I'm a huge fan of the stock turbo on the Evo. With the correct mods and some TLC, they are great units and have great potential, best of all, they come with our cars out of the box.

For our never-ending search of getting all we can out of the stock turbo, we try alot of different things at the shop.

Recently a local enthusiast has been doing some great porting work, very time intensive, but the end product is pretty much a work of art.

I had the opportunity to do some testing on a 2005 Evo 8 that was equipped with a stock turbo ported by this enthusiast. So far the testing is looking good.

I have never, ever seen a stock 05 turbo, or even a 06 turbo hold this amount of boost for this long.

3rd gear, taken to 7800 rpm:



4th gear, taken to 7800 rpm:



So far, fantastic data, over 24psi held from spool up all the way to 7800 rpm. Next testing is to see if this makes more power or not. I can say so far this specific evo only dropped approx 18whp from peak horsepower all the way to 7900rpm. I usually see a much larger drop on the stock turbo. Also this was only at 78% WGDC, so there might be more in it.

This testing was done on a stock motor, stock cammed, 2005 Evo 8 using a GM 3 port boost solenoid and ECU-controlled boost.

 

24psi doesn't seem to high.

this is Evo VIII turbo with the 10.5 hotside right, just with a ported housing, correct?

 

Wow very impressive!

 

Very impressive

 

I forgot to mention this is also on a stock "9/JDM" bov that has been crushed with TLC.

 

I look forward to your dyno results Razorlab, what makes it possible to hold like that? Do you have any photo's of his porting work? Well done to the person who did this porting too.

Cheers Steve

 

The point was not the boost, it was that it held all the way PAST redline!!!!

Great work as usual Razorlab

 

Pleased to be sending me PM of said enthusiast's contact info for port work...

Thank you!

-E

 

Bryan, how do you think this will reflect on the IX's? I usually see the IX's tend to taper a bit more because of the more efficient head design.

 

That is correct, hopefully we will have a chance to see what the porting does on a 9 as well.

 

Is this with an increasing ebc duty cycle over the rpm band?

 

This is very impressive. I have been wanting to do some major porting on the IX turbo. Any pics of the turbo?

 

this is 75% all the way to 7k?

My IX turbo on the GM 3 port holds 23/24 till about 6k rpms at that point my wgdc goes 100% and it falls to 20 psi by 7k... (his is an VIII, I know)

Does this car have a stock wastegate or any modification to the wastegate?

 

here is the duty cycle from 3500 rpm to 8200 rpm:

73.5
73
73
73
73
73
73
69.5
68.5
68.5

 

Stock cams and FMIC I assume?

Edit: Just saw the stock cam remark in your first post.