I recently installed a Grimmspeed ceramic coated crosspipe(and invidia catted DP) on my 2007 STI. When I recieved it I must admit it was very nicely made. Nice welds, smooth as butter inside, great ceramic coating.
When I tried to install it I noticed it was 1/2 inch short (why?!). I called Grimmspeed and they told me it was all made that way (why?!). They instructed me to loosen the exhaust manifolds bolts(to the engine block), bolt the crosspipe and retighten the manifold bolts and the flex section will stretch 1/4 inch and the manifolds will stretch the other 1/4 inch. I'm not a metalurgist but iron does not like stretching! They also assured me the crosspipe flex section is lifetime warranteed (what about my exhaust manifold??).
I wanted to finish the job so I followed their instructions(OEM 5 layer gaskets) but I did noticed a lot of stress both on the crosspipe & bolts, and exhaust manifolds. It took alot or torquing to tighten the bolts on the crosspipe flange to compress the metal gaskets. I ran the car afterwards and did not notice any leaks.

2 days later I got my car dyno tuned. I was very happy the results, 290whp, and 320wtq on a Dyno Dynamics dyno!(only those with expierence will know how conservative they are!) The gaskets held throughout the dyno tuning and the crosspipe gave it good power.
The next day while I was destroying a Lexus GS430, I heard a loud screeching sound from the front at 6500 rpm. My thoughts immediately turn to that damn stunted crosspipe. I verified the sceeching noise the next day, only now it's occurring at 5500 rpm.
I unbolted the crosspipe and noticed a dark streak between the gasket and crosspipe flange where the exhaust escaped. I also noticed the bolts on the flange was highly stressed.
I was determined to fix this gap but not the grimspeed way!! I searched for an exhaust flange which will fill the gap and made of stainless steel. 2 fustrating and aggravating days later I decided to harvest the flange from the OEM crosspipe. After cutting off the flange I noticed that it was made of stainless steel (nice build subaru!) but it took 2 hours for me to grind away the welds and smooth the flange for proper metal gasket compression. After installation I performed some road compression tests and no leaks.

All I wanna ask is why??!! Why build it 1/2 inch short? GrimmSpeed got the curve and bolt placement perfectly, why 1/2 inch shorter that the stock pipe. To save $$?? Better perforamnce?? They build it 99% perfect, but that last 1% fit made it all useless.
Anyone thinking of buying one should get a 1 7/8th inch 2 bolt 12mm flange (stainless optional), or you can hope and pray for no leaks and the exhaust manifold doesn't break. You can also try www.stainlessteelworks.com ($25 for 1 flange)
Thanks for listening to my rants & raves.

 

I had one on my car for years, I loved it and got some great hp gains from it.

 

I guess you're one of the lucky ones. The added power is good as long as it fits correctly. Maybe it's their quality control. Who knows. I know it was a Pita.

 

I have tgv from them and ported intake manifold and it all fit and works great. Must have just been the one you got...

 

I asked them that and they told me it was all made short. I dunno...maybe because mine is an 07?

 

I know that Grimmspeed just changed over their crosspipe to a new flex section. I have the new version.