High rpm guys: anybody playing with cam timing?

[TDIMeister]

I have done some work on a TDI cam, both from benchmarking existing OEM cams as well as some aftermarket offerings with known specs.

http://forums.tdiclub.com/showthread.php?t=123951&highlight=cam
http://forums.tdiclub.com/showthread.php?t=108233&highlight=cam

The result was that I had a small run of 5 cams made some months ago, and I'm eager to hear how they work on the cars of the customers as spring draws near.

One is already installed in Gerry's (DIESEL DAZZLER) HOT Caddy TDI.  Gerry set a 1/4-mile trap speed last year of 112.99 MPH, but traction hampered his E/Ts and he blew the turbo 2/3s of the way down the track on his best (and obviously last) E/T of the day with 14.511 .

This year, we're aiming for 240 HP from the TDI with a hybrid VNT turbo from a Dodge Sprinter CDI, phat hole injectors, 12mm pump, cam and custom programming.  Being able to extend the useable RPM range to 5500 RPM or so will really help E/Ts since a shift into 5th might be dispensed with.  I have a feeling we are going to see 12s this year, if not in North America then in the U.K.  There is a feverish competition going to to have the first documented 12-second TDI with only Diesel (i.e. no methanol or propane injection) and no giggles.  Gerry's Caddy is 2200# loaded with driver, so you can imagine what that, slicks and 240 HP can do...

There is a planned dyno day at a state-of-the-art facility in London with an eddy-current unit sometime in April.  You guys in the area should attend.

Edited to correct typo on trap speed.

[TDIMeister]

Even have an extra couple cams sitting here too 1 TDI spare and a couple IDI units...

Even if you don't decide to put in a reground cam, the AAZ cam has a little more duration than the TDI cam.  This alone would be worth for the small effort to install into your M-TDI if you already have the cam.

[andy2]

Hopefully My 18.5:1 compound (K24/hx30) AAZ will be ready for then,as I may not only attend the Dyno day .I was making somthing like 160-165 hp when I bent the rods with 37 psi on 21:1, Also on #2 only(no drugs yet :lol: ).With the Passenger Preformance stage 3 cam,12mm head and big FMIC to work with this time it should be very interesting.Not trying to say I'll be up there with Gerrys TDI,only that the IDI won't be too far behind.

[TDIMeister]

Have you been able to come across any maps of the Holset turbos?  I can't seem to find any without resorting to pay-for sites.  Infuriating, really, when opportunists like that don't have to pay Holset to get a hold of maps...

[RabbitGTDguy]

Even have an extra couple cams sitting here too 1 TDI spare and a couple IDI units...

Even if you don't decide to put in a reground cam, the AAZ cam has a little more duration than the TDI cam.  This alone would be worth for the small effort to install into your M-TDI if you already have the cam.

Only have the 1.6 IDI cam and my spare TDI unit...no AAZ units around...though, if someone has one they'd like to sell to the cause...i may be willing to try

I remember reading about your cams on TDI club... quite impressive...can't wait to see the results. They were drawn from blanks too weren't they? Not just the regrinds like some are offering...

Joe

[TDIMeister]

From what I understand, the 1.6 cams will not swap over to the AAZ/1Z/AHU...

[andy2]

Havn't come across any Hx30 maps either only HY/Hx35 ones I think.The sprinter CDI is only a 2.5 or is it 2.7L,do you think mabye its still not big enough for the amount of power you'll be at?The HX30w I'm using comes of a 3.9L cummins it makes up to 150 hp stock I believe.I'd imagine the EGT's/backpressure would still be through the roof when using the CDI turbo.If Gerry had a quick reacting thermocouple(not VDO) and mounted Pre turbo I think he'd be shocked at the EGT's even with that turbo,I'm definitely no expert though, only commenting as I've taken numerous pre turbo pressure readings while playing around with different turbos for my setup.It takes a pretty big turbine to flow 150+hp at 35-40psi properly.What boost levels are you guys wanting for 240hp on the TDI?

BTW RabbitGTDguy the 1.6td hyd cam is almost identical to the aaz cam.

[TDIMeister]

I would greatly appreciate it if you could post or otherwise somehow share the HX35 maps that you have.  Seems really hard to come by... There are envelop maps out there but they don't give the depth of data I like...

I don't think an even bigger turbo nor compounding is in the cards, but that's Gerry's call, not mine.  Even with crazy fuelling, there's light to moderate smoke with 20 PSI of boost.  A single stage GT22V is operating near peak efficiency at about 1.9 bar of boost (approx. 28 PSI).  If VW Motorsports' race TDI can be used as a template (and a very good one at that), I'd say we can easily meet the 240 HP goal on 28 PSI quite smoke free and less stress on the bottom end...

Gerry does have an EGT gauge, but not pressure transducer.  As for this thing about EGTs, etc., being affected by turbo size, I've spent exhausting years trying to debunk that myth.  But I confess it all depends on what one is looking to get out of the turbo.  If maximum, unadulterated HP is desired, with no consideration for spool and low-RPM driveability, sure go with a massive turbo or two.

I seem to go against the grain and advocate what I should call the "Goldilocks" approach to have a "right-sized" turbo for the engine's breathing capability and power output, and I also would rather choose a VNT turbo over a WG unit any day.  But I guess being the unfortunate combination of a perfectionist engineer with an eye for hard numbers rather than intuition, and being an efficiency freak, puts me at odds against the tide...

A thread worth reading on the subject:
http://forums.tdiclub.com/showthread.php?t=130109

[SMOKEYDUB]

when is dyno day? Maybe ill show up! :twisted:

[malone]

I have a 1.6 cam in my 1.9 AAZ head. Works fine.

12mm pump, cam and custom programming. Being able to extend the useable RPM range to 5500 RPM or so.

I'm curious as to know how you or Gerry will overcome the RPM limitation with the 12mm pump. Many people are afraid to go over 4,500 RPM with 12mm. Even Jeff @ Rocketchip avoided going above 4,000 RPM on a dyno with his 12mm.

Secondly, for 5,500 or above ("or so", as you put it), what is his solution for timing advance?

In the TDIclub.com thread you posted, you mentioned that a Porsche has a VNT. IIRC it is VGT. They both have the same concept but not the same technically.

[DVST8R]

Some stuff about compound turbocharging that i'm sure Tdimiester is well aware of.  :wink:

Mark, I think you just jumped in over your head...  :lol:

[malone]

Mark, I think you just jumped in over your head...  :lol:

Yes I did.. I just skimmed through a few posts and then typed too quickly :oops: I edited my post to remove the pointless bit.

[DVST8R]

Mark, I think you just jumped in over your head...  :lol:

Yes I did.. I just skimmed through a few posts and then typed too quickly :oops: I edited my post to remove the pointless bit.

Hey, thats what friends are for.   :wink:

[TDIMeister]

I have a 1.6 cam in my 1.9 AAZ head. Works fine.

OK, my bad.  I was going from second-hand information from somewhere I don't remember that someone had tried to fit a cam from an ME into a TDI.  The AAZ and 1Z/AHU swap nicely, but IIRC the was some issue over fitting the ME cam into the TDI.  I must have mixed something up... maybe the issue was over valve-to-piston clearance...

I'm curious as to know how you or Gerry will overcome the RPM limitation with the 12mm pump. Many people are afraid to go over 4,500 RPM with 12mm. Even Jeff @ Rocketchip avoided going above 4,000 RPM on a dyno with his 12mm

Secondly, for 5,500 or above ("or so", as you put it), what is his solution for timing advance?

To be honest, the 12mm pump bit is my little contribution... I got a brand new AHU pump a while ago, and sent it to Marc to install a 12mm head kit into it.  It is still sitting in Gerry's garage and I'm hoping it gets some use because it's a lot of money being tied up doing nothing...

At the moment, Gerry's truck has a bit of a Frankenstein pump with AHU pump body, 11mm plunger and solenoid portion from an ALH to be compatible with the 98 New Beetle wiring harness and ECU that is being used.

We don't really know what the 12mm pump will do much over 4,000 RPM, but several Europeans (Stefan @ Digital Racing, TDIFreak in Finland, etc.) are running 12mm pumps and don't report problems up to the TDI's conventional redline... I seem to be more keen on the 12mm than Gerry but to answer your question, Gerry's truck is running an 11mm and a 12mm just waiting to be used.

As for timing advance, Gerry and I have met with Jeff @ Rocketchip several times since Waterfest 2004 and he has shown us his pump mod in the timing control collar to allow greater advance.  Gerry is in the process to do that mod over this winter.

In the TDIclub.com thread you posted, you mentioned that a Porsche has a VNT. IIRC it is VGT. They both have the same concept but not the same technically.

From what I have seen of pictures, the BorgWarner turbo still uses guide vanes in the turbine, just like Garrett.  The adjustment mechanism might be different though... Some years ago Garrett won a patent infringement case against BW and an injunction on BW's KP39.  BW was forced to change the design so that it did not infringe, but I don't know the details.  I think VTG is just BW's way of calling more or less the same technology as Garrett's VNT.  Holset variable turbos use a completely different mechanism that looks like a big single swinging arm in the turbine.  The Porsche turbo definitely doesn't use this from the pictures I have seen.  Guide vanes are nothing really new.  They are used almost universally in gas turbines, and many of the same technologies for gas turbines trickle into turbocharger designs.

[TDIMeister]

when is dyno day? Maybe ill show up! :twisted:

Date not confirmed yet but here is the thread you can follow up:
http://forums.tdiclub.com/showthread.php?t=128725