Ok...... I got my car dynoed today on a dynojet dyno. The exact same one I used before during the summer. With only a Weapon R intake, I made 217 hp and 223 tq. Today with the same Weapon R intake, Cattman Y-pipe, Budget b-pipe, Magnaflow muffler and some different wheels, I am making 211 hp and 214 tq. The wheels are 18's compared to the stock 17's. They only weigh 1 lb more than the stock rims that I had in the summer. I am making more power just about everywhere except peak. The obvious hinderance is the wheels, but 1 lb shouldn't make that big of a difference. Car runs great and feels really strong. I'm stumped. Where is my peak horespower gain, and why did I lose power?

 

Change in ambient temps? Do the dyno folks pop open the garage door to allow outside air in, so a fan can aerate the engine bay during the dyno runs???

Reason I ask, is because I never thought much about changes in temp until one day last year I ran 94mph traps consistently, where I had never run better than 92.5. The diff - 94mph trap day it was 45 degrees and perfect humidity. I was just making more hp on that particular day compared to the 80 degree 92mph trap days...

 

winter gas has all sorts of additives in it. not sure if that will affect it but is certainly possible. mine does feel sluggish too. went to florida in december and power was back once i fuled up down there.

 

The door to the garage was left closed. The dyno was sae corrected to the weather conditions outside though. It's just kind of upsetting when you spend all this money in modifications and the gains are not there. Once again, my car pulls really hard! The numbers just aren't there. I'm considering trying a different dyno, because none of this makes sense to me.

 

get headers.. and you'll get more high end horse

 

I was looking at your mods list, and with you having a 6spd, and Im thinking, you should be around 235whp 235wtq. I feel bad for ya man, and it only concerns me since Im thinking about the Catt y-b pipe combo, but if it's gonna lose hp, wtf! Im still going to get either the y-b pipe combo or HS headers, but having to modify the mod (weld bungs for O2 sensors) just to not throw SES lights sorta bothers me.

BUT then again, if you go to the track (if you frequent the strips) and you can run decent traps (~98mph) you know the mods are making a diff.

Maybe the winter fuel is worse than the usual fuel, I've never known anybody to dyno in Spring/Summer, and then in Winter w/same mods, so I don't know if your results are typical. Try some BG 44K engine treatment and run through a few tankfulls of gas before you re-dyno.

 

I appreciate your input. I'll probably try this.

 

Any other opinions on what the problem could be?

 

....I dynoed 220.2whp/231.7wtq on a dynojet with a closed garage with intake/b pipe only.....I would like to see your dyno chart....I too am interested in the cattman y and UDP- to finish my N/A modding...

 

Way too many factors man. Wait till Spring. Or it could just be that you lost power. A lot of mufflers have been dyno'd by various magazines and on various cars, and in some cases they lose power with a new muffler. Who knows man.

Try it at the track.

 

If the car "feels" stronger, who cares what the dyno says...unless you spend all your time at the track. It's all about the everyday driving performance, at least for me. You spend what, a few days a year at the track, and all the rest on actual roads without a stopwatch.