[DWR]

Talking with Geoff at Colt Cams gave me some insight as to what to expect and not to expect with the cam upgrade. Geoff would not share specs, but was kind enough to give info that would allow a knowledgeable person to figure out a couple of things.

First, the OEM cams are surprisingly small. From a cam grinder, that is an important piece of info. I had heard previously what the differences were between the OEM and Colt cams and I thought it was overkill. That was part of the reason I called Geoff. It turns out, my impression was partially correct, it was a big jump. However, the OEM is so small the Colt camshafts are still on the conservative side.

Second, the Colt cams are not going to drive big power numbers in isolation. They are going to interact with the turbo to provide faster spool up. It is going to change the pressure waves in the manifold to help with cylinder evacuation. Given proper tuning, the torque peak is going to move up the rpm range. The biggest difference is the torque should carry out further in the rpm range. Everything else needs to support that though. To give you an idea of what I am talking about, the graph below shows how the delivery of power over time changes with cam timing in a turbo diesel. You will see the horsepower difference is not the whole story. Stock 12v Cummins cam is the black line, 181/210 blue, 188/220 light green, 200/220 green. The graph is plotted as a function of time instead of rpm. . I do think the green lines look suspicious, as they are not starting at the same level, so take it with a grain of salt.


I have seen a fair amount of data logs from stage 4 cars, including too many from 335dsleeper ( just kidding, really just kidding). One of the issues we tried to understand was how his car was making as much power as it was and still having generous headroom with AFR, especially at the top end. I came to the conclusion the difference was the cams. I am not trying to endorse or discourage the Colt cams upgrade. Just trying to put things into perspective and provide some info.

[Soonerbilly]

Well I'm sorta on the fence currently on the CAMS....mine is torn apart awaiting parts. Spun #6 rod bearing. So NOW is the time to get them if the gains are for real. It's right at a grand. Been talking to 335sleper and he likes them a lot and has all but talked me into them, but if I wont see any real gains without a different turbo and lots of specialized tuning maybe they aren't for me. ( I'm not nearly as smart as you guys and a lot of this stuff is all new to me. ) But I don't want to leave power on the table since like I said its currently all apart. SO DWR give it to me in idiot terms lol.

[Yozh]

Originally Posted by TDIwyse

Some Redneck One-Off stuff such as.

TDIwyse, thanks for the update. It’s the custom one-offs I like. But to achieve this level of power is amazing.

[tryingtobebest]

Originally Posted by DWR

... One of the issues we tried to understand was how his car was making as much power as it was and still having generous headroom with AFR, especially at the top end.
I came to the conclusion the difference was the cams. I am not trying to endorse or discourage the Colt cams upgrade...

So, simly saying whats you honest opinion? Do the cams actually work and worthwile?
Aaand, am i missed it somewhere, whats his power level, any dyno graphs?

Also, difference in Cummins cams looks negligible (imho, taking into consideration that tuner "fix" graph in favour of cams, like most of them do), and both green lines are offset, i agree with you, they should be closer to a blue line.... And another thing, maybe its just me but "area under the curve" looks better on the black line (but its a time graph, so maybe this point is irrelevant here!)


Excuse me for OFF TOPIC:

Originally Posted by Soonerbilly

Well I'm... Spun #6 rod bearing....

Mind telling us a bit more info, particularly interested in:
Whats a Mi-
Tune/Stage/Whos tune is that-
How many mi on tune-
Meth-
Oil brand/weight/life in mi-
Any issues with hardware(cooling/fuel system)-

Thanks

[Lindgren87]

FYI DWR, if this helps:

DBilas cams.
Duration: : 256°
Peak timing: : 110
Valve lift: : 9,2
Lift at TDC: : 0,5
Valve timing: : 18/58 - 58/18

I pulled the trigger on these cams, and they should arrive at my place in a month or so. Unfortunately i won't be able to compare anything regarding cam performance, since i've converted my 530D into 535D setup in the meantime - a hell of a task BTW!
Also i own a so-called pre LCI, which means its an older model of the M57 with Solenoid injectors compared to your Piezos.
My base is a 530D, 218PS (single VNT turbo) from 2005.

I know of Tuikku who made some decent output on my type of engine.
My aim is to get up around the 500 PS mark and see if it's possible to keep the torque down in the 750-850NM area

[DWR]

Originally Posted by Lindgren87

FYI DWR, if this helps:

DBilas cams.
Duration: : 256°
Peak timing: : 110
Valve lift: : 9,2
Lift at TDC: : 0,5
Valve timing: : 18/58 - 58/18

I pulled the trigger on these cams, and they should arrive at my place in a month or so. Unfortunately i won't be able to compare anything regarding cam performance, since i've converted my 530D into 535D setup in the meantime - a hell of a task BTW!
Also i own a so-called pre LCI, which means its an older model of the M57 with Solenoid injectors compared to your Piezos.
My base is a 530D, 218PS (single VNT turbo) from 2005.

I know of Tuikku who made some decent output on my type of engine.
My aim is to get up around the 500 PS mark and see if it's possible to keep the torque down in the 750-850NM area

Thanks for the info. European specs on camshafts are a little different than here in the states, so I will make sure I get it "translated" correctly.

I have not communicated with tuikku in quite a while. Hope he is doing well. I know his health was failing, very sad. I also know he gave up on the BMW. He is a Mercedes guy at heart. Still, he had fun with the BMW until he sold it for an older Mercedes diesel.

Good luck with your project. That does sound like a major undertaking. If you need a TCU tune to extend the shift points, I can help you out. Your strategy to limit torque and extend Hp is a good one.

[Lindgren87]

Little question:
Does the Whitbread cams keep the assymetrical shape on the intake lobes?

[Rx7boost]

Any news?