Hi all, i had a question involving a 04 r53. I went to a local dyno to see what kinda gains I got out of my car from bolt ons. I made 172.4 hp, and 158.2 ft-lbs. All I've done is header, cat delete, MSD coil, NGK wires, and 16% pulley. Are those decent numbers.

 

For having a header it seems weak....
I did 180 with the stock tune, 17% , a CAI, AND JCW380 injectors, 100% stock exhaust......think I had a coil (zero gain, and wires, again, just mataince parts).
I was able to do 200 with a RMW TUNE same 101° f day.....

How many miles?
How far above sea level?

 

Whose header?
Which belt size?
Which dyno manufacturer?

But yes, that does sound a bit weak for those mods. We've seen bigger numbers from just installing pulley kits.

 

Zippy, did you do your tune with Jan in person and a dyno? or remotely? I've been wanting a RMW tune but I haven't had a chance to get to a tune party or to his shop.

 

Did it in person at a tune party years ago in Norwich CT ....I was running rich with the 380's untuned, but it was very streetable.
Be sure to chat with him about what you want...I asked for a very safe tune, with wide safety margins...so in my case I was actually fuel limited with the 380 injectors.
Also most tuners will adjust the DSC a bit...makes it a bit less aggressive.
Nicest gain was extra tq from the tune ...forget the change, but that alone made it worthwhile.

Back to the op...What are you running for a header?
In all honesty I have seen guys running RMW SHORTY HEADERS with the stock cat welded to it, making 250+....imo just not much to gain from going catless...just gain a light, a stink, and more ploution...that and a ticket if you get caught.

Please list some more info about your car....
Maybe we can help you get a few more HP out if it. And as Detroit tuned has eluded to, the brand of dyno and how it is set up makes a difference....
Just like basic upkeep....things like filters, recent plugs, wires, etc.

 

I'm running the m7 header, and I had to run Catless for the time being, my stock mani split at the pre cat and haven't had the chance to get it welded on. But I can't remember belt size, I know I ran the same size as what a 15% pulley calls for. But if it's under powered I wonder why, any suggestions. BTW I live in a non emissions county so I don't half to worry about the cat

 

Since the typical front mounted fans in front of a dyno don't push much air through the top mount air cooler...so many folks when they dyno's them hold a "floor" dryer style fan aimed at the intercooler area....
Elevation also plays a role ..
How far above sea level are you?
Fuel? Best grade you can get locally as "common" pump fuel? Special racing fuel is not needed...but "premium is...
Happen to know which size belt? Mm sizing or us sizing numbers are fine.
Sometimes a JCW belt is used on a 15....ok when new, but far too loose with a bit of age.
Did you change you sparkplugs when you got the pulley?

 

I live around 1000 feet above sea level and I think it's a gates 535

 

And I run high test fuel all the time

 

Ugh sorry for all the replies to my post internet quit working and deleted all I said but I'm running the NGK brand jcw plugs

 

Personally, I don't think that's bad at all, that's about +5 hp, over a factory '05 JCW car, so with a stock head and no tune, I think that's pretty avg., esp. if it was on a Mustang or DynoJet.

 

I'm. It saying any screaming out of place...on how the car is setup...
With a header, I would have expected a bit more...but some parts are better than others I guess.
But the car might have lots of miles and it wear.....or maybe the dyno is set up a bit different (euro/metric up vs SAE)?
biggest thing is enjoy your car.
We like to say that the dyno is a tool...so you can kinda guage you mods...guess you can say you have a baseline with your numbers.

 

Well I appreciate all the info from you guys, I do love my car, i am doing a cam next then injectors and tune, just gotta save the money ha ha.

 

Really? My completely bone-stock 05 JCW (210kit) was dyno'ed at 184whp (but I left the AC on - whoops).

I was under the impression that the 183-189 whp range was normal for the 210hp JCW kit.


Agreed on using the results as a baseline since the dyno's, altitude, etc leave so much variance.

 

Since the cars computer is smart, it should have disabled the ac compressor WOT....
What's telling about a JCW vs an S the TQ band....a car with headwork will be more street-able , aka perform better on the street than their numbers might indicate.
Some tunes can give GREAT PEAK tq, but a good tuner will ensure you get good tq in the band the car is going to be driven in....a street car with a street tune might not go above 5000 rpm much....but a race/track car and tune might spend much time within 500 rpm of redline....
And the diffent years of JCW kits...the standard 200 JCW kit(no airbox, no injectors) vs the 210 JCW kit (injectors and airbox, and the revised gearing, and better 2005+ ecu) did make a noticeable difference.
I can only compare the op's numbers vs mine when my car had 45,000 miles or so when it was dyno's....but I know I beat some JCW cars untuned that were higher mile examples....heck untuned I beat one poor guy with a header, 550 injector and meth before I was tuned...but he had 2x my miles....
The dyno can be a humbling place....some cars came out if the factory with plenty of margin left to make more hp....but some were not so good....even new....same is true as the miles accumulate.