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D-camshaft in B230FT, too much overlap?

Sjeng

Sjeng

Member
Joined
Sep 3, 2017
Currently have a stock T cam in my b230.

I have a D cam laying around here. At 11.2mm lift it could be an improvement over the T cam.

However, what worries me is that there is 20 degrees of overlap at 1mm(0.025") lift. (lash taken into account). For comparison, this is only 8 degrees for the VX cam.

Now my understanding is that overlap does not have to be too bad for a turbo engine, as long as exhaust backpressure is not too large. Now I currently still have the 7cm TD04HL turbine, so backpressure is there.

So, swap my T for a D cam or am I better off with the T and save up (yes I am a bum) for a decent turbo cam?

Many thanks.
 
A lot of this is going to depend on the rest of the combination. I'm not a turbo guy (yet), but as I understand it, yes, modern turbocharger designs on modern engine platforms can utilize cam profiles in many ways similar to a naturally aspirated engine. Unfortunately, you have neither. I certainly wouldn't spend money on the VX, but seeing that the D is on hand, you can try it out and see what happens. I think that the earlier exhaust valve opening on the D may help to spool the turbo, but again, I'm not thoroughly educated on the topic. Hopefully someone else with more knowledge on the subject will chime in here.
 
109328 - Billet HD Turbo Performance Camshaft

fullsize_35727.jpg


If you ain't got a couple hundred bucks you need a new hobby.
 
Redwood Chair said:
109328 - Billet HD Turbo Performance Camshaft

https://www.ipdusa.com/uploads/images_products_slideshow/fullsize_35727.jpg[/IMG]

If you ain't got a couple hundred bucks you need a new hobby.
Click to expand...

Have these always been Billet? I know it doesn't really matter for my setup but just wondering. I don't remember mine being labeled as such when I bought it a year or 2 ago. I know they used to have an issue with the lobes wearing down prematurely.
 
shoestring said:
A lot of this is going to depend on the rest of the combination. I'm not a turbo guy (yet), but as I understand it, yes, modern turbocharger designs on modern engine platforms can utilize cam profiles in many ways similar to a naturally aspirated engine. Unfortunately, you have neither. I certainly wouldn't spend money on the VX, but seeing that the D is on hand, you can try it out and see what happens. I think that the earlier exhaust valve opening on the D may help to spool the turbo, but again, I'm not thoroughly educated on the topic. Hopefully someone else with more knowledge on the subject will chime in here.
Click to expand...

Ty, yes might as well just try it.

Redwood Chair said:
109328 - Billet HD Turbo Performance Camshaft

If you ain't got a couple hundred bucks you need a new hobby.
Click to expand...

My other hobbies are hookers and cocaine. That leaves me with enough budget for a flap disc to reduce some duration from the D-cam with an angle grinder. Question is, is this necessary?

And in all seriousness. Now that I look at it, this IPD cam has 256 degrees of duration and 112 degrees LSA. The D is supposed to have 253 degrees of duration at also 112 degrees LSA. Can I conclude that therefore the overlap is also very similar for both cams?

Or are these cam lobes asymmetric?
 
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They're symmetrical on the IPD turbo cam, and the intake/exhaust profiles are the same. I'd run the D and see what happens. I bet it'll be very similar to the IPD turbo cam. I have an IPD turbo cam in my b230f+t and it's great.
 
PromiseRing said:
Have these always been Billet? I know it doesn't really matter for my setup but just wondering. I don't remember mine being labeled as such when I bought it a year or 2 ago. I know they used to have an issue with the lobes wearing down prematurely.
Click to expand...

nitroboie said:
The billet is something recent, not sure when it changed but it hasn't always been labeled that.
Click to expand...

It's all marketing wank
 
I think you'll like the D. It has less lift and duration than the IPD cam or V15 but for a fun daily you won't miss much. It will definitely be more fun than the stock cam. An adjustable gear is nice to help dial things in too.
 
Harlard said:
It's all marketing wank
Click to expand...

The pictures look a little different though. Not that it matters and it is marketing wank but it looks like it was turned down between the lobes instead of just the rough casting? Or is that my imagination. That seems like it would make them way more expensive.
 
CAPT_BLOTTO said:
The pictures look a little different though. Not that it matters and it is marketing wank but it looks like it was turned down between the lobes instead of just the rough casting? Or is that my imagination. That seems like it would make them way more expensive.
Click to expand...

https://web.archive.org/web/2015030...oducts/6214/109328-turbo-performance-camshaft

https://www.ipdusa.com/products/6214/109328-billet-hd-turbo-performance-camshaft

Same part number, same reviews as forever ago. The only difference is that the front nub is now polished ( :oogle: )
 
It does look fully machined. Maybe its cheaper to machine from "billet" than casting in Taiwan for the quantities IPD is ordering.
 
Realistically any of these cams will work fine.


As the turbo motor has very low compression, it will be a little bit of a dog down low. You can get an adjustable cam gear and advance the cam timing to boost some of the low speed compression. Just be aware of knock as the boost builds. It'll be more fun than the T cam you have now for sure.
 
Swapped it in yesterday.

The torque kick in of the T cam is more dramatic than the D, which is more of a gradual build up of torque.

The D does seem to lose some peak torque compared to the T, but it keeps pulling up to 6000 rpm without problems. The powerband is way wider now than when using the T cam.

I tested this at 1 bar ~15psi from a 15g. Perhaps the difference will be larger when the engine is fed some more air.

Overall I would say it depends on what you want with the engine. The T is actually matched pretty well to the small mitsu turbos imo and can provide some big low-mid rpm torque . Ofcourse if you are going for a bigger turbo which spools later a T will be a bad choice.
 
I believe sim has a K cam in his B230FT in his 79 245 and loves it.

If it's not that cam, it might be a slightly more mild one? But I'm 75% sure it's the K cam.

Can't find anything in page 1 of his thread, and it's moot as you've swapped in the D now anyway, but thought I'd add this here second hand.

Upshot: None of these factory cams are super hot/wild/crazy and all will work with boost.

So from my angle: as hot as possible. (and fix the rest to suit)
 
<iframe width="560" height="315" src="https://www.youtube.com/embed/kSntEyH4KTg" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

They describe the new "billet" process...
 
Sjeng said:
The torque kick in of the T cam is more dramatic than the D, which is more of a gradual build up of torque.

The D does seem to lose some peak torque compared to the T, but it keeps pulling up to 6000 rpm without problems. The powerband is way wider now than when using the T cam.
Click to expand...

Yep, that sounds about like my IPD turbo cam. It's not bad on grunt down low, but isn't extreme either. Once you get above 2800 or 3000, it's great all the way to redline.
 
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