So I had a shop do a baseline dyno for me before installing any parts. My max hp was 228 and max tq was 221. All I had was a z-tube/pop charger. After installing a MD 5/16 iso thermal spacer, berks hfc, and hks replica exhaust, I only gained 12 hp. I have a dyno sheet to show this but I'm on my phone right now. I think I actually lost about 2 lbs of tq. I was told I was running kind of lean so this may be the problem? Also, the AC was running on the last dyno so I'm not sure if that would factor in to my results but I don't know if the baseline had the AC on. Anyway, I was told a tune would net me about 25 more hp and would counter the lean running problem. I just feel that these gains are kind of sad for those three mods. Any input?

 

I have a 2004 5at by the way..

 

if everything is mechanically sound, a tune will greatly improve power. Don't look at the numbers itself, look at the curve where you are actually gaining hp. And why the hell did they dyno with the AC on? I wouldn't even trust those numbers and dyno/shop if they let you dyno with the ac on

 

Not sure about the AC. I have never done a dyno before so I didn't think to ask about it.

 

Yeah i would not trust that shop/dyno. Just looking at your average AFR which is in the 13s does not look right.

 

I'd bet it's now running a little too lean or rich which is common once you replace the OEM cats.

As stated, a simple tune will help maximize the potential of those mods you have listed and help get your A/F ratio on point.

 

That's a tough call bc it's a highly recommended shop in my area. I guess it could have been a mistake?

 

Like others said, don't just consider peak power. Many of MD products especially are created with the interest of "usable" power rather than just top end numbers. Also without being tuned you aren't nearly utilizing the entire benefits of the mods, just keep doing whatever bolt on mods you want and then finish off with a tune.

 

Yea I'm definitely getting an osiris tune in a few weeks. I'm hoping the raspyness goes away because at WOT this setup has some nasty rasp lol. At low rpms it sounds amazing though. I have heard that berks hfc needs a few hundred miles to break in. I'll see what happens. If not, ill just put my stock exhaust back on.

 

Bolts on dont do anything on these cars. You need some type of boost to make real power. For now get the tune it will help you gain atleast another ten plus whatever the mods make.

 

Well I knew I wouldn't gain much but just thought it would be atleast 20hp gain. This place told me I should gain 20-25 with the Osiris tune. I hope!

 

Eh, I see NA applications hitting 300whp with bolts on and a tune. I remember back then when 300whp seemed impossible. Now that osiris came out with easy tuning I think that's a pretty decent increase from stock. Now yeah 300whp isn't anything amazing but its a nice feat considering they were rated around 300 at the crank.

 

Are we talking rev or non rev. I think OP has a non rev. Besides those are just numbers depending on what dyno they were done on. Only way would be to baseline it like OP did then re-dyno.

 

I seen it on both, and yeah they are peak numbers but look at the increase from base runs. most of them are 30-45+ hp to the wheels increase from base stock dyno runs. Compare the hp curve to the baseline curve. Thats making power from boltons in my book. Jairens G35 is impressive https://g35driver.com/forums/6084116-post3.html OP sorry for hijacking

 

No worries. I like learning lol. Yea I have seen dyno's of revups making 300 but haven't seen the non rev. Not saying it's impossible and I hope it's not bc I have a non rev but mine is automatic so that doesn't help much! I don't really care though bc I don't race. Just wanted a few extra ponies for my pleasure lol. This is my dd and I do a lot of city driving.