[turb0mik3]

I like civil discussion!!! I have no say because I think anything above 550whp is useless on a road course, hehe. I do, however, really think they both have their perks, and both Shiv & Tony have done LOADS for the N54 community!! I want to thank both of you for your hard work!!!

[BEAR-AvHistory]

Originally Posted by AltecBX

This is the meth run in green.

Nice 602whp, read that it was a" lets see what happens" run when they got heat soaked during the test.

[cstavaru]

I agree with the fact that the single turbo spools faster than the twin-turbo, for these two particular setups. The single turbo is fed by 3 liters of exhaust flow while each of the twins is fed by 1.5 liters of exhaust flow and the combined flow of the twin-turbos is higher than the single.

My opinion is that using larger turbos compromise the trademark low-end torque of the N54 engine. The 10.2:1 compression ratio of this engine does not allow timing advance to be raised too much at lower RPMs (as I found out by playing with ATR on RBs), and the turbos do not provide the necessary pressure. So the low-end becomes weak. Even with RBs. I would say that's why Alpina chose a lower compression ratio for the N54 engine that they used in the previous B3 car.

Some solutions that I would see:

- Tune and use the "Timing (Spool)" map of the ECU (which is by default disabled in Cobb maps)
- Choose the turbos for the exact final power target - there is technical documentation available on this
- A twin-scroll single-turbo setup (this would be the most "correct" and also the most cost-effective solution, why hasn't this been attempted until now ? I read HPF is working on this)
- Smaller turbos for the bi-turbo setup

[Dave W.]

So wait, if I'm reading this right Vargas dyno'd in 5th gear to make his spoolup look quicker, then compared it to one of Vishnu's early AT dyno runs? That doesn't seem right.

Shiv, in your experience how much quicker does the turbo spool up in 5th gear compared to 4th? How much worse would spoolup be on an AT car?

[Rob@RBTurbo]

I dont think anyone did anything to make things look better than the other. At this point the answer to your question really is not necessary, provided you'd wish to use it to use the data already provided to make any fair comparisons. Either way all the data is flawed to make ANY comparisons whatsoever regarding spool up.

I believe this thread was started to counter some conjecture about the TT setup blowing the snot out of the ST, and that is it. Not to say it is better or worse. The forums conjecture can turn into truth in the matter of seconds, so it makes sense to clear the air ASAP IMO.

My understanding was that there was going to be a Beer N BBQ friendly pump gas match up in the next week or two, where all factors can be monitored appropriately, and compared for the sake of ending an argument that would otherwise never reach a mutual conclusion.

Originally Posted by Dave W.

So wait, if I'm reading this right Vargas dyno'd in 5th gear to make his spoolup look quicker, then compared it to one of Vishnu's early AT dyno runs? That doesn't seem right.

Shiv, in your experience how much quicker does the turbo spool up in 5th gear compared to 4th? How much worse would spoolup be on an AT car?

[Rob@RBTurbo]

I believe there would be most value in a thread like this, to involve technical discussion on what factors are most important to maintaining a fair comparison. I realize there is alot of talk about turbo flow potential, but all I am seeing is compressor sizing talk and although surely that is a factor in spool up... I'd consider it much less than turbine flow potential. Other things such as gear ratios, fueling used (thus tuning tweaks), RPM at WOT onset, etc. are all very important. This is assuming all other factors are the same (same dyno, same day, same operator, etc).

[Tony@vargasturbotech]

Originally Posted by Dave W.

So wait, if I'm reading this right Vargas dyno'd in 5th gear to make his spoolup look quicker, then compared it to one of Vishnu's early AT dyno runs? That doesn't seem right.

Shiv, in your experience how much quicker does the turbo spool up in 5th gear compared to 4th? How much worse would spoolup be on an AT car?

you might want to go back and read a little more, cause no you are not reading anything right. We Dyno'd in 5th as do most MTcars(shiv Dyno's his car in 5th). People want us to dyno in 4th, no problem we will, we do not care no are trying to do anything in secret. As far as comparing spool, we did not overlay any maps, that is all other people's doing. Bottom line in spool is this, we've been tuning for 2-3 weeks. First time on the dyno, with turbos that flow 850 hp. If you want do an apples to apples spool comparison, have vishu put a single that supports 850, easily done, and we will put one of our smaller options that flow about 700 and get the car fine tuned for E85 and meth. Until then a spool comparison is moot. What's not moot, is the power we are making, and where we are making it, how close it already spools the single with much more flow potential, on 91 octane only so far.

[turb0mik3]

Originally Posted by Vargasturbotech

you might want to go back and read a little more, cause no you are not reading anything right. We Dyno'd in 5th as do most MTcars(shiv Dyno's his car in 5th). People want us to dyno in 4th, no problem we will, we do not care no are trying to do anything in secret. As far as comparing spool, we did not overlay any maps, that is all other people's doing. Bottom line in spool is this, we've been tuning for 2-3 weeks. First time on the dyno, with turbos that flow 850 hp. If you want do an apples to apples spool comparison, have vishu put a single that supports 850, easily done, and we will put one of our smaller options that flow about 700 and get the car fine tuned for E85 and meth. Until then a spool comparison is moot. What's not moot, is the power we are making, and where we are making it, how close it already spools the single with much more flow potential, on 91 octane only so far.

Correct, comparing spool time is relatively stupid when you have only been tuning for 2 weeks... Just like every other upgrade for this platform, it takes time to perfect the equation. I mean, how many twin turbo upgrades do you know of for the N54...

[Dave W.]

Originally Posted by Vargasturbotech

you might want to go back and read a little more, cause no you are not reading anything right. We Dyno'd in 5th as do most MTcars(shiv Dyno's his car in 5th). People want us to dyno in 4th, no problem we will, we do not care no are trying to do anything in secret. As far as comparing spool, we did not overlay any maps, that is all other people's doing. Bottom line in spool is this, we've been tuning for 2-3 weeks. First time on the dyno, with turbos that flow 850 hp. If you want do an apples to apples spool comparison, have vishu put a single that supports 850, easily done, and we will put one of our smaller options that flow about 700 and get the car fine tuned for E85 and meth. Until then a spool comparison is moot. What's not moot, is the power we are making, and where we are making it, how close it already spools the single with much more flow potential, on 91 octane only so far.

You're the one who started the spoolup comparison including an overlay, that's why Shiv started this thread, saying;

Originally Posted by shiv@vishnu

I do want to clear up a little bit of misinformation regarding this post that Tony made regarding boost response difference between our single turbo set-up and their twin GT turbo set-up. The said that their big twins offer "identical" low end toque up to 4250rpm. But in the graph he posted, he compared a 6MT to a 6AT and a 5th gear run to a 4th gear run. With both variables having a big effect on low end torque when tested on an inertial dynamometer (Dynojet). While we have plenty of customer single turbo 6MTs dyno results, we rarely dyno the cars (with stock final drives) in 5th gear.

You compared your MT car doing a 5th gear pull against a Vishnu an AT car doing a 4th gear pull. Here's your post

Tony, I don't mind if you want to play it a little differently now, it probably wasn't a good idea to try to attempt that comparison in the first place.

[The Ghost]

Originally Posted by Vargasturbotech

We Dyno'd in 5th as do most MTcars(shiv Dyno's his car in 5th).

Most MTs dyno in 4th. That has been the standard here.

[BEAR-AvHistory]

The whole spool thing is just a diversion to get people talking about spool time instead of what the post was about. The thread was about 3 weeks in development, first time on a dyno = 572WHP on 91 Cal piss. Throw in some “hey lets try some meth while we are here” so we get 602WHP on Cal piss & meth without any other changes.

I would say these guys really know what they are doing & can’t see why they will have any spool time problems with a little more development work. As for our standard on the forum is 4th gear, give me a break, they are running what they need to run for development tests not catering to E90post.

Maybe the guys who want this dyno run or that dyno run can step up & buy some time on the machine.

[Rob@RBTurbo]

How is it a diversion? Spool is a big issue to most customers, is it not?

So if competitor "A" comes out with data suggesting that competitor "Z's" spool sucks donkey ass, and shows a chart (data) to the masses as proof (many of which would just run away with that with no further research)... then potential customers will no longer be interested in competitor "Zs" product due to that conjecture from competitor A. This may seem like semantics to those who have not put their own blood sweat and tears put into a product, but it is quite offensive to those who have.

Data is great, and so is competition, but at least keep the comparisons without gaping fundamental flaws before taking the approach of comparisons. Simple as that, and it goes both ways.

The lack of tech talk (as was proposed above) in favor of constant pissing matches really gets old. How about some tech talk, and perhaps a real comparo for us to look forward to, eh?

Rob

Originally Posted by BEAR-AvHistory

The whole spool thing is just a diversion to get people talking about spool time instead of what the post was about. The thread was about 3 weeks in development, first time on a dyno = 572WHP on 91 Cal piss. Throw in some “hey lets try some meth while we are here” so we get 602WHP on Cal piss & meth without any other changes.

I would say these guys really know what they are doing & can’t see why they will have any spool time problems with a little more development work. As for our standard on the forum is 4th gear, give me a break, they are running what they need to run for development tests not catering to E90post.

Maybe the guys who want this dyno run or that dyno run can step up & buy some time on the machine.

[TurboBimmer]

Originally Posted by turb0mike

I like civil discussion!!! I have no say because I think anything above 550whp is useless on a road course, hehe. I do, however, really think they both have their perks, and both Shiv & Tony have done LOADS for the N54 community!! I want to thank both of you for your hard work!!!

+1

More power sounds nice on paper but I don't think our chassis can handle that much, at least not on tracks with corners

Still it's amazing to see how much the N54 can handle on stock internals!!

[BEAR-AvHistory]

Originally Posted by RobBeck

How is it a diversion? Spool is a big issue to most customers, is it not? Rob

Yeah its a big issue so why not give them more then one dyno session to work on it before jumping on their case. As I said earlier the thread was about a lot of horsepower out of the box on 91 cal. If they can do that they can certainly do something to improve the spool time.

I think some people might be unhappy that Vargas came so far so fast after a lot of "experts" were shooting off their mouths how the effort would not be successful. I remember a lot of snarky knocks & comments about the “new guy’ who would find out real fast its not easy.

What he found real fast was 602whp @ 5500rpm. Instead of all the snipping the big “advancing the platform” guys should be passing out atta boys to Vargas & PTF.

[Rob@RBTurbo]

Pretty sure the "atta boys" have been passed along. The power numbers are great, and it is agreed there is much room for improvement. But you keep missing the point about how it all started, and I am done trying to explain it.

As for the new guy, if I recall correctly, he did find out that it is not that easy. He also found it that it is a real pain in the ass to install to the last of my reading (projecting 2x the man hours). Also I am not sure the kit is even complete as far as the plumbing goes, as it was just quicker to get the numbers out than to complete it. He definitely took it all in stride though, and never gave up. So gotta hand it to him for that. And I guarantee he did the best that can be done with the space that there is to work with. But until you get an installers opinion, or bill, you may want to reserve judgment on whether those snarky knocks and comments were flawed or not. Of course that is topic for another thread.

All of that aside, it is great to have options. And I'm sure this kit will fit the bill perfectly for some percentage of people out there looking to really push the platform.

Originally Posted by BEAR-AvHistory

Yeah its a big issue so why not give them more then one dyno session to work on it before jumping on their case. As I said earlier the thread was about a lot of horsepower out of the box on 91 cal. If they can do that they can certainly do something to improve the spool time.

I think some people might be unhappy that Vargas came so far so fast after a lot of "experts" were shooting off their mouths how the effort would not be successful. I remember a lot of snarky knocks & comments about the “new guy’ who would find out real fast its not easy.

What he found real fast was 602whp @ 5500rpm. Instead of all the snipping the big “advancing the platform” guys should be passing out atta boys to Vargas & PTF.

[Ænema]

Rob, you truly are the master of backhanded compliments

[BEAR-AvHistory]

Originally Posted by Ænema

Rob, you truly are the master of backhanded compliments

+1

[Young_Man]

Can we give the Vargas guys more dyno time before doing all these comparisons?

[Jeff@TopGearSolutions]

Originally Posted by RobBeck

How is it a diversion? Spool is a big issue to most customers, is it not?

So if competitor "A" comes out with data suggesting that competitor "Z's" spool sucks donkey ass, and shows a chart (data) to the masses as proof (many of which would just run away with that with no further research)... then potential customers will no longer be interested in competitor "Zs" product due to that conjecture from competitor A. This may seem like semantics to those who have not put their own blood sweat and tears put into a product, but it is quite offensive to those who have.

Data is great, and so is competition, but at least keep the comparisons without gaping fundamental flaws before taking the approach of comparisons. Simple as that, and it goes both ways.

The lack of tech talk (as was proposed above) in favor of constant pissing matches really gets old. How about some tech talk, and perhaps a real comparo for us to look forward to, eh?

Rob

[OpenFlash]

Originally Posted by RobBeck

How is it a diversion? Spool is a big issue to most customers, is it not?

So if competitor "A" comes out with data suggesting that competitor "Z's" spool sucks donkey ass, and shows a chart (data) to the masses as proof (many of which would just run away with that with no further research)... then potential customers will no longer be interested in competitor "Zs" product due to that conjecture from competitor A. This may seem like semantics to those who have not put their own blood sweat and tears put into a product, but it is quite offensive to those who have.

Data is great, and so is competition, but at least keep the comparisons without gaping fundamental flaws before taking the approach of comparisons. Simple as that, and it goes both ways.

The lack of tech talk (as was proposed above) in favor of constant pissing matches really gets old. How about some tech talk, and perhaps a real comparo for us to look forward to, eh?

Rob

Ah the voice of reason.

[OpenFlash]

Originally Posted by Dave W.

So wait, if I'm reading this right Vargas dyno'd in 5th gear to make his spoolup look quicker, then compared it to one of Vishnu's early AT dyno runs? That doesn't seem right.

Shiv, in your experience how much quicker does the turbo spool up in 5th gear compared to 4th? How much worse would spoolup be on an AT car?

On a dynojet, the shorter the gear, the shorter the run duration, the less engine load and the higher RPM the boost comes in at. So running in 5th (instead of 4th) gear can result in 300-400rpm quicker spool up. And on top of that, the 6at has even shorter heads than the 6my so spool up is compromised even more. So there is more to it than just testing in different nominal gears. It's the actual gear ratio that matters. Fortunately, the dynojet logs this and stores it in the run file since it has such a profound effect on turbo cars.

And just to remind Tony, my own personal 6mt car is dynod in 5th because of its shorter 3.46 final drive (from a 6at). This is close to 4th gear (in terms of effective gear ratio) to a standard 6mt car. So you can't just say that all 5th gears are alike because there is more to a drivetrain than the gearbox.

[805beemer]

Originally Posted by Ænema

Rob, you truly are the master of backhanded compliments

+100000000 So glad I sold your turbos before installing and having the seals go bad like on themysts car and sooooo many others it seems.