View Full Version : Header Dyno results on a stock 91 Z

10-04-02, 10:46 PM
Hi everyone,

I just wanted to pass along the results I acheived from adding headers to my 91 ZR-1. I do most of my Forum posting over on the CorvetteForum. First off my car is a 91 with a flipped air filter housing and an OTS DRM chip with 97k miles on the clock. So I would consider it to be pretty much stock. I recently added a set of headers to the car and finally made another trip to the dyno. My first trip to the Dyno was on 2/09/02. I got to meet JT ZR-WON and a few other ZR-1 owners that day. The results were 328 rwhp and 333 rwtq. Temp was ~72. Here is a link to the dyno graph from that day.

This past Tuesday (10/2/02) I made a trip to the Dyno to see what kind of results the headers would add. The temp was ~94. The results were 345 rwhp and 336 rwtq. Here is a link to that graph.

I am very pleased with the results. Needless to say, in better air I will see an even better gain. I gained 17 peak rwhp. The part I really liked was after peak power. Notice in the first graph how the power starts to drop to close to 300 rwhp near 6600 RPM. With the headers the motor continued to make power. At 6600 RPM the motor was making 30 rwhp more than without the headers. That really put a smile on my face. Now to install the Flowmaster cat-back and see what kind of power I can get from that.


10-06-02, 01:42 AM

10-07-02, 06:14 PM

Those are some good #'s! You have the X-pipe right? Also, did that Tune Tech Auto close down?


10-07-02, 08:23 PM
No X-pipe, just coated headers and the stock exhaust. I just had the Flowmasters put on this past weekend. I can feel more of a gain from them than I did the headers. I have to be near 360 RWHP now. Actually maybe I gained more torque than I did with the headers. Maybe that is why I "feel" it. And as for sound, well you already know that.

TuneTech did close down. Steve received an opportunity he could not refuse. It is for sale as a turn key operation. Looks like Fordspeed will be the dyno I will be going to for the time being. I have an appointment this Thursday to see what kind of gains the Flowmasters added.

BTW, on that second dyno graph look at the third pull. I took the air filter housing out on that pull. Take a look at what happened.


10-07-02, 09:54 PM
That's strange that you would lose power on the third pull. Looking forward to seeing the numbers from Thurs.
Jason, are you heading out to Orlando this Sat morning? If so, let me know and we'll cruise out there.....


10-08-02, 04:29 PM
I don't know if I will be making October Vettes. I didn't work last weekend so as of now I may be working this weekend. They rarely give me weekends off.