Spec Miata Community   
search | help | calendar | games | forum home

  next oldest topic   next newest topic
» Hello Spec Miata Community » Spec Miata Archives » Garage 2002-2009 » Need help with dyno results

 - Email this page to someone! | Subscribe To Topic  
Author Topic: Need help with dyno results
Teamfour Verified Driver Made Donation to Website
Member

Region: WDCR
Car #: 04
Year : 1993
Posts: 519
Status: Offline
Icon 1 posted  Profile for Teamfour   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

Took the car to the dyno today. The Dynojet equipped shop specializes in Chevy tuning, so the operator really couldn't help much with analyzing the results or suggesting adjustments other than timing. In fact I actually sat behind the wheel for the pulls since the operator didn't want to climb into the car.

Engine background: 1.6 crate motor with maybe 20 hours on it, Sutton intake, SD exhaust, ART tuned AFM. Timing set initially at 14 and moved to 16 for third pull.

The bad: the best pull I could get was 109hp and 102tq. The AFR seemed to start lean and ended up at 12.6 from 4500 rpm to redline.

Is there anyone willing/able to take a look at the Dynojet files to maybe point me in the right direction or offer a reason for the low hp? Obviously the easy answer is a pro motor, but Santa isn't that nice to me.

Also, I have noticed an antifreeze smell after running th motor hard ever since I bought the car. I have never been able to find a leak. Past experience tells me there is the possibility of a head gasket issue, but it would seem the dyno results would be even worse. Anyway, a leakdown test is in order.

--------------------
Lee Tilton
1993 Meowta #04
Brimtek Motorsports/ Team Four Racing
Team Four Racing

Jamie Tucker Series Champ

ARRC 2010 Champ

Region: CFR
Car #: 97
Year : 1990/99
Posts: 788
Status: Offline
Icon 1 posted  Profile for Jamie Tucker     Edit/Delete Post  Report this post to a Moderator

Lee,
If you would like to PM a copy of your dyno run I will take a look at it for you. I own a dynojet as well. The timing you have seems correct although to get it perfect you would have to start at 13 and slowly move up until you found the max power. Even then you are only looking at a 1 to 3 HP swing. The AFR issue is normal as a 1.6 will start at a leaner AFR and richen up as they increase in RPM. At the very top of the rpm you will see a dip where it goes very rich quickly. Thats why there are people who Mod the MAF; which is very easy to see on a dyno and not legal. 109 HP is right in the ballpark for a crate engine. PM me with your spark plug type (and numbers), what filter you are running, and the fluid types in your car and I will take a look and see if I can get you a few more HPs. Your tq of 102 is very good for a crate. I usually will see 102 to 105 for a promotor. As far as the fluid I doubt you have a head gasket issue. What kind of radiator do you have? Is its cap new! Do you have a real water temp instrument or just the factory Mazda one and what are you using for coolant.

--------------------
2010 ARRC Champion
2010 CFR Champion
2010 instigator of the year
2010/2011 Andrew Von C Wingman

fleming Made Donation to Website
Member

Region: northeast
Year : 90
Posts: 162
Status: Offline
Icon 1 posted  Profile for fleming     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Teamfour:

Also, I have noticed an antifreeze smell after running th motor hard ever since I bought the car. I have never been able to find a leak. Past experience tells me there is the possibility of a head gasket issue, but it would seem the dyno results would be even worse. Anyway, a leakdown test is in order.

I had this problem, everytime I got out of the car I could smell coolant. On colder days, it was worse, thought I had pickup a hitchhiking
Ms. Butterworth. Did several pressure tests, never found the culprit, had the car on a lift running, nothing dripped. The thermostat/heat gauge never hit the middle or above. Finally, took my car to Windsor customs, Chris found the
problem(s), every hose had to be replaced and
the thermostat housing was replaced. Plus the heater box hose connection had to be fixed due to the connection wasn't round anymore. So no
more coolant smell.

--------------------
"where one ends, one shall begin".

trimless1 Verified Driver Made Donation to Website
Low Budget Member

Region: Southwest
Car #: 11
Year : 99 and 93
Posts: 347
Status: Offline
Icon 1 posted  Profile for trimless1     Edit/Delete Post  Report this post to a Moderator

Lee,

Those dyno numbers are not bad at all. The HP figure is about average for the 1.6 crate but the torque number is very good.

You can most likley get the HP up a bit with more tuning and taking some advice of the folks here. I think you know that seat time will reduce you lap time much more than a few HP so I won't bother to tell you that [Smile]

Good luck on chasing down the collant issue, doesn't sound like a major problem.

--------------------
Gale Corley
99 SM GRE Super Deluxe
93 SM GRE Jr. Deluxe

Tyler Dahl Verified Driver Series Champ
Member

Region: Utah
Car #: 70
Year : 1991
Posts: 169
Status: Offline
Icon 1 posted  Profile for Tyler Dahl     Edit/Delete Post  Report this post to a Moderator

Hey Jamie, what is illegal about adjusting the AFM on a 1.6 to smooth the A/F if it is open?

--------------------
Tyler Dahl
Race Engineering
Miatacage.com
Carbotech

Blake Clements Verified Driver Series Champ
MegaModerator

Region: SW - Houston
Car #: 6
Year : 99, 96
Posts: 2262
Status: Offline
Icon 1 posted  Profile for Blake Clements   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Tyler Dahl:
Hey Jamie, what is illegal about adjusting the AFM on a 1.6 to smooth the A/F if it is open?

Where does the rules say the AFM is open? The AFM can only be ADJUSTED, not modified like Jamie is talking about.

--------------------
Blake Clements

PhillipsRacePrep/SP Induction Systems/East Street Racing/MiataCage.com/Carbotech/WBR Graphics

www.blakeclements.com

Tyler Dahl Verified Driver Series Champ
Member

Region: Utah
Car #: 70
Year : 1991
Posts: 169
Status: Offline
Icon 1 posted  Profile for Tyler Dahl     Edit/Delete Post  Report this post to a Moderator

Sorry Blake I meant, you can open and adjust, what modification are you talking about Jamie.

--------------------
Tyler Dahl
Race Engineering
Miatacage.com
Carbotech

Jamie Tucker Series Champ

ARRC 2010 Champ

Region: CFR
Car #: 97
Year : 1990/99
Posts: 788
Status: Offline
Icon 1 posted  Profile for Jamie Tucker     Edit/Delete Post  Report this post to a Moderator

Tyler the rule is as follows,
GCR 9.1.8. Spec Miata Class Specifications
3. 1.6L cars may open and adjust, but not modify, the OEM airflow meter. For 1.6L cars, the position of the air flow meter may be moved provided it remains attached to the unmodified factory intake tube.

There are people and engine builders that modify the AFM in order to maintain a flat AFR throughout the entire RPM range; which is much different from adjusting the spring in order to move the whole curve up or down in the same shape. Depending on how its done it may be very easy to see or it may take a little time. The down and dirty method is 2 fold. First if someone tells you to run their AFM because it will add HP; you may want to investigate it further. Second take the intake tube off the AFM and push on the flapper (as I call it) and if it moves very easily (like the spring is no longer doing anything) than it has most likely been modified. They can even be heard sometimes depending on the car (but not always). If a person is running that AFM this year they are asking to be DQed. Too many people know where they come from and it is too easy to detect. Thanks for asking!

--------------------
2010 ARRC Champion
2010 CFR Champion
2010 instigator of the year
2010/2011 Andrew Von C Wingman

AllardK3 Verified Driver Made Donation to Website Series Champ
Member

Region: Az
Car #: 13
Year : 1993
Posts: 59
Status: Offline
Icon 1 posted  Profile for AllardK3     Edit/Delete Post  Report this post to a Moderator

Wouldn't lowering the spring tension fall safely under the term "adjust"?

As long as no new parts are added, I would call it adjusting. Has anyone actually been DQ'd for this before?

Thanks,
Mike

--------------------
Mike Donick

AllardK3 Verified Driver Made Donation to Website Series Champ
Member

Region: Az
Car #: 13
Year : 1993
Posts: 59
Status: Offline
Icon 1 posted  Profile for AllardK3     Edit/Delete Post  Report this post to a Moderator

double post.

--------------------
Mike Donick

Richard Pressman Verified Driver Made Donation to Website
Veteran Member

Region: WDC
Car #: 87
Year : 1991
Posts: 520
Status: Offline
Icon 1 posted  Profile for Richard Pressman     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by AllardK3:
Wouldn't lowering the spring tension fall safely under the term "adjust"?

I don't think so.

The spring you are referring to is not meant to be adjustable. It is manufactured with a certain wind, tension and length. Changing any of those would be considered a modification, not an adjustment.

The spring under the removable cover is meant to be adjusted. There is a ratchet held in place by a screw just for that purpose. That is an adjustment since the spring itself is not being permanently altered.

At least that's the way I see it. [twocents]

CP Verified Driver
Member

Region: NER
Car #: 7
Year : 1999
Posts: 636
Status: Offline
Icon 1 posted  Profile for CP   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

Man, you 1.6 guys have all the fun in your garages "adjusting" your cars between races. I can't do jack to my 99 8^(

--------------------
-Cy
Supported by LTD Racing & Speed Shack - New England's Premier Auto Accessory Store
Rt1 AutoMile - Norwood, MA
http://www.speedshackonline.com

Jamie Tucker Series Champ

ARRC 2010 Champ

Region: CFR
Car #: 97
Year : 1990/99
Posts: 788
Status: Offline
Icon 1 posted  Profile for Jamie Tucker     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Richard Pressman:
quote:
Originally posted by AllardK3:
Wouldn't lowering the spring tension fall safely under the term "adjust"?

I don't think so.

The spring you are referring to is not meant to be adjustable. It is manufactured with a certain wind, tension and length. Changing any of those would be considered a modification, not an adjustment.

The spring under the removable cover is meant to be adjusted. There is a ratchet held in place by a screw just for that purpose. That is an adjustment since the spring itself is not being permanently altered.

At least that's the way I see it. [twocents]

Thats the way I see it as well but the mods that I am talking about actually require a soldering gun to be used before you unwind the spring. It is not the unwinding of the spring that is illegal, it is what's done that allows you to unwind the spring that is.

--------------------
2010 ARRC Champion
2010 CFR Champion
2010 instigator of the year
2010/2011 Andrew Von C Wingman

AllardK3 Verified Driver Made Donation to Website Series Champ
Member

Region: Az
Car #: 13
Year : 1993
Posts: 59
Status: Offline
Icon 1 posted  Profile for AllardK3     Edit/Delete Post  Report this post to a Moderator

Jamie and Richard,
I agree with you guys about the intent of the rule, but per the wording I think one could make a case for "adjusting" other things. Does anyone know of a DQ or ruling on this item.

Thanks,
Mike

--------------------
Mike Donick

Shop Teacher
Member

Region: SF Nor Cal
Car #: #39
Year : 1990
Posts: 457
Status: Offline
Icon 1 posted  Profile for Shop Teacher     Edit/Delete Post  Report this post to a Moderator

I had a car that had a lack of HP and tracked it down to the fuel pump. later i found out that all of the front runners change their fuel pumps every year. It made a night and day differance.

--------------------
Al Angulo
Auto Instructor
Ford Senior Master Tech
ASE Master Tech

cam Verified Driver
Cheap member

Region: southwest
Car #: 14
Year : 90
Posts: 739
Status: Offline
Icon 1 posted  Profile for cam   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Shop Teacher:
I had a car that had a lack of HP and tracked it down to the fuel pump. later i found out that all of the front runners change their fuel pumps every year. It made a night and day differance.

But doesn't that imply that the AFR is going lean at the top end? From what I've read on this thread, it is too rich at the top end, implying that either his AFM is off or there is an intake restriction, or that is an exhaust restriction. But it is the torque values that throws me off, that motor has great torque. So then it makes me wonder about the shop he did this testing at. Misleading test results can be worse that no test results. Just thinking out loud, good luck Lee, you might consider a shop that has done other Miatas. If you do not want to go all the way to Hallet, then there are several in the Houston area that can help.

--------------------
"The problem with Socialism is that you eventually run out of other people's money."
~Prime Minister Margaret Thatcher
"A government big enough to give you everything you want, is strong enough to take everything you have."
~Thomas Jefferson

Teamfour Verified Driver Made Donation to Website
Member

Region: WDCR
Car #: 04
Year : 1993
Posts: 519
Status: Offline
Icon 1 posted  Profile for Teamfour   Author's Homepage     Edit/Delete Post  Report this post to a Moderator

Thanks for all the postings. I have expressed elsewhere my lack of confidence in this dyno shop. I really need a place that will make sure I test properly, but not necessarily hold my hand. Sam Henry told me the four pulls I made didn't really get close to warming up the drive train. I would think an experienced dyno operator would at least voice that opinion knowing that I had not been on a dyno before. Not pointing fingers here; I take full responsibility for not being prepared going in, but still....

I am willing to pay for the time it takes to do the recommended 30-35 pulls for a proper test session. But that requires the dyno operator to be dedicated to the time I paid for, not wandering around tuning Chevy pickups in between pulls.

I do have a bad rattle in the muffler and am wondering if the exhaust is restricted. Another item for the todo list.

--------------------
Lee Tilton
1993 Meowta #04
Brimtek Motorsports/ Team Four Racing
Team Four Racing

Shop Teacher
Member

Region: SF Nor Cal
Car #: #39
Year : 1990
Posts: 457
Status: Offline
Icon 1 posted  Profile for Shop Teacher     Edit/Delete Post  Report this post to a Moderator

the o2s is what tells the ECU to rich lean. It cycles hundreds of times a minute. If you have low fuel pressure the o2s are going to tell the ECU to richen up. when the ECU has seen it has not it will set that as max.

--------------------
Al Angulo
Auto Instructor
Ford Senior Master Tech
ASE Master Tech

Cajun Miata Man Verified Driver
Overdog Driver

Region: Houston; SWDIV
Car #: 15
Year : 99
Posts: 680
Status: Offline
Icon 1 posted  Profile for Cajun Miata Man     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Shop Teacher:
the o2s is what tells the ECU to rich lean. It cycles hundreds of times a minute. If you have low fuel pressure the o2s are going to tell the ECU to richen up. when the ECU has seen it has not it will set that as max.

I believe, at wide open throttle, the ecu goes open loop and the O2 feedback is not utilized for controlling the AFR.

--------------------
James York


sponsored by:
Stan's Auto Center, Lafayette LA
powered by:
East Street Racing, Memphis TN
set up guru:
Gilfus Racing, Austin TX

Shop Teacher
Member

Region: SF Nor Cal
Car #: #39
Year : 1990
Posts: 457
Status: Offline
Icon 1 posted  Profile for Shop Teacher     Edit/Delete Post  Report this post to a Moderator

You believe wrong, If the ECU went into open loop at WOT it couldnít control timing and other functions. Open loop is only used during warm up. That is why the ECT is so important. This is very easy to check if you hook up your Miata to the factory NGS with a Mecs on OBDI and right to the DLC on 1996 on. I have one and used it every day for over 20 years with Ford/Mazda. Iíve seen it using PID monitor. You should know this being you drive a OBDII 1999. Check your manual its all in there. Check Fuel pump pressure is just one of many possibilities and it is really easy. im out on this subject. Buena suerte

--------------------
Al Angulo
Auto Instructor
Ford Senior Master Tech
ASE Master Tech

Cajun Miata Man Verified Driver
Overdog Driver

Region: Houston; SWDIV
Car #: 15
Year : 99
Posts: 680
Status: Offline
Icon 1 posted  Profile for Cajun Miata Man     Edit/Delete Post  Report this post to a Moderator

WOW, I didn't mean to hit a nerve and get a acronym filled reply. It is possible I am incorrect but since you are out on this subject I won't debate. I'll check my manual for my 99.

--------------------
James York


sponsored by:
Stan's Auto Center, Lafayette LA
powered by:
East Street Racing, Memphis TN
set up guru:
Gilfus Racing, Austin TX

Keith in WA Verified Driver Made Donation to Website
Pack Fodder

Region: NWR / Oregon
Car #: 88
Year : 95
Posts: 2000
Status: Offline
Icon 1 posted  Profile for Keith in WA     Edit/Delete Post  Report this post to a Moderator

Lee,
If you want to be sure you don't have a head gasket issue causing that coolant smell, do a quick combustion gas test on the cooling system. The "block test" kits are less than $50 and it only takes a couple mins. I couldn't find one at most auto parts stores but NAPA usually has them in stock. If you don't find a leak than at least you have some extra piece of mind.

--------------------
Keith Novak
(Will work for tires)

Jamie Tucker Series Champ

ARRC 2010 Champ

Region: CFR
Car #: 97
Year : 1990/99
Posts: 788
Status: Offline
Icon 1 posted  Profile for Jamie Tucker     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by Shop Teacher:
You believe wrong, If the ECU went into open loop at WOT it couldnít control timing and other functions. Open loop is only used during warm up. That is why the ECT is so important. This is very easy to check if you hook up your Miata to the factory NGS with a Mecs on OBDI and right to the DLC on 1996 on. I have one and used it every day for over 20 years with Ford/Mazda. Iíve seen it using PID monitor. You should know this being you drive a OBDII 1999. Check your manual its all in there. Check Fuel pump pressure is just one of many possibilities and it is really easy. im out on this subject. Buena suerte

Shop teacher on 1.6 the o2 does nothing at WOT. It tells the ECU nothing and the car will run exactly the same with or without the o2 hooked up. We have dynoed 1.6s both ways and it makes no difference. On 1996 or later cars I have no idea but the 02 on a 1.6 has a very limited function at idle. On my 99 it made no difference either so I suspect they work like the 1.6 but I don't know for sure. They are not wideband o2s so I am not sure how they would do anything at WOT anyway.

--------------------
2010 ARRC Champion
2010 CFR Champion
2010 instigator of the year
2010/2011 Andrew Von C Wingman

Jamie Tucker Series Champ

ARRC 2010 Champ

Region: CFR
Car #: 97
Year : 1990/99
Posts: 788
Status: Offline
Icon 1 posted  Profile for Jamie Tucker     Edit/Delete Post  Report this post to a Moderator

quote:
Originally posted by AllardK3:
Jamie and Richard,
I agree with you guys about the intent of the rule, but per the wording I think one could make a case for "adjusting" other things. Does anyone know of a DQ or ruling on this item.

Thanks,
Mike

Mike the rule is very clear; no gray area here. You cannot modify the MAF period! Adjusting does not mean you can put new pieces in, take out parts that are there, or change what their functions are.

--------------------
2010 ARRC Champion
2010 CFR Champion
2010 instigator of the year
2010/2011 Andrew Von C Wingman

   

   Close Topic   Feature Topic   Move Topic   Delete Topic next oldest topic   next newest topic
 - Printer-friendly view of this topic | Subscribe To Topic
Hop To: