So I take my car to a well known nissan shop. Tuned, I made 515whp on a dd. I get the car back and it has timing issues/stumbling, car runs so rich under boost my afr gauge won't read it, and it stalls when I turn the a/c on at idle. Still runs fast but has a lot of problems.

Fast forward 2 months and I get my car off the trailer after moving to north carolina, I take my car to another well known shop in the area to make a couple pulls on their mustang dyno to see what I make. The most I got out of it was 390whp, that being with the car in the same condition it was when I got it back from the other tuner, (its not a daily driver, it's seen maybe 100 miles since it was last tuned)

The tuner here says it looks like whoever tuned it was in a hurry to get it done and it lacks a lot of refinement.

My big question is, has anyone else seen this much of a change in power displayed between two different types of dynos? Both shops showed corrected power.

 

stumbles, etc can cause unreal peaks in the power graphs.

post both sheets, or even tell us what FI kit and psi level.

corrected power can be all over the place depending on the correction factor obviously. that why dynojets are the standard bc there are no correction factors.

 

Spill the beans, who originally tuned it?

 

Yes, it's completely possible to have such wide disparity - dynos can be manipulated to show certain results like anything else. If the car was stalling, and running so rich that it won't even show on a wideband, frankly, who cars what power it was 'making'? Better to have it running correctly.

The data output is only as good as the data input, and every dyno relies on the user to input certain data. Skewed input data yields skewed output data

 

Post up the graphs with the AFR for both. I would focus on why the car is running rich - could be misfiring...

 

you thought you were a star with the 515...'somebody lied'

mine charts were off 40 horsepower, you can make the numbers say whatever you want it to. are you stock block?

 

greddy 20g twins, arias 9.5, ID1000cc, jwt s2 cams, cj stage 2 and cj twin pumps. 15psi.

I realise that the latest dyno I run on could not have been set up right, or it could have purposely been set to read low to drum up more business. The car that ran before me was a stock c5 vette, 363whp. I'd rather not post the dyno sheets yet without a bit of cropping to avoid 'calling out' the shops involved.

 

tuned out right, sounds like you should be able to make 550-600rwhp on a dynojet. probably should just get it retuned, especially if it runs like crap anyway.

 

First off, you aren't "calling out" the shops, they sent the car out the door running poorly, not you.

Second, shops can make a dyno do whatever they think a customer wants (within reason). This includes corrected numbers, setting the dyno to show bhp instead of whp, setting up hero pulls where you sit guys in the hatch for traction and remove the intakes for unrestricted flow and bump the timing.

One thing I learned the hard way was don't chase a number (not saying you are). The car and setup makes what it makes and if a tune is solid you will go out the door with the same whp you have on the best dyno pull the car made. Don't fall for the tuner saying "The car made 6XXwhp, but I backed it down for safety"

 

this actually happened to me, I wanted to make 550 with my build and when I picked my car up and asked for the Dyno sheet all they gave me was a sheet that showed a pull of 529, no TQ curve, no boost data, no AFR curve... long story short, took the car to get re-tuned with a new ECU (moved from a Utech to a Hydra) and they could only muster 450

 

yea the first shop gave me a dyno sheet with hp and tq only. this latest one gave me a sheet with afr and a couple other lines lol. It plunks along at 9.2 during the beginning of the pull, tops out around 11.4

 

ya 15 psi should be right in the 500 range assuming no mechanical issues.

 

.csv from the dyno run

 

15psi on those mods should be 600+ on a DJ IMO

 

Thats about what I was aiming for when I built it. I've been going over the car to see if theres any way it could have been damaged parts causing it to actually read that low.

Either way I'm going to take it somewhere this week to get it retuned.

 

you'll need pretty aggro timing ( compared to common forum timing generalizations) to make 600+DJ on 15psi.

Alberto has been the only person (to report it) to make that kinda power/psi on that size (actually smaller) turbo.

 

Phunk like 4+ years ago made almost 600whp at 15psi pump on 18G's (583whp @ 14.5psi IIRC). That is still hp per psi still up there compared to the crap we see today. The PFS Greddy Z with less than a build compared to mine makes more power on 18G's than me.

Just because its not the norm doesn't mean its not possible.

Instead of people doubting it or thinking its a one person wonder, they should be asking why their similar setups are weak fawking sauce in comparison....

 

I make 577whp with 18g's at 15psi and 603whp at 17psi with 18g's, no meth, no plenum spacer. At the same time I make 682 with MS109 unleaded. I too was tuned at PFS.

OP, you should be in the 15psi range, easily into the mid 500's... You need to get retuned.

 

Dropped it off just a few min ago. Made sure to tell them I wasn't interested in them pushing more boost. Just fixing my tune. The guy seemed to know his way around the haltech ui. I ll keep my fingers crossed

 

GL, post up the nubers when you get it back, very interested in the results.