dimpled intake/header (what's your thoughts/experience?)
 

So the the winter is comming in Sweden and the Subaru is about to be put in the garage soon, and by that it also means its time for some minor projects! This is my first boxer engine but i have some experience in inline engines. I got a saab 9-3 from -02 that is loaded with 650hp/850nm, and one of the bestest mods I did was to dimple the valves, intake header and throttle body. I also know for fact that especially Honda have being tuning some of their racecars successfully with this technique. So what do you guys say? Anyone that has some experience in "dimplening" their boxers or as well just your thoughts!

I've only had one dimpled header. I used to nearly faint. *sigh*



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In your place i wouldn't bother with "dimplening" .. and wouldn't put it in garage during winter. These cars are not THAT bad if equipped with proper winter tires, and if anything i find RWD winter driving more fun then in summer and am eagerly waiting forward to it to have more sideways fun on snow/ice tracks again.

Living in the road salt rust belt we have in the midwest, taking your vehicle off the road us wise if you are able.

Meh. I also live in the midwest and my car has already been through 4 winters, including road trips and lots of ice racing. I've only had to deal with a few stubborn exhaust bolts and a little surface rust on some parts, no structural or body rust. They are a ton of fun in the winter, and I've had essentially no issues getting anywhere. Plenty of times I've passed stuck AWD and 4x4 crossovers and SUVs that were likely on all-seasons.

https://scontent-ort2-1.xx.fbcdn.net...c6&oe=5C5383D3

I haven’t seen this done on the forums. I think it wouldn’t be possible to dimple the intake on the 13-16 models due to it being plastic. I’m assuming you are trying to promote atomization and better homologation of the air/fuel mixture, or is flow unintuitively increased by dimpling? How is the process done? I suppose I could just google.

If you can find a good software to simulate and measure the swirl/friction against different patterns of dimpling, in theory it should benefit.

Or, because Sweden has long winters, maybe you just need to know "that guy in a barn"

From one Saab guy to another, good luck

[ame]https://www.youtube.com/watch?v=22kPfqRmShI[/ame]

Pfft, I've had enough of rusty undercarriages personally through the years. Thats what my dd CRV is for.

I was arguing with my self for a long time, if I should put it in the garage or driving the car in upcoming winter, however i wouldn't feel comfortable about it and i really appreciate the amount of time I spend in the garage with my cars. :)

I have som pictures of my own work, but I didn't manage to solve it on my phone:mad0260:

The intake is as you said not optimized for this, but almost anything else that is linked to intake or the cylinder head would work properly. The process is simply done by a small rotating cutting tool (a dremel for example) the idea is to use the same technique as a golf ball use, the small holes is as you saying promoting the atomization, there are other benefits that you receive by this method, but since both my knowledge and my English is lacking i will not try to examine those parts here... :D

Well the technique works for saab engine's, so i guess it would be good enough for those boxer engines as well.

O.T. Good to have another saab guy in here! Nice pictures! Is all yours?

I've never heard of dimpling exhaust ports or headers. I doubt any modern engine would benefit from dimpling the intake ports or manifold. Imo anything done before the injectors would be a waste of time.

I imagine Direct Injection negates a lot of the benefits of dimpling for air/fuel atomization.

I agree. Head shops used to use muriatic acid to dimple intake ports. All theory.