58 replies to this topic

[Ron Alan]

So Ron, to be clear, you are saying that a good unrestricted na 1.8 will make 133 to 135 hp?

James...the actual number means nothing...it is the comparison on the same dyno of 2 different cars...and ideally on the same day and time!

My comments are in reference to what I know and have seen on my own personal cars, friends cars, and cars I have dynoed as an official...all using the same 2 dyno's in NORCAL which are consistently the same +/- 1

 

I will use Jim as an example since he has posted HIS dyno numbers in the past. When his motors end up on the west coast they always make good numbers in relations to others...but they are usually 3-5 off what he gets on his dyno.

 

Nothing to hide here...here are a few of the best numbers I've seen here on motors that I feel confident would pass a tear down or have!

 

1.6...123

NA 1.8...130(125-6 restricted)

99-00...128

VVT...126

 

THEN...set those numbers aside and look at the torque! I would take any of the above numbers -2 if the torque was at the top of the spectrum!

[davew]

I know you are talking about NA8 cars, but to add something:

 

We have tested my 1.6 at both Road America and Gingerman. Back to back to back with a 99. Same engine builder, same driver, same day, same tires. Within 0.1 seconds difference. We even tried the 1.6 topless at Gingerman, gained in the twisty's but lost on the longer back straight. Still equal lap times with 0.1.

 

At the Road America vintage race, my 1.6 ran with Marc's NA8 the entire race.

 

Remember 3rd grade math? If A equals B, and A equals C, then B must equal C.

So if 1.6 equals 99, and 1.6 equals NA8, then 1.8 must equal 99.

 

Saying that, driver always chose the 99 to race. he feels easier to drive at the limit, not as razor edge all the time. This may be the front suspension or the lack of 1.6 torque. or a combination.

 

I have a NA8 built the same, maybe I will bring that to VIR to test at SVRA.

 

Dave

[Jamz14]

Ron. That makes sense and inline (as far as a 99 and na 1.8, never looked at a vvt) with my numbers. I know it's claimed but never seen 130 motor yet. But I use a particular dyno too. Only seen your numbers on a dyno jet correction. The superflow I use reads about 5 hp lower and is only close after applying a dj correction.

[Jamz14]

So I retract the bull shit comment if we throw out the 130 number being used for methane infused air at dynos in the Midwest. If we are just saying that the na 1.8 will pickup 3 hp uncorked , then I agree. Plate is worth a few hp.

[Steve Scheifler]

Ron. That makes sense and inline (as far as a 99 and na 1.8, never looked at a vvt) with my numbers. I know it's claimed but never seen 130 motor yet. But I use a particular dyno too. Only seen your numbers on a dyno jet correction. The superflow I use reads about 5 hp lower and is only close after applying a dj correction.

Why, isn’t everyone using the same SAE correction?? It has evolved a bit over time but anywhere close to current should be very close, certainly not in the range 5hp difference. More likely the raw HP calculation is the main difference, and it seems to vary by at least that between brands & types. And of course the correction requires accurate input/sensors for temp, baro and humidity. I keep a separate sanity-check gauge for temp & humidity, I should do the same for baro. I also monitor IATs and override the temp real-time (or stick the probe into the intake). If your dyno shop isn’t doing all that then I question the accuracy and repeatability of the numbers anyway. We’re talking small enough variances that I can make it show a very healthy number if I choose to, but I prefer reality.

[Jamz14]

Steve, not sure about everything you mentioned just because I am not a dyno expert and didn't get into all the details with them but did get a layman's overview from them that convinced me they are accurate before corrections. So i assume and check with them that I get a sae corrected number before they hand me the much higher dyno jet correction they provide me for reference. I don't worry myself about atmospherics much when going to the dyno as usually I'm just looking for relative changes same day same conditions. I try to control for engine temp , tire pressures, and rear end setup. Not the most detailed controls but I thought it enough for what I was using it for. If I wanted greater accuracy is pop the engine and take it to the guy I use with an engine dyno.

That said. What is the average number people would see in your opinion of power gain without the plate? What's the plate worth.

[OrangeCrush86]

Why not just buy a 99? They are for sale all the time.

[Jamz14]

I have a 99. It's a good car and has been doing well. Will be fun seeing how it goes against the Midwest eastern boys at the nats. I just do not like driving it as much as the 97. The 97 was edgier than the 99 and that is why I liked it. It is very possible that in a race id do better in the 99 as it is...... more forgiving? Not sure I like that descriptor but you get my meaning. But I love driving!! Im in a car probably 6 to 7 hours a day. And I love an edgy car. Not unpredictable, just edgy. IMO the thing that gives a car that feel is the weight and the suspension. I'm not a motor guy. So for me what this has all come down to is I miss driving the 97 and at some point I will bring it out of retirement to just drive and have fun. Id like to be competitive regionally too, but sometimes I need to remind myself why I drive and not get sucked so easily into the competition of it all.

So thank you all for helping me remember that driving is fun and bench racing is tedious work. Wrenching alone at the shop is fun. Debating minutia not so much. So next time i bitch about the weight , someone just slap the shit out of me and bring me back to my happy place.

[Steve Scheifler]

Allow me to provide an example of why atmospherics should matter to your dyno shop even if not to you as such. Obviously the logic below applys to every point on the power curve, not just peak HP or torque.

Raw uncorrected HP: 125
Actual temp: 77F
Humidity: 0
Baro: 29.23 inHg

SAE Correction Factor = 1.000
SAE Corrected HP = 125

It’s a very dry mild day near sea level so your enviro factors match the SAE standard/reference and measured HP equals corrected.

But your dyno operator has the temp probe hanging above the dyno cart while the car is sucking in air from in or near the engine compartment and the intake tract is getting warmer and warmer, transfering some of the heat to the intake air. You hook up your OBD tool and check IAT during the pull. Woah! At the start of a pull it is 102 degrees and by the end has dropped to “only” 90F. So let’s recalculate the SAE correction with that information using the lowest 90 degree value.

SAE Correction Factor: 1.01416
SAE Corrected HP = 126.8

For 99% of all normally aspirated cars the average shop sees that amounts to BFD, but for us it matters even when simply comparing your own runs during a single session. Once a car is pretty close, the impact of rapidly changing IAT makes more difference than any actual tuning tweaks, you can chase your ass forever looking for that last HP.

Of course few of us live at sea level in the desert so there are also corrections happening for baro and humidity, with the latter more likely to vary by a meaningful amount over a short time. What do you suppose happens to our 125 raw number at 70% humidity with the rest as calculated above?

SAE Correction Factor: 1.056
SAE Corrected HP = 132

Garbage in garbage out, all of the environmental inputs are important and temperature in particular matters even in a single short session.

[luvin_the_rings]

I thought we covered this already, comparing dyno numbers from dyno to dyno is useless.

[Michael Colangelo]

Why not just buy a 99? They are for sale all the time.

 

For many of us, it's about price.  NA6/8 SMs tend to be much cheaper.

[Mike Tesch]

Oh and the Brewers still trail the Cubs. 

Who cares... I don't like hockey.

 

… oh yea, the Bears still suck.  

[Danny Steyn]

This is pure bullshit. If true people would be flocking to the car. I don't doubt what you saw on the dyno, the bullshit part is that the change in plate is the cause. So when are you building one Danny? You of all people can't tolerate driving your now underdog to a 97 vvt. Put the old plate in the na you are talking about and dyno. Pull the plate and dyno. Tell us what the total gain in hp you see. Then all of us will do the same. You don't need a top prep car to do this test. You don't need to be on the same dyno as you. All we need to know is what was your relative hp change. Then I will see what my relative change is.

What you are implying is that a top prep na 1.8 will now make 133 to 135 hp. Bullshit.And if any of you saw those numbers on the dyno at the track, you would be pulling the car apart down to the last bolt. But please discuss with Xavier so he can change the dyno guidelines in the NASA rules to reflect the new reality of 135 hp na 1.8s.

 

" This is pure bullshit" - really James - your ????????  speaks volumes with this comment. I spoke about what I have seen with my own two eyes with three cars tested on the same dyno (NA 1.8 (not mine), My best NB 99  at the time and and my best NB VVT at the time). I also referenced acceleration traces that I overlayed on my computer from two different drivers in two different cars on the same track on the same day. 

 

And you call BULLSHIT??? Really - What do I gain by these claims, whats in it for me? Why would I mislead you?

 

My best 99 has never made more than 128HP on Rossini Dyno, my best VVT has never made more than 126HP on Rossini dyno. If you do the math with what I stated above you can get PRECISELY what the unrestricted NA1.8 made in terms of HP. Note that I did NOT supply you with ALL the information you might need to make an assessment of which of the three the better weapon is for you, but for everyone, there will be a preference.

 

If you are a competitive person I suggest you watch MMA. It is pretty brutal, but it is very pure. Some fighters are technical and their attacks are surgical in nature, well thought out, in and out, strike and retreat out of harms way, others rely on ground and pound, and others prefer submission tactics.

 

As drivers we all bring certain personalities and characteristics to this game we play in James, and the sensible fighter/driver chooses his weapons to favor his strengths and weaknesses. I have no idea what your strengths are, but I certainly know what mine are and I have chosen my weapon accordingly. 

 

So I call BULLSHIT on you James. Do your homework, Put in the time. Stop whining. Make it happen, Show us what you got 

[Danica Davison]

LOL! patiently waiting Jamz response now. I love a good internet brawl.

 

SOMEBODY HIT SOMEBODY!

[Danny Steyn]

LOL! patiently waiting Jamz response now. I love a good internet brawl.

 

SOMEBODY HIT SOMEBODY!

 

Danica - the reason for my testy reply is simple -  Over the years I have gone out of my way to be as open and helpful as possible on this forum, supplying information that helps others shortcut the learning that we have all invested in, so when someone calls me out with a comment like that, I have two options:- Let it slide, or respond. Historically I have let it slide, but this commented was directed at me personally, so what the hell, this forum needs some life!!!! So Flamesuit on, bring on the heat, let it fly.

 

PS good to leave the chaos of Zambia and return to the chaos of MRF!

[Jamz14]

Danny,

 

Did you read my follow up comments before your latest post? I agree with what you are seeing if we don't use 130 HP numbers being reported from back east. If we use 125 hp numbers we see out hear, then yes I believe you. I made a mistake in using reported absolute numbers when what I should have done was to just look at relative performance gain from the restrictor being pulled. Looking at it that way , then I agree, you will see a 3 hp gain over the 99 with the a pulled restrictor plate on a NA 1.8 .

 

But HP isn't the whole picture. Ive been studying your COTA video closely. You shift better than anyone I have seen. There was a spot in the video when the car next to you seemed to have more power than you, but as soon as you both shifted, you pulled away. Point being that there is a lot more that goes into those acceleration traces than just pure HP.

 

So Danny, I apologize. Want more? Happy to give it but I want more then too from your mistakes and offenses given to this group.

 

Look, this is now a dead issue. Danica can wait around with glee for more drama, but it isn't coming from me. There is no change coming!!!!!! I hear you and everyone else loud and clear. Still doesn't change the fact that you guys should have defined what rule change success or failure looked like prior to changing a car you don't drive.

[Jim Drago]

" This is pure bullshit" - really James - your ????????  speaks volumes with this comment. I spoke about what I have seen with my own two eyes with three cars tested on the same dyno (NA 1.8 (not mine), My best NB 99  at the time and and my best NB VVT at the time). I also referenced acceleration traces that I overlayed on my computer from two different drivers in two different cars on the same track on the same day. 

 

And you call BULLSHIT??? Really - What do I gain by these claims, whats in it for me? Why would I mislead you?

 

My best 99 has never made more than 128HP on Rossini Dyno, my best VVT has never made more than 126HP on Rossini dyno. If you do the math with what I stated above you can get PRECISELY what the unrestricted NA1.8 made in terms of HP. Note that I did NOT supply you with ALL the information you might need to make an assessment of which of the three the better weapon is for you, but for everyone, there will be a preference.

 

If you are a competitive person I suggest you watch MMA. It is pretty brutal, but it is very pure. Some fighters are technical and their attacks are surgical in nature, well thought out, in and out, strike and retreat out of harms way, others rely on ground and pound, and others prefer submission tactics.

 

As drivers we all bring certain personalities and characteristics to this game we play in James, and the sensible fighter/driver chooses his weapons to favor his strengths and weaknesses. I have no idea what your strengths are, but I certainly know what mine are and I have chosen my weapon accordingly. 

 

So I call BULLSHIT on you James. Do your homework, Put in the time. Stop whining. Make it happen, Show us what you got 

when you are correct, you are correct and this is spot on!   +1 on this

[Danny Steyn]

Danny,

 

Did you read my follow up comments before your latest post? I agree with what you are seeing if we don't use 130 HP numbers being reported from back east. If we use 125 hp numbers we see out hear, then yes I believe you. I made a mistake in using reported absolute numbers when what I should have done was to just look at relative performance gain from the restrictor being pulled. Looking at it that way , then I agree, you will see a 3 hp gain over the 99 with the a pulled restrictor plate on a NA 1.8 .

 

But HP isn't the whole picture. Ive been studying your COTA video closely. You shift better than anyone I have seen. There was a spot in the video when the car next to you seemed to have more power than you, but as soon as you both shifted, you pulled away. Point being that there is a lot more that goes into those acceleration traces than just pure HP.

 

So Danny, I apologize. Want more? Happy to give it but I want more then too from your mistakes and offenses given to this group.

 

Look, this is now a dead issue. Danica can wait around with glee for more drama, but it isn't coming from me. There is no change coming!!!!!! I hear you and everyone else loud and clear. Still doesn't change the fact that you guys should have defined what rule change success or failure looked like prior to changing a car you don't drive.

 

All good James!!!! 

[Jamz14]

Cool! Thank you for letting me eat crow without having to swallow the beak.