hey guys, i was just able to dyno my headers. my results were very good.

run 002-my base was 237.7hp and 230.9tq

run 3(1) was 249.2hp and 246tq

run 4(2) was negated cuz it was a mistake of 4th gear..still, 246.6 and 243.4tq though

run 5(3) was 249.3 and 249.4 tq.

peak gain of 11.6hp and 18.5lbs of tq

edit: conditions were about the same, being in favor of the baseline dyno... thursday was about 66* and stock dyno was 62* and on the first run, the fan turned off midway through the pull.

would post a bigger pic to see more clear, but had to resize it for forum purposes..would need a host to load larger file

btw..look at the fat torque gain all throughout the rpm band, especially at 4k

 

Not bad... still an ugly drop in power around 5750...

You're not running a Crawford plenum are you?

 

nope, no plenum yet...

waiting on seeing the results of the dyno day here, and also lsdunique's plenum design. we will see though, i got some more tricks though too open up the upper end

 

Yeah I'm eager to see this new design...

Kudos if he gets it to fit under the OEM bar!!!

Remember though, no matter what you do the front cylinders are getting restricted. Those HAVE to get more air... not many more tricks.

 

hehe, unless i get the TS plenum

 

stock car?

 

yes, totally stock vs. headers

 

nice.

 

Now get those RT Cat's on there and show some more numbers!! Glad your happy with the headers..

 

Thanks for doing the independent dyno. Nice numbers.

 

Anyone know if the Nismo headers are CARB approved?

 

they are R-Tune, so i doubt it, but i could be wrong. Time to tag in Jeff/Mr. Nismo

 

Performance guys-- would you recommend cats first or headers? Congrats Daytona on the great dyno-- you got me damn near decided on doing a mod i didn't plan on!

 

I would consider CATS first, as they're the most restrictive part of your exhaust system.

 

I am adding cats to my baby in the next couple of weeks. I am installing thim w/ NISMO exhaust. I have noticed some places sell the "y" pipes. Is this necessary to change also when going with single tube / NISMO exhaust as opposed to Borla duals?

 

which would only benefit FI cars IMHO.

 

This is slightly off the thread topic. Are there still concerns about running lean with the rt cats. Want to get these but worried about the running lean thing. On the dyno above is it running rich? I thought the 12 to 13 was best.

Thanks, Dan

 

The NISMO exhaust has a new Y-pipe that is better than the stock. It is similar in design to some of the Y-pipes being sold by themselves.

 

Thanks for doing this before/after. Nice gains!!

Interesting tho, your chart looks very similar to mine now. The slopes are practically crossing at the same spots. Although the headers seem to have leaned you out a little from 4500+ which is a good thing since theres some room for it.

Here's mine:


I've made some interesting observations... Looking at various comparisons, seems that the nismo headers are built for less backpressure. With the slightly more restrictive stock or nismo exhaust, they give you a nice boost in torque... but with a more free flowing true-dual you'll probably lose torque. Crawford's high velocity design seems to work better with less restrictive exhausts like the borla or stillen.

I'd be curious to see how hf cats would do on your setup, but I think the next move should be a crank pulley. Should put your whole curve up a notch, and you'll be probably where i'm at in terms of numbers. At $200 it's a no-brainer.

 

All dynos with equal graphs for HP and torque cross at the same spot. 5250.