BrokenTusk's Dyno w/ Pic: WTH happened?!?!!

Finally got my truck dyno write up done!!

I was getting some really crazy numbers, wondering if someone could help explain wtf happened. First the stats, please read below if you can help or want to see the dyno picture.

My Truck:
2007 Toyota Tacoma X-Runner
4.0L V6
6 Speed Manual
Stock Engine HP: 242 (+6 off base 236hp due to premium fuel)
Stock Chassis HP: 205-208 (Commonly accepted # from xr-u.com)
Before someone says it, Throttle Body cleaned during install of AFE CAI 3 weeks ago.

Current Upgrades:
AFE Stage 2 SI Cold Air Intake w/ ProDry-S Filter
Magnaflow Cat-Back Exhaust
UNICHIP bought preprogrammed for previous 2 upgrades

Dyno Machine: Mustang Dynamometer
Dyno Results:
Gear Chip Off Chip On Gear Ratio
2nd 160 hp 174 hp 2.19
3rd 161 hp 179 hp 1.49
4th 173 hp 172 hp 1.19
5th 173 hp 170 hp 1.00
6th 168 hp 163 hp 0.85

3rd Gear w/ Chip On highest: 179 HP

Okay so as the story goes, I rented the dyno for an hour (134$ if anyone is curious) and did the better part of 15 dyno runs. Some were redone just to find the right base speeds for the run. Neither me OR the dyno tech figured out why it was doing what it did. According to the Dyno Tech, this machine was equipped to provide “wind” resistance specific to the speed range your in by increasing the resistance on the dyno rollers as you increase speed. This shows the realistic available power at higher speeds and also tending to give lower HP numbers then most people expect. I said that’s fine and we continued on our way

It’s a general consensus that the 3 part performance package I bought gives in the vicinity of + 42-52hp, depending if you stay with the Unichip’s manufacturers Map for your upgrades or if you get the Chip custom mapped (aka Tuned) for your specific vehicle.

The “Wind” formula the tech gave me was an average 15.5 hp loss for every 50 mph of speed. This # was specific to the 2nd Gen tacomas for our wind drag. The 15.5 hp/50mph formula came from a book that came with the machine.

Some basic math:
I’m going to be conservative in all estimates just to show how much I have no freaking idea what happened

So:
Stock Engine: 242 + 42 = 284 hp
Stock Chassis: 205 + 42 = 247 hp
“Wind” Factor: 247 – 15.5 = 232 hp at 50 mph
“Wind” Factor: 247 – 31 = 216 hp at 100 mph
Hell, suppose I’ve got super dirty plugs and I live at a moon height elevation and was driving 100 mph on the dyno:
216 hp - 20 = 196 hp (STILL HIGHER THEN THE 170 I AVERAGED)

So we did several runs with this wind factor at 15.5 and several runs with this wind factor set to 0. It changed absolutely nothing with Hp or Torque proving the whole wind factor he was trying to use to explain my numbers meant nothing. At some points I lost power turning my chip on, during others, I gained hp from turning it on. I dicovered after the whole thing was over the technician was brand new and had only been using the dyno for 3 weeks AND I was the first gas vehicle he ever did. There is someone on xr-u.com with just a CAI and a MAF Calibration that he got tuned for himself and dyno’d 229hp just last week.

Someone please enlighten me. Here was the curve I was getting + The dyno page from the UNICHIP website with near the exact same set up I have:

 

interesting...subbed for what others have to say

 

Dude.... Never never ever compare your dyno results to others with the same truck. When i built my IS-300 I went to 4 different dynos and did a huge write up on different types of dynos and the numbers they produce. There is such a massive variance in the brand/type of dyno, how its programmed, altitude, and the operator. Use a dyno to chart your progress. you have gains when you use your uni chip and that is good. keep dynoing as you go and watch your gains. Too often dyno charts are an online pissing match, but the reality is the operator can fudge a couple numbers in the climate compensation or get the gear ratios programmed wrong and give you completely different results. Mustang dynos tend to read lower. Go to a dynojet and you will most likely get the same results as others. I got 248 on a mustang with my super charged IS and a week later got 305 RWHP on a Dynojet. Just make sure you keep going back to the same dyno to chart your progress.

 

Alrighty, If you say that kind of variance is normal then I suppose. I would'nt have thought THAT big a difference from machine to machine..

 

Yeah... it is crazy.... you will probably match better with others at a Dynojet... I assume you were on a mustang AWD and only using one set of rollers?

 

Nope, mustang with rear rollers only.

Also, anyone who has ever done a dyno understands, going 200km/h when your bolted to a brick wall is so errie, like I hit 100 just sitting there and the wheels and exhaust were so loud I put on my seat belt haha

 

Try it when you have a ton more power and your wheels want to hop off the rollers when you shift..

 

See heres the thing though, my ass dyno feels the world of difference from my current set up and stock. All my buddies and gf agree too.

 

Yeah.. that's good... you're making progress... just don't try to compare your numbers to others unless youre side by side on the same dyno on the same day.

 

You'd think that Horsepower would be a standard unit of measurement across the board though. so the machines would be at least similar..

 

You have a unichip. They do nothing for performance. It may actually decreased it.

 

What makes you say that?

 

Might want to consider investing in a G-tech, or something similar, to get speed measurements instead of just using Dyno results. You've already heard the input on dyno reading differences due to dyno type, correction factors, operator experience, etc. To that end I see dyno's as good tuning tools (AFR especially), but I don't think that the results help that much due to factors above.

End of the day, what are your mods trying to do? If it's make it faster, get something to measure that whenever you make any changes. Granted speed measurements are also affected by weather, road conditions, launch ability, etc., but at least it's something you can realistically see and feel. Besides, buy something once to measure speed factors, or keep paying for dynos over the course of your mods.

 

If you think intake, exhaust, and a chip on any NA vehicle is gonna give you 42HP, that's a pipe dream.

As others said, dyno results can vary based on the dyno, the altitude, humidity, temp, etc. NEVER go by the HP gains the parts manufacturers claim. They're all full of shit even the big name manufacturers. The only accurate way is to test is to run a baseline without mods, then compare your results from there after adding the mods.

To the comment of the car wanting to jump off the dyno, the best is when the tires start spinning on the rollers Watching 700+ HP supras dyno is quite entertaining. There's a reason why they use so many heavy duty straps and criss cross them.

It's always a good idea to keep checking strap tension throughout the test.

 

so if my UNICHIP is piggybacked to my ECU, would any OBD2 reader pick up the AFR's??

 

Depends on your O2 sensor. I don't think toyota uses a wideband sensor so your AFR's won't be very accurate. The best and most accurate way of measuring AFR's is with a Wideband Sensor PERIOD. Also make sure it is mounted between the collector and the Cat...preferably closer to the collector.

 

UNICHIP's Reply:

Sent on the TELUS Mobility network with BlackBerry
-----Original Message-----
From: "Aaron-Tuner Sales" <tunersales@unichiptuner.com>
Date: Thu, 10 Mar 2011 10:57:21
To: Marcel Corbin
Subject: Re: Unichip Automotive Performance Contact: Sales
Marcel,
Looking at what your telling me and many other factors I will tell you right now that a mustang dyno is not the best dyno to be doing runs on (not very
accurate) Also 15 runs? I sure hope you had it all setup correctly. If you didn’t 15 runs all in a row I am not surprised at all if you loose power..
the longer you run you vehicle hard the more power you loose.. Its just common sense. Also If your vehicle is an Automatic it is very difficult to get accurate readings since the transmission shifts at different points. If you have other questions I am more than happy to help you out.


Thanks


Sent on the TELUS Mobility network with BlackBerry
-----Original Message-----
From: marcel corbin
Date: Thu, 10 Mar 2011 19:24:24
To: Aaron-Tuner Salestunersales@unichiptuner.com
Subject: Re: Unichip Automotive Performance Contact: Sales
Hi Aaron,
First off, thank you for your timely reply. My vehicle is the 6 speed manual type transmission. Regarding the loss of power over time, I had started with the first few baseline runs in 4th gear and actually finished an hour later with one last 4th gear run because this thought had crossed my mind. I plan on taking my truck to a tuning shop in Calgary in the next month or two to get proper readings and AFR's. I noticed you have an internet tuning options online, would that tell me the proper numbers or would you suggest getting an OBD2 reader of some kind to give real time data?