Honda engine management

[JagtechOhio]

That Honda engine picture is pretty cool, it was from Kansas this year according to the file description. If you save it and blow it up, there are some details that you may have known about, but are news to me.

The first is that I haven't yet been able to get a look at the Dallara undertray (except in a CFD video), and at least this shows some of the configuration.

I'm assuming that's the ECM on the back of the airbox: you can see the lambda sensor harness connections, and another harness that looks like it's going to the A bank cam position sensor. Maybe it's for the A bank coils instead, I don't know. Is that the ECM, or just a transponder? During one of the races, a pit reporter mentioned that a car was having a Lambda sensor issue, which showed up on telemetry. I'm guessing that's the ECM, since backing it up against the airbox like that is probably the coolest (in temperature) location you could select on the car.

Sorry, ECM is Jaguar speak for Electronic Control Module, and A bank is the right bank to the Blokes. I don't know any Japanese.

The throttle arrangement is just as rrrr described, at least as much as can be seen before the secrets begin.

Please point out anything else you see, I am curious as to what the gold component is which is just aft of the 180 DEGREE headers.

I recall a brief segment on one of the excellent Versus broadcasts (maybe it was ABC during the 500) where the left sidepod cover had been removed, and things looked pretty busy on that side. The accompanying explanation given was that alot of the onboard electronics were better protected (side facing away from the wall), which sure makes alot of sense.

What surprises me in the photo is that the right side pod looks pretty vacant. I think some similar open wheel chassis designs mount the radiators at an angle, which would permit narrower sidepods IF you had a motivation to modify them. Is there room on the left side to do the same? And yes, I understand the value of weight biasing to the left side for an oval track like Kansas, if in fact that is being achieved by relocating some components to keep the right sidepod empty.

This isn't a parlor game to me, I'm trying to gain understanding about the equipment to proof some specific thoughts I have on modifications to the existing equipment that will improve the competitive balance, without sacrificing top speed or safety.

The parlor game is speculating about all sorts of new goodies that Santa won't be bringing anytime soon. Like new engines and new chassis, and tube frame cars with front engine locations that have room for a fancy set of street racer headers. If that day comes, maybe somebody here can explain to me how to calculate the rarefaction pulse wave length. Until then, it's as meaningless as the price of a turbocharged four cylinder. Now matter how many f***ing camshafts it will have.
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Andrew Bernstein
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[Jakester]

The exhaust now uses 180-degree headers, which are currently manufactured by two firms for Honda.

Please point out anything else you see, I am curious as to what the gold component is which is just aft of the 180 DEGREE headers.

I can point out what I don't see...an exhaust pipe crossing over between the two cylinder banks...which would make them 180 degree headers.

I'm guessing that's the ECM, since backing it up against the airbox like that is probably the coolest (in temperature) location you could select on the car.

The ECM is located in one of the sidepods, which would be quite a bit cooler than under the engine cover.
http://www.aaim1.com/pdfs/anatomy.pdf

[Jag-lover]

The gold component appears to be a heat shield. I noticed that when I zoomed the picture the gold component also goes under the headers. There appears to be either one or two wires leading out of it though. I don't know enough about the engines to hazard a guess on the purpose of the wires.

[JagtechOhio]

I didn't write this line, it is straight from the artice:

"The exhaust now uses 180-degree headers, which are currently manufactured by two firms for Honda."

So we can argue some more semantics, or just call a spade "a spade" and be done with it.

Thanks for the pdf link, there is some relevant information there. I had seen it before and not paid enough attention.

So the electronics in the photograph on the back of the airbox is a transponder, or a junction box?

The schematic in the pdf is not recent, as it shows the earlier headers and no mufflers. Interesting to read that they are quoting 670 HP, that's the highest number I have seen written (the low is 630). The description makes no mention of the paddle shift arrangement, progressively introduced in '08 (?).

So I think this schematic is from like '03, and they are talking about the original Honda 3.5...before it went down to 3.0, and then back up to a new 3.5 when ethanol use was mandated. I don't believe the 670 is a current number.

What else may now be different? Not the basics I would guess, which is about all the schematic shows.

It does show the single radiator. Is that setup utilized for both car configurations? IF you wanted to balance the weight for road courses, or narrow the sidepods, you could divide cooling by placing a smaller one in each sidepod. So that was a help, thanks.

Sure looks like that chassis is set up wrong, though: they're going to eat up tires with that much negative camber.
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Andrew Bernstein

[JagtechOhio]

Yeah Jag, my fault for not explaining it clearly. The component on top of the gold heat shield is what I couldn't make out.

There should be garage pics from Indy somewhere that show greater details, I haven't found them yet.
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Andrew Bernstein

[Jakester]

Sure looks like that chassis is set up wrong, though: they're going to eat up tires with that much negative camber.

<snicker>

Yes, they run that much negative camber. Heck, my mild street alignment on the Miata uses 2 degrees of negative caster.

You should see the oval track setup. The left front has major positive camber.

What do you think the tire life is on these cars? 50-75 miles or so...

[flatlander_48]

Cheers for that Professor,

There's a few answers, thanks. As for questions:

It has to be a four cam, right?

I have read 650, even 670 on Rahal/ Letterman's site (2008). Is 630 HP correct?

I believe the new redline is 10,500 RPM with the overtake assist. Apparently that's a remap to advance ignition timing, enrichment and raise the revs a bit, but that's about the ceiling for this engine. Does that agree with your information?

Thanks for your contribution.

Andy

Seeing as how the engine rules for the IRL have undergone a number of changes over the years: 4.0L, 3.5L, 3.0L, 3.5L; in short, it's been all over the map. With that in mind, it is not unreasonable that someone listed current size, but previous horsepower numbers.

[KenK]

Well, Andrew, I apologize for treating you like you were ignorant, but the way
you worded your question led me to believe you were one of those "one make"
technicians...and your screen name only reinforced that impression.

I've worked with guys who knew one make and were incredibly ignorant of
anything else. One particular guy stands out. He had 20 years experience
in Ford dealerships, Ford training, and never owned anything but a Ford.
When he came to work with us, the boss gave him some other brands to
work on and they may as well have been alien spacecraft. He could not
change a GM starter without help. He could not locate the oil filter on a
Mercedes-Benz. He eventually quit for another job at a Ford dealer.

Obviously, you're not like him.

BTW: we don't have "rubes" on this board, only these:

[JagtechOhio]

KenK,

Duly noted and much appreciated.

The points you inferred previously about the universality of design are true. I have worked exclusively on Jaguars for the last 26 years, but recent designs have evolved to the point that the walls between Jaguar and the rest of the world have eroded. In prior years I worked a fair bit on March, Lola, and Tiga.

As for hardware, I expect the Jag AJ26 pictured previously is very similar in configuration to the Honda HI9R. The major exceptions are that the Jag has Variable Valve Timing (that's the round drum assemblies on the intake cams), a wet sump and a much less rigid cylinder block/ bedplate assembly.

The induction system differences, however, remain a mystery to me. The small block Can Am engines I am familiar with had a mechanical injection system with an electric pump. I am under the impression that the Honda uses a mechanical pump and electronic injection. But many of the other engine management components and functions are probably similar to the Jag V8.

When I can get a look at the new Jag 5.0 L direct injection system, I suspect there will be clues to the Honda setup. Independants like me are outside the Factory loop, and have to do a lot more research to stay current. I ain't there yet, most of my learning is done online and that is how I stumbled in here.

For a minute I was thinking about the Jag as a possible Honda substitute. Apex in England and Rocketsports in the U.S. have done extensive development work with the subsequent Jag 4.2 V8 and now the 5.0 L V8 engines. But the stressed engine configuration of a formula car would require a redesigned block, and would likely result in the addition of a serious amount of "ballast" in the engine bay. There goes that brainstorm, but if I ever get my hands on that Tiga Can Am car I used to know, it won't be Chevy powered anymore.

Back to reality, learning about the Hondas and Dallaras is what I'm after. There is room to modify the characteristics of both to yield better racing. I have my ideas, but no access to information to refine them: more wishful thinking is about all that's in the toolbox.

So I'll hope for other resources to materialize, and photos if I can find them. That's my story: I don't have an axe to grind or a point to prove... until somebody starts sniping, that is. Thanks for holstering your iron.
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Andrew Bernstein

[JagtechOhio]

Reading through this, there's a question that some of you may know the answer to: is the radiator setup changed for road course configuration? I would guess not, they more likely just ballast the car to the right of Cg and equalize the weight. Please straighten me out if you know.

A picture of a car with the right sidepod off at a road course event would help.

Oh yeah, about tires: At least one of the reporters started saying that Briscoe's stagger helped aim him into the pit wall*. I measured alot of bias ply racing tires with a stagger tape, but I would guess that the current radials are built to much closer tolerances. So you'd still want to measure your tires to build sets, but most of the stagger you would have would just be set with pressure differentials. Can anybody inflate my knowledge? Thanks.
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Andrew Bernstein

* I think that's baloney.

[Marc P. Gregoire]

Oh yeah, about tires: At least one of the reporters started saying that Briscoe's stagger helped aim him into the pit wall*.

On the oval tracks, they run a solid spool axle with no differential. There is an amount of stagger built into the rear tires right from the factory, usually between 0.7 and 1". I believe they use something like 0.7" on the superspeedways and at Indianapolis, and the higher stagger tires at places like Richmond.

[JagtechOhio]

Thanks for that, Marc. That's alot more stagger than I would have guessed.

[Marc P. Gregoire]

Thanks for that, Marc. That's alot more stagger than I would have guessed.

It is more stagger than you would have guessed. The stagger range is from 0.32 at Indianapolis to 0.60 at Richmond, with most tracks at 0.45.

[JagtechOhio]

Thanks for the clarification, I was remembering .30 range but it has been quite a long time.

The inconsistancies were alot more apparrent with the older bias ply tires, I suspect. Before breifly working under Mr. Unser, I had never even heared of a stagger tape. The minute I saw the principle, I realized what all the Formula Atlantic and FF drivers were experiencing when they bitc**ed about a bad set of tires. Nobody I had worked with knew the answer, so we'd check corner weight and chase the setup.

Later I'm at the first event for a 5L Can Am car, the practice ends and out comes my stagger tape. The crew chief looks at me and says "We don't do that here".

"We do now", I replied, and started marking tires so I could build sets of scuffs. Then we look down pit lane, and Little Al's Galles crew has the Frissbee jacked up and the stagger tape out.

Our guy finished third in class and spent the rest of the season as a midpack runner at best, but he never had room to blame a bad set of tires. Getting a free ticket to watch Al Holbert, Danny Sullivan and Al Jr. duke it out every race was even more staggering.
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Andrew Bernstein

[sightlines]

Found a few images of Honda Indy engines through Google

Sorry about the size

2008 Engine

[JagtechOhio]

Sightlines,

That's a great shot, thanks!

Amazing to think that a flywheel and clutch that small can handle 650 HP.

That's the Engine Control Module: black cables on top are for each bank of coils, yellow and light blue wrapped harnesses for fuel injectors, yellow caps where lambda sensors connect, three on the left are maybe crank position sensor, coolant temp sensor, oil pressure. Two on the right for fuel pressure monitoring and regulator control?

Vehicle harnesses attach to the empty right side terminals, or the one on top with the red cap?

It didn't seem a good idea to put the ECM in the sidepod, you could get punted during a road race and disable a car even if it was still driveable back to the pits.

Looks like six mounting points at each end, oil cooler hoses to lower RF corner.

Four cams, not much exotic. This is probably as complete as it comes out of the crate from Honda.

I'd guess an hour for a well organized and full crew, 1 1/2 for the real world to do a swap under the gun.

The worst deal with the lease program is that if you wreck your car, you have to buy the engine. And I'd bet they don't let you keep it!

Anybody who can correct any false assumptions in all of that is invited to do so.
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Andrew Bernstein

[Novi-]

Oh, OK. That means a Jaguar V 12 is a single overhead camshaft engine, beacause it has one per bank. News to me, and I've counted an awful lot of pairs of them. Here I thought a single overhead cam engine was an old straight six Pontiac Firebird mill.

Equally enlightening is the Porsche lineage, which I will be anxious to read more about. Please instruct me further, but I was really looking for Honda HI9R information.

Apparently I have more to learn than I thought. Thanks for the help.

Andy

Here's my intro to a SOHC motor:



as in 427 SOHC as it's been known since the '60's. Affectionately called "Cammer" or SOHC (sock) motor.



Currently Ford has a 4.6 known as SOHC with either 2V or 3V heads. There's also a 4.6 DOHC 4V that's in Cobra's and MachI's.

The I6 SOHC that Pontiac first put in the Tempest in '63 IIRC was a POS.

[JagtechOhio]

OK, that satisfies my question about the terminology and makes me a loser in the argument over the semantics of the designation.

If you read all of the preceding posts, you can comprehend the point I was inquiring about, and realize that the whole issue was clarified with the anticipated answer once I had a glimpse of the HI9R photo posted by sightlines.

The straight six Pontiac SOHC engine was a piece of sh*t from everything I have read as well. Mine was a 400, 4 speed.
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Andrew Bernstein

[flatlander_48]

Reading through this, there's a question that some of you may know the answer to: is the radiator setup changed for road course configuration? I would guess not, they more likely just ballast the car to the right of Cg and equalize the weight. Please straighten me out if you know.

A picture of a car with the right sidepod off at a road course event would help.

Oh yeah, about tires: At least one of the reporters started saying that Briscoe's stagger helped aim him into the pit wall*. I measured alot of bias ply racing tires with a stagger tape, but I would guess that the current radials are built to much closer tolerances. So you'd still want to measure your tires to build sets, but most of the stagger you would have would just be set with pressure differentials. Can anybody inflate my knowledge? Thanks.
__________________________________________________ __________
Stay on track
Andrew Bernstein

* I think that's baloney.

Justin Wilson's winning car at Watkins Glen, 2009...

[flatlander_48]

Partially assembled Gear Box innards. Two years ago a technician from Emco told me that a full complement of Gear Box parts was ~$40,000.

[JagtechOhio]

Thanks flat, you're the man.

That looks like a water radiator to me: I think the pipes that run along the top are for the oil cooler that sits in front of it. All guesses though.

The gearbox shot is awesome, now I have a lot more homework to do. Thanks (I think).

[flatlander_48]

Thanks flat, you're the man.

That looks like a water radiator to me: I think the pipes that run along the top are for the oil cooler that sits in front of it. All guesses though.

The gearbox shot is awesome, now I have a lot more homework to do. Thanks (I think).

I believe I have a photo from 2007 of a similar view, but with a full complement of gears. If I find it I will post it...

[rrrr]

Sightlines,

That's a great shot, thanks!

Amazing to think that a flywheel and clutch that small can handle 650 HP.

That's the Engine Control Module: black cables on top are for each bank of coils, yellow and light blue wrapped harnesses for fuel injectors, yellow caps where lambda sensors connect, three on the left are maybe crank position sensor, coolant temp sensor, oil pressure. Two on the right for fuel pressure monitoring and regulator control?

Vehicle harnesses attach to the empty right side terminals, or the one on top with the red cap?

It didn't seem a good idea to put the ECM in the sidepod, you could get punted during a road race and disable a car even if it was still driveable back to the pits.

Looks like six mounting points at each end, oil cooler hoses to lower RF corner.

Four cams, not much exotic. This is probably as complete as it comes out of the crate from Honda.

I'd guess an hour for a well organized and full crew, 1 1/2 for the real world to do a swap under the gun.

The worst deal with the lease program is that if you wreck your car, you have to buy the engine. And I'd bet they don't let you keep it!

Anybody who can correct any false assumptions in all of that is invited to do so.
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Stay on track
Andrew Bernstein

The object in the photo is more of a junction module. Notice the large diameter cable on the left, it goes to the ECM (which is actually two boxes) mounted in the left sidepod. The telemetry modules are in the right sidepod.

The two upper RH cables going into the airbox are the MAP sensor and TPS. The connections on top and on the lower RH side are for the gear position indicator/rear suspension telemetry harnesses IIRC.

Note the radiator expansion tank mounted on the left rear of the tub bulkhead. The radiator is on that side, the oil cooler is on the right hand side. The multistage oil pump is on the right hand side of the engine block. The oil tank is just behind the engine, mounted above the drive centerline.

A complete spare gear stack cost about $28K in 2004-2005. The individual gears were just under a grand each. It's fairly easy to have $50K in the transporter gear drawer. The clutch is a multiplate design having four friction plates and three floaters IIRC.

We did engine changes in 1:10-1:20 with a small but experienced crew. More than once we lit off the car well before other larger and better funded teams. The engines were placed in custom aluminum shipping boxes and sent back to Honda for rebuilds. Back then we got the same three engines in rotation; S/N 007 was a good one!

I will check my photos to see if I have some that will offer better views of how the car is constructed. While my photos are mostly of G-Force and earlier Dallaras, not much has changed in the layout of components in the last five years.

[JagtechOhio]

rrrr,

Thanks a MILLION for straightening out my false assumptions. About the only think I had correct was recognizing the radiator expansion tank.

The oil cooler is larger than I would have expected. I'm guessing the size permits it to be a thinner core and thus creates less drag? Why I'm on about this is I am trying to learn if it would be feasable to narrow the sidepods to a minor extent without re-engineering a great number of components.

Any other information you can provide is greatly appreciated. Why the details of a seven year old spec car should be held as closely guarded secrets is beyond me. Up until now, so have been the details. Thank you for sharing some of them.
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Andrew Bernstein

[rrrr]

rrrr,

Thanks a MILLION for straightening out my false assumptions. About the only think I had correct was recognizing the radiator expansion tank.

The oil cooler is larger than I would have expected. I'm guessing the size permits it to be a thinner core and thus creates less drag? Why I'm on about this is I am trying to learn if it would be feasable to narrow the sidepods to a minor extent without re-engineering a great number of components.

Any other information you can provide is greatly appreciated. Why the details of a seven year old spec car should be held as closely guarded secrets is beyond me. Up until now, so have been the details. Thank you for sharing some of them.
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Stay on track
Andrew Bernstein

A lot of heat is rejected through the oil cooler. I can't recall the oil temp numbers when we warmed the car for a few minutes prior to practice (I want to say 90C), but it climbed quickly. The oil system holds 7-9 quarts.

I don't remember the exact changes the road courses brought to the water and oil heat rejection systems, but obviously they had to be made larger. The size of the duct and the heat exchangers themselves closely mimic the sidepod size and shape. As you can see, the inboard side of the heat echangers are right against the tub. I don't believe there is much that can be done to make them smaller.

[Jakester]

Why I'm on about this is I am trying to learn if it would be feasable to narrow the sidepods to a minor extent without re-engineering a great number of components.

Technically feasible perhaps, but for safety reasons narrowing the sidepods (in vertical or horizontal dimension) is a bad idea. In fact the sidepods were made slightly larger over time for safety reason, both to provide additional crush space and to lessen the chances of one car "overriding" another.

[JagtechOhio]

rrrr,

Thanks again, I noticed the inboard side of the cooler. Wilson's is the road course setup, and is sure looks like it fills the sidepod as you pointed out. The previous small photo of the Kansas car doesn't reveal the size of the oval course oil cooler.

Jakester, I understand your point. It doesn't change the intended effect I am looking at.
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Andrew Bernstein

[JagtechOhio]

Just adding a snippet. This confirms Marc P.'s HP figure of 630, according to Less MacTaggart in August '09:

“The driver is already driving at maximum power and maximum fuel, so he gets an extra five horsepower,” Mactaggart said. “It’s no more than that. If you consider these engines are making 630, five horsepower is not a great deal.”

[JagtechOhio]

Just a couple of footnotes to this discussion:

Speaking with one of the Honda engineers Saturday, it was confirmed that the valve train in the HI9R is not designed to handle RPM's in excess of the current maximum.

I asked one of Patrick's crew about the front camber settings: the car had just been fueled and they were ready to push it into the tech inspection bay. You could see the massive negative camber on the left front. I guessed 3 degrees, he said that was about right and the LF was about plus two. I'm not sure what the banking was at Homestead (I think 26 rings a bell), but it was pretty amazing to stand in turn one and imagine how much the chassis is leaning at speed.

[cleanupcrew]

Just a couple of footnotes to this discussion:

Speaking with one of the Honda engineers Saturday, it was confirmed that the valve train in the HI9R is not designed to handle RPM's in excess of the current maximum.

I asked one of Patrick's crew about the front camber settings: the car had just been fueled and they were ready to push it into the tech inspection bay. You could see the massive negative camber on the left front. I guessed 3 degrees, he said that was about right and the LF was about plus two. I'm not sure what the banking was at Homestead (I think 26 rings a bell), but it was pretty amazing to stand in turn one and imagine how much the chassis is leaning at speed.

camber is all about tire contact patch ... I encourage you to get and read Carrol Smiths great series of books - Engineer to Win, Tune to Win, Prepare to Win etc

both front wheels effectively have "negative" camber when looking at perspective of side loading on an oval ... the purpose is to increase tire conatct patch at speed when large lateral loads are polaced on the tire and it rolls over

You can do a simple but very effective demonstration of this effect ... go grab a lead pencil with a full/new eraser ... hold the pencil perfectly verticle with eraser on the table ... push down on the pencil vertically .... while pushing down try to use your other hand to push the pencil sideways at its base

You will see the eraser rolls over and the flat face lifts up from table ...

Mow hold the eraser with top angled to left slightly .... push down vertically again and then try to push the eraser to right again at its base ...

You will see the eraser still rolls over - but this time as it rolls its face becomes flat with the surface - giving more contact area

here is a graphic I did a while back that shows the effect: