Zep's Underwhelming VF 540i

[mcgnms]

The tune VF provides raises the rev limiter unless you ask them not to if I recall correctly. Though it maybe different for automatic transmissions.

1)Without an rpm pickup for your dyno, are you sure the graph ends at 6100RPM?

2) You measured powered on a DynoDynamics which is not showing any form of atmospheric corrections and the loading factor can be adjusted by the operator. These numbers are too inconsistent in the field to be valid for comparisons regardless of "accuracy". If you want comparable results to RedShift or Philly98540 you MUST use a DynoJet and preferably get ignition pickup so the X-Axis is not speed, but RPM.

3) 5.3 PSI at 6,100RPM seems low for a 3.8"/6" pulley setup. Either your exhaust is more efficient like mine or you have a leak or the gauge is inaccurate. RedShift was at 6.5 PSI at 6,000RPM on the original setup for example. Where are you measuring pressure from?

4) It is also good to get another wideband on the measurement for consistency at a different shop.

5) Try to measure pressure before the supercharger. The pipe they provide has a small hole for an IAT used for pre-tu engines I believe. The hole should be there. See if you can fit a pressure gauge inside. Under full throttle at high RPM's, if there is a vacuum in it then your filter might be restrictive. I know a person who runs a 3.47"/6" setup on this supercharger and has to clean the filter often because he looses boost. The pressure before the supercharger should optimally be atmospheric under all operating conditions.

[geargrinder]

you MUST use a DynoJet

That's a load of crap. Plenty of American DynoJets are fluffed up. Most foreigners laugh at American dyno numbers purely because of this.

Stop spouting this silly line Marc. Franks legit dyno numbers are much more plausible than the fluffy ones, and happen to be consistent across the cars we know have been there as well.

I'm not saying a Dynojet can't be properly calibrated and legit but when the numbers aren't plausible in context and vs respectable known shops and benchmarks... they are probably classic 'murcian fluffer dyno numbers. Run on a GOOD dyno i.e. well set up at a proper shop with the proper intentions, thats the important thing. Pretending they can't possibly be compared is buying into phony dyno operator BS.

- - - Updated - - -

The guy who installed the kit says that the slow starts are due to excess fuel and that its fouling the plugs.

Here are two dynos plotting boost and afr over power. The ink line on the AFR is what the mechanic said they should be if the tune was better. Boost is about 5.3psi@6100rpm.

Attachment 551772

Attachment 551774

Fuel filter and FPR were replaced about 1 month ago and the pump replaced with the S62 pump 2 weeks ago.

5psi? Problem right there. I am pretty sure your belt must be slipping. Did anybody watch the blower as it was running on the dyno? Either that or you have a huge boost leak. Or perhaps the bypass valve is not rigged properly or is stuck partially open or not sealed?

[mcgnms]

That's a load of crap. Plenty of American DynoJets are fluffed up. Most foreigners laugh at American dyno numbers purely because of this.

Stop spouting this silly line Marc. Franks legit dyno numbers are much more plausible than the fluffy ones, and happen to be consistent across the cars we know have been there as well.

I'm not saying a Dynojet can't be properly calibrated and legit but when the numbers aren't plausible in context and vs respectable known shops and benchmarks... they are probably classic 'murcian fluffer dyno numbers. Run on a GOOD dyno i.e. well set up at a proper shop with the proper intentions, thats the important thing. Pretending they can't possibly be compared is buying into phony dyno operator BS.

You're spreading misinformation GearGrinder and you have been doing it for a while with regards to Dyno's.

I have already explained this concept and I will do it again.

DynoJets may not be accurate, but accuracy does not matter. Consistency does. Consistency lets you compare numbers. DynoJet's in the field are the most consistent dyno. Dyno in America, Australia, or Mars and the numbers will be very similar. This does not apply to DynoDynamics or DynoComs for example. On a DynoCom I can change a correction factor and make the numbers anyway I want them to be. In this situation with one guy in Australia, Dyno'ing on Frank's dyno isn't feasible. So consistency BETWEEN dyno's is what matters.

DynoJets are calibrated from the factory. Each one has drums with a finely measured rotational inertia. It does not matter how accurate it is. It does not matter if a DynoJet measured 10x more power than is actually produced or 1/10th of the actual power. The point is all DynoJets measure extremely similar power, because it doesn't allow an operator to mess with it. I have explained this to you numerous times.

Accuracy and consistency are different things.

The same thing applies to Dyno's measuring torque values without an RPM pickup. It cannot be done.

If you would like, I can explain this further using concepts in Newtonian Physics. The mathematics behind this also helps.

You can spout silly phrases and profanity all you want. If you want to continue purposefully spreading misinformation, it is your freedom to do so I suppose. I advise against it however.

[geargrinder]

Face it, son. You have very little experience here and are pretending to be some kind of world expert on things from reading internet and lecturing in a confident expert voice like you've been around. Have you EVER had your car on a dyno before? Ever?

I have personally helped to rig cars on/off dynos many times. My own cars. My friends cars.

I have watched the same cars go on different dynos.

Can you expect the exact same number every time? No. But for a good setup you can expect roughly comparable numbers.

But gee son. Now you're changing your tune. You're now saying its "all about comparability". What happend to "you HAVE TO USE A DYNOJET"?

Because comparability is that's exactly what I am saying. That Philly and Brians local dynos are the ones that seem a bit out of whack and in fact Franks dyno is the one with more credibility and more comparability on a number of angles (angle 1 - that it reads the 'about right' numbers for other cars we know have been on it, angle 2 - that it provides numbers that make sense vs my car on another dyno that I have experience and reason to trust... angle 3 - that Frank is about as straight up a tuner shop as you can get and is exactly the kind of guy who would have a properly calibrated setup vs a fluffy one, etc. )

Dynojets are calibrated? Oh golly gee I'm so surprised. Of course they are "calibrated". But any dyno can be fudged and those numbers are just not plausible. I already said - can a DynoJet be calibrated and legit? I am sure it can. I hear there's one near me that's pretty legit in fact. Its just that they so often seem not to be. And when I hear somebody has DJ numbers that don't gybe with another set of more "makes sense for what it should be" numbers I consider that DJ is probably fluffed. And unlike yourself I'm not making up my own experience pretending to have some vast years of dyno experience when I've just read a few things on the google machine.

I'm sorry man but I'm at the end of my rope here. How you also now are "VF tunes are great and if there's a problem it must be cause your install is bad." when you are the guy who was Mr. Poster Child for "VF Sucks and their tunes suck and they should pay us all money and give us new injectors and tunes cuz they suck!". What happened to change your tune anyway?

[mcgnms]

Face it, son. You have very little experience here and are pretending to be some kind of world expert on things from reading internet and lecturing in a confident expert voice like you've been around. Have you EVER had your car on a dyno before? Ever?
I have personally helped to rig cars on/off dynos many times. My own cars. My friends cars.
I have watched the same cars go on different dynos.

I have watched buildings being built. Am I now experienced in architectural design? Watching cars on a dyno does not qualify me as an expert.
The point is not experience, its understanding. I know plenty of experienced and knowledgable people who do not have the slightest understanding of things such as horsepower or torque. Many of them think horsepower is less important than torque. Experience is great, but it does not give you the right to change physics or change facts. I really do respect your experience and help on this forum. Misinformation however is misinformation regardless of who its coming from.

Can you expect the exact same number every time? No. But for a good setup you can expect roughly comparable numbers.

Not on different dyno's you can't.
Edit: On a good setup? Sure. You need two of them though. Find me two of them. Thats the only way to make valid comparisons.

But gee son. Now you're changing your tune. You're now saying its "all about comparability". What happend to "you HAVE TO USE A DYNOJET"?

More misinformation. I never said Dynojets were accurate. I have from the very beginning said that they are consistent, not accurate. More consistent than any other for that matter. Not perfect.

Because comparability is that's exactly what I am saying. That Philly and Brians local dynos are the ones that seem a bit out of whack and in fact Franks dyno is the one with more credibility and more comparability on a number of angles (angle 1 - that it reads the 'about right' numbers for other cars we know have been on it, angle 2 - that it provides numbers that make sense vs my car on another dyno that I have experience and reason to trust... angle 3 - that Frank is about as straight up a tuner shop as you can get and is exactly the kind of guy who would have a properly calibrated setup vs a fluffy one, etc. )

More misinformation. You say words like "seem" or "about right". These words are forbidden in science. I only go by factual information. I am not saying TTFS is inaccurate, because it will be consistent compared to other Dyno's. Remember...we do not care about accuracy. Consistency is what matters. They are different things. On a DynoCom, the operator can play with results, on a DynoJet...they pretty much can't and its a lot more difficult to manipulate results. More on that next.

I'm simply saying if Zep wants more comparable numbers, he needs to use DynoJets and compare that to RedShifts numbers.

Dynojets are calibrated? Oh golly gee I'm so surprised. Of course they are "calibrated". But any dyno can be fudged and those numbers are just not plausible.

No they can't. You have a misunderstanding of how a DynoJet works.

I already said - can a DynoJet be calibrated and legit? I am sure it can.

DynoJets are calibrated from the factory and the factor of inertia is in its specific software which is taken into account when results are printed. This is part of what makes them so consistent. RedShift or Philly can dyno on a DynoJet anywhere in the country and will likely get the same results within a very small margin of error. Unless their dyno's had bad calibration. Anything is possible. We're going off probability. You can't do that with other Dyno's as much. Its not perfect, but better.

Do you not see that there is a difference?

I hear there's one near me that's pretty legit in fact. Its just that they so often seem not to be. And when I hear somebody has DJ numbers that don't gybe with another set of more "makes sense for what it should be" numbers I consider that DJ is probably fluffed. And unlike yourself I'm not making up my own experience pretending to have some vast years of dyno experience when I've just read a few things on the google machine.

So you are basing your assumptions on "what it should be in my opinion". That is not scientific.
Also, more misinformation. I have never claimed to have experience in Dyno's. I just know the basic principles of their operation. Your experience is fantastic, but facts are facts. Are you going to claim different laws of physics to be valid because your "experience"?

I'm sorry man but I'm at the end of my rope here. How you also now are "VF tunes are great and if there's a problem it must be cause your install is bad." when you are the guy who was Mr. Poster Child for "VF Sucks and their tunes suck and they should pay us all money and give us new injectors and tunes cuz they suck!". What happened to change your tune anyway?

More misinformation. I never said the tune gave me drivability issues. I was always honest and factual where I liked it and did not like it. The tune's quality was my opinion. The OP provided specific examples of issues with it. I provided specific ways to diagnose it. My opinion on the matter is irrelevant in this case.

I am sorry to the OP that he has to read conflicting information. It appears we've reached a disagreement. Perhaps more of a misunderstanding. Regardless of what that disagreement may be, why not be respectful? Are we not all here for the same purpose of helping each other out?

[toybreaker]

Both of you cool it and get back to the OP's issue.

Zep, you have gains to make in your tune for sure, you can figure out why you are only pushing 5psi,
and work on your 60 foot and reaction time. greatest gain in your E.T. right there...
but BMW's are not, nor will they ever be a good drag car.

[mcgnms]

I don't think reaction time is part of ET. I could be wrong.

With regards to belt slip I would think that you would see boost flatten out at some point or drop if that were the case. According to the graph is seems boost climbs steadily until the operator let off. GearGrinder, what do you think about this?

Though maybe how badly it spins matters in this case?

Also if the leak only occured under boost then I would imagine a similar effect. Judging by how boost still seems to climb at a smooth rate perhaps the leak is there all the time and not just under increased pressure. Perhaps it explains the fuel trim behavior at part throttles? Just logical thought train here.

[philly98540]

Sheesh you two. Nothing to prove here, let's just help Mr Zep. Kay?

BTW, I can't wait to get back to my Uber reputable fully calibrated local DYNO JET... um so I feels more better about my car.

[Tutti57]

Check belt tension to start. Do you have under drive pulleys?

[Zep]

This is why I was dubious about the dynos I received as they are too easy to fudge.

Essentially, this is the story about the install and dyno of my car:

I get a call from the younger mechanic at the workshop to say that the install is complete and that they are going to dyno the car to see how goes. He calls back to say that it made 210wkw/281whp. I was a bit incredulous as the car made 175wkw/235whp stock, which would mean less than 50whp from the VF kit, M60 manifold and meth.

So I go to the shop and check out the install and it looks good except I notice that the FPR is plumbed to the intake snorkel and not to the manifold as directed by the VF addendum. I mention this to the shop owner and discuss how the car should have picked up about 100whp. I leave to go back to work and later get a call saying that they plumbed the line into the manifold and ran it again and lo and behold, it made 253wkw/340whp. Could be true, could be total BS to keep me happy and get my wallet out. IMO the 1/4 mile times have more weight behind them as they dont make adjustments between cars and you get what you run.

The car doesn't have any specific drive-ability problems but for the occasional warm slow start. The belt tension appears fine and the boost appears to be quite linear and unaffected by any external factor. No underdrive pulleys.

I considered the prospect of a boost leak but figured the car would be running rich from lack of boost to match fuel, but the car runs lean if anything. Or at least has run lean, the latest LTFT appear to be almost prefect in comparison to how they have been...and I still dont know why that is??

reaction time doesnt impact on ET.

[tptrsn]

Zep, thank you SO MUCH for taking your car to the old black quarter mile dyno! :-) I wish more of the people with forced induction setups would follow suit. Trap speed at the drag strip tells a lot about how fast a car really feels. ET doesn't tell as much, though taken in the context of the 60' time(s), it sort of helps.

At any rate, in the old days our SWAG from your trap speed info would have been that you gained about 60HP, 10HP/MPH-ish. That does correlate pretty well with the initial dyno numbers they gave you, so I think that feels pretty credible in this case.

If you want to have an actual decent handle on what is going on with your F/I engine, you absolutely need to have a wideband or widebands installed before the converter(s), and you need to have a boost gauge. Without that sort of information, you are just swinging in the dark. If the people who did your install had a proper wideband setup to your system when they dyno'd it, they would have probably had more to say when you told them that they hooked up the FPR reference line to the wrong location.

As in, they would have said something like, "Well, your AFRs are right where we like to see them, so we recommend against moving it" or, "Oh, great, we'll try that location and see if it rectifies the AFR problems we were seeing."

At any rate, I will be very excited to see what happens when you remove your converters (I think you said?).

Oh, and just to leave this post with an inflammatory comment, Lol, I will add that I have been uniformly underwhelmed with most installs of centrifugal superchargers. They never seem to make the power that they should/could. I guess it's because they are quite parasitic in nature.

Furthermore, when you compare trap speeds at the drag strip, what you are really seeing is the difference made by the change in average horsepower throughout the runs. The nature of centrifugal superchargers in factory add-on applications like this is that they slowly ramp the boost in with increasing RPM. That's all good and safe for the engine, but what it really means is that the change in peak horsepower is rather overstated compared to the increase in average horsepower that is expressed through the entire course of the quarter mile.

Having said all of that, I would say that your 6mph increase in trap speed isn't too bad under the circumstances.... Just MHO.

[Zep]

OK, so the 3.25" pulley and 42# injectors have been installed, and so I am now just waiting to get the TTFS software. I have paid for the tuning to be done remotely but I havent been able to get the cables and related software to work so far, but hopefully they will get back to me with a fix soon...unless they have closed for christmas already?

[AnotherGeezer]

The saddest fact of life today is that even a 13.5 quarter mile is pretty blase. Most modern supersedans do that without breaking a sweat.

[fullthrottle540]

Shoulda gone the nitrous route....

[joekitch]

aaand this is why i'm really looking forward to one of those m62 jaguar blower projects getting repeatable and popular. Even if you don't get that much extra power, if it's concentrated in the mid range, you get a ton more smiles per gallon in daily driving, which i argue is more important than track performance.

because let's face it, a brembro big brake kit and pilot super sports would probably shave more off your track times than a blower unless you make a loooooot more power with that blower

[philly98540]

Let's see how the new tune works before condemning the VF kit. My set up is working very good, so must be something with Zeps. Any boost or afr gauges on your car Zep?

[angeleye540i]

Both of you cool it and get back to the OP's issue.

Zep, you have gains to make in your tune for sure, you can figure out why you are only pushing 5psi,
and work on your 60 foot and reaction time. greatest gain in your E.T. right there...
but BMW's are not, nor will they ever be a good drag car.

Leave it to the Mustangs and chargers, not worth snapping the driveshaft over... unless for serious $$$... anybody can squeeze straight-line acceleration out of just about any car if you do a number of things we all know about, it takes a true engineer to make an ultimate driving machine not just an ultimate straight line wheel spinning machine

[mcgnms]

OK, so the 3.25" pulley and 42# injectors have been installed, and so I am now just waiting to get the TTFS software. I have paid for the tuning to be done remotely but I havent been able to get the cables and related software to work so far, but hopefully they will get back to me with a fix soon...unless they have closed for christmas already?

Email sent.

The saddest fact of life today is that even a 13.5 quarter mile is pretty blase. Most modern supersedans do that without breaking a sweat.

A quarter mile time is cool, but a 13.5 is not hard to get with a good launch. The traction is half the battle. However the trap speed is a different story. A 13.5 at 103mph is different than a 13.5 at 115mph.

aaand this is why i'm really looking forward to one of those m62 jaguar blower projects getting repeatable and popular. Even if you don't get that much extra power, if it's concentrated in the mid range, you get a ton more smiles per gallon in daily driving, which i argue is more important than track performance.

because let's face it, a brembro big brake kit and pilot super sports would probably shave more off your track times than a blower unless you make a loooooot more power with that blower

The power in the midrange with a centrifugal setup here is very good and its questionable how much higher it can get safely.

[fullthrottle540]

but BMW's are not, nor will they ever be a good drag car.

BMW's are not for drag racing.

There are a few boosted LS1 E39's on this forum... in the 600-700 whp range... that looks like the way to go for a fun E39

[Zep]

taking the car to the drags was only to have a true before and after delta of the supercharger install, as I dont really trust dynos. A stock f30 328i 2 liter would run a similar time as my modified 4.4liter v8.

The transmission is a big let down in these cars and I am sure it costs some precious performance.

According to Frank, I might need different cables and software to use the ME7.2 - I hope I dont as it would take a while for new cables to be shipped.

[philly98540]

Something ain't right if your not easily beating the 328 f30.

[mcgnms]

Trap is a far better indicator of power. Time is a terrible way to compare horsepower generally.

[Zep]

Something ain't right if your not easily beating the 328 f30.

Some of those new x28i turbo cars are running very low 13s with JB4 and e85

[tptrsn]

Trap is a far better indicator of power.

Agree 100%, and he's only trapping 102. In a car that trapped 98-100 stock, with an additional $6k supercharger on it. I'd be angry.

Hopefully Frank will be able to make some real speed materialize from the potential that exists in your setup, Zep!

[philly98540]

Definitely something wrong. Get that tune installed and reevaluate. I'm not convinced that something else is not at play, as your numbers are way off from the other VF kits.