MPR

So I just bought a jdm itr 4-1 header. ($100)

As some of you know, from the factory they weld the pipes to the flange from the insides of the ports. This creats a lot of restriction as the welds stick out into the flow. What a lot of ppl are doing is welding the pipes to the flange on the out side and grinding down the factory welds on the inside so the flow is not disturbed and the ports are much larger.

This should be a piece of cake for me to do, I have all the necessary tools etc....

Just a few questions:

Has anoyone had personal experience with doing this before? Have any tips or tricks to share? Anybody have any dyno results, before and after porting? I've heard this results in a significant gain in many cases.

I'll be posting up a DIY after I've done it for all to see.


Thanks.

MPR

Ok, don't know if anybody cares but I welded up the header and it's now ready for porting. I forgot my camera so I couldn't take any pics which means no DIY.

TRex

i think when you port you need a special type of bit or else you will just go through 10 bits tryoing to get the job done. I think its carbide bits that your looking for.

MPR

Went to princess auto and picked up a new dremel rotary tool and carbide bit all for $26. (Princess auto FTW!!!) Tried it out, works great. Going to take some time though. Will post up pics of the results.

MPR

Alrighty, took some pics. She's all ported, thermal wrapped and ready to go. (took pics before putting on the thermal wrap)

Enjoy.


^(only 2 ports were completed when this pic was taken)

Here's the $20 dremel tool and $6 carbide bit from princess auto: (despite being cheap, the tools survived hours of grinding without any significant ware or issues)



My ugly but strong welds:


The ports before grinding: (you can see how much the factory welds intrude on the inside of the ports)



Here they are after grinding:



Took a lot of material out. Spent at least 45mins to 1 hour per port. And they could still use a little more smoothing out.


Thanks for reading.

Trybal

Such a huge diff. Looks good!