268 replies to this topic

[MPR22]

Jason thermocouple in middle of air flow.
 
Thank you folks. Because according to some of you folks, it does zero good so ya'll wouldn't mind if I leave my wrapped plastic tube in  place. I'm also going to procure an aluminum flywheel because those in the know say there's minimal value. You all wouldn't care about a header because in the past, over and over people said, no value. And a thinner head gasket may be over the top but a bit more compression is about to join the party. It these items don't help we'll do an honest 10:1.
 
There's a 1.8 NA and a couple 99's from his past Sunday wondering what happened to their straight line suspensions.
 
Nuff on this subject, because ya'll say whatever ya'll all say and it don't do nutten anyway.
 

 
 
 
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I think what people are trying to do is find the real cause of the EXTREME rise in temps from intake to the throttle body. It is highly unlikely that it's heat transfer through the intake tube. The physics just don't support it. If the 1.6 is experiencing this increase in air temps the. The cause should be identified and a real solution proposed. Do any of us care if the tube is wrapped, probably not , will it help you , probably not

Instead of attacking those that are questioning the cause of the temp increase, use them to help identify the problem. Get them to agree to helping reduce intake temps. It would be unfair for a 1.6 to suffer from 20-30 degrees of higher intake temps vs other models.

[Bench Racer]

Potential other theories could be the thermocouple/multi-meter or my data system which is my eyes and memory.

Michael, ^ sometimes folks forget to mix in my humor. Also a potential cause ^ of for the higher temperature. Some frugal/poor folk don't have data recorders.

[MPR22]

Michael, ^ sometimes folks forget to mix in my humor. Also a potential cause ^ of for the higher temperature. Some frugal/poor folk don't have data recorders.

I think the subject if worth exploring on multiple cars of each model and see if there is significant delta T on throttle body temperatures.  If it is caused by the water jacket on the 1.6, which I suspect it is, then can we block/bypass it and test.  

[Tom Hampton]

I have the inputs available on my g2x and can instrument it with a few thermocouples. I may be able to get that done before msrh next month.

[mhiggins10]

I have the inputs available on my g2x and can instrument it with a few thermocouples. I may be able to get that done before msrh next month.

 

If you can tell me how to do this, I'm happy to take data as well.  I have the basic installation done on my g2x (no extra inputs- just the standard tach connection) and an intermediate knowledge of 12v automotive wiring (my days as a young kid with a loud stereo may come in handy here...)

[OctaneNation]

The voltage of the AFM thermistor should also be logged to see if anything funky is happening versus the thermocouples.

[Tom Hampton]

The voltage of the AFM thermistor should also be logged to see if anything funky is happening versus the thermocouples.

Tapping into ecu sensors is risky. Parasitic leakage can perturb the ecu measurement. Has anyone tapped into the thermistor with success? Besides, I'd rather know the flapper door position.

[OctaneNation]

Tapping into ecu sensors is risky. Parasitic leakage can perturb the ecu measurement. Has anyone tapped into the thermistor with success? Besides, I'd rather know the flapper door position.

 

As long as the impedance is large enough then tapping into them shouldn't pose a problem. I've done some logging of the flapper door position on a Dynojet. In one session I did back-to-back tests with 1) hood open, 2) hood closed to safety catch, and 3) hood closed to safety latch with rad fan turned on. Coolant temp was constant (~180F). If anything the last test showed the flapper slight *more* open, and the AFR went slightly richer on each test. Peak power went from ~120 to ~116 to ~113.

 

I did some more research on the AFM and it's widely referred to as a Air Flow meter, and not a Mass Air Flow meter. I don't understand how the flapper wouldn't respond to the density of air. So the temp sensor is key for the ECU density calculation. 

[Tom Hampton]

Uh, yes thanks. I've been an electrical engineer for the better part of a quarter century. Input impedance is only part if the equation, ecu measurement circuitry plays a big role too. 1989 technology is a long way from 2015...i was there. So, without knowing the input circuitry Tapping into it is risky.

I also spent a number of years as an engineer at a firm designing mass flow meters for industrial process and control applications, specifically for gas measurement. Its not that the flapper is immune to air density, it's a question of sensitivity. In the range we are interested the flapper is largely a velocity measurement device similar to a turbine. Besides, All mass flow measurement techniques are inherently inferential and generally require a secondary correction due to one variable or another.

[OctaneNation]

Uh, yes thanks. I've been an electrical engineer for the better part of a quarter century. Input impedance is only part if the equation, ecu measurement circuitry plays a big role too. 1989 technology is a long way from 2015...i was there. So, without knowing the input circuitry Tapping into it is risky.
 

I'm a ME with a bit of EE knowledge... What are the risks? 

 

After one AFM adjustment I noticed the AFM voltage was all over the place, bouncing erratically and not a smooth line as before. It made a bit of a difference in the power curve but it didn't run nearly as poorly as you'd expect. I carefully bent the wiper to make better contact and the signal cleaned right up. Given this I think the ECU does a lot of averaging of input signals.

 

I also spent a number of years as an engineer at a firm designing mass flow meters for industrial process and control applications, specifically for gas measurement. Its not that the flapper is immune to air density, it's a question of sensitivity. In the range we are interested the flapper is largely a velocity measurement device similar to a turbine. Besides, All mass flow measurement techniques are inherently inferential and generally require a secondary correction due to one variable or another.

I can make spring or wiper change and see a very noticeable change in AFM voltage. But a change in the hood opening (inlet temp) which reduced power by 6% was barely registered on the AFM. That's what surprised me.

 

How is altitude density corrected for if the AFM largely measures velocity?

[Bench Racer]

How is altitude density corrected for if the AFM largely measures velocity?

The atmospheric pressure sensor is built into the ECU.

[Tao]

hi all,  thought I would weigh in here,

I race a 1.6 in the SFR and IMO it needs a lot of help......when I can go in, thru and out of the corners as

well as some of the front runners but am 2-3 seconds off the "pace" per lap there is a reason.

I don't have a pro built engine but I do what I can;   change fluids, set up the car before every race and I don't race on tires past their prime.

I love the racing and there is always someone to race with but any chance of doing respectfully well at the run-offs or even getting on the podium in the regional races is not going to happen with the 1.6

 

Speaking for myself only...I would gladly invest $2 - $3000 for higher compression, headers, some head

machining etc..   to make my 1.6 more competitive.....rather than spend $10,000 on a pro built motor or

$12,000 plus to build a N/B

QUESTION:     when my motor was in its prime it dyno'ed around 117 hp, which I though was pretty good..

                      HOW ARE YOU GUYS GETTING UPTO   125 HP?????

please reply here or to my personal e-mail......thanks

 

 

[steveracer]

I don't have a pro built engine but I do what I can;   

QUESTION:     when my motor was in its prime it dyno'ed around 117 hp, which I though was pretty good..

                      HOW ARE YOU GUYS GETTING UPTO   125 HP?????

please reply here or to my personal e-mail......thanks

 

Answered your own question, didn't you?

[steveracer]

At minimum, you need a pro prepped head on a fresh bottom end.

 

And an AFPR, a tuned AFM, and dyno time.

[chris haldeman]

hi all, thought I would weigh in here,
I race a 1.6 in the SFR and IMO it needs a lot of help......when I can go in, thru and out of the corners as
well as some of the front runners but am 2-3 seconds off the "pace" per lap there is a reason.
I don't have a pro built engine but I do what I can; change fluids, set up the car before every race and I don't race on tires past their prime.
I love the racing and there is always someone to race with but any chance of doing respectfully well at the run-offs or even getting on the podium in the regional races is not going to happen with the 1.6

Speaking for myself only...I would gladly invest $2 - $3000 for higher compression, headers, some head
machining etc.. to make my 1.6 more competitive.....rather than spend $10,000 on a pro built motor or
$12,000 plus to build a N/B
QUESTION: when my motor was in its prime it dyno'ed around 117 hp, which I though was pretty good..
HOW ARE YOU GUYS GETTING UPTO 125 HP?????
please reply here or to my personal e-mail......thanks

This is the exact reason the 1.6 gets no help. Guys not willing or able too do what is already legal asking for hp help. This likely represents the vast majority of 1.6 owners right now. Very few guys have spent the money and time too even try too get the power availible too the 1.6 now. Some how the people who can't afford or just plain won't spend the money and time feel the need too get a special allowance performance wise. Please stop posting about cars that are not prepped fully needing help you are only hurting the vast efforts of the people trying too help the car. I'm sorry if this sounds mean. It is just how it is. 1.6 car could use at most a perceived torque boost either a flywheel as some suggest or the 4.44 rear gear. Personally I have mentioned the rear gears many times in the past and feel it is the best answer. Tho I think that 4.44 is availible only for the larger torsen diff from Mazda. Not sure if there are aftermarket 4.44 gears availible for the small 1.6 diff

[Jim Drago]

hi all,  thought I would weigh in here,

I race a 1.6 in the SFR and IMO it needs a lot of help......when I can go in, thru and out of the corners as

well as some of the front runners but am 2-3 seconds off the "pace" per lap there is a reason.

I don't have a pro built engine but I do what I can;   change fluids, set up the car before every race and I don't race on tires past their prime.

I love the racing and there is always someone to race with but any chance of doing respectfully well at the run-offs or even getting on the podium in the regional races is not going to happen with the 1.6

 

Speaking for myself only...I would gladly invest $2 - $3000 for higher compression, headers, some head

machining etc..   to make my 1.6 more competitive.....rather than spend $10,000 on a pro built motor or

$12,000 plus to build a N/B

QUESTION:     when my motor was in its prime it dyno'ed around 117 hp, which I though was pretty good..

                      HOW ARE YOU GUYS GETTING UPTO   125 HP?????

please reply here or to my personal e-mail......thanks

I have to agree with Chris here... When people are talking help.. we talking tenths per lap or doing the exact same lap times in a more similar manner.  Being 2-3 seconds off lies squarely in driver and/or car prep. BTW you pro built engine prices are almost double what most pro builders charge.

[Bench Racer]

TAO, without the torque and horsepower numbers similar to a pro motor your complaining being off 2-3 seconds per lap off is wasted energy. I own a 1.6, MazdaComp LS diff and SCCA legal 2275 pounds and am off by 3-4 seconds. The seconds off issue is the 73 year old spacer between the seat and steering wheel. That being said, the 1.6 does require a torque bone or two.  

 

Joe Dad, pretty quite. 

[Steve Scheifler]

Irresistible opportunity to agree with Jim, Chris and Bench all at the same time. (That alone should tell you something!)

Tao, I've already made it clear that I think parity potential matters even for people not able to run at the front for whatever reasons, but I hope I've been clear that I mean equally prepared and driven cars. Of course that's hard enough to judge at the front and just about impossible toward the back, but my point is that we shouldn't just write off the 90+% of cars/drivers who can't win a majors as irrelevant, and therefore conclude that 1.6 parity no longer matters.

That said, what we are talking about here is fine tuning on the order of perhaps a couple tenths of a second per lap minute or better low-end grunt out of corners. If you are 2-3 seconds off the pace at an average track then you have much bigger issues than the rules. In power terms that's WAY more than the difference between a bone stock crate engine and a "pro" unless we're talking about someplace like Daytona and you can't even hold a draft. Bottom line, either the car is a real mess or the driver is not getting nearly all there is out of it. Most likely some of each.

My advice would be to start by getting help with going through your car mechanically and putting a good basic setup on it ACCURATELY. If you can get on a dyno that already does other SM cars then sure, before your next event check the power and tune a bit if possible. Just keep in mind that even the 7-8 hp you think is missing are not going to improve your times by whole seconds. If you don't run any kind of data acquisition, beg borrow or buy whatever someone much faster runs if they are willing to share. It is very common to think we are fast out of the corners only to have unbiased data prove that we are wrong. If you can get a good setup and collect data, it might be most instructive of all to have someone who runs at the front drive your car one session. There is always a risk with that, but they don't need to go at 10/10ths qualifying speed to record a couple solid laps for you to work from.

[Tom Scheifler]

What Steve said but adding I disagree with Chris that Tao "is the exact reason the 1.6 gets no help". Faulty reasoning by some does not mean you can ignore everyone else.

[Ron Alan]

Tao my friend...see what happpens when you poke the nest??

Granted...SCCA we haven't had many top 1.6 drivers in the last couple years in SFR. That said...when they were winning with "pro" motors and well prepped cars no one was making over 120hp on our local dynos. A couple that did or were seeing 105+ torque numbers didn't stick around long. Polsley, Holifield, Makishima, Loustanaou and the Oregon crew among others were winning with power you had. The difference has always been what fills the space between the seat and steering wheel!

The difference among the guys up front can be attributed to power or one mistake...the difference betwween the front pack and the mid pack guys is mostly driving skill IMO.

This debate is about tenths not seconds...so I to must agree with the pack who is chasing you out of the forest