The SC400 headers i am selling dynoed anywhere from 17 to 25whp gain. Keep in mind different dyno's were used for testing and the customers had different setups on their cars. You should expect similar gains for the v8 GS models and probably about 15-20whp for the GS300's.

Of course, i will test and provide actual dyno numbers once i have the final product. For now i just need to see interest. Please make sure to include which model you have when you post. Thanks.

 

Depending on the time frame that these will be available, at this price I am interested in a set for a GS400.

 

The SC400 headers do not allow the stock cats in the stock location. Is this your plan for the GS headers? Have you posted dyno numbers on the SC400s somewhere or has someone else that we can review?

 

I have not posted any dyno results for these headers as i dont have the originals which were done over 2 years ago. I do have a couple of customers on here who did dyno i believe and even tested their cars on the track. The results were posted awhile ago but you'll have to search for them.

I believe for maximum performance it is better to remove the two pre-cats however if people want to retain them in place then i will design something that will allow it. I will let the people decide what they want and go from there.

 

I would definitely be interested in 304 ( even better -321 SST headers for a little more $$ in material costs ) stainless headers for the GS430. I would prefer to keep my precats, though, since I've already removed my third cat and replaced it with an X-pipe set-up. Personally I would want my stainless headers Jet Hot coated, too. Also please machine the crush gasket groove into the collector interface with the precats. You make them and I'll buy a set!

 

17-25hp gain ey? any dyno graph (interested in the graph....peak power is great but I dd my GS)?

and how do you install these...? take off steering rack?

 

I do not have a dyno sheet to post as it was done two years ago and i dont have a copy. It will be a direct bolt on, remove stock manifolds, bolt on new ones. No need to remove the steering rack.

 

oh, didn't know it was that recent.
I can't imagine removing the exhaust manifold without removing some parts of the suspension/steering...but maybe there's a trick to it.

anywho, keep us updated.

 

I have a 98 GS4 and would be all over these at this price!!

As another member pointed out, I would also want to keep the precats and with that said, I would prefer if the triangular/cat mounting flanges have the proper machined groove for the crush gasket. FITMENT would be paramount to HP in my opinion, of course they will perform better over stock but there is nothing more annoying then dealing with improper fitment during an header installation. When flange angles aren't precise and gaskets don't line up perfectly etc., this usually leads to the most annoying exhaust leak noise. Oh, and 1/2" thickness's for the precat and head flange's would be great.

Please keep us Posted.

 

at this price I am interested in a set for a 2004 GS430

i need it long tube like the sc400 headers on ur site its bitter to be single pipe i dont need my cat its ok withe me

im waiting for the headers lol

 

U have my interest, 2001 GS430

 

OP any updates on your headers?

 

Count me in, I am interested for 2GS400 as well.

 

Count me In! Once i find a gs of course...

 

Interested only if I could keep my cats.