TL;DR 2008 350z with intake, exhaust, high flow cats, and tune, doesnt make more than 285 hp.

I have a 2008 350z hr. I put on an intake and exhaust, and took it in to my local tuner to have it tuned. They said normally HRs make around 300 hp on their dyno. The first time I was there I was using 91 octane instead of 93 () so I left and came back a few weeks later when I had a tank full of 93. This time it couldn't make more than 260. They said maybe the cats were clogged, so we replaced the cats. I came back a third time with the new cats, and it was still struggling to make power. After a lot of adjustments, it maxed out at 285 hp. They can't figure out why it isn't make more power, it should be making at least 10-15 more. Ideas?

Intake- Takeda dual short ram
Exhaust - Megan Drift Spec
Cats - Kinetix High Flow
Tune - Osiris

 

I made 286 on mustang dyno, same intakes, art pipes, tdx2 exhaust, uprev tune. Don't sweat it, it's only a number. Remember most De with full bolt ons only make 240 ish hp

 

This was a dynojet, arent those notorious for reading high? And alright, its just everybody was stunned when they saw it only made 285, and the tuner spent a lot of time trying to make it higher. He seemed really confused as to why it wasnt making more. It also has a weird resonance around 5,000 rpm

 

And mustangs are low...There are so many variables.

 

Was that corrected? Yea compared to some threads here some people easily make 300whp on their HRs with similar mods.

Could be the tune? Along with too many variables to really say what it might might not be....

Did you have a baseline done

 

I think the baseline was roughly 250 without the cats and then 260 with the cats.

 

whos doing the tuning?

 

If your baseline is 250 and you got to 285 I say that's pretty good.

 

Zfever in Tampa

 

What's the mileage on the engine?

I don't know $hit.....but dirty injector/s? Fouled spark plugs?

 

You won't pick up a ton more than that. The short intakes don't gain power, the people making 300 are usually using long tubes. It also varies from dyno to dyno.

Have you run the car at the track?

 

Barbie or stick?

 

OP, throw a spacer on it, and maybe some headers, and that should put you over the 300 mark, but with what you have that looks about right

 

They don't have plenum spacers for the hr's, if you are going to go through the pain of headers (hr motors are a little wider) get long tube headers

 

45k. And maybe? I was using the 91 for a while

I was thinking that, but i didnt think it would make a 15 hp difference

stick

 

HP is just a number. Track times are more important IMO.

 

sounds like your turbo has gone missing, go find it and your power will come back

 

I c wut u did ther

 

It could. The long tube intakes are good for about 10hp at the very top of the graph, where people finally sneak into 300hp territory.

And the shorty intakes can actually lose power, since they draw warmer air from the engine bay. I switched from the fujita short rams to stock airboxes and the car definitely has cooler intake temps with the stock cold-air design.

 

I think you're focusing a bit too much on the number. if the car drives great and you picked up gains over your baseline, don't sweat it. sorry you didn't hit that magical 300 number, but not all cars are built equal. you could have a friday car. I've seen two cars back to back dyno tune with the same mods and one made 20hp higher than the other one.