After installing a few engine mods to an '05 350, I went and had it dynoed. The mods installed are: U/R underdrive pulleys, Stillen Cat Back exhaust, AAM plenum spacer, grounding kit, HKS air filter. Did 3 runs on the dyno and the best result was only 245 WHP. WTF !! I was hoping for at least 20 more considering that a stock 350 is usually putting down 235-240. Just wondering if my dyno #'s seem low or am I expecting to much from the mods. And what would be the recommendation to get the last 20 RWHP I'm looking for.

 

If you don't have a baseline run on the same dyno theres nothing I can say....there are people making 210whp + baseline... . IF this was your case that would be a huge improvement...

 

Your dyno is right. 5 hp+ equals 15 hp at the crank.
Stock Z already has good exhaust, intakes

 

I just thought that there would be more with the mods I put in. The Stillen exhaust alone was supposed to give me 16 WHP.

 

yeah for all you really know, your base line could have been like 200whp and you got a 42whp gain! jk that's an exageration, but you still don't know what stock Z's let alone YOUR stock Z dynos at stock.

Also, seems like the 2005 ECU doesno't react so well to intake mods

 

Could you scan and post the chart? Thanks.

 

ya, how was your a/f?

 

And you have the grounding kit too? Actually, you really don't have enough performance mods to even overcome the tolerance or variance among dynos.

 

every dyno is different... you cant really compare to others...

 

This is the whole point nothing else matters. If you don't have a baseline done in near the same conditions, you really can't tell how well your car did.

 

NO. What kind of drivetrain-loss calculation are you doing?

A 15% loss fro 15 hp is 12.75 whp.

 

also, power gains from breathing mods on the z are not additive; that is, a 15hp exhaust+10hp plenum+ 5hp intake won't add up to 30hp increase on the dyno.

 

IF you really want to know how much better your mods were and if you dont want to spend the money on DYNO's everytime you should really consider getting like a device like the GTech pro. Those are not as accurate as a dyno. But if you know you dyno'd at 287 and your GTech pro sais 270 and you add a mod on your car and after that it sais 274 you know you have gained 4HP so you know on a true dyno it will be 291. They are pretty accurate as far as that goes. Just a thought though.

 

your going to continue to be disappointed with NA mods, performance wise. that's my experience.

 

6MT or 5AT?

 

Thats because you ran on 19's.
People ran 240+-whp on stock wheels.

 

What dyno was this on ??

 

Very true...I had mine dynoed with an INJEN CAI, Pulleys, and Stillen Cat-Back and ran 254 on a dynojet...

aA_

 

Thats not bad, given that SCC did a test of the Nismo R-Tune Z and made 249hp and 242tq. This is what the car had:

NISMO intake
NISMO headers
NISMO exhaust
NISMO cams
NISMO 21.6-lb. flywheel
NISMO clutch
NISMO 18-in. wheels

http://www.sportcompactcarweb.com/ro...0405scc_nismo/

After reading the article, I felt a little better with my results. All cars will dyno differently AND all dynos will read differently. 19" wheels will not necessarily make a huge difference in HP #'s.

 

Yup I ran 265whp on the dyno with my mods... see sig.