Just got my G-Tech performance meter installed:

http://www.socalhhr.citymax.com/i/Hidden%20Pics/0-60_Time_Sm.jpg
http://www.socalhhr.citymax.com/i/Hidden%20Pics/1-4_Mile_Run_Sm.jpg


This will be a great asset in determining the effects of performance modifications. I'm still dialing it into the car's launch characteristics, but once it's set, it will be worth its weight in gold!

For those not familiar, the G-Tech Pro SS measures:

Horsepower
Torque
60ft (reaction) times
1/8 and 1/4 mile times
0-60 & 0-100 times
RPM & Shiftlights (for those with 5-speeds)
Handling G's
Records up to 30 runs

Find out more and see a video HERE (http://www.gtechpro.com/test.html)

Pretty handy for anyone interested in how modifications are affecting your performance. We will be using it a lot around here... :thumb:

I like the warning. :D That will sure to deter me! ;)

Congrats, broke into the 15s...is that with the muffler being the only mod? I think it was Motor Trend that said the 5-spd is about 1/2 sec quicker in the quarter mile (16.6 vs 16.1). It seems like the HHR has a decent amout of power to be tapped into and let loose. To each their own, but I for one am all about making my ride quicker...hell, they even have lawn mower races on ESPN.

That thing is small! In fact, I don't think it's much bigger than my pacemaker :p:

Congrats, broke into the 15s...is that with the muffler being the only mod? I think it was Motor Trend that said the 5-spd is about 1/2 sec quicker in the quarter mile (16.6 vs 16.1). It seems like the HHR has a decent amout of power to be tapped into and let loose. To each their own, but I for one am all about making my ride quicker...hell, they even have lawn mower races on ESPN.

Thanks! Actually, I have the automatic, so it's really a bump up in power. :thumb: We'll see how things progress as more parts are added...

Do you think those times are fairly accurate? I really hope so! Here are some comparison figures for other cars that were tested in stock form. Most times are from published car magazine tests. The 0-60 times are first then the 1/4 mile times are next.

'79 L-82 Vette 7.3/15.7
'03 PT Cruiser 10.9/18.2
'03 PT GT with turbo & auto 7.2/15.7

Watch the video in my post above and you will see just how accurate the G-Tech is!
Of course, it doesn't help to have a little racing experience either...

Here are some comparison figures for other cars that were tested in stock form.

'79 L-82 Vette 7.3/15.7
'03 PT Cruiser 10.9/18.2
'03 PT GT with turbo & auto 7.2/15.7

My next door neighbor had a '79 'Vette - I don't think his grandmother could have driven it that slow. :D

I'm wanting high 14's. That is if mine ever gets here. It's been a full month now and the salesman told me Saturday that 2-13-06 is supposed to be the build week, but he still doesn't have a VIN yet. Sounds like it will be another month.

I'm wanting high 14's. That is if mine ever gets here. It's been a full month now and the salesman told me Saturday that 2-13-06 is supposed to be the build week, but he still doesn't have a VIN yet. Sounds like it will be another month.

To break into the 14's in an HHR, you will need 182.64hp at the wheels - that's about 215 or more engine hp.

Sounds like "turbo time" for you... :eek:

Nice..........i've always wanted one myself :thumb:

To break into the 14's in an HHR, you will need 182.64hp at the wheels - that's about 215 or more engine hp.

Sounds like "turbo time" for you... :eek:
Yeah, I know. I'm just hoping when more turbo kits become available, the price will come down. $4K seems kind of expensive to me. I know a guy here, where I live, that is into turbos and has done some really slick installations. He is a NASA welder and does some nice fab work.

I wonder how yours compares to mine-the Escort G Timer GT2?

I plan on running my car on the track with my GT2 on for a direct comparison..

G-tech is is only so-so in the accuracy department. Doesn't take into effect some things, mainly that the HHR is as aerodynmaic as a brick. Works really well with some cars and not so well with others. YOur gonna need a lot more hp than 215 to break into the 14's.

G-tech is is only so-so in the accuracy department. Doesn't take into effect some things, mainly that the HHR is as aerodynmaic as a brick. Works really well with some cars and not so well with others. YOur gonna need a lot more hp than 215 to break into the 14's.
Hey, I can dream can't I? :roll: :D

Hey, I can dream can't I? :roll: :D

Go right on ahead. :beer:

G-tech is is only so-so in the accuracy department. Doesn't take into effect some things, mainly that the HHR is as aerodynmaic as a brick. Works really well with some cars and not so well with others. YOur gonna need a lot more hp than 215 to break into the 14's.

You are waaay off on this. The G-tech TOTALLY takes into effect aerodynamics and gives a truly accurate reading. Don't believe me - watch THIS (http://www.gtechpro.com/test.html) video.

DYNO's do not take into account the effects of poor aerodynamics. the G-Tech is giving you actual readings of your speed, rpms, distance travelled, and G-forces sustained, which translates into the actual performance of your car. And, unlike many other systems on the market, the G-techs use three separate axis' accellerometers to increase accuracy.

Even supposing you were right and the G-Tech is way off (which it's not), - it still would be a valuable tool for comparison runs against a baseline to check whether your mods are increasing speed/response or not. Watch the video and see how it compares to the track timer...

Regarding this:

"Your gonna need a lot more hp than 215 to break into the 14's."

Why not just go HERE (http://www.ultimateresourceguides.com/content/index.html) and enter in the data for yourself. To break into high 14.s (14.97), that's what it comes out to.

Let's play nice for a change... :cool:

That calculator is way off. I entered some real figures from Car & Driver and in every instance the calculator and the actual results ended up about a full second off from each other. For example the Cadillac STS-V weighs 4371# and has 469 BHP so acording to the calculator they should have got 12.258 in the quarter, C & D got 13.2 in real life. I know Car & Drivers editors and testers aren't that bad in the quarter to be a whole second off from what they should be. :roll: It ended up that way on 5 different cars so I gave up. I wouldn't trust that calculator at all.

Cap'n...the calculator is off because you are entering the HP measured at the engine and it wants the HP at the wheels.

Cap'n...the calculator is off because you are entering the HP measured at the engine and it wants the HP at the wheels.

That would explain it I guess. :beer: You would think that it would use engine horsepower because it's easier to get the number. :confused: But I guess if it's using horsepower at the wheels it would be more accurate. :confused:

It would be interesting to see the numbers of a 5 speed HHR, with the same mods, for comparison.

Well, I know I can outdrive any 5-speed. Just looking at the times shows that.
Car & Driver posted 16.1 (5-speed), and 16.6 (Auto), and I'm turning 15.86's.
A lot of time is lost shifting in HHR's - the throw is immensely long, whereas shifting is instant with the auto.

You are waaay off on this. The G-tech TOTALLY takes into effect aerodynamics and gives a truly accurate reading. Don't believe me - watch THIS (http://www.gtechpro.com/test.html) video.

DYNO's do not take into account the effects of poor aerodynamics. the G-Tech is giving you actual readings of your speed, rpms, distance travelled, and G-forces sustained, which translates into the actual performance of your car. And, unlike many other systems on the market, the G-techs use three separate axis' accellerometers to increase accuracy.

Even supposing you were right and the G-Tech is way off (which it's not), - it still would be a valuable tool for comparison runs against a baseline to check whether your mods are increasing speed/response or not. Watch the video and see how it compares to the track timer...

Regarding this:

"Your gonna need a lot more hp than 215 to break into the 14's."

Why not just go HERE (http://www.ultimateresourceguides.com/content/index.html) and enter in the data for yourself. To break into high 14.s (14.97), that's what it comes out to.

Let's play nice for a change... :cool:

Maybe all you need is 215 hp in Death Valley with perfect conditons. In the real world 215hp will never net you a 14 sec pass especially in an HHR. I'll let real world time slips and passes speak the truth, not a G-Tech. Are you trying to tell me that a G-Tech is more accurate than a dyno?? The only thing a G-Tech is really good for, is as you said, doing a before and after comparison.

Well, I know I can outdrive any 5-speed. Just looking at the times shows that.
Car & Driver posted 16.1 (5-speed), and 16.6 (Auto), and I'm turning 15.86's.
A lot of time is lost shifting in HHR's - the throw is immensely long, whereas shifting is instant with the auto.

Your cutting 15.8's on a G-tech, take it to the track then brag about your driving and slips. :roll:

"Are you trying to tell me that a G-Tech is more accurate than a dyno??"

Regarding 1/4-mile times it most certainly is. The G-tech measures actual ground horsepower - and that is what takes you through the traps. Dynos give a more accurate representation of actual engine horsepower, but by the time you subtract engine movement from motor mounts, transmission (or clutch) slippage, other driveline loss from CV joints and half-shafts - you still have slippage from poor traction - a dyno can never account for all these factors. There are plenty of "tricks" you can use to get good dyno numbers. Actual "ground horsepower" is what you need to get moving fast.

Of course you should know all this, being a mechanic. Why don't you just get hold of a G-Tech and make your own comparisons - I have! They are very accurate.

I also have plenty of confidence in my driving - and I'm willing to show you anytime you want to drop by... :cool:

P.S. Talk is cheap = bring your keys & pink slip.

Well, I know I can outdrive any 5-speed. Just looking at the times shows that.
Car & Driver posted 16.1 (5-speed), and 16.6 (Auto), and I'm turning 15.86's.
A lot of time is lost shifting in HHR's - the throw is immensely long, whereas shifting is instant with the auto.
You aint never lined up against me neither! :one:

"Are you trying to tell me that a G-Tech is more accurate than a dyno??"

Regarding 1/4-mile times it most certainly is. The G-tech measures actual ground horsepower - and that is what takes you through the traps. Dynos give a more accurate representation of actual engine horsepower, but by the time you subtract engine movement from motor mounts, transmission (or clutch) slippage, other driveline loss from CV joints and half-shafts - you still have slippage from poor traction - a dyno can never account for all these factors. There are plenty of "tricks" you can use to get good dyno numbers. Actual "ground horsepower" is what you need to get moving fast.

Of course you should know all this, being a mechanic. Why don't you just get hold of a G-Tech and make your own comparisons - I have! They are very accurate.

I also have plenty of confidence in my driving - and I'm willing to show you anytime you want to drop by... :cool:

P.S. Talk is cheap = bring your keys & pink slip.

Are you serious?? A dyno gives you the numbers to the wheels and is much more accurate than a G-tech. Is HHR.net a parallel universe or something, everything that is common knowledge on every other car forum on the net is the exact opposite here. You dont have to subtract drivetrain loss from a dyno it is already given. You said you had you car baseline dynoed at AEM for your intake what were the numbers stock and what does your G-tech say?? The auto trans in the HHR shifts slow as hell, I guarantee somebody who is halfway decent with a stick will cut better mph, but didn't we have this discussion before. :roll:

Is HHR.net a parallel universe or something, everything that is common knowledge on every other car forum on the net is the exact opposite here.

I have noticed that also. :confused: But it's not just this site it's all HHR sites. ;) HHR owners are an odd bunch when it comes to technical know how and weird theories on how vehicles work. :D Wait....did I just insult myself in that last sentence? :confused: Now I have succeeded in offending myself! :p:

Anyone local to SoCal with a 5-speed HHR contact me. We need one to finalize some numbers for the AEM intake. You will get your dyno numbers from the testing plus a FREE intake as soon as it is released.

Also, perhaps we can have a drag race as well to put this thing to rest. We can meet at Pomona or Irwindale for anyone interested. Shoot me an email.

I'll be out most of today getting some sidepipes installed, but will try to respond to emails this afternoon. Thanks.

Skinner is right. Dyno gives you actual HP at the wheels. All mechanical losses are already taken out. However, Dynos don't (ans can't) take into account Aerodynamics. That's why Dyno results on cars and motorcycles with ram air don't give you accurate results.

SoCal is right too though. G-Tec uses all of those velocity, acceleration, horsepower, efficiency... equations that I learned in college and applies them with the values it measures from the GPS, accelerometers, and the other values that are user defined. So it gives you the mathematically exact figures.

The real truth lies somewhere in between.

I did an experiment in a fluids lab in college where we actually dyno'ed an engine - straight output from the engine - no mechanical losses. Then took all kinds of measurements of the engine during operation to calculate theoretical HP. Results were quite a bit different.

And my point... I don't know. I guess I agree with Snake and SoCal. Either method will work just fine for delta changes before and after mods. Just make sure you use the same method before and after. G-Tec vs Dyno is never going to give you an aples-to-apples comparison. Beyond that, prove it on the track. Reaction time, shifting expertise, and the perfomance of your specific car at that exact instant is what really matters.

Sounds like an episode of PINKS is in the works... :thumb:

So-Cal you still didn't answer my question. You said you got before number on your car stock. What did it put down and what does the G-Tech say your putting down. Answering that question will put all this to rest. I guess if G-tech is the greatest thing we better tell all those who tune on a dyno all they need is a G-tech, and better bring it up to the NHRA as well, no need to race at the track just slap a g-tech in the car and use that to figure out point standings.

I guess you don't understand that since I had my "stock" HHR dyno'ed at AEM I have changed the exhaust - so those numbers won't tell us anything. Apples and oranges.

I never said the G-tech is "the greatest thing" - but was merely pointing out innacuracies in your statements regarding it. A dyno can never take into account aerodynamics - but the G-Tech has to! It's accelerometers are sensing G-forces against time and this equates to distance travelled. If you have wheelspin off the line; G-forces go down and it is factored in. If your engine is putting out good power but the HHR is "built like a brick wall" at 90mph - G-forces exerted show this and it is also factored in. Dyno rollers "move" when you push the gas - the ground doesn't. The ground also has different effects on your suspension, motor mounts, frame flex, etc. than a dyno does. Real world values will always be lower than dyno figures - but they (real world ground horsepower), are the most accurate.

Face it, a dyno was designed to be a tool to allow engine builders to repeat testing in a lab under (nearly), identical conditions. Aerodynamics are not included, real-world airflow into the engine compartment is not included (*there is still much controversy over this.), suspension torque and frame flex against an unmoving earth are not included. Have you ever seen someone do a full 1/4-mile run from a dead stop on a dyno? That's not how they are used and it was never intended to be.

The G-Tech was designed and built specifically for this application and if you took the time to watch the video I provided a link to above, you would see just how accurate a properly calibrated G-Tech is (dead accurate), compared to the trap lights. Welcome the technology.

Both are great tools (dyno & G-Tech), both operate differently.
I think we should just agree to disagree and leave it at that.

I think you should stop side stepping my question and post what your car put down stock. All you've added since then is what, a muffler?? Difference won't be that great. What did your car put down stock and what does the G-Tech say you are putting down now. If it is as accurate as you claim it to be they should be fairly close. My feeling is the numbers are far off and thats why you wont post it.

All I'm saying is that the G-tech is only accurate in certain cars, in my experience. Then you went spouting off how your the worlds greatest driver because you ran a 15 according to your g-tech, which is all fine and dandy but go back it up at the track. I know exactly what a dyno was intended for, it's a tuning tool nothing more nothing less.

I think the rule of thumb most users use is for every 100 pounds of vehicle weight removed equates to one tenth of a second off on the quarter mile. Vehicle weight accuracy is very important.

Since all the results are mathmaticlly related as Long Tall Texan point out (thanks for that, too) it seems to me that the accuracy of the G-Tech is only as good as the accuracy of the vehicle's weight and cargo entered in to the device. A few pounds of difference is going to influance the results.

Would this not be true?

FYI, some of the guys on the GTO boards (ls2gto.com) use G-Tech or simular devices and they are saying the results from these devices match very close to the time and speed tickets issued by the track.

I am under a non-disclusure agreement with AEM and cannot release any information gained during preliminary testing. Sorry, you'll have to dyno your own stock HHR.

Once again - you've misread my post. I'm not sidestepping anything. The G-Tech numbers WILL NOT match dyno numbers. It's never going to happen. Reread my post above to understand why...hopefully (jeesh!).

"All I'm saying is that the G-tech is only accurate in certain cars, in my experience."

Very limited experience too, I'm guessing. The G-tech must be calibrated properly to give accurate results. If you move it from car to car (unless they are identical models), the results will be waaay off.

Your hoopla about "aerodynamics" was a bunch of pootie and it is clear that you don't know what you're talking about when it comes to the G-Tech regarding this. Any basic physics student can confirm this.

I think the rule of thumb most users use is for every 100 pounds of vehicle weight removed equates to one tenth of a second off on the quarter mile. Vehicle weight accuracy is very important.

Since all the results are mathmaticlly related as Long Tall Texan point out (thanks for that, too) it seems to me that the accuracy of the G-Tech is only as good as the accuracy of the vehicle's weight and cargo entered in to the device. A few pounds of difference is going to influance the results.

Would this not be true?

That is all part of the calibration process.

Here is something else to consider.

All dynos do not offer the same result. For example, a GTO measured on a Dynojet will show 400 HP and 400 Torque, but on a Mustang Dyno, the same vehicle will show around 5% less. All dynos are not created equal.

A dyno (same model) is a good baseline for comparision, but I think you will find devices like the G-Tech (properly calibrated) closer to real word results.

I am under a non-disclusure agreement with AEM and cannot release any information gained during preliminary testing. Sorry, you'll have to dyno your own stock HHR.

Once again - you've misread my post. I'm not sidestepping anything. The G-Tech numbers WILL NOT match dyno numbers. It's never going to happen. Reread my post above to understand why...hopefully (jeesh!).

"All I'm saying is that the G-tech is only accurate in certain cars, in my experience."

Very limited experience too, I'm guessing. The G-tech must be calibrated properly to give accurate results. If you move it from car to car (unless they are identical models), the results will be waaay off.

Your hoopla about "aerodynamics" was a bunch of pootie and it is clear that you don't know what you're talking about when it comes to the G-Tech regarding this. Any basic physics student can confirm this.

i actually don't give a shit about the G-tech, because I personally don't like them, I'd rather go to the track. My hoopla about aerodynamics and such might be "a bunch of pootie" regarding there newest version, but with the older ones it wasn't. So if you can't say what your car put down stock, which is total BS, what does the g-tech say it is putting down now? Or can you not disclose that either. :roll: How do you calibrate this nifty little device of yours for aerodynamics, just out of curiousity.

Here is something else to consider.

All dynos do not offer the same result. For example, a GTO measured on a Dynojet will show 400 HP and 400 Torque, but on a Mustang Dyno, the same vehicle will show around 5% less. All dynos are not created equal.

A dyno (same model) is a good baseline for comparision, but I think you will find devices like the G-Tech (properly calibrated) closer to real word results.


I agree like I said all a dyno is, is a tuning tool, nothing more nothing less.

Good Gosh. What an interesting read....pootieheads :) I don't know much and don't pretend that i know much either. BUT i can understand how a dyno can't account for aerodynamics, etc. The car isn't moving. It just can't. However whatever socal has, (if calibrated correctly) would account for everything, bc the car actually is moving and having to deal with all aspects, aerodynamics, bla bla bla.

So if you can't say what your car put down stock, which is total BS, what does the g-tech say it is putting down now? Or can you not disclose that either. :roll:

If you look on his Car Domain page it says 166 HP.

If you look on his Car Domain page it says 166 HP.


Thank you detective Howdy! So much for disclosure, huh, So-Cal :roll: . No what is your G-tech saying you are putting down. You took a picture of it with the other functions, why not hp and torque??

Thank you detective Howdy! So much for disclosure, huh, So-Cal :roll: . No what is your G-tech saying you are putting down. You took a picture of it with the other functions, why not hp and torque??

That was the G-Tech result. Sorry I didn't clarify. There is no mention of the dyno numbers, but there is a HP shot of the G-Tech. The one thing I worry about from that shot is if the G-Tech is fairly accurate (which I believe it is even though I trust a dynos numbers more) and Chevy's power rating of 172 HP is also fairly accurate then it looks like you lost 6 HP by changing the muffler. :confused: The G-Tech is still a valuable tool if you don't want to take a trip to the dyno shop for every small mod. The dyno can't tell you things like how many Gs you are pulling on a skidpad also. Of course track results are track results - undisputed. Like snksknr94 said the only way you are going to get the true 1/4 mile time is to go to the track.

That was the G-Tech result. Sorry I didn't clarify. There is no mention of the dyno numbers.

Your demoted back to captain, no more detective for you. :p: :beer:

That was the G-Tech result. Sorry I didn't clarify. There is no mention of the dyno numbers, but there is a HP shot of the G-Tech. The one thing I worry about from that shot is if the G-Tech is fairly accurate (which I believe it is even though I trust a dynos numbers more) and Chevy's power rating of 172 HP is also fairly accurate then it looks like you lost 6 HP by changing the muffler. :confused: The G-Tech is still a valuable tool if you don't want to take a trip to the dyno shop for every small mod. The dyno can't tell you things like how many Gs you are pulling on a skidpad also. Of course track results are track results - undisputed. Like snksknr94 said the only way you are going to get the true 1/4 mile time is to go to the track.

Ummm....Captain - you're forgetting something; the 172hp number is GM's "engine" horsepower. My G-Tech reading is actual at-the-wheels horsepower - which should be a considerable increase over stock (you're going to lose way more than 6hp to the wheels).

Nice try though - detective! :D

I keep forgetting that. :roll: It's been on of those days. :roll:

No problem.

Well, I can tell you what my dyno sheet from K&N says. My 2.4L puts out 144.22 hp on their dyno. It was run yesterday morning before the intake test. I do not know what the numbers are with the intake. They are still developing it.

Just an FYI if you are interested in the actual readings completely stock :)

Becky

It would be productive if it was mentioned the brand of the dyno when quoting dyno results. As I've posted before, different brands offer up different readings which can have deltas of around 5%.

I am sorry I forgot to include that, it was a Dynojet dyno. I was going to put that in my post because I knew it makes a difference. I wasn't sure if anyone was even interested in the before results since I do not have after results. Also the test was done in second gear according to the report.

I am sorry I forgot to include that, it was a Dynojet dyno. I was going to put that in my post because I knew it makes a difference. I wasn't sure if anyone was even interested in the before results since I do not have after results. Also the test was done in second gear according to the report.

I'm interested in all results so thanks for posting. You don't by chance have the torque value, do you?

Most all dyno runs will be in a second or third gear, this way the engine is under a strong load while the power band is traveled.

I'm interested in all results so thanks for posting. You don't by chance have the torque value, do you?
Sure, Max torque is 129.38.

I'm interested in all results so thanks for posting. You don't by chance have the torque value, do you?

Most all dyno runs will be in a second or third gear, this way the engine is under a strong load while the power band is traveled.

A dyno pull should be done in a the direct drive 1:1 ratio. Anything lower and your getting a false reading due to torque multiplication through the trans.

A dyno pull should be done in a the direct drive 1:1 ratio. Anything lower and your getting a false reading due to torque multiplication through the trans.

I dissagree, and this is why:

The purpose of a dyno is to baseline performance which is useful for discovering gains/losses when tuning. It is not a good tool for comparing another same vehicle or comparing data, across days, because of environmental issues.

As long as you profile the powertrain using the same gearing on each pull, your results are fairly accurate with respect to the engine's environment (e.g.: engine temp., air temp., humidity, etc).

When doing a dyno run, you capture the engine's abilities (ability to apply torque with respect to time (HP)) begining in a mid gear all the way through to the end of the gear's range (max RPM).

If you ever get a change to watch a dyno pull, you will see what I'm talking about. Check out some of the car shows on the speed channel or spike TV.

When my tuner does a dyno pull on my GTO, they get the car 's speed up to the low end of 3rd gear and then go wide open throttle to red line. Then they make adjustments to the timing or fueling or what ever they are tweeking this day, give the engine a 20 min. cool down, and start over.

I dissagree, and this is why:

The purpose of a dyno is to baseline performance which is useful for discovering gains/losses when tuning. It is not a good tool for comparing another same vehicle or comparing data, across days, because of environmental issues.

As long as you profile the powertrain using the same gearing on each pull, your results are fairly accurate with respect to the engine's environment (e.g.: engine temp., air temp., humidity, etc).

When doing a dyno run, you capture the engine's abilities (ability to apply torque with respect to time (HP)) begining in a mid gear all the way through to the end of the gear's range (max RPM).

If you ever get a change to watch a dyno pull, you will see what I'm talking about. Check out some of the car shows on the speed channel or spike TV.

When my tuner does a dyno pull on my GTO, they get the car 's speed up to the low end of 3rd gear and then go wide open throttle to red line. Then they make adjustments to the timing or fueling or what ever they are tweeking this day, give the engine a 20 min. cool down, and start over.

Is your GTO an auto?? Third gear is the 1:1 ratio in a 4 speed auto.

Is your GTO an auto?? Third gear is the 1:1 ratio in a 4 speed auto.

This is interesting, when I got to work this morning I looked up both the auto and manual trannys for both the GTO and the HHR, here is what I found:

On both vehicles, a 1 to 1 ratio was in third gear for the automatics as you indicated. For the manuals, the GTO had a 1:1 in fourth gear and the HHR's manual had a 0.98 ratio in forth gear.

My GTO is a manual and third gear has a ratio of 1.43. Should my tuner be doing my dyno pulls in forth gear?

I think you are trying to teach me something here but I'm missing it....

This is interesting, when I got to work this morning I looked up both the auto and manual trannys for both the GTO and the HHR, here is what I found:

On both vehicles, a 1 to 1 ratio was in third gear for the automatics as you indicated. For the manuals, the GTO had a 1:1 in fourth gear and the HHR's manual had a 0.98 ratio in forth gear.

My GTO is a manual and third gear has a ratio of 1.43. Should my tuner be doing my dyno pulls in forth gear?

I think you are trying to teach me something here but I'm missing it....

Doing a pull in a lower gear will skew your final numbers, they will inflate the number as the wheels are turning faster than the motor is, making it seem as if you are putting down more than your are. I guess if all your doing is just tuning and not going for a true number it doesn't matter. I could be completely off base on this, but this is just how I always understood it, and if you think about it, it makes sense. Each gear in the trans should get lower as you go up in gear, with anything above 1:1 being overdrive, 4th gear in an auto and 5th and 6th in the GM manual tranmissions. Usually you won't get a perfect direct 1:1 ratio, it is usually off just a little bit like the HHR having a 0.98:1, but it should be within a tenth or 2.