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No offense but that did not answer how a midpipe affects AFR's (if boost is kept at a constant 10psi). Let me try this another way: You stated that a MP is a no-no because he will lean out. Ok so I am asking you to please explain how a midpipe increases the AIR going into the intake stroke of the engine provided the boost remains constant.
I did attempt to answer that, but it appears you are not comprehending my explanation.
So, I will try again. Please do not be insulted by the simplicity of my questions, I am trying to guide you to an "a-ha" moment- not be an ***.
Do you agree that adding modifications to de-restrict intake and exhaust on the FD RX-7 increases peak engine horsepower even when the boost is held exactly at 10psi peak?
If the answer is yes, see below.
Do you agree that the engine horsepower increased because more air molecules were entering the engine?
If the answer is yes, see below.
Do you understand that a MAP based ECU (such as in the FD) does not measure the volume of air entering the engine, only the boost pressure and temperature of that air?
If the answer is yes, see below.
In order for more air molecules to enter the engine and the ECU to be injecting the exact same amount of fuel (based on boost pressure and air temperature) the resulting exhaust gasses will have less free Oxygen per volume (the definition of running more lean).
If the answer was no for any of my questions, please let me know your reasoning.
...and more fresh air molecules enter the engine because the engine is better at pushing out exhaust molecules from the last cycle, due to less exhaust restriction.
On the intake side, less restriction before the compressor inlet makes the turbocharger work more efficiently, allowing it to push denser air into the engine at the same manifold boost levels.
I did attempt to answer that, but it appears you are not comprehending my explanation.
actually that's because you didn't really answer it. Look at arghx's answer he hit it dead on..
Originally Posted by BLUE TII
So, I will try again. Please do not be insulted by the simplicity of my questions, I am trying to guide you to an "a-ha" moment- not be an ***.
No its is fine, we are having a simple conversation. I'm not trying to be an *** either
Originally Posted by BLUE TII
Do you agree that adding modifications to de-restrict intake and exhaust on the FD RX-7 increases peak engine horsepower even when the boost is held exactly at 10psi peak?
Yes I do agree. However this is irrelevant since you are adding modifications to de-restrict intake to the mix. The question is very simple: How does adding a midpipe increase the air going into the engine? A midpipe...Everything else remains the same.
Originally Posted by BLUE TII
Do you agree that the engine horsepower increased because more air molecules were entering the engine?
Irrelevant, you never answered HOW you get those extra air molecules
Originally Posted by BLUE TII
Do you understand that a MAP based ECU (such as in the FD) does not measure the volume of air entering the engine, only the boost pressure and temperature of that air?
yes but irrelevant since the question at hand is again, how a MP increases the volume of air entering the engine. Very simple.
Originally Posted by BLUE TII
In order for more air molecules to enter the engine and the ECU to be injecting the exact same amount of fuel (based on boost pressure and air temperature) the resulting exhaust gasses will have less free Oxygen per volume (the definition of running more lean).
Yes I agree 100% but once again irrelevant. The question at hand is not the definition of going lean which is the answer you provided.
Now take note that you did not answer my question:
that's why I asked about the validity of the equipment that you based your results on. So basically the answer is no to my questions and therefore maybe your injectors were lacking a bit, or your boost gauge was off (I've had that happen), or your O^2 sensor was not reading quite right. I don't know but I do know that unless the equipment used to take measurements is validated, then any conclusion based solely on those results should be taken lightly. Do you agree or disagree?
And I know why you didn't answer it, it's because it has merit and you really do not know if your measurements are trust worthy. But if that's the way you want to this to go and not answer it, I will end this conversation as it will lead us to no where.
Originally Posted by arghx
Reduced backpressure can reduce the residual gas content that dilutes the intake charge air. It's easier to evacuate the combustion chamber during the exhaust stroke.
So with less inert exhaust gas carried into the intake stroke, there is more room for combustible fresh air. Combustible fresh air requires more fuel mass in order to maintain the appropriate air fuel ratio. ...and more fresh air molecules enter the engine because the engine is better at pushing out exhaust molecules from the last cycle, due to less exhaust restriction.
On the intake side, less restriction before the compressor inlet makes the turbocharger work more efficiently, allowing it to push denser air into the engine at the same manifold boost levels.
Thank you. With that said, those extra molecules are minuscule in comparison to say an increase of let's say 1 lbs of boost (from 10 psi to 11 psi). (that's the a-ha moment) That is why I said:
Wade back in the day ran multiple lambda tests and he proved that the stock ECU runs rich enough to support all boltons at 10 psi.
Key words: Runs rich enough, 10 psi.
So yes freeing the exhaust *and* keeping the boost at a solid 10 psi does increase the air going into the engine. However, it isn't leaps and bounds and therefore that extra air is not sufficient enough to make us go lean since the stock ECU runs pig rich.
For what it's worth, here's a graph of airflow into a medium sized V8 engine at WOT (naturally aspirated). It's a back to back run, with the second run having the main cats gutted.
There's a difference of about 3.5% airflow between the two runs near redline.
And I know why you didn't answer it, it's because it has merit and you really do not know if your measurements are trust worthy. But if that's the way you want to this to go and not answer it, I will end this conversation as it will lead us to no where.
I didn't answer each of your bullet points because I believed I could enlighten you to my point with a lot less words typing what I did.
Reading boost-
My FD has an Autometer boost gauge which is complete crap, so after I installed a Knight Sports EBS III boost controller and found it did not control the stock twins as well as my old dual Hallman Pro RX MBCs I kept the EBS III in the car while using the MBCs for boost control since the digital display shows boost in KiloPaskal (Kpa). I am sure it isn't laboratory grade equipment, but I have no reason to believe when it shows 69Kpa one day it won't show 69Kpa the next at the same pressure. And it has a peak hold feature which is great for full load road testing.
Reading AFRs-
I used my Innovate LM-1. Again, not lab grade; however, I used the same wideband tuning my FC and when it was on the dyno on 5 different occasions it always read within several 10ths of the dyno tailpipe wideband.
Applying load-
I did this at night for the coolest densest air and 4th gear for full load up a steep hill on the freeway that starts right around sea level. I want to see the results of the highest possible load when I am tuning WOT.
Key words: Runs rich enough, 10 psi.
That is subjective.
My highest AFRs with the midpipe showed high 12s and low 13s and I decided that was fine with me for racing with some 110 leaded mixed in the tank and I had no problems for that season of racing.
Obviously, it doesn't have the same safety factor as stock pig rich 9s to low 10s AFRs.
The question is very simple: How does adding a midpipe increase the air going into the engine? A midpipe...Everything else remains the same.
For me a midpipe, for you it would be a higher flowing cat-back. Less exhaust restriction improves engine Volumetric Efficiency which means the engine takes in more air- that is where the power increase is from.
arghx
For what it's worth, here's a graph of airflow into a medium sized V8 engine at WOT (naturally aspirated). It's a back to back run, with the second run having the main cats gutted.
I wold expect to see similar airflow with a stock FD cat and a gutted FD cat.
We are discussing a stock cat with its 2.5" piping, bends, diffusers and brick versus a mandrel bent 3" midpipe.
To illustrate the difference in flow in order to run the 3" midpipe and maintain 10psi peak boost I had to put a reducer with 2 1/8" hole in it at the far end of the midpipe- but the stock cat kept it at 10psi fine.
Wade back in the day ran multiple lambda tests and he proved that the stock ECU runs rich enough to support all boltons at 10 psi.
That is a ridiculous statement. You can do around 340rwhp on 10psi with the stock twins and and full bolt-ons. The stock (injector size/fuel pressure) fuel system cannot support that let alone the ECU.
That is a ridiculous statement. You can do around 340rwhp on 10psi with the stock twins and and full bolt-ons. The stock (injector size/fuel pressure) fuel system cannot support that let alone the ECU.
I have never seen that capability at only 10 PSI. I am genuinely curious if you can provide proof that this is possible at only 10 PSI rather than 14, 15, 16, or 17 on the twins?
I didn't answer each of your bullet points because I believed I could enlighten you to my point with a lot less words typing what I did.
If you say so but I wish I didn’t have to ask the question 3x. But thank you for finally answering.
Originally Posted by BLUE TII
Reading boost-
My FD has an Autometer boost gauge which is complete crap, so after I installed a Knight Sports EBS III boost controller and found it did not control the stock twins as well as my old dual Hallman Pro RX MBCs I kept the EBS III in the car while using the MBCs for boost control since the digital display shows boost in KiloPaskal (Kpa). I am sure it isn't laboratory grade equipment, but I have no reason to believe when it shows 69Kpa one day it won't show 69Kpa the next at the same pressure. And it has a peak hold feature which is great for full load road testing.
So in between all that verbiage: You had an autometer gauge that didn’t match your KS EBS, turns out KS didn’t control boost well and yet you decided that piece of equipment was reading correctly. Ok if that is good enough for you then so be it.
Originally Posted by BLUE TII
Reading AFRs-
I used my Innovate LM-1. Again, not lab grade; however, I used the same wideband tuning my FC and when it was on the dyno on 5 different occasions it always read within several 10ths of the dyno tailpipe wideband.
Now that is a viable comparison and proof of your wideband. Too bad you don’t have that type of comparison with your boost gauge
Originally Posted by BLUE TII
That is subjective.
Wrong. I told you that Wade ran back to back tests and thus gathered EMPIRICAL DATA with CALIBRATED EQUIPMENT. That is not subjective it is OBJECTIVE.
It is your conclusion that is subjective since your boost gauge and injectors are questionable. Now the reason I keep going back to your measurements is because I know first hand that one HAS to be able to trust the readings first and foremost. Here is a real life example: So out of the blue one day, all of the sudden I started to go lean under boost (low 12's). Immediately I thought WTF? am I over boosting.. Checked my boost gauge and it matched perfectly with the PFC. Check. Is it my O^2 sensor? Well it displays normal readings at cruise... Doesn't seem likely... After diving into the problem it turned out that it was a stupid injector that was faulty.
Originally Posted by BLUE TII
That is a ridiculous statement. You can do around 340rwhp on 10psi with the stock twins and and full bolt-ons. The stock (injector size/fuel pressure) fuel system cannot support that let alone the ECU.
Ridiculous statement? Yeah who in the right mind would believe AFR’s readings based on a controlled test.
340 RWHP at 10 psi and you have the audacity to claim that my statement is ridiculous? You realize that you are claiming that 115RWHP above stock is achievable just by boltons… You said it. Well I guess everyone on this thread just runs like crap then:
I’m sorry man, but your statement is so full of wrong I don’t even know where to start… One thing for sure is that it clearly shows that you don’t quite understand CFM with respect to PSI. As you are claiming that the stock fuel system will not support all boltons at 10 psi and yet it has been proven that the stock fuel system is able to support 12 psi (as long an ECU is in place). So in other words, you are under the impression that adding full boltons requires more fuel than increasing the boost. Seriously?
Ah, according to my research on this forum I'm pushing unkown limits so I thought maybe my 99 spec just has better wiring or a better fuel pump or something. But I guess you have to be careful what you read on forums because everyone's case is different and you can't assume that just because a few people back in 2003 or something had issues with fuel pump voltage that it affects everyone, or that various issues reported over the years are true on every car.
Wrong. I told you that Wade ran back to back tests and thus gathered EMPIRICAL DATA with CALIBRATED EQUIPMENT. That is not subjective it is OBJECTIVE.
What AFRs you decide are safe to run with is subjective as I showed by choosing to run a set-up that could lean out to 13s. I would not have recommended that set-up as safe to others.
Wade's objective test tested the bolt-on parts he put on his car.
You claim all bolt-ons are safe as long as you run 10psi boost. That is a HUGE leap.
Wade did not test a SMB 3.5" turbo back exhaust or an HKS downpipe back 4" exhaust. Wade did not test removing his air filters and running velocity stacks on the hardpipes to the turbos. I don't know if he was using extrude honed flow matched intake manifolds and a larger ported throttlebody or an aftermarket intake manifold and throttlebody combination.
For example the Racing Beat catback no doubt sounds good but cost you around 15rwhp over most other 3" catbacks at the ~300rwhp level and will cost you more like 30hp over most 3" catbacks at the ~400rwhp level.
If Wade's tests would have been done with the usual 3" downpipe, midpipe and 3" Racing Beat catback they would have different results versus using an SMB 3.5" turbos back exhaust.
SMB (the company the designed the exhaust for the Bathurst winning RX-7 SPs) claim there are gains using their 3.5" downpipe over the usual 3" downpipe on stock twin turbos. They both bolt on.
Yes, maybe my view of bolt-on is skewed toward the highest performing pieces instead of the most widely used because I race my FD in a class where near any bolt-on is allowed as long as the engine block and the two turbos are stock.
You realize that you are claiming that 115RWHP above stock is achievable just by boltons
Well, around 200rwhp above stock with stock turbos is possible with just bolt ons; but yes, only around 115rwhp if limited to 10 psi.
What AFRs you decide are safe to run with is subjective as I showed by choosing to run a set-up that could lean out to 13s. I would not have recommended that set-up as safe to others.
Wade's objective test tested the bolt-on parts he put on his car.
You claim all bolt-ons are safe as long as you run 10psi boost. That is a HUGE leap.
Says the guy who can't explain how a MP affect AFR's
Wade did not test a SMB 3.5" turbo back exhaust or an HKS downpipe back 4" exhaust. Wade did not test removing his air filters and running velocity stacks on the hardpipes to the turbos. I don't know if he was using extrude honed flow matched intake manifolds and a larger ported throttlebody or an aftermarket intake manifold and throttlebody combination.
For example the Racing Beat catback no doubt sounds good but cost you around 15rwhp over most other 3" catbacks at the ~300rwhp level and will cost you more like 30hp over most 3" catbacks at the ~400rwhp level.
If Wade's tests would have been done with the usual 3" downpipe, midpipe and 3" Racing Beat catback they would have different results versus using an SMB 3.5" turbos back exhaust.
SMB (the company the designed the exhaust for the Bathurst winning RX-7 SPs) claim there are gains using their 3.5" downpipe over the usual 3" downpipe on stock twin turbos. They both bolt on.
Yes, maybe my view of bolt-on is skewed toward the highest performing pieces instead of the most widely used because I race my FD in a class where near any bolt-on is allowed as long as the engine block and the two turbos are stock.
Yep... and yet you can't explain how a MP affects AFR's and also believes that the stock fuel system cannot sustain all boltons at 10psi.
Originally Posted by BLUE TII
Well, around 200rwhp above stock with stock turbos is possible with just bolt ons; but yes, only around 115rwhp if limited to 10 psi.
yeah, you really need to stop repeating that... Because it pretty much solidifies your comprehension of these cars.
I'm sorry but you lost all credibility and I'm not in the mood to get in a tiresome debate with someone who lacks fundamental concepts. It will lead to nowhere
The stock coolant temperature gauge is fine. It tells you when you are too cold and it tells you when you are too hot. There are millions and millions and millions of cars on the road with the non-linear stock gauge. If your cooling system is maintained and you'll be fine. If you are racing that's a different situation.
We're going to have to agree to disagree on this one. The Third Gen is not like the millions and millions of cars with non-linear temperature gauges, it's different (no one should be surprised at that statement). So, here are my points for "you need to modify your temperature gauge" or at least get an aftermarket gauge and place the sensor in an intelligent location:
.
Unfortunately, not everyone has the same gauge. There are two types of gauges installed in the third generation RX-7, a "cold region" gauge and a "all other regions" gauge. If your car was not new when you bought it, location is not a good way to tell for sure what type of gauge your car has or what temperature the white line at the top represents. In addition, gauges go out of calibration as they get old so what ever temperature it was in 1995 it probably isn't in 2017.
Mazda issued a coolant recall. Part of this recall involved replacing the original 1.3 bar radiator cap with a 0.9 bar radiator cap. With a 0.9 bar radiator cap and a 50% antifreeze mixture, the coolant boils at approximately 127 °C. The white hot mark on a new unmodified "all other regions" gauge indicates 130 °C. Do the math, 130 °C was fine with a 1.3 bar cap, not with a 0.9 bar cap. Most owners assume that the red mark is the danger zone on a temperature gauge, with the coolant recall the white line is the "Oh ****" line. Part of the "linearization process" is re-calibrating the stock gauge, so the middle is normal operating temperature and the upper white line is as high as your coolant should normally go with a 0.9 bar radiator cap and red is the "pull the f#$k over dumb ****" mark.
Since the stock unmodified gauge is non-linear it will stay in the middle "everything's all right" zone over a wide temperature range and then rapidly shoot up with as small as a 25 degrees C change in coolant temperature. As it approaches the red mark it it becomes very sluggish again. The typical owner thinks "WOW it got very hot very fast, but I'm OK because it hasn't risen to the top of the red mark". Well, guess what Bunky, you're going to be past 135 °C before that happens, you've been driving a steam cooled rotary engine for the last 10 minutes!
.
That was a little tongue-in-cheek, but you get my drift, what's OK in your Mom's Camry is not OK in the Third Gen.
Last edited by mdp; 10-04-17 at 06:12 PM.
Reason: grammar corrections
Well you hit on a good point. You have to interpret it. If it moves above the midpoint it's too hot. To me, that's good enough for a near stock car. On modern BMWs they have an idiot light only, no gauge.
From the perspective of a 100% stock car, if you linearize the stock gauge or install an aftermarket gauge, you will probably break interior parts in the process and potentially create new rattles. So ask yourself if you want to do that.
A decently accurate 52mm temp gauge placed on a single ‘A’ pillar pod using double-sided tape and a sensor in the throttle-body coolant line is completely reversible and requires no interior panel removal. And it may save that totally stock engine.
And Montego...you’re wrong on the Y pipe. And I’m not going to go into a tiresome debate with you on it. You’re just wrong. The only take-away for the OP from this thread should be getting an efini ‘Y’ pipe. Done.
Originally Posted by BLUE TII
Well, around 200rwhp above stock with stock turbos is possible with just bolt ons; but yes, only around 115rwhp if limited to 10 psi.
yeah, you really need to stop repeating that... Because it pretty much solidifies your comprehension of these cars.
Well you hit on a good point. You have to interpret it. If it moves above the midpoint it's too hot. To me, that's good enough for a near stock car. On modern BMWs they have an idiot light only, no gauge.
Yea I know, I have a 2012 135is and a 2016 M235i. The 135is has a temperature gauge my M235i got a temperature gauge on the 2nd day of ownership. Now why didn't BMW put a gauge in the 2016 car? Well, I can tell you first hand cause last week my 135is went into limp mode because the computer thought something was amiss. The computer (there are 6 computers and three computer networks on these cars) monitors the engine temperature, oil temperature, electric water pump speed, and controls the coolant flow with a servo controlled multi-way valve (its position is also monitored). Last week I was driving around town and the car threw up a message on the screen that there was a cooling malfunction. The car instantly went into "cooling malfunction mode" radiator fans on high, electric water pump on high, valves wide open, and only about 5% of throttle available with a 1,500 rpm rev limit. A quick glance at my temperature gauge and it hadn't moved off of normal!! WTF? Luckily, I was only 3 blocks from my favorite independent BMW repair shop. It turns out that the computer increased the voltage to the electric water pump to increase the rpm of the pump to 57% of maximum and the pump only responded with a rpm of 40%. Bottom line is, the computers will not let the car operate normally if they detect the slightest anomaly. My mechanic said that since converting over to this monitor-and-control-everything system he has never seen a BMW overheat. What's the down side? Twenty-five years from now can you imagine people replacing capacitors on their no-longer-available 32 bit multi-core BMW ECUs?
^^^Started on 10/4/03 and current to today. So that's 14 years and 22 pages full of data. So please PROVIDE a dyno plot of an FD with stock turbos and full boltons that produces 340RWHP AT 10 PSI. Show the link to the page as well. If you do that, I will apologize to you and BAN MYSELF from the forum a for week. If you don't, well that's easy enough to deduce that you didn't find anything to back up your claim. And of course it would show that you really don't comprehend the effects and limitations that mods have on these cars.
Remember mods have to be listed as well as boost setting.
Well you hit on a good point. You have to interpret it. If it moves above the midpoint it's too hot. To me, that's good enough for a near stock car. On modern BMWs they have an idiot light only, no gauge.
If we are talking absolute necessity here then I agree with you on stock cars and OEM coolant gauge. I had my stock gauge for about 6 years and I knew if that thing ever got past center then there is a problem. And that's all I needed to know. Now I have a PFC and one of my displays is H^2O. and I find that I'm always staring at the stupid thing....
But this a preference thing as some people want to keep a constant vigilant eye on actual temperature, and I get that.
Originally Posted by Sgtblue
And Montego...you’re wrong on the Y pipe. And I’m not going to go into a tiresome debate with you on it. You’re just wrong. The only take-away for the OP from this thread should be getting an efini ‘Y’ pipe. Done.
So please PROVIDE a dyno plot of an FD with stock turbos and full boltons that produces 340RWHP AT 10 PSI
There are none yet as everyone pushing the stock twins is doing it to make high power.
It is within the bounds of the stock compressors and larger than single turbo exhaust wheel area and combined exhaust housing's A/Rs.
I know I did 340rhp on my TII at 10psi on gas and during the same dyno session that stock hybrid turbo maxed out at 18psi and 385rwhp (more boost just raised midrange power after 18psi).
Here is 100% stock twins making 411rwhp at 18psi with basic bolt-ons (very little fabrication) back in 2011 and gas not even E85. Dyno figures backed up with 10.87 ET in 1/4 mile with 129mph trap speeds.
There are none yet as everyone pushing the stock twins is doing it to make high power.
Actually that's incorrect... That thread has a quite a few people with boltons at 10psi and none are close to 340RWHP.
See here is one:
Originally Posted by cruiser
I dynoed again this weekend.
280rwhp/268tq@10 psi
Mods: from his sig M2 Stage3 ECU, HKS TwinPower, PFS Cold Air-intake, PFS SMIC, Pettit DP, 3" Midpipe, NTech catback, Profec B, Efini Y-pipe, Koyo radiator, Aluminium AST, CWW swaybar mounts, Eibach springs, Momo Millenium 320mm, Feed ETB, Autometer boost gauge, Enkei RP01 8x17" 235/40/17, 9x17 255/40/17 , Alu door sills
In any case, going through the thread you can see which mods get people closer to 340RWHP. Really all of those people are boosting more than 10 psi. Closer to 13-15 lbs
So it took that guy with a TUNED ECU, Injectors, Ignition, and 14lbs of BOOST to reach what you claim can be achieved at stock boost... But go ahead dig through that thread as there are plenty of examples where people needed a lot more than 10psi to come close to 340RWHP.
Originally Posted by BLUE TII
It is within the bounds of the stock compressors and larger than single turbo exhaust wheel area and combined exhaust housing's A/Rs.
I know I did 340rhp on my TII at 10psi on gas and during the same dyno session that stock hybrid turbo maxed out at 18psi and 385rwhp (more boost just raised midrange power after 18psi).
How about we compare apples to apples. Anyway didn't you do that with a BNR Stage IV stock hybrid turbo? Just as an FYI, you can't use boost pressure as reference when comparing TWO DISTINCT turbos. As different turbos produce different CFM's at the same boost level. And it's the CFM what counts with respect to power. Psi is only an indication of a higher and lower CFM that particular turbo is producing. For example we know that turbo X produces a higher CFM at 12psi than it does at 10psi. However turbo Y produces (could) produce a higher CFM at 10psi than turbo X at 12psi. So technically we can't baseline HP numbers based on psi while using two distinct turbos. Apples to oranges. In this case it's the hitachi H12 turbos compared to your BNR hybrid turbo.
Originally Posted by BLUE TII
Here is 100% stock twins making 411rwhp at 18psi with basic bolt-ons (very little fabrication) back in 2011 and gas not even E85. Dyno figures backed up with 10.87 ET in 1/4 mile with 129mph trap speeds.
So you find the one guy that holds the record for the most power with stock twins and you make it the norm?
BTW: 18lbs of boost is WORLDS away from 10 lbs. You don't seem to comprehend that elevating the boost is what provides us the most power. Yes boltons do up the power but the real gains come in when the boost level is raised (higher CFM). The caveat is the supporting mods have to be in place before boost is raised .
Also, you call what he has basic boltsons and gas? I call BS: As he had a streetport, 50% race gas (RACE GAS not just gas), rewired supra pump, Power FC, 3-bar map sensor upgraded injectors, fuel rail, upgraded KC fuel system... Not so basic boltons... Don't believe me? Look below:
Originally Posted by tom94RX-7
Thanks. It's a standard streetport. About 50% sunoco gt100 race gas and 1 oz per gallon premix penzoil 2 stroke oil. No water or meth injection, I tried that a few years ago, my tune and low knock is good without it and more power.
and
Originally Posted by tom94RX-7
A downpipe with exhaust wrap and a rx7store resonated midpipe, this is all I run when drag racing and when I was on the dyno.
Here are some of the mods from my mods list. Power FC, PLX R-500 Wideband, KGParts.com Kit C fuel system, 550s in stock primary rail & 1680s in Keiths top feed rail, aeromotive fpr & electrical fp gauge in car, RX7.com Cosmo/Supra fuel pump, rewired fp, greddy profec b-spec 2 boost controller. Apexi 3 bar map sensor. PFC datalogit. Fast reacting ait sensor in the greddy elbow.
Unfortunately stock turbos aren't really built to withstand that kind of power. Just look at what happened since the turbos were being run so hard:
Originally Posted by tom94RX-7
Thanks guys. I just recently blew my primary turbo at the track when shifting into 3rd gear right after getting a 1.48 60 ft time on my 3rd run of the year, (more about that in this thread), I was going to buy another set of stock twins and try to get a perfect pass and get a time closer to 10.7 which I think was possible with the 1.48 60 ft time, but then I was thinking about buying some bnrs, and then decided to buy a T04R single turbo kit for more power potential and all the other benefits of going single, so no more record setting passes haha.
Twin power and 14.4 peak boost yielded 340rwhp/283tq. I kept it on the rich side for safety, could have squeezed a few more out it, but why push the car that hard for something that can't be felt. The injector duty cycle was at 91.3% so we are done until the fuel system is stepped up. Keep in mind this car still has all of it's smog equipment intact and functioning. So from where we started on Monday morning we have picked up a total of 86rwhp & 61tq and have only raised the overall boost by 2.7psi.
He left the stock cat in place while on the stock ECU even with the upgrade fuel pump and running the stock 8psi boost at peak power.
I hope new owners follow that upgrade path instead of the "10psi on stock ECU is fine with any bolt on" rule of thumb that I followed (thankfully with a wideband).
Agree, looks good. Not sure if it’s been mentioned previously but seeing these pictures made me think of one other reliability mod you might consider...stock dual oil coolers. Finding a good used set might take some time but a worthwhile mod imo.
10-03-17, 06:04 PM
A quick glance at my temperature gauge and it hadn't moved off of normal!! WTF? Luckily, I was only 3 blocks from my favorite independent BMW repair shop. It turns out that the computer increased the voltage to the electric water pump to increase the rpm of the pump to 57% of maximum and the pump only responded with a rpm of 40%. Bottom line is, the computers will not let the car operate normally if they detect the slightest anomaly. My mechanic said that since converting over to this monitor-and-control-everything system he has never seen a BMW overheat. What's the down side? Twenty-five years from now can you imagine people replacing capacitors on their no-longer-available 32 bit multi-core BMW ECUs?
