SDI Intake on ALH with Dyno Data

[brum]

So, if I follow your logic correctly, we should install a throttle in the intake tract for better performance?

Nope . Just reduce the boost. If I'm right the SDI manifold should be able to deliver the same volume of air to the cylinder with less boost.

Actually some diesel engines do have throttle. But the EGR is able to do the same job regarding emissions. Regarding economy - its different story. The diesel engine have to do a lot less work when working at atmospheric pressure compared to the petrol one. The diesel compress air and the petrol creates vacuum in the cylinder. The first require less energy than the second. This is one of the reasons for the diesel engine to be more efficient than the petrol engine.

 

[m1ketdi]

No MAF on the TDT tune

This invalidates any comments made by me about QA and MAF.

An interesting test would be how much fuel can we inject between 1500-2000rpm until smoke with the different manifolds.

I think the sdi may well be flowing better just the MAP based tune worked to it's disadvantage as it wasn't optimized for the better flowing mani.

Thoughts anyone else?

 

[TDIMeister]

The throttle in Diesels IS for EGR and also LNT regen cycles that require fuel-air mixtures rich of stoichimetric. It does not replace EGR regarding emissions.

Both Diesel and petrol engines can produce a partial vacuum in the cylinder during the early part of the intake stroke. Not a distinguishing factor of the different cycles.

 

[TDIMeister]

What we need are more data points of dyno results between the SDI and stock manifolds from more people with the same attention to data collecting as F_U_B has done. Not a slight on F_U_B, but he will also appreciate that a single data point does not a trend make. The conclusion *could* be that the scroll manifold is inferior -- I can't see how, but we cannot be in denial if multiple data points turn out to show the same thing. The plastic 2-piece SDI manifold remains my favourite.

 

[TDIMeister]

F_U_B, if you don't mind, I've brought your plots from the other thread here for convenience...

 

[TDIMeister]

The peak powers of the ALH runs with 3 different tunes cluster tightly, with the lone SDI result way below it. Again, I can't explain such a large magnitude of loss, when boost, EMP and fuel quantity seem to be more or less equal when you pass the peak torque hump.

I would suggest another set of runs with only the SDI manifold with whatever tunes you have at your disposal. We should put a fund together to help with the cost of the dyno. I'd happily contribute in the name of science.

 

[ryanp]

I'm no manifold expert, but I'd be hard pressed to see a difference between flowing in one side versus the other on this design. It's pretty symmetric inside.

What I mean was due to the offset of the ports in relation to the manifold:

http://i1219.photobucket.com/albums/dd425/euroshack/TDI Club/SDI3.jpg

So it is designed to come in from one side, yours comes in at the opposite side. The difference would probably be minimal, but I was just making the observation.

Cheers

Ry

 

[Fix_Until_Broke]

In hindsight I should have run through all 3 tunes on both intakes - it would have been easy enough to do, just didn't think of it at the time .

Brum, I understand what you're saying, but am trying to figure out how significant those differences are at 100% throttle. The three different tunes behave quite differently in how they control boost. If you look at the above exhaust manifold pressure measurements done during the dyno runs, it would suggest that exhaust manifold pressures are not significantly different, beyond spool up. If you look at the VNT actuator vacuum in the data above (Pink trace at the bottom), the ALH intake runs the actuator in a more closed position, particularly in the 2000-2500 RPM range on the same tune with the SDI. VNT position does not equal a given exahust or intake pressure - you can have widely different intake and exhaust pressures for any given VNT position depending on engine RPM and load.

The data also shows that the exhaust pressures are not crazy high on the 17 hot side as some have suggested. Only exceeding boost pressures above 3500 RPM and then only by a few psi. Then again, I'm only putting down 125-130 HP as well so maybe that has more to do with it .

Like TDIMeister stated, this is just one sample with data. More people doing comparative dyno testing will support or conflict with my data. I don't expect that there will be a big number of people able to do back to back dyno's like I did, but even same car, same dyno should give some indication as to what's going on.

Taking a step back and looking at this whole thing...

1) Regardless of what different variables are at play (tune(s) need adjustment, how tightly it was/was not strapped to the rollers, phase of the moon, etc) there is just not a big difference in power between two very different intake manifold designs. The dyno data shows it and my super accurate and repeatable NIST calibrated butt dyno can't tell any difference driving around with either manifold (and I can definately tell you within 1 block which tune I'm driving and there's not that much difference in the power of the tunes either).

2) Maybe my car is an anomoly - Given many other members cars with similar equipment making ~175 HP or so, maybe there's some other limiting factor that is not letting the intake manifold differences show through. If I remember right, someone at the dyno day had PP520's, 10mm, 17/22, RC4 or 5 and put down 140 HP/300 ft-lbf.

I'll do more dyno testing if I get the opportunity - there's a shop up in West Bend that has a similar Mustang dyno as the one at UWP. Most of my weekends are pretty booked up for the summer, but maybe I can run all 3 tunes on each intake in 1-2 hours while it stays strapped down to the dyno. But if #2 is correct above, it might be a waste of time/effort/$$$

 

[Ben Dur]

just digging through some threads... interesting results.
definitely a bummer, as i was hoping to get one of these.

has anyone seen different results?

and BTW do i see my old cylinder head in the original post? glad its being put to use

 

[Fix_Until_Broke]

Yep - that's your old head

I hope that this does not deter anyone from getting/testing one of these manifolds. There were many factors/variables in the above tests that could have skewed the results one way or another. It would be great if someone could run a similar test without removing the car from the dyno to minimize that variable. Even without all the data acquisition, the dyno data would give another data point.

If I wasn't working 60-70 hours/week and also trying to finish up some outdoor projects before winter I'd put some more time into this, but as it stands now I'm just too busy with other things. Maybe next year...

 

[Ben Dur]

the only thing that really stand out to me is that there is a variable between tunes here.

the SDI with MAF
the ALH without MAF

both on TDTuning
could it be possible that the maf is bad? or going bad?
this would show why the dyno is lower... leave the RC aside as this is a different tune (or tunes)

this manifold would be a nice option for those with complete custom setups, but with a run of the mill plug and play (vnt 15 17 or 1752 or even 1852 or 1856) it requires some modifications to both TIP and Manifold.

this wouldn't be an issue to many, if it showed obvious benefits, but here we are debating whether it was actually negatively affecting the setup.

bummer to be honest. but im not ruling it out just yet

 

[Fix_Until_Broke]

All the TDTuning runs are MAP based - no MAF - only difference being weather or not the MAF was plugged in electrically or not between the two runs. Maybe that matters, but I doubt it.

 

[Ben Dur]

i was under the impression that they were not in fact speed density, but rather they defaulted to max. somewhat different. but i may have been under the wrong impression???
given that VWMikel has posted in this thread himself i imagine he would have picked up on it if it was the issue. It is just the only thing that stood out to me.

lets also remember that there is a margin of error inherent to the dyno itself. and there are some factors at play here. the margin may not be as great as displayed. By the same token, it may be worse.
if we see 2 or 3 other threads showing adverse power effect, and no other dyno's showing improvement, that may indeed substantiate your findings.

cheers to great work though. If nothing else this what certainly unexpected. I would have imagined the SDI to produce MORE power, even with all factors working against it (ambient temp, dyno error, etc) I am now a skeptic

 

[vwmikel]

i was under the impression that they were not in fact speed density, but rather they defaulted to max. somewhat different. but i may have been under the wrong impression???

There are two different scenarios that people like to call "MAF Delete". The first being where the default is reset and the ECU does not run on a smoke map. it just sorts it out based on a maximum default value and torque limiter. This usually results in excessive smoke.

The second is true speed density. A typical speed density system as is typically used on some gas cars such as Hondas and most any standalone system takes into consideration throttle position, manifold pressure, and air temperature to come up with a calculated air volume based on density. This is what I do with any of the speed density systems where it uses the MAP sensor to meter fueling rather than the MAF. In case anyone is wondering, the MAP sensor is where temperature readings are taken and not the MAF. If the MAF is so equipped with a temp sensor it is not normally wired to the ECU.

 

[Ben Dur]

so TDT is true speed density? or is it specifically some tunes?
if so which tunes, or how much additional?

 

[vwmikel]

so TDT is true speed density? or is it specifically some tunes?
if so which tunes, or how much additional?

I can't speak for others, but what I offer in the race tunes is true speed density. It can be done with other stages and whatnot if the need arises.

 

[A7djc]

sorry to bring up an old thread, the sdi manifold in this case was modified so it could fit standard alh pipework, could the fact the manifold was designed to be fed from the right to induce swirl be why this example has low readings

 

[Fix_Until_Broke]

I think Ryan P suggested that earlier (maybe in another thread). Inside of the center of the manifold it's pretty symmetric. I'm not sure if it makes a significnat difference which side the air comes in - it's a cylinder with tangential radial ports evenly spaced along the length.

Someone had an excellent picture of the inside of this manifold, but I can't seem to find it now...

 

[A7djc]

i was under the influence it was a corkscrew effect to get the air turned in to the runners, because if you fut an inlet with a fan blade in to help the air turn would it not benefit the inlet air speed greatly

i ask because i'm after an inlet manifold for 300hp mark

 

[mk1-83]

you can also look at the golf mk4 sdi inlet mainfold it's a 2 piece thing.

 

[VWBeamer]

I have a SDI intake like the one used, it appears to be symetrical to me. I can't see a reason why changing the inlet from one side to another would have a significant effect.

 

[COMP461]

If you want to test this one, I'm down for 5 weeks until the Houston Mile. We whipped this one up in a few hours for the late intake closing event. I feel that a bigger plenum, with more taper in the runners will help.
The next picture is what the new runners will look like.

 

[Fix_Until_Broke]

Here's the picture I was thinking of (shamelessly stolen from fenwick458's for sale thread).

As far as runner tuning and resonances, etc there is not really anything that will practically fit on a frist order resonance length. At 5000 RPM you need an 18+" runner at atmospheric pressure/temp - increase pressure and temp (density) and the runner length gets longer yet. This is assuming 85 crank degrees for one pressure wave period. 15" @ 6000 RPM, 23" @ 4000 RPM.

My main goal was to test two very different manifolds and see if there was a significant difference - the testing variables clouded the results, but there was not a significant difference between the two in my opinion.

The sharp corner of the ALH/PD130/150 manifolds at the entrance of the head vs the more straight on approach of the SDI or the one LandSpeedTDI shows above were where I assumed any gains would be had.

 

[COMP461]

I am told that taper on the runner will widen the band that the where the first order resonance will most benefit the port. My manifold calculations are similar to yours, but my manifold guys always come up with shorter runners. I feel anything is better than the stock ALH manifold.
here is what a 7500 rpm super charged 632 looks

 

[oldpoopie]

Here is what a rubber ducky looks like

 

[DPM]

nice rubber duckie!
and just as relevant

 

[snadam]

... I feel anything is better than the stock ALH manifold.

Evidently not; it would appear from the data in the first few posts that the stock ALH manifold is better than the SDI.

 

[red golf tdi]

Wow So What about the PD150 With the R32 Snorkle and TIP kit?

What happened to this question? I'm curious too about Euro R32 DSG snorkle!

 

[Fix_Until_Broke]

I have ordered a complete R32 Snorkle back TIP kit as well as a PD150 Intake From Ryanp. I will get it Dyno'ed with a before and after. Ill let you guys know.

I've got a 3" TIP, but don't have an R32 DSG snorkle or PD150 intake otherwise I would have tested them.

I have not seen any dyno data from JarHead on this. Maybe it's in another thread?

 

[mech644]

Here is what a rubber ducky looks like

What an awesome rubber duck! Anyone see the similarities between the taper on the 632 mani and the ducks beak?

Good one Poopie!