Paging PatrickG, PredatorZ and the other cam guru's
 

As with many I've been reading with great interest PatrickG's progress with his now famed "Torque Cam". - Thanks Patrick for keeping us updated with events. :)

I have a few questions:

Question 1:
I haven't seen this answered anywhere, PatrickG you said the TR Trak cam was difficult to tune, would your Torquer Cam be any easier to tune? I would be running either cam with a MAF and tuned with EFI Live or HP Tuners.

Question 2:
In the UK I'm pretty much limited to the equivalent of 91 octane fuel, would this affect the specs of the cam or would it be more down to tuning/setup? If cam, what would you recommend as an alternative?

Question 3:
As the Torque Cam makes more low end torque would I still be able to keep my 2.73 rear? My car is an A4 and I want the ability to hit 150mph at WOT which means using OD/4th is out of the question, or would I still need to change the gears something more like 3.42's?

Question 4:
I still really like the look of the TR Trak cam, although my car doesn't see the track very often it is purely a play thing and gets a good spanking ;) whenever it's used. Pissing about in heavy traffic isn't a regular occurrence whereas bouncing off the red line is. :D

With the same mods how would a car equipped with the TR Trak cam compare to one with the PatrickG Torque Cam in say 20-150mph roll race and in the twisties coming on off the power at various speeds from 20mph all the way up to over 80mph?

Mods to a 1999 z/28 A4:
-stock heads
-LT headers, catted Y and catback
-lid, ported stock TB and LS6 type intake manifold
-stock MAF
-3600rpm stall
-supporting suspension/chassis/brake upgrades

Question 5:
Would I need to upgrade my fuel system, I believe 99 model years had the smaller 26lb injectors, I might plan on a 100 or 125 shot of nitrous in the future?


PatrickG (and others) thanks in advance for your help. And I understand that getting better heads, FAST 90/90, etc. would all make good sense. And I agree however my wallet doesn't, so I'll have to play ball with what I've got.

Patrick's Torque cam makes great low and midrange numbers, even up high is isn't but a few short from the TRak cam, but you also have to remember that he has a nice set of heads on there, which help out the TQ tremendously I would think. With it tuned right, you can get awesome results from the TRak cam in a cam only setup. I may even have a few more in it with a good dyno tune vs a street tune:)

I forgot you had the Trak cam also, although I do remeber reading you thread in the dyno forum. I see some rather nice numbers in your sig. How do you find the cam when your not at WOT?

And yeah I'd love to get some 205 AFR heads but money is being spent on other things at present. I might consider the TSP CNC LS6 heads but for the gains I'm not sure if I can justify the price especially considering the shipping costs to the UK for heavy items like heads. I'd rather save the $1000 and spend it on a nitrous setup on a cam only LS1.

You might rethink the MAF part...a cam with a pretty good overlap like that is gonna really mess with the MAF readings at low throttle/idle. If you are looking at a cam like that, you clearly don't care about emissions, so why even think about keeping it?

Going MAFless is always an option but finding tuners here in the UK is hard enough let alone deviating from a regular setup. I'd probably keep the MAF at least at first, if it proved to really be a pain then I'd go SD but apart from some time on the dyno it really shouldn't cost anything to try it with the MAF. Plus many other people have had no problems running MAF's and wild cams.

Emissions are a big issue but going FI is far too expensive so I'll just have to cross this bridge when I get to it.

Why are you even looking at those cams if you are worried about emissions? Neither would pass, unless you are gonna do a cam swap every time you need to get tested.

As with many I've been reading with great interest PatrickG's progress with his now famed "Torque Cam". - Thanks Patrick for keeping us updated with events. :)

I have a few questions:

Question 1
I haven't seen this answered anywhere, PatrickG you said the TR Trak cam was difficult to tune, would your Torquer Cam be any easier to tune? I would be running either cam with a MAF and tuned with EFI Live or HP Tuners.
It's a matter of overlap. The Torque Cam only has 5 degrees of overlap at .050", whereas the TRak has 10 degrees. Both run fine with MAFs. The TRak Cam is just more aggressive and therefore takes more time to get the low speed driving manners perfect. FWIW, the popular F-13 cam has 7 degrees of overlap (with 112LSA).
Question 2:
In the UK I'm pretty much limited to the equivalent of 91 octane fuel, would this affect the specs of the cam or would it be more down to tuning/setup? If cam, what would you recommend as an alternative?
With stock heads, the Torque Cam would be the better alternative because the dynamic compression would be the highest (but still under 8.5:1).
Question 3:
As the Torque Cam makes more low end torque would I still be able to keep my 2.73 rear? My car is an A4 and I want the ability to hit 150mph at WOT which means using OD/4th is out of the question, or would I still need to change the gears something more like 3.42's?
The Torque Cam pulls very nicely to 7000 rpm because how it positions its overlap (intake biased). It would hit 150 mph easily in 3rd. FWIW, I hit 150 mph in 4th gear with a 3.42 gear. Granted, it's 7000 rpm, but it will do it with no problem. 150mph with 2.73 gears would happen at a much lower rpm giving the advantage to the torque cam.
Question 4:
I still really like the look of the TR Trak cam, although my car doesn't see the track very often it is purely a play thing and gets a good spanking ;) whenever it's used. Pissing about in heavy traffic isn't a regular occurrence whereas bouncing off the red line is. :D

With the same mods how would a car equipped with the TR Trak cam compare to one with the PatrickG Torque Cam in say 20-150mph roll race and in the twisties coming on off the power at various speeds from 20mph all the way up to over 80mph?
With a 3600 stall converter, the advantage would go to the TRak cam, but it would be a small one.
Mods to a 1999 z/28 A4:
-stock heads
-LT headers, catted Y and catback
-lid, ported stock TB and LS6 type intake manifold
-stock MAF
-3600rpm stall
-supporting suspension/chassis/brake upgrades

Question 5:
Would I need to upgrade my fuel system, I believe 99 model years had the smaller 26lb injectors, I might plan on a 100 or 125 shot of nitrous in the future?
You would need bigger injectors for sure. The stock fuel pump is good for 500 rwhp, but the injectors are only good for the low 400s (reliably).

PatrickG (and others) thanks in advance for your help. And I understand that getting better heads, FAST 90/90, etc. would all make good sense. And I agree however my wallet doesn't, so I'll have to play ball with what I've got.

I will leave that one to Patrick

Well you need a cam that makes ~8.5 DCR with your stock compression, (but no more), so yeah different specs are in order.
Why would OD/4th be out of the question? What you want is a great trq producing cam with the ability to carry nicely into the high rpms. Keep in mind that the 99 con rod bolts should be changed to stronger ones if you want the block to survive.

They will be very close, but all else being equal Patrick cam should get a slight advantage due to more trq.

Yes, at least 36 lbs/ hr injectors (SVO 30) if you will use wet juice and 42's if you'll use dry.
As far as pump, I recommend a Racetronix PnP pump and harness to supply fuel.



That is why we love this forum, IMO you might want to look at a smaller cam (whether XE-R or LSK) is up to you. Like i mentionned above something that will give you loads of mid rpm trq, 6200 peak and the ability to carry till 6500+.
Also it should make a DCR of 8.5 with your current compression.

Being A4, going beyond 6300 rpm on stock tranny, well better budget for a rebuilt one. A4's do not really like high rpms for extended period of times.
Also you have to take your TC in mind and fit the cam power range into the shift extentions of that TC.

I was gonna mention that too...the 4L60Es don't like RPMs at all.

Cheers for the responses guys :)

If I wanted to bump the DCR up to ~8.5:1 while maintaining stock SCR what sort of variation should I go for on the Torque Cam?

As for the rear end/tranny issue, it appears to be a rather grey area. But from reading in the Automatic forum it's not good to do WOT kickdowns from 4th nor is it recommended to go WOT 3rd to 4th so I don't see how you can use 4th gear in anger without the risk of damage. Which leaves the only obvious answer to be to use 3rd.

I was thinking more along the lines of 6300rpm shift points and 6500rpm limiter. So with 3.42's 6500rpm would only be 145mph.

If I could use the tranny as a full 4 speed autobox and leave it in 4th then I'd go 4.10's but unless someone can tell me differently I don't think it's an option.

An auto is an auto unless it has been transformed with a manual valve body.
So being in 4th and manualy going through the gears is not good, but WOT from 4th and it kicks down on itself is fine (that is what it is su[pposed to do).
In general the 3/4 clutch pack in the tranny is what will go first.

If you want 6300 shift points, then you should get a cam that peaks around 6000/6100 or 40/41 IVC

umm still not sure about the tranny, from my understanding it's not really a true 4 speed but a 3 speed plus overdrive and due to that fact 3rd to 4th at WOT will always cause some kind of issue as will WOT kickdowns from 4th to 1st.

I don't manually shift, I leave it in OD for normal driving and put it in D when in a spirited mood which is good to hit the 158mph limiter.

I think a PatrickG cam may be the answer or at least something similar, if I did do anything else to the motor it'd most likely be a ProCharger but again I'm up against the cost issue.

If Patrick is seeing ~460rwhp/410rwtq with his setup what would the same cam make on my setup by comparison? I see Hoss is running the Trak cam and is making 416rwhp and 397rwtq cam only although I guess it's the numbers between 3000-5000rpm are the ones which are in a way more important as the motor will spend more time at them than at 6000+rpm.

If you must pass emissions with this car, then neither cam is going to work for you. I believe Patrick answered an emissions cam question in the Torque Cam thread. You could use either LSK or XE-R lobe.

Link to emissions question

Passing emissions is important as each year the car will have to go thru a sniffer test. However I'm not certain how the UK tests vary from the US. I'm trying to find out what levels and what gases they look for.

Also going with an emissions cam limits choice and performance. I'd rather just get the one I want even if it means having to swap in the stocker just to pass the emissions tesat and then swap it back out again.

Then buy yourself a QTP 2 piece timing cover, so you can swap cams without removing chain or oil pump.
Need to use single chain with that.

But man, really, re-evaluate your comments.
You Said:
Shift 6300
Limiter 6500
As I mentionned you are picking the wrong cams if those are the parameters you want.
As i said, if you shift at 6300, then you need a cam that peaks at 6000/6100
That means an IVC of 40/41*

Cheers for the advice, I'll possible re-evaluate before comitting to any one setup. If I need to spin the motor faster to get the most then so be it.

But by the looks of PatrickG's results both the cams PEAK at 6300rpm and appear to make almost the same HP at 6000rpm, so maybe I'd look at raising the shift points and limiters up a couple of 100rpm or so to make better user of the power band. Would 6600rpm shift and 6800rpm limiter sound better? What would I need to spin the engine this high?

...........TRAK.......Torque Cam
5500...419/400.....428/409
6000...455/398.....452/396
6300...461/384.....459/383
6500...461/372.....459/371
7000...454/341.....446/335

This aside what would you recommend as an alternative? If the autobox doesn't like high revs yet most of the bigger cams all require high rpms what choice do I have? If I went with a MS3 or TSP Torquer cam I'd still need to spin the motor just as hard wouldn't I?

Cheers :)

damn driveability is like stock once past 1400 rpms, but Mike also has it tuned very well, with numerous amounts of logs in it. I am not sure how it would do with any auto.:)

See, a cam is not only judged by the size of their durations. It is also a function of its VEs (valve events).
You can get a custom cam with VEs specialy tailored for the powerband you desire.
Bottom line is the autobox will require to be "upgraded" if you want to spin high.

Cheers. Think I might just take the plunge and see what happens, hopefully the tranny will last for a bit then I can decide what to do with it later on.

What emissions requirements do you have? idle and speed tests? Any OBD2 scanning?

Cheers,
Chris

ps- I got a 230/230 112LSA cam to pass idle and speed tests on the rollers. It took a lot of tuning though.