Hi guys. Just finished up a multi-stage intake project and here are the results. Here is some background. My car is an "03 350z Performance model with K&N Typhoon intake, MD MREV2, MD 5/16" spacer, UR pulley set, Helix test pipes and a MD catback exhaust system. I have also tuned it with Osiris.

Part one I consisted of sending the throttle body to Proflow designs to get the TB bored out and polished. I also sent the upper and lower plenum along with the intake runners out to Extrude Hone for them to do their magic on. They also port matched the plenum neck to the throttle body. Here are some pictures.

 

I installed these pieces and then went to the dyno. Dyno results to follow.

Stage 2 I had an intake tube constructed of 3.5" tubing. This is actually a little bigger than the throttle body. The previous tube was a little smaller than the bored out throttlebody. Here are some pictures.

 

Here are the results and some pictures of the dynos.

The TB and manifold combo made some power from 4500 up and lost nothing anywhere else. Made a lot of power from 5500 up. 11 horsepower peak and closer to 15 higher up.

With the addition of the 3.5" intake tube it did absolutely nothing. No losses or gains. Enough for now. Hope this info helps. If anyone has any questions just let me know. Thanks guys

Bob

 

How much did it cost to do both?

 

How much did the work on the intake manifold and the throttlebody cost? Do you feel the gains at 5500+RPM were worth the expense?

Thanks for trying this and sharing the results BTW.

 

This is something I have had a curiosity about for a long time. Did you completely retune for the 3.5" intake?

 

I like that this mod makes the upper rpm range more usable. Curious to know the cost for this work as well.

 

$760.00 for the Extrude Hone process. Here's a link.

http://www.boneheadperformance.com/M....mvc?Screen=EH

$260.00 for Proflow Designs to port out the throttle body.

Grand total $1,020.00.....about the price of an average exhaust.

Bob

 

That's a lot of $$$ for 15whp between 5500-6500RPM. Are you satisfied with the dollar to performance ratio? Did the gain meet your expectations and was it worth it in your opinion?

 

See the above post for the cost. Gains and cost are on par with an average exhaust. Granted the gains were limited to a narrower band but it did extend my torque curve up the rpm band so that was helpful. It also did not lose power anywhere. For me it was definately worth it. When I get home from work I will try post up the torque graphs as well.

I am always willing to share with the community whatever I can.

 

Yes I completely retuned after I put the 3.5" pipe and filter on. Took quite a bit of time because during one of the last flashes the ECU crashed. With the help of Jared from Uprev I was not only able to recover the crashed ECU but continue on with the tuning process. Thanks for the help Jared!!!!

Bob

 

Oh, yeah. A dynosheet showing the torque curve will definitely add some perspective to this.

 

Very nice information, thanks for posting this up. Concerning the air filter, does it have a flow stack? Is your TB now 80mm?

 

By the way guys and gals, stage 3 of my breathing mods is up next. I have a set of crawford headers that are ceramic coated and wrapped sitting at home waiting to be put on the car. I will install, tune and dyno these shortly. I am curious to see how they will react with all of the other breathing mods I have done.

Bob

 

There is a picture of the new filter in post #2. If you are asking if there is a velocity stack on the inside, the answer is no. Proflow Design does the following:
78mm mouth which tapers to 74mm before the butterfly. After the butterfly it is 72mm. They polish the butterfly and use low profile screws.

Bob

 

This is awesome stuff Bob!

Its quite rare that people will do rare modifications like this. Let alone do a real pre/post dyno on them... and then publish the results! Great job.

On the TB porting and intake extrude honing, do you know which was more or less responsible for the gains shown in the plot?

Tony

 

Interesting......may have to look after this.

 

I second that as well.

 

Hi Tony!! Thanks for the kind words. Honestly, I don't. The two were tested at the same time. While I think it is a combination of things, my hunch is the Extrude Hone is responsible for the majority of the gains. The reason I say that is from previous posts from other individuals that did the throttle body and showed minor to no gains. Still just a guess. Wait till I post the torque curve. It definately has extended the curve up the rpm band without adversely affecting the lower rpm range. Now I can't wait to see if the Crawford headers augment these gains. Especially at the upper rpm's.

Bob

 

How was your AFR and MAF prior to tuning the car with the TB+Honed Plenum? Did those change at all below 4500 rpm? I'm assuming that most or all of the changes were observed at higher rpms with better airflow. Did you tune the car yourself? Thanks.