Exhaust & TB Mod = Less ITSOTP Feel!!!

[M4T5]

ITSOTP (In The Seat Of The Pants).Anyways, I have the Element114 cat back kit and did the TB mod. The car feels slower with less throttle response. It could be faster on the upper end of the RPM band, but I'm not so sure.What could have gone wrong?I feel like maybe putting the factory exhaust back on now.Even my wife made a comment today saying that the car feels heavier. Her meaning from that is saying the car is just not as responsive as it used to be. What is everyone elses take on this that did exhaust upgrades? I believe the ECU would need to be reprogramed to actually get the car running like it should with the exhaust.This was not what I was looking forward to!!!!

J
Modified by M4T5 at 9:37 AM 2/26/2009

[maxnix]

Everything works in balance and OBD II allowed the OEM engineers to pretty well push the envelope to the edges.

Anything less than a 10% gain in torque is generally unnoticeable by 95% of the population of drivers.

Most modifications are esthetic in only unless developed as part of a complete package on a bench dynamometer. Usually engine internals must be changed on a modern OBD II naturally aspirated engine along with ECU parameters to get any meaningful gain in power.

Real change costs real money and must invovlve engineering expertise.

[rmezz13]

do any intake work? i know intake and exhaust combo on most V8's is amazing, sometimes one is required for the other to perform.... if you are pushing more air out, you have to be sucking, or forcing more in to get a good result...

(coming from someone who is not proficient on this car)

[ken in az]

Everything works in balance and OBD II allowed the OEM engineers to pretty well push the envelope to the edges.

Anything less than a 10% gain in torque is generally unnoticeable by 95% of the population of drivers.

Most modifications are esthetic in only unless developed as part of a complete package on a bench dynamometer. Usually engine internals must be changed on a modern OBD II naturally aspirated engine along with ECU parameters to get any meaningful gain in power.

Real change costs real money and must invovlve engineering expertise.

Serious? We have to change engine internals to get any benefits for performance? Wow! what do we need to do to get more power? Should we get higher compression pistons?

So every aftermarket company out there is just a joke and people only mod their cars to make them look and sound nice? I wish I would have known this before I started modifying cars 15 years ago. would have saved me and alot of people I know alot of money.

Oh yeah....it must be esthetics when we are actually are faster in the quarter mile.

really, try thinking before you post.

M4T5 - We have all came to equal conclusions that you only perform one modification or the other - not both. You have now leaned out your engine because the way the factory ECU is set up is that it works off of set parameters. It can only compensate withing a specific range and once you leave that range of airflow the ECU can no longer enrich the mixture. Also you have left the range of effective engine timing so you will definitely loose power with both mods.

***But*** I do want to thank you for proving that the TB Bypass mod actually increases airflow into the engine

[M4T5]

So everyone claiming an increase in power with this mod is only feeling under WOT events?I wish I knew this because then I would have never done it. I pretty much sacrificed the normal driving rpm band. Would a tune from UpRev possibly cure this lack in low end power?I want to even think the car lost 1-1/2 mpg's as well. My car did not like the exhaust!Now I'm afraid of doing the cold air kit....but then again, that's very easy to swap out. Also, since I removed the resonator/ water catch under the air box assembly unit, I'm thinking this may created turbulence or possibly caused the air flow to be diverted away from the air filter. Just my thought, but I don't see it being impossible.This car was just really not designed for modifications without tuning to go along with every single change made.Conclusion, upgrades to the 06' & 07' M45's are worthless unless the car is tuned per application and or just looking for a decibel/ sound tone change.....

J

[ken in az]

Conclusion, upgrades to the 06' & 07' M45's are worthless unless the car is tuned per application and or just looking for a decibel/ sound tone change.

Ding Ding Ding! We have a winner! Yup I somehow knew you did the airbox mod also.

too much air into the engine = lean condition = lack of power

[ATSELLAB]

I think you just need a different car, I love power and I did the basics and im satisfied.

If you really want the power, stop messing with the little guy mods and jump to the twin supercharger. If 390 hp aint good enough for you then, trade it in.

Reading the threads alone, especially with the guy who dyno'd the exhaust, its obvious you should only do 1 mod. So im just gonna leave it as that unless one day I feel I need the 390, but by then they may come out with a new M with more horses.

I understand everyones need to want to mod there vehicles which is a good hobby and time killer but dang, just reading everything makes you just leave it alone, atleast for me and I bet there are plenty more of you out there.

[M4T5]

I think you just need a different car, I love power and I did the basics and im satisfied.

If you really want the power, stop messing with the little guy mods and jump to the twin supercharger. If 390 hp aint good enough for you then, trade it in.

Reading the threads alone, especially with the guy who dyno'd the exhaust, its obvious you should only do 1 mod. So im just gonna leave it as that unless one day I feel I need the 390, but by then they may come out with a new M with more horses.

I understand everyones need to want to mod there vehicles which is a good hobby and time killer but dang, just reading everything makes you just leave it alone, atleast for me and I bet there are plenty more of you out there.

Twin supercharger??? Who offers this kit? I've never seen a forced induction kit offered for a 06' & up M. Sounds very interesting, but I was only after a slight improvement or cutting edge over stock. Sad to say, it didn't work out. The car just may very well offer more upper rpm power, but I was hoping for an increase in power throughout the entire rpm band, not for just a WOT scenario.

Ken, why wouldn't the ECU compensate for a leaner condition? Isn't that why there is electronic fuel injection? To automatically correct for small changes in the air/ fuel ratio?I'm thinking there is more to this. Maybe the airbox mod is the problem. To be honest, I'm not seeing the exhaust freeing up that much more cfm air flow. You would have to delete a set of the cats to really accomplish that scenario.

J

[New2Import]

There is no way a TB bypass made a car slower. Maybe its that exhaust you claimed made so much HP. BUT remember they advertise their gains.df

[M4T5]

There is no way a TB bypass made a car slower. Maybe its that exhaust you claimed made so much HP. BUT remember they advertise their gains.df

I never claimed it made SO MUCH HP!! If anything I only stated what their website showed.People here really need to stop placing quotes onto people who never stated the damn comment.TB bypass is bogus too! Don't give me all of that $hit. There were no gains from this. That too was a waste of time. Go to the dynometer and prove me wrong. TB bypass is another mod not worth the time doing. Same goes for the airbox mod. These mods do effect the cars drive ability, but not in a good sense.Mod this car without tuning....and your only gaining noise decibels!

J

[New2Import]

LOL it will be ok. The TB mod is just a free mod. Makes no sense to have coolant going thru the TB. Its just for the northern states so the TB want freeze stuck and damage them. Not gonna gain HP it just benefits not having heat going to the intake. I was just jabbing at you about what you said Element stated was the gains now you say the car is a dog down low. I think it may be the intake piece that you removed.

[ken in az]

Oh Gawd...I think I'm close to being done with posting performance related threads and responses. You guys are just so not educated in performance and just because something doesn't work and you don't know how to make it work doesn't make it "BOGUS" as you claim.

I was told by a wise person that the reason most people are angry or upset is because they stupid on the subject. I'm not calling you stupid, but your knowledge is lacking as far as performance modifications and understandin of how these ecu's compensate for increased airflow.

The computer has a set range of adjustment that it can compensate for. I'm sure nissan set the range so that the car can compensate for stock components ranging from 0ft altitude to the highest spot on the US highway the continental divide at 10,500ft. If you get outside of that range it will read too much oxygen content in the air and will not be able to add the additional fuel. Like I said in another post, these ECU's are calibrated to last the full 70,000mi powetrain warranty so they tune the computer to allow the engine to last within that range. I know, this is a difficult concept to grasp and it is much easier communicated in person verbally rather than in a web forum.

I've done only the TB Bypass and the Airbox Mod and have converted it back to stock - I can feel the difference. to those naysayers you can say whatever you want, but you can actually feel the difference.

You sir have modded both the exhaust and the intake - which all of us has come to an agreement - do one, or the other, but not both or you'll loose performance. Since you did both - you lost performance. Don't be mad, just convert it back to stock or buy a Cifer and do some data logs so you can prove that the TB Bypass is a Bogus mod. Till then stop whining like a little girl.

[ATSELLAB]

Till then stop whining like a little girl.

Chalk it up. I thought i was the only one noticing it.

[M4T5]

Ahhh...whatever man. Your not able to rattle my chains bud.My knowledge is not lacking.....not 100% knowledgeable on the programming of ECU's.....but then again...are you? I should have been more clear or specific. It just baffles me that the M is so sensitive to such minor mods. I guess I'm more use to how domestic vehicles seem to gain power from these basic mods.I understand that the ECU has preset parameters that limit it's availability to adjust the air/ fuel ratio to a certain extent. I just didn't think it would have such a limited range on the M that wouldn't allow the the ECU to adjust to the exhaust and the air intake. I would totally understand a lack in torque if I place headers on the car, but not these simple bolt on items. Either way, try to not lunge out so harshly at me or others next time. You could put it in another form or fashion instead of calling me out as being lacking in knowledge. This isn't my first vehicle to modify by far. Most of my other vehicles (namely Ford & GM) that I have modified had tuning done along with my mods, but not for just a basic cat-back system or air intake swap.

I have to agree that with other people's statements that the Infiniti engineers have put much time and research into the components surrounding the engine for near maximum output for the ECU programming that it currently has in OEM form. Any change will indefinitely require ECU tuning to benefit any worth while gains.

As for me whining.....yeah, I'll agree with you guys on that. I just feel I hit dead ends with the basic bolt on mods and was a waste of time. If tuning was available at my disposal, it would be a different story, but that's not the case.Yeah, UpRev can supposedly tune these cars....but I haven't seen any results to justify getting a tune from them at this time.Even when you (Ken) get results, it really will not be results that most of us could relate to due to your extensive mods that you will have done to it during tuning. Removal of the cats and diverting your exhaust through cut-outs is by far quite a bit more drastic than a simple cat-back kit. I really cannot see me being a little upset over these failures not being somewhat justified. In my case, I was looking for more performance from these add-ons. In other peoples cases, the sound change alone was more than enough to satisfy their justification for the aftermarket exhaust kit. Not me. To each his own I guess.By the way, you say only do either exhaust or the airbox mod right?To me, the car performs the same before I removed the lower airbox resonator tube.Therefore, to state do one or the other really makes no sense. To tell you the truth, I wouldn't recommend changing anything unless you have the ECU reprogrammed for the change.I'm ranted out for today...................

J

[exbmwdude]

Priceless....

This is exactly what you were told would happen. You did it anyway and you are surprised at the results ? You made a classic mistake of assuming a less restrictive exhaust would net you a faster car. You lost torque over 90% of the RPM band to get a 2% boost in peak HP at redline. Congrats, you bought the exhaust company marketing hook, line and sinker.

This "lame old man" is lauging his a** off !

I'll say it one more time in the hopes that perhaps you will understand where I am coming from:

This is NOT a car for the "DIY" or aftermarket crowd. There are TONS of other cars out there that are far better suited to those who wish to make them faster, handle better, etc. Nissan did a really good job of tuning these cars to do just about everything well (and they have tons of magazine kudos to back that up) but they left little on the table for the aftermarket crowd. We're locked out of the engine/transmission programming and the way all the various processors are linked together virtually guarantees you no end of trouble if you decide to avoid all the warning signs and mod the car anyway.

Seriously, if you've got the need for speed, look into a CTS-V, or an S4, or a 335i, or an S60R. Any of these cars are as fast or faster than the M45 from the get-go and have better aftermarket support to boot.

And for Pete's sake, invest a couple hundred in a G-Tech or some kind of data analysis tool to MEASURE your performance mods. At least take it to the track or something and get some real data on how well it performs.

You claim to be knowledgeable but you're making one rookie mistake after another....

exbmwdude2006 M35S

[imsello]

Maybe m45t just cant read, i know I saw the posts stating not to do exhaust and intake together because you will lose power. I must have read it 100 times. The worse part is that we know he read it and still did both mods and then claims hes upset at the power loss. (like its new news). I Mean really are these cars made to be modded like crazy. I dont think so. all i did was put on the exhaust which gives it a nice rumble, ( not to loud) and maybe this spring ill throw on some 20's. For you guys thinking u want to mod these cars, you probbaly should have bought a g35 or something in those lines....The M series is a LUXURY vehicle not a modders dream, So lets stop worring so much about performance and just realize we own one of the HOTTEST "sport" luxury sedan on the Market.. evertime I go anywhere I get double and triple takes from lots of people and that makes me feel good ( probably cuz I think im the only one to own a M45 in CT) but hey it still feels good with all these people Sweatin my ride, even if it doesnt have 500hp. If I wanted that I would have bought a M5

[M4T5]

Just because I don't have a G-Tech I'm a rookie now?? Give me a break. All of my tests have been done at the track in the past. I really do not see the point in bringing this type of car to the track really. I don't think the addition of the exhaust will really net much improvement if any.I might think about it if I went and had it tuned, but not for these simple additions.

By the way, I didn't place a cold air kit on my M. I only removed the lower resonator tube. Hardly a mod to say the least. Like I said...if you "READ" what I said, my M's performance was the same after I added the airbox mod. Meaning, the performance was diminished when it only had the exhaust done to it.The airbox mod, made no difference what-so-ever.You guys act like these are serious mods or something. These are just cheap basic bolt ons.........

J

[Mark Linkous]

Gents,This thread is getting pretty nasty. For many years around here the general consensus has been little is to be gained from exhaust mods. The utter lack of an aftermarket and tuning support is both frustrating and well chronicled. I think it might be advisable to have a sticky pertaining to this.

Forced induction seems to be the only possible answer. Unfortunately, part of the equation entails the engine blowing up owing to the VK45 not being a stout powerplant. I hate admitting this as I love my car.However, it is what it is.

Jet Chips does offer a reflash. Short of turning off the speed limiter, I have not heard anything affirmative about this being a worthwhile modification.ML

[ken in az]

M4T5 - I did not mean that you weren't knowledgable on modifying cars, just specifically on modifying "these" cars. I should have been more specific.

I have extensive background in engine tuning, building, racing, etc....but I don't want to post about all that because it really doesn't mean crap about the subject on hand.

I don't want to be the guy that says "I'm the resident expert because I have done all this and I have had that, and I've made XXXHP from this" because it doesn't matter. Now if I was a business and I was trying to earn your business that'd be a different story. I'd want to lean on all those resources to bring credibility to my name to propel my future in the business world.

Results will speak for them selves and those that want to mod - will.

I just thought it was humorus that you got all in a bunch after everyone has said to not do intake and exhaust mods because you'll loose power, and you did both and were bad mouthing other effective mods that when compounded with oher mods - they don't work out so well. You say the airbox mod didn't do anything, but before then then you say the TB mod was bogus because it made your car run like crap, then you said you did do the airbox mod, now you're saying that the exhaust made the car run like crap by itself....you have a CAI kit that is made for our car but yet you said you went to install it but can't figure it out......you can see where i'm going with this is that the credibility of your statements are diminishing.

And you do post alot about your problems, which is good...I thank you for that....you are one of the few that are actually modding their car but you also go very negative very quick without too much supporting information other than your girlfriend said the car felt "heavier" and examples as such which is hardly any conclusive evidence of negative performance.

We all just need to breathe. I hope to have some good information about modding these cars. Again, you need tuning to take advantage of the added airflow. The exhaust on this car is pathetic, 4 cats and the pipe is less than 2" and in my experience 2.5" dual exhaust on a 7000rpm 4.5 liter V8 is not going to effect your low end torque like so many are quick to say. The ecu programming is what the problem and the biggest hurdle is and will be. We need the CIFER program so we can datalog the vehicle in action. Hell the ECU could be closing the throttle because it is recognizing that the engine is accelerating faster then it was designed to do.

We will get there - trust me - we will.

And who said that this is just a luxury car and it wasn't supposed to be fast so be happy with what it is and not to modify it? Then why did BMW make the M series for any of there cars? M3 M5 M6 are some of the most sought after vehicles because they have it all. Luxury and performance - is that too much to ask from the M45? I don't think so and I intend to prove that the VK45DE is not made of glass like everyone thinks.

BTW - why does everyone think the M45 is a weak engine? has anyone blown one up? has anyone ever made more than 300rwhp with it? I haven't found anyone that has and I'm an internet junkie so until someone can provide difinitive proof then can everyone stop saying that!

[ly5598]

I also removed the air resonator...but while i was there decided to clean up the throttle a bit. For 40k it was not as dirty as i thought it would.I also did an idle learn and reset the Ecu's self learn. I wouldve done the TB bypass but being that its winter i wouldnt want to deal with a sticking throttle plate. I can say that i do feel a difference and i dont think that its just a difference in noise, but at the same time it couldve been the combo of thing done...just thought i would share my experience.

[M4T5]

Ken, your still twisting my statements.Never said the TB mod made my car run bad. I just don't "think" it made it run any better. The TB is in direct contact with the intake. It's going to get hot either way is how I look at it.Once again, the airbox mod made no difference in performance either.Put it this way, before I did either of those two mods, the car ran the same as it did since the exhaust was added.I was merely making a statement in my title stating they do not really do not net you any gains.

As for the cold air intake kit, the guy at Element114 did tell me he left a few parts out of the kit. When did I say I couldn't figure it out? I figured out exactly where and how the air intake tube needs to set, but the mounting L or ear was not even remotely close to bolting onto anything. What's their to figure out? It was lacking parts in the kit.

Also, you said my girlfriend said the car felt heavy? That's really funny as I stated my "wife" said this statement. Pretty much everything I said was twisted to make some of you guys sound more justified in your rash remarks to my findings.Sure my findings are not proved so to speak. I would need a before and after dyno run and 1/4mi track runs to confirm this. Though if the car feels more sluggish in the low rpms, I can justify this to a certain degree.Basically.....get off my NUTS already!This is all just ridiculous now......

J

[M4T5]

Forced induction seems to be the only possible answer. Unfortunately, part of the equation entails the engine blowing up owing to the VK45 not being a stout powerplant. I hate admitting this as I love my car.However, it is what it is.ML

Where's the proof that this engine is built poorly??? That statement alone is pretty resentful to many people that own the M45.Have you had a bad experience with your engine? Surely Infiniti has updated their many problems they had with these engines since the first gen 4.5L cars were born. That would be very ignorant on their part if they didn't.If it wasn't a stout powerplant, Infiniti would not have given it 325hp and the ability to rev up to 7,000rpms on the factory rev limiter. If you have proof of this I will take back anything I just said. Hell, I don't know enough about the M45's to really say your wrong.

J

[M4T5]

I also removed the air resonator...but while i was there decided to clean up the throttle a bit. For 40k it was not as dirty as i thought it would.I also did an idle learn and reset the Ecu's self learn. I wouldve done the TB bypass but being that its winter i wouldnt want to deal with a sticking throttle plate. I can say that i do feel a difference and i dont think that its just a difference in noise, but at the same time it couldve been the combo of thing done...just thought i would share my experience.

What is an idle learn and how did you reset the ECU's self learn?I have not heard of anyone ever doing this before.Do you work at a dealership or have the software to accomplish these tasks?

J

[ly5598]

Yeah I work at a dealership...i did it with the Consult II. Anytime the throttle body is removed its necessary to reset the idle. The idle learn is basically an automated way the ecu sets the idle.

[Double E]

Whoa! The throttle body being removed for cleaning requires a visit to the dealer?

I'm planninng to clean it soon, myself. I expect that it will need a gasket replaced at most and plan to buy it ahead of time...but that's it.

My old VQ didn't require any re-learning....are you saying that in order for the engine management system to immedaitely realize any ADVANTAGES from the TB cleaning that idle has to be re-learned with the consult?

Isn't it true that the EMS will eventually re-learn anything it needs to over time anyway?

In case the topic seems unrelated to prior discussion, this response is related mods mentioned above and how that the ECU/EMS will constantly adjust for changes in airflow, O2 content and fuel octane. I'm thinking a TB cleaning is in that category as well.