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True, many feel this way and there is nothing wrong w/ that, it is a matter of feel/taste. I don't have that experience w/ high performance cars. I came from a Subaru BRZ, then a VW GTI and now the Stingray and I felt the difference in throttle response since day one. Both the BRZ and the GTI felt smaller, nimbler. But; how come? The C7 has more than double the HP and it is lighter. I thought it was in my head, until I measured/calculated the weight to power ratio at part throttle of the C7, then went into a 375 HP/ 5700 lb SUV and did the same. The weight to power ratios were the comparable and felt comparable (200-300 lb/HP) at part throttle. Then, I knew it was real.
Okay....since you sent me a message and I read, I'm going to drop a comment here. It sounds interesting and neat. I'm not against people making things better in any way that works and provides a level of reliability in concert with what's expected.
For full disclosure I have a 2019 Z06 with a Tony Mamo PTB and currently a BMS filter on board. Borla X pipe waiting for me to get a chance to install it. No other mods. My biggest issue was just that barely off idle needing to get into the power to pull away from a stop or back into throttle at lower rpm which others have mentioned as well, in particular having rpm above 2k by one poster saying he had no issues above that.
You mention coming from 2 other vehicles....neither of which is heavier than the Stingray, not even close in fact. Both of those vehicles are in the 2900-3000 pound range and your Corvette is 3400+ pounds. Both of those vehicles are smaller and nimbler. My Miata is smaller and nimbler than my Z06. It will never change no matter how fast or how much horsepower I have in the Z. The Miata is physically smaller and has less weight and less for the suspension to deal with. Any vehicle with a good weight difference will feel different than another heavier one. You can take a lot of weight outta the Vette and maybe, maybe get it close....install a racing seat, insulation, carpets, etc. But you'll not make it smaller and I can do things with traffic in the Miata the Z would never fit into. But the Miata stands no chance against the Z when any kind of power is on the line. The vehicles you're talking about also are going to be likely revving quite a bit higher and away from that really low rpm cruise and even in weight of the drivetrain and flywheel for revving speed in that initial throttle response in a much better place in the power curve for it. So yes, there's great response in those vehicles with a light reciprocating mass compared to the Corvette and already probably moving along at greater rpm in any given gear for a given speed. My Miata is cruising along at nearly 4k at 70mph....up in the meat of the powerband. A quick search shows many GTIs are likely 2300~ or so at 70mph. My Corvette even in 6th is closer to what, 1500? It's just barely chugging along. I even see people discussing their GTI being at 4k at 70mph for perhaps some of the older ones...so they are in the meat of their powerband with nothing but the opening of the throttle while at part throttle making only a modicum of road hp to keep that given speed. So there is a difference there...comparing similar rpm the Corvette is likely to be more than the lower rpm cruising for mpg once on the move. However with the Mamo PTB and BMS it takes very little throttle to be making boost and making speed with mine now. Yes, at 1200 rpm in 7th it's slower to respond...and honestly I wouldn't expect more at that rpm...but cruising down a hill or on level ground like that and getting nearly 30mpg in a Z06 isn't bad on a long road trip. Can't go 100mph+ everywhere revving the car....although it would be fun if legal....down to 6th and up toward 1700rpm or so and it's much more responsive if I need acceleration.
My biggest issue was more getting going...I've never stalled a vehicle like this Vette and I've never owned an automatic. Ever. Even my anemic off boost 944 Turbo I don't stall. The Mamo PTB took care of that...maybe my style with my other vehicles wasn't entirely compatible with the standard off the line Vette operation. Of course I've gotten 150k out of clutches with other vehicles as well....so I'm not hard on them But yes, it almost seemed like it wasn't getting enough air or something there and now it works just fine.
Your chart is interesting to say the least with comparison between OEM, a PTB and your TB. It only goes up to about 38 degrees of throttle opening which I understand is what you're selling, that narrow window. It shows the PTB you tested against OEM basically being on top of one another along with yours by around 35% opening. This I find interesting as in Tony's testing he got (testing CFM at 20" water) of 36 CFM OEM stock and 59 CFM in his PTB. By 40% on the other side just beyond where your data goes, 81 stock to 124 for his. So I'm guessing this isn't his throttle body on the chart even though you are measuring grams/s vs CFM without sitting down and doing some conversion, aren't easily comparable and a quick conversion page for g/s to CFM doesn't seem to exist. Based upon this I really cannot compare his numbers to yours and whether or not and how much if so, your reworked throttle body provides over that one. His open information was part of the reason I chose his product along with lots of good reviews. The discount for Black Friday didn't hurt either! That page is here: https://www.corvetteforum.com/forums...ts-inside.html
I see from the other pages that data has been sent to you, however right now only a few butt dyno comments have been included. I'm curious to see what you're actually getting in actual performance numbers from that. Now, I don't have a tune and don't plan on getting one in the near future. The two upstream mods I've done can be swapped back in about 30 minutes to stock if need be. Down the road I may consider a full on tune and some additional work, but for the time being I'm pretty happy where I am and with what I get to use the car for. I know that based on what you're doing that this is more part throttle and by 40+ degrees opening there's likely little difference between yours and the others PTBs and even within their work that the numbers on flow start getting closer as you approach 90 degrees/full throttle opening (if it will allow that in the ECU based on it's tables stock). So it may take timing runs from xx mph to xx mph in a particular gear for the same vehicle with different configurations to show the difference or two vehicles identical except in the throttle body to see actual on road performance in pulls (in Mexico or on racetracks of course.....).
Out of curiosity if you're willing to discuss it, how much and many of the throttle bodies that you've built have needed gears swapped to get ideal and how well are these sets generally made stock? It would be curious based on manufacturing and assembly tolerance how much having the "ideal" built throttle body would have as an effect on the performance of the unit...ie one unit might only actually give you 26 degrees instead of 29 degrees at a given position for the throttle or play allowing the airflow to push it further closed than the position motor is trying to maintain. This alone...getting what the computer is trying to select as an opening compared to the actual opening based upon those tolerances might be interesting as a data point alone.
To me a nimble car, or anything nimble for that matter, is something able to accelerate in straight or curvilinear motion. The higher the acceleration, the nimbler it is. No matter its weight, mass moment of inertia (how easy/hard is to turn), size, or power, but rather the ratios between them, specially weight-to-power. This is what I’m looking at.
Usain Bolt, for instance, is taller and heavier than I am, yet I’m not nimbler than him. Neither is a slug nimbler for being smaller. Agree?
So, for its weight and the way it is distributed/located, the C7 has a tremendous amount of power at full throttle, and I’m sure it is nimble at the track. That’s 9.4 lbs/hp for the LT1 cars and 5.4 lbs/hp for the Z06.
That is at WOT, but, for every other position of the throttle, there is also a specific power to weight ratio, proportional to the air admitted by it. So, we can say that since the weight is fixed and power depends on the amount of air admitted, that the only remaining variable is throttle %. Just imagine running several dyno tests at fixed 5 deg, 10 deg, 15 deg and so on up to 90 deg (WOT).
At less than 30% throttle the power to weight ratio of our C7’s falls in the range of trucks and SUV’s (measured). I’m not the first to notice that, there are many accounts of people trying any other cars (sedans etc) and they feel them more responsive, and yes, nimbler too.
To some extent I agree w/ you, it doesn’t matter how much more power you add to your Z06 at WOT, if you don’t let it breathe at part throttle it won’t feel nimble at part throttle.
Looking at it from the RPM point of view is confusing, driving is not a dyno test. Low RPM’s are a consequence, not the cause of the problem. The reason we cruise at 1200 rpm is b/c the shift points (A8) are set to throw 7th and 8th at a relatively low speed (mph) than it should. You shouldn’t expect a better response than that at 1200 rpm, what you should expect is higher rpm’s for that cruise speed.
For crying out loud, they stumble, they hesitate, they can’t barely meet the road load and are unpredictable at part throttle. I don’t think there is doubt or lack of examples that this is the case. This is not normal, there are no excuses for a car to do that.
Not going to mention other vendor names here. All I can say, is that I have seen many PTB’s from the same vendors and there is a particular brand with all the hallmarks of a manual job, no surprise they were not all the same. Yet, we were able to remove material from all of them where needed. These were from members that have seen the before and after and they have also measured them themselves.
The data on the link you provided confirms our findings, the units don’t matter, no need for conversion. Look at the % increase over OEM. That is what we measured; PTB ~ 25% over OEM, Soler Eng ~ 100% over OEM. In the first 30% throttle.
Be very careful about the data above 30%. Under 30% b/c the body is chocked, you can make the approximation that testing a TB by itself is the same as testing it in the car. At more than 30% and the closer you get WOT the more deceiving the data becomes, the fact that the TB on its own flows that much does not mean that as part of the system it will flow that much.
In fact, if you test in the car at WOT, you get manifold pressure equal to atmospheric pressure, meaning the pressure drop across the TB is negligible, meaning it effect of the TB in the system is negligible. So, who cares how much it flows by itself at WOT?
Also, be careful about the test itself, I would not use plywood on an airflow bench/fixture when looking for small flows at 10-14 psid.
No butt dyno, HP tuners data from members and butt dyno from people that have already butt dyno’d a previous PTB and know corvettes very well. The reviews are here and posting by the day.
I only swap gears for new parts when I get batches of them. Reworked units keep the same gears. The backlash I’m seeing is about 1/8 pitch at the motor pinion, which by the time you get to the sector gear it is ~22 times higher. The performance does not change b/c you swap the gears. The motor keeps moving until the angle is right, the ECM goes by the sensor, so it gets what it wants. Now, when it goes in the other direction, then the motor moves and it has to move the backlash amount before it actually moves the blade (dead band) but ends up going where it wants looking at the sensor. There must be a tiny amount of time that gets saved in decreasing backlash, but I'm not going to bother to measure it.
Thanks, interesting conversation.
Last edited by Mike@SolerEngr; 03-07-2019 at 05:52 PM.
Reason: typo
Okay....well, let's start with nimble...nimble to me isn't always just how fast you can run, it's how well you avoid. A rhino can get a head of steam up running, but it isn't nimble enough to get out of the way of a hole that it suddenly sees in front of it. Same way a football player can be as fast as they want in a straight line, but when it comes to dodging that player coming at them, they must be able to change direction quickly or they get tackled. While looking ahead on a racetrack you are anticipating each turn ahead of you and working traffic, the Miata feels as the definition of nimble from dictionary.com goes....as deft and light. The Corvette to me doesn't feel light, but a lot of my more recent experience is with a car that weighs nearly half a ton less and a classic Porsche...which compared to the Miata also feels less "nimble". The Miata has racing suspension, roll bar, much bigger rubber and a street/track alignment, so it's no slouch in the handling department and pulls well over a G on street tires on track. The Corvette doesn't feel as ready to change direction as quickly but it can maneuver well. The Vette is quick, I love to drive it and it performs great, but to me acceleration is one thing, moving around is another. The first is related more to how much power you can put down, the other to the suspension, tires, steering and mass that has to change direction. Yes, there are bigger guys with great nimbleness than me, same as the Corvette is more nimble than say a Cobalt or a Honda Pilot, but it doesn't feel light....except in comparison to heavier cars. I've flown jet warbirds which would easily out accelerate an Extra 300 and much faster top end, but the Extra with much less power and weight would fly circles around the warbird.
I'll agree with you about the amount of air coming in, but power to weight ratio is dependent entirely on how much power the engine is making at any given moment based upon that throttle opening/throttle position....correct? If that is the case, in admitting more air that the ECU can capably handle with fuel, then yes more air and more fuel = more power. You say it matches trucks and SUVs on power to weight ratio...but then again, my Miata even at full throttle is 17:1 power to weight....17 pounds per hp! The BRZ you mention is almost identical to a Chevy Colorado and if it was lightly optioned, would have a better full throttle power to weight ratio than the BRZ you were discussing above. I'm really not getting your application of power to weight at full throttle to a truck....to my ears it's a strange comparison. If you simply mean it feels like a truck...I'd love for my Miata to have the feeling of a Colorado...it would be faster! By feeling truck like I am taking it that you mean it feels big and heavy and sluggish. I can't say I really feel that with my car, but I have only about 3000 miles on it and about half of that was highway driving where yes...at those low rpms it took a moment to get going, but outside of that I didn't think it felt like any truck I'd driven...the closest truck/SUV comparison would be the Porsche Macan GTS...and it's really in a different class than almost any other SUV and even still, not that close to me, the Z would eat it alive in a couple of seconds. Maybe the LT1 feels that way...after driving the Z I knew I wouldn't be happy with only 460 hp. I've driven lots of other performance vehicles, but my feeling of speed may be dulled by driving jets at work. 150 mph is normal to me on a runway, even one that ends in water or a wall, so some experience differs here again.
Once above that discussed above 2000 rpm, I don't seem to feel a "lag" in my Z. Perhaps some of the more recent changes have affected them in different ways or perhaps within manufacturing differences something is just really close to the right numbers. Perhaps there is more to come from additional porting and working of the throttle body, but the Mamo PTB and my foot doesn't seem to find it. Then again, perhaps I need some more time out driving it, which will be coming with warmer weather and hopefully when it's not raining. I know there were some changes in 2017 and 2018 with some of the software and while many also used to complain on the Z of getting supercharger coolant tanks with large bubbles, my tank has nary a bubble in it and was pulled for quality control as one of the 2 that day. Not saying supercharger coolant has anything to do with it, but I am saying that along the way some changes were definitely made that may have changed how mine runs and thus some earlier complaint areas may have been addressed. My M7 also gets some nice burble on the decel which earlier drivers on the M7 seem not to have at all. So yes, I've read plenty of people discussing some lag or hesitation and finding some solutions or not and living with it and the changes I've done to mine got rid of the areas I seemed to feel and encounter it. Even down at the low end of the rpm range in 7th, I haven't had any issues after the PTB swap in operation to speak of. Small throttle inputs keeping a set speed on the interstate up and down some hills. It takes little input to watch the boost gauge race toward 0 and positive pressure and the corresponding gas mileage drop...but I've been able to get nearly 28 mpg on the highway without strange or unusual behavior using small throttle changes to keep my speed within 1-2 mph. Again, mine might be the one that doesn't see some of that...I don't know. But having driven a turbo Porsche for 140,000 miles that needed some good revs and load before it had power and then it had A LOT, my foot had to learn to work with the boost as it came on and again, that might color my experience compared to others as well.
In looking through the threads of people who had received them I saw only seat of the pants discussing difficult revving and running really well afterwards or not finding those issues...but all references to the actual data seemed to go to an "I sent you a link to the PDR data" and you mentioning that one bluetooth OBD link app wasn't standard for swapping data easily. If there are some actual data postings, I'd like to see them please when ready. I tried all of your links to reviews and all of them were butt dynos and a discussion that people should feel it as a "1" and not a "0" when people asked if it felt different or not. But nothing beyond butt dyno, even if they were perhaps very well calibrated butt dynos.
Thanks.... I'm one of those people who spend a LOT of time researching before buying anything rather than someone who jumps in and goes and sees what happens. I spent a year searching for a vehicle and from May until November last year before I got my car (including the order and waiting for it to be built), so I read on here A LOT. I am reasonably technically minded and like data
Agree to disagree in what nimble means. Concentrate on the first 1/3 of the throttle and only on straight line performance for simplicity.
Miata, is 17:1 at WOT; what is Miata X:1 in the first 1/3 of the throttle? I don't know but I'll bet it is better than that of our C7's.
Don't go too far, I logged this on a Land Rover LR4, 5700 lbs, 375 HP, it felt better than the C7; looked at the results and it had in fact better weight-to-power ratio than the C7 (200-300 lbs/hp) in the first 1/3 of the throttle. Remember, full throttle ratio is irrelevant for daily driving, we spend most of our driving time in the first 1/3.
The Z06 flows the same amount of air as the LT1 car in the first 1/3, have data to show that. I don't have a Z06 but presume it would feel equally slow there.
I'm also sure the ECM is compensating correctly after the first few drives, have monitored AFR and it is on point. When it is outside compensation limits, you'll get a lean code for sure.
Here is a link to a data log, from a customer that switched from PTB to ours, I have another one but sifting through 80k+ data points is a lot of work, I see if I find time to crunch it and publish it.
If you see somebody that paid $400 for a PTB and sends it to us for rework and they say it is better, believe them. Because, had they not liked it, they could have gotten a new of the same PTB they had from us, yet they did not do it. I don't think anybody here has openly tested 12 TB's with random members in front of the whole community.
Thanks,
Last edited by Mike@SolerEngr; 03-07-2019 at 08:16 PM.
Reason: Added signature
Fine with me....but I'll never think of an NHRA Top Fuel dragster as "nimble" just because it can accelerate quickly.... Everything else would just be....silly slow....and pretty much everything else is just plain non-nimble at all because it is so far beyond them. It does however create the complication of imprecision when having a discussion...fundamentals of instructing for flight instructors. Use of the same words meaning different things to different people a concept trying to be discussed may never be properly understood.
Frankly I've logged data with it from HPDEs and on the road when testing things, but I couldn't begin to tell you. My Miata is a 99 so I while I can data log, not everything is recorded with my app...although perhaps if I went into another app or a different mode I could figure something out. Got me curious now. But in many cases it is woefully under-powered, but it's also cheap to run and easy to park for days while I'm gone to work. Perhaps somewhere there's an option for current horsepower, but road horsepower to keep a vehicle at a given speed on a flat surface in a selected gear is the base point for anything here. At 4k rpm the engine is already moving a fair bit of air just to run at 70mph. With the earlier OBD-II and not as many parameters available to record, I may not have any way to trying to find out. Yes, same throttle body on LT1 and LT4, so yes, same amount of air especially if the supercharger isn't doing any work.
For the first third that's probably also accurate that the ECM could compensate for it, it's much less of an excess fuel requirement for small throttle openings than it would be going over the full throttle injector pulses.
Ah, there it is...it looked similar to some of your others and thus it wasn't immediately recognizable as a different log of data. Nice. I'm hoping the weather cooperates enough tomorrow so that I'll feel decent about taking the Vette....and I'll play some and see if I can feel anything.
I think its unfair to ask that a throttlebody makes a car turn or feel like it can change direction better.
He's fixing the throttle response so that the engine responds quicker and applies power in a more responsive way.
Maybe I'm missing your point? It seems like an argument over symantics
Semantics. Throttle Body. Now that that's out of the way, I think it's fair when people read the entire conversation before replying to something already discussed. I didn't come into this conversation out of the blue. Because I bought a Mamo PTB and posted about it in a PTB thread I got an unsolicited private message from Mr Soler. Before you go thinking it upset me, it did not. But instead of replying there, since there are numerous threads I came here and read about it and asked questions.
In reading to understand here he mentions that his Corvette felt heavy and not as nimble as a BRZ and a GTI, both of which he said weighed MORE than his Corvette. They don't weigh more and many lighter cars feel more tossable (nimble to me) than heavier cars. Part of the reason Miatas and other light and low powered cars can keep up with much more powerful, bigger and heavier vehicles at an autocross. His answer is that he's defining nimble as the ability to accelerate and that is all that's needed to define it and I disagree...that's acceleration and doesn't have to do with cornering. So the discussion is NOT about cornering but acceleration....so the word NIMBLE is not really appropriate in my lexicon and I would never use it with a flight or racing student to simply define that the most nimble car out there is a Top Fuel Dragster that does 300mph in 4 seconds or some crazy number. Nimble isn't about how much power you can put down...nimble is defined as deft and light by the dictionary. So fine...I don't care that he doesn't define it the same way I do. We discussed that above already once. Using words that don't mean the same thing to different people ALWAYS causes confusion and we cleared up that we both see it different ways.
Now, he felt that at some kind of speed and some kind of rpm that at part throttle his car didn't feel like it accelerated as well as they do. I'm still not certain on some of how he's defining things like truck power at 20% throttle being the same as in his Corvette. Nor when you are at 4000 rpm in your Corvette or Miata or whatever and accelerate lightly vs being at 1300 rpm in your Corvette and 4000 rpm in your GTI and accelerate slightly from the same speed. There's not been any definitive testing here showing that a Vette which has great torque and should be moving just fine isn't keeping up with the aforementioned cars...going to around 30% throttle yields maybe 100 horsepower in my Z...it's not on boost. It accelerates very well...I just drove it today and did a short PDR recording and viewed it in Cosworth Toolbox where it shows my throttle percentage.
With the Mamo PTB and 30% throttle in a decent gear for it, I'm seeing even uphill like 2mph per second around 2500 rpm. On level ground 4 or so mph per second. I drove around 120 miles today, part on the interstate in 4th-7th and about 1/3 of it on backroads. I have no noticeable lag, no "jump point" from the throttle opening up, no hesitation, none of the nastiness people are discussing. I slowly opened it numerous times in numerous gears at numerous rpm to see if I could feel some "transition" beyond 30 degrees. I could not. There may be performance left on the table from moving to the Soler TB, however I cannot find one of the aforementioned reasons why it is "needed" to address an issue.
Around 30% throttle (was able to see the recorded percentage from the PDR data) the "horsepower" gauge--right or not--shows around 100 horsepower or so (the lines are halfway at 325 and full is 650 so some technically the first like is more like 108.333). So I'm getting 34 pounds per horsepower there. Not the mentioned 200-300 or so pounds mentioned above. 200 pounds per horsepower would be about 17 horsepower being produced and 300 would be 11 horsepower being produced at 3400 pounds roughly of a Stingray without anyone on board. I'm not sure why a nearly 400 horsepower Land Rover couldn't have that at least while moving. It's something else that isn't making sense to me here. At 60 mph or so a Corvette, especially one with any of the aero bits added, would probably require about 20 or so road horsepower to maintain speed on a perfectly level surface. So even a neutral throttle should be producing MORE than the aforementioned 200-300 lbs per hp. Even at 20hp it's already 170 lbs per horsepower. In fact since the Z has lower compression for the supercharger, I would surmise that the LT1 should be making a bit more power at that same point.
I'm not saying that his throttle body isn't fixing issues others are having or that it wouldn't increase the performance in my car. But I mentioned...I study and read everything I can before I make a purchase and right now although he is showing data from a couple of people, I've not seen any actual performance metrics of how this is helping on the road as far as how much nimbler the car is getting from it (see...that just sounds weird to me....oh well)--just that it may be able to pass more air and people seem to like it on their butt dyno. I don't feel my car is lacking right now in any way at this point since I am experiencing none of the issues brought up and being a 2019 with some changes done to software over the years and the fuel pump this year, maybe that combined with the Mamo PTB is giving me a great deal of this and while I have some lag or something it is minimal by comparison to some others. Some PDR video links with data shown before and after so that actual performance metrics can be revealed would make a decision more possible or other data points simply besides that it is moving more air.
I think the idea is neat overall, I think he's found something worthwhile to pursue, but since he came to me first in a private message asking me to buy his product, all I'm asking for is data in a format I can actually understand...BRZs and GTIs don't weigh more than Corvettes. 200-300 lbs per horsepower is exaggeration at best at 30% throttle and it isn't even realistic if you're driving 60 mph on a level road with just enough throttle to hold it. And 400 horsepower SUVs shouldn't be far off the power curve of horsepower from a 460 horsepower car anyway....although cams and other various intake and exhaust differences can have the peak forward or backward. It's that torque that's moving the car ahead anyway and pushes you back in the seat.
It is very simple; you keep bringing absolute mass when it comes to nimble then absolute power when it comes to the "truck feeling", I've said many times it is neither. Look at the ratio, only at part throttle. From idle to 33%. Don't bring the number right at 30% b/c that is already good and makes it look like I lied. Look at the average number from idle to 33% and you will find the 200-300 lb/hp.
About nimble, I said it clearly, "...and curvilinear motion...".
Okay, I gave you weight/power ratio; do you want me to define the "nimbleness coefficient" and measure it just for you? Or, you can name it. What did you look at when making your purchase? What were you promised?
For everyone else, this was my PM to Redbaroness;
"I see you have a PTB and wanted to let you know that there is much more that can be extracted from them. We can rework yours to do just that (numbers, not gimmicks). Please check us out when you have a chance."
What makes you so offended, about it? What part is not true? And; how do you know? BTW, I only asked you to check and used PM b/c did not want to get that thread off track.
I may not answer any further post from you, I apologize for having PM'd you.
Here is a Z06 log from a member in CA, and this one was already ported. Cumulative Average in the fist 33% > 300 lbs/hp.
Last edited by Mike@SolerEngr; 03-08-2019 at 06:09 PM.
Reason: Added log from customer
I don't want to add fuel to the fire, and I have a Mamo TFB and I just sent my original (unmodified) TB to Mike for his mods ... but I do want to bring up one point that occurred to me as I was driving my C7 last night, "feeling out the throttle" (I'm a satisfied Tony Mamo customer, BTW).
I have a couple of cars (Alfa, BMW) that have individual throttle bodies (all mechanically linked). The throttle response on those cars is fantastic. But they have nowhere near the power-to-weight ratio of my C7. Last night I found that at low speeds, I seem to unconsciously refrain from really mashing the load pedal, because the torque of the LT1 may require me stepping in to manage a stepping-out rear end. Whereas in the Alfas and BMWs, I can definitely floor it without concern. Also, on a racetrack at bigger throttle angles, this doesn't come up, but that's not the issue that Mike is addressing.
So, this is a roundabout way of saying that in the C7, _I_ am part of the throttle response (at low, street speeds). I'l be very interested to see how the Soler TB compares (for me) to the Mamo TB.
I have a couple of cars (Alfa, BMW) that have individual throttle bodies (all mechanically linked). The throttle response on those cars is fantastic. But they have nowhere near the power-to-weight ratio of my C7.
Right, for 100% throttle and perhaps anywhere beyond 50% those cars can't touch the C7 and you can feel it.
I wonder what that ratio is in the first 1/3 throttle for those other cars? I bet you it beats our C7's there.
What I found is that we are not that bad as sensors, and this is not in our heads. Usually when you feel a car is faster at a given throttle range that sensation is the result of real physical phenomena going on there, and I firmly believe the "feel-good" factor is related to specific weigh-to-power ratio in that range, 0-33% throttle. That is where I worked on to reduce it, and it does feel good, like a true driver's car, without affecting its already great track capability.
Personally, I am most concerned about the lazy throttle response of the Z06. Off idle throttle response, low rpm response - with smaller throttle openings. Blip the throttle in neutral in a BMW - and compare the response to ours.
Ours feel like it's half asleep...
In my opinion there is now doubt that a well done PTB flows significantly more at low angles.
However, I wonder if and how torque management reacts to it.
If TM recognizes via the MAF that more air flows than desired by the TM , TM might command the TB to Close, until the desired MAF is reached. In that casethere is Little - if any - gain.
Does anybody know how TM reacts to a PTB ?
In my opinion there is now doubt that a well done PTB flows significantly more at low angles.
However, I wonder if and how torque management reacts to it.
If TM recognizes via the MAF that more air flows than desired by the TM , TM might command the TB to Close, until the desired MAF is reached. In that casethere is Little - if any - gain.
Does anybody know how TM reacts to a PTB ?
Götz
Nobody who puts a PTB on their car is doing it because they want more performance from 0-30 degrees throttle. They do it for WOT flow performance and combine with a ported Intake manifold for average of 16rwhp gains. The only ones who would worry about that are those that are OCD about throttle response with a stock tune. All of this is fixed with a proper tune.
TM is affected by Torque not airflow, hence Torque Management. If increased airflow causes the ECM to see higher torque values than the tune calls for then it will limit, which generally results in throttle closure.
03-02-2019, 08:52 PM
We Are Officially Open For Business
But yes, it almost seemed like it wasn't getting enough air or something there and now it works just fine.
