1001 replies to this topic

[SaulSpeedwell]

Bennett had a top prep 1.6 and he was also one of the first people to throw in the towel on the 1.6 (although he has since said he wishes he kept it)

LOL, if I said that it was only with the idea of vintage racing my first race car and the original Miata, which is much more fun to drive than the NB "tractors"

[SaulSpeedwell]

His 99 wasn't any faster (with the ruleset in 2008). So "throwing in the towel" isn't quite an accurate statement, nor is "one of the first". He thought the grass was greener in the 99 pasture.

As with most things in my head, it was a lot more complicated and nonlinear than that. 

 

I absolutely thought the NB was the better horse for Mid Ohio because Mid Ohio is a torque track.  If you plot the histogram of RPM at Mid Ohio, it was the lowest average RPM track in all of GLDiv/CENDiv.  Anyone getting ready for the Runoffs there should be looking at that issue re: the VVT NBs versus the 99-00.  Add in the backfield traffic jams, and the 1.6 is hard to race against an equal NB there.

 

You're right, my '08 season NB wasn't any "faster" than my '07 season NA, but it could turn the same laptime the whole session.  It was the better race car, no doubt.  The NA was a qualifier car that left you weak in the race, especially after all the grid and pace lap shenanigans.

 

Over the years, as laptimes fell and 2nd gear corners became 3rd gear corners, the 1.6 got hurt.  It also got hurt by big sticky tires.  And "heat soak" (high underhood air temperatures, really) has ALWAYS hurt that car, and I don't understand why so many in the 1.6 Union refuse to believe something backed by physics, automotive industry tech papers, and on-track measurement and testing.  The 1.6 will always be a parity misfit as long as it is fast early and when ambients temps are cool, and slow late and when amibient temps are hot. 

 

Give the car cool air before pursuing all the complicated, expensive, labor-intensive hard parts.  If it isn't being tested on track in consideration of the under-hood temps, then it is just dyno fiction.

 

The NB Union will whine just because they fear someone might actually make a 1.6 that can win, but tell them to calm down - simply giving the 1.6 cool air won't make it a dominant rocketship - it will just help it be as fast as it is in qualifying and be able to turn its fast lap from start to finish like the NB does.  It will make the car much easier to fit in with the others on overall parity.

 

Something to consider:  I know about 3 guys talking about taking 1.6s vintage racing.  I think 10, 20, 30 car SM fields could be quite achieveable in vintage racing 5 years from now.  It might be the best way to recreate the fun low-contact low-drama days of 2002-ish, and do it with $15K cars. 

[OctaneNation]

 

Give the car cool air before pursuing all the complicated, expensive, labor-intensive hard parts.  If it isn't being tested on track in consideration of the under-hood temps, then it is just dyno fiction.

 

 

Why is the 1.6 more susceptible to this vs 1.8 cars?

[38bfast]

Same for the 1.8 cars.

[cam]

On the 1.6, there is an air temperature sensor built into the AFM.  When the ECU received input from this air temperature sensor that the incoming air is above a preset range, then it pulls timing advance and adds fuel.  Safe for a production car but very annoying on a race car.  It is my understanding that the air temperature sensor in the AFM is more sensitive than the 1.8 version.  There is also a water temperature sensor on the back of the cylinder head (CHT) that has a similar function, pulls timing and adds fuel if hot.  Think the CHT functions the same for all years of SM.  Therefore, the 1.6 version will benefit more towards the end of a race from cooler air than the other cars, but do not know by how much. 

 

Also, keep in mind that the 1.6 style of AFM is a built-in restrictor plate and is using fuel injection technology from the 1970's. (inspired by Bosch L-Jetronic)  While Mazda did an amazing job of making a safe, reliable, and EPA compliant system; it is not a great race car system.

[SaulSpeedwell]

Why is the 1.6 more susceptible to this vs 1.8 cars?

 

Let's assume we don't have any idea why or we are wrong as to why -  the laptime and IAT data still clearly support the hypothesis.  Every weekend at every track I have data for, the NA slows down in the heat and throughout the session, and the NB slows down "less" in the heat and, if anything, gets faster at the end of the session.  Both were "top prep" cars (for their time), only one season apart, teardown-proven (for their time), and at tracks where I held records and was hanging on to the rear bumper of Gods like Lamb.

 

To be clear, I only campaigned a 1.6 and an NB, but I suspect the 94-97 is better than the 1.6 but not as good as the NB, mainly because the stock airbox and better EFI is more immune to IAT than the 1.6 "dyno queen" intakes.

 

Having said that, I think we do, in fact, have some objective evidence as to "why" the 1.6 is hurt more by IAT.  The 1.6 "straight shot" air intake provision is sucking stagnant underhood air, through a (usually) metal intake tube and a metal flapper-door vane meter (AFM) with an IAT sensor stuck into it..  The NB has a purposely designed inner fender liner that "pumps" cold high pressure air from the pre-radiator bumper cover and the front of LF tire, directly to the intake of the all-plastic airbox. 

 

I ran IAT instrumented in my NB the entire time I had it.  Unfortunately, I did not have this on the NA - but there is no doubt that car was fast cold and slow hot (compared to the NB).

 

Both cars have IAT sensors and attempt to adjust for it accordingly.  I also believe the NA is a less heat-efficient setup than the NB.  The deadheaded coolant "mixing chamber" is one reason I can think of - but I also believe there is every reason to expect that Mazda was working very hard to make the NB motor lose less power through heat losses than the 1989 design.

 

Emissions and MPG were barely on Mazda's mind in 1989 compared to the 99-00, which itself is a pig-rich ozone-destroyer (when open-loop, which is almost always except at steady light-throttle cruise) compared to the 2001-2005 version. 

 

Even if I'm wrong as to why, the data supports the hypothesis.  The NB Owner's Union must think there's something to it, too, or they'd have less objection to letting the 1.6 have some cold air.

 

Disclaimer:  0 dogs in the hunt, and history will show that the last rule change I campaigned for (also while I had 0 dogs in the hunt) was AFPR and open timing for the NBs

[LarryKing]

Saul, you may recall that Tony Coello ran a stock airbox on his 1.6 back in the day. Maybe he knew something about air temps?

I still have my stock airbox what breathes through the inner fender in a box in my basement. What do you think? (I think I've purchased three different aftermarket intakes over the years.)

[SaulSpeedwell]

Saul, you may recall that Tony Coello ran a stock airbox on his 1.6 back in the day. Maybe he knew something about air temps?

I still have my stock airbox what breathes through the inner fender in a box in my basement. What do you think? (I think I've purchased three different aftermarket intakes over the years.)

 

Hmm, are you sure about that? Tony's 1.6 was the red/yellow "McDonald's" car that later became Huffmaster's #24, if you are thinking of Tony's red #18, that was a 94-97 car and thus would have had the "stock" airbox.

 

I don't think Tony or Niki ran stock airboxes in their 1.6s, or we all would have been doing it!

[LarryKing]

Saul, didn't Tony have a black 1.6? I remember asking him about the airbox at Grattan and he said he made more power with it. Not sure, it was ten years ago. Any who, what's your thoughts on using the stock airbox?

[OctaneNation]

I considered testing it but realized you can't rotate the AFM with the stock airbox...

[LarryKing]

 

I considered testing it but realized you can't rotate the AFM with the stock airbox...

 

Per the GCR the intake is open upstream of the AFM. One could engineer a short 'adapter' between the AFM and stock airbox that would allow clocking the AFM.

[chris haldeman]

Waffle maker anybody?

[SaulSpeedwell]

Saul, didn't Tony have a black 1.6? I remember asking him about the airbox at Grattan and he said he made more power with it. Not sure, it was ten years ago. Any who, what's your thoughts on using the stock airbox?

 

A.  I love Tony, but anything he said when he was racing was an outright obfuscation meant to disadvantage you!   

B.  I never saw Tony in a black 1.6, unless he was borrowing Niki's old car.  But Niki also had a black 1.8, especially if you are literally talking about 10 years ago and not 11-12.  2005 is about the time they switched to 1.8s.   

 

I think the stock airbox is better than the dyno says it is, but probably not "the hot ticket".  Although I put a lot of effort into the CAD plastic Wafflemaker and ran it most of the time, I also know it is somewhat of a hood-up dyno queen like the other straight intakes.  I often ran a custom elbow similar to the "Racing Beat", but that was with a lifted hood, a depressed headlight door, and a trimmed turnsignal lens and bumper cover recess to try to get cold air into the thing.  The best we could do for testing at the time was test with the hood down with a squirrel cage fan aimed at the headlight gap.  In that scenario, it was better than the straight intakes.  Was that test bogus?  Maybe ... because all dyno testing is, to some extent, bogus.

[Todd Lamb]

Qualifying yesterday at Barber. That #6 car is a 1.6.

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[Steve Scheifler]

As is SO common, the Race Monitor results are a complete mess and I can't even find that session. But from what I can find, that was his only decent session and he didn't even run the last race. What happened?

Once upon a time the SCCA recorded qualifying lap records as well as race lap records. If we still had that the 1.6 might hold quite a few, but there's no $5 trophy for Q or even fast race lap.

[B(Kuch)Kucera45]

Qualifying yesterday at Barber. That #6 car is a 1.6.

Did he race that car and how did it do ?

If he did race a 1.6 is the car legal and coud you use his data for comparison ?

Personally I would rather see race results and race data over qualifying because we all know they can qualify well but fall off during a race.

[Bruce Wilson]

A good 1.6 with a good driver should be able to be on the pole at pretty much most tracks. 

 

Lap times are not the problem. 

 

And I've said it many times -- falling off is not the problem. 

 

Heat soak is a red herring and a waste of everyone's time.

 

The problem is getting passed and/or not being able to pass because of torque.   This will NOT change if a 1.6 is a bit faster in the second half of a race.  You'll still get held up in the corners and pulled out of the corner.  I just don't see the logic!

 

Compression is the best, low-cost, long-term solution!

[Todd Lamb]

I will have the data for comparison this week. It had a cheapo header and turn signal removed, otherwise legal. The car was able to pull alongside my 99 in the race.

[Brian129]

As is SO common, the Race Monitor results are a complete mess and I can't even find that session. But from what I can find, that was his only decent session and he didn't even run the last race. What happened?

Once upon a time the SCCA recorded qualifying lap records as well as race lap records. If we still had that the 1.6 might hold quite a few, but there's no $5 trophy for Q or even fast race lap.

 

the last race on sunday was a bit of a wet mess.  

it went from a little misting going to grid,  to drizzle, to light rain with moderate rain in different sections of the track.  

Tom had a "this car is for sale" sticker on the front fender,  maybe he didn't want to risk it? 

Edit, : Im a dumb Noob, ill shut up now

 

 

the car was definitely fast!  Nice to see something coming from this all 

[Jim Drago]

Qualifying yesterday at Barber. That #6 car is a 1.6.

That's not a fair comparison... As Tom is a a good driver, the car wasnt torn to pieces and you can argue that track with the hills and elevation favors the 1.6 and everyone knows the 1.6 qualifies well, but he didn't win.