was only running a narrow band 02 at the time but i did knowtice it leaned out. Maybe it did so much it pulled timing and I don't mean like partial throtlle loss . It drove just fine , no yoyo or high or low or fluctuating idle. If I went wot from a stop it felt like I lost a good bit of power until about 40-50mph and then it just began to pull like a freight train BUT the loss downlow wasnt justifiable so if i can get that top end increase and no low end lose I'd be happy. I really gotta start learning to tune my self , unfortunately I'm a hand on kinda guy so I'd need someone actually sit me down with PC n all and teach me. I try n try to watch videos but omg its all a foreign language lol I'm pc stupid asis. I also ordered a wideband kit so I can keep an much better eye on afr instead of using the inpa
Anyway, the first proper 3rd gear wot log that I took back in 2014 with stock limiter is showing peak power at 6872rpm in Virtual Dyno. That's where the TB started closing. The only engine mod back then was a -17% pulley, and I was doing AFR tuning for E85. I aim for about 12.0 - 12.2 with it.
