Carburated IT Cars - Balancing the system

[Ron]

I just meant more air and fuel, a few more HP. Sure it will not be as good under the curve a as good ecu set up. I was just looking for a simple and as the ECU guys want a cheaper way. Holley 350's are way cheaper than a good weber set up, jet changes on the outside and parts in every circle track catalog. It is just a quick way to give us old timers something. I don't have an idea for CIS cars, on BMW's we always took off CIS and went to weber side drafts. ( 1970's vintage stuff)

Just to be clear I have no problem with the the new ECU rule. Cheating would be too easy if we went back to the "stock ecu" way. I choose to run a carb because it is simple. I might give up a little but it has been super dependable

[Knestis]

Come on guys... I'm waiting for someone to address this... After all the assurances that there are "limits" and that the playing field will be "more equal/fair"... Please explain to us how "modified or replaced" does NOT mean "add" or "remove"... especially in this context... especially when the rule it's replacing, which is also being used to justify the change, uses that exact same language... Show us where the "limits" are... Please...
[/b]

Sorry, Darin - I got lost. What is the concern exactly? Rule says...

The engine management computer may be altered or replaced. A throttle position sensor and its wiring may be added or replaced. A MAP sensor and its wiring may be added. Other existing sensors, excluding the stock air metering device, may be substituted for equivalent units. ...Wires and connectors in the engine wiring harness may be modified or replaced.

The worry is that someone will use a new combination of wires to come up with a killer system using the stock injectors?

K

[Joe Harlan]

Joe--If there is no allowance for additional wires to the injectors how will it be converted from batch to timed? Only wire I see allowed is for a map and a tps. Am I missing something? Not being a smart--- < just asking.
[/b]

K the response was in regard to this question. The fact is yes there will be some cars that will see large gains. And yes once people start to take hold of "modified or replaced" the will be some interesting arguments over it.

The engine management computer may be altered or replaced. A throttle position sensor and its wiring may be added or replaced. A MAP sensor and its wiring may be added. Other existing sensors, excluding the stock air metering device, may be substituted for equivalent units. ...Wires and connectors in the engine wiring harness may be modified or replaced. [/b]

Stock to what?

[Knestis]

...Stock to what?
[/b]

Que?

Stock to the car in question? I&#39;m afraid I just don&#39;t see where this is headed. Or are you suggesting that the wording invites people to make a case for chucking, say an e36 M3 "air metering device" into their e30 318 ITA car, because "it&#39;s still stock - I haven&#39;t changed it?"

Seriously? Or am I confused.

Even if this IS the point, it&#39;s an enforcement issue at that point - not a rules writing issue.

K

[Joe Harlan]

Que?

Stock to the car in question? I&#39;m afraid I just don&#39;t see where this is headed. Or are you suggesting that the wording invites people to make a case for chucking, say an e36 M3 "air metering device" into their e30 318 ITA car, because "it&#39;s still stock - I haven&#39;t changed it?"

Seriously? Or am I confused.

Even if this IS the point, it&#39;s an enforcement issue at that point - not a rules writing issue.

K
[/b]

So why write a rule that cannot be enforced? I am sure if Dr Amy were feeling playful he could give you more examples. The wiring harness is free now by the replaced rule.

[Eagle7]

So why write a rule that cannot be enforced? [/b]

I&#39;m totally lost, Joe. The proposed rule says you can&#39;t change your air metering device. You&#39;re saying that restriction can&#39;t be enforced? Well if that&#39;s the case, maybe I should take my son&#39;s (joking) advice and put that 350 small block into the RX-7.



On the other hand, if you&#39;re seriously concerned about enforcability issues, requiring a stock ECU with only rechip/reflash allowed would be a nightmare.

[Knestis]

Sorry - not getting how this one in particular "cannot be enforced." And if it&#39;s a blanket statement about enforcement, i don&#39;t know what to tell you. That&#39;s another thread entirely.

And, yeah - the engine harness is free. That should thrill the guys with &#39;70s and early &#39;80s cars that have rot and replacement issues. I&#39;m struggling to see how connecting the stock parts together in some automagical way is going to generate some big gain in power. Even area under the curve, etc., in a way that can&#39;t already be achieved.

OR if you are arguing that the existing rule should never have been made, just stick to that agenda.

K

[Joe Harlan]

Sorry - not getting how this one in particular "cannot be enforced." And if it&#39;s a blanket statement about enforcement, i don&#39;t know what to tell you. That&#39;s another thread entirely.

And, yeah - the engine harness is free. That should thrill the guys with &#39;70s and early &#39;80s cars that have rot and replacement issues. I&#39;m struggling to see how connecting the stock parts together in some automagical way is going to generate some big gain in power. Even area under the curve, etc., in a way that can&#39;t already be achieved.

OR if you are arguing that the existing rule should never have been made, just stick to that agenda.

K
[/b]

Your still right the existing rule should have never been made,

Marty actually if we were to limit to chipping and flashing at least you would be limited to functions that weren&#39;t beyond the stock hardware. So even if you rubbed on it really hard it could do more than the existing hardware it came with. Example: a batch fired ECU does not have the hardware or abilty to be converted to sequential injection. most of these cars cannot do traction control on the stock board. And in the enforcement side a protest can be resolved by opening the box and comparing the hardware to an OE unit.

[shwah]

Joe, you need to stop typing and start printing some money with this new rule! I keep reading your references to building cars for people, but you are perpetually posting on this and other forums. Do you just not sleep, or are there Umpa-Lumpa&#39;s involved?

All joking aside, can someone offer some data on the performance differential between batch fire and sequential fire, at racing engine speeds (lets say 4k up). That would be interesting to see.

[Joe Harlan]

Joe, you need to stop typing and start printing some money with this new rule! I keep reading your references to building cars for people, but you are perpetually posting on this and other forums. Do you just not sleep, or are there Umpa-Lumpa&#39;s involved?

All joking aside, can someone offer some data on the performance differential between batch fire and sequential fire, at racing engine speeds (lets say 4k up). That would be interesting to see.
[/b]

Chris its all of the above. I work all the time don&#39;t sleep and post way too much on this forum. oh and have a couple if lumpa&#39;s the umpa&#39;s wanted to belong to a union... There is lots of decent information all over the web on Sequential V batch fire injection. At peak the gains are small it is from the middle up to peak and how far you can hold peak that makes the largest gains.

[Knestis]

Do we need to set the traction control thing free? It&#39;s my understanding that rev rate-of-increase modules are available and pretty cheap, that can be run within even chip-only rules, just like a rev limiter in even a relatively simple ignition system.

K

[lateapex911]

Fot the umpteenth time, the fear mongerers keep bringing up traction control. TC won&#39;t exist in any form that doesn&#39;t exist now, unless people decide to cheat, and that is a whole different issue.

[Joe Harlan]

Fot the umpteenth time, the fear mongerers keep bringing up traction control. TC won&#39;t exist in any form that doesn&#39;t exist now, unless people decide to cheat, and that is a whole different issue.
[/b]

Jake, to start with im not a fear monger second traction control will be used more than it is now once you make it easy and once you make it part of the FREE ecu how are you goin gto say its illegal? Once it becomes part of the allowed engine management system i don&#39;t think there is anything you can protest.

[shwah]

One reason that it is nice to only be racing an ITB car. I can&#39;t spin the tires in the dry, unless I specifically try to.

Traction control!

On the batch vs. sequential, I was just wondering if anyone here had actual hands on knowledge of the benefit - in our operating conditions. How much hp/tq at which rpms? I understand the theory behind it, but don&#39;t have a good feel for the order of magnatude the difference is.

[jlinfert]

On the batch vs. sequential, I was just wondering if anyone here had actual hands on knowledge of the benefit - in our operating conditions. How much hp/tq at which rpms? I understand the theory behind it, but don&#39;t have a good feel for the order of magnatude the difference is.
[/b]

The biggest benefit of sequential injection is fuel economy. The power/torque improvements are small, 2-3% an average, but are across the entire power band. Some engines do respond better than others and typically an increase in the WIDTH of the powerband is the best thing that happens.

[Banzai240]

The power/torque improvements are small, 2-3% an average, but are across the entire power band. [/b]

Small??? "2-3%" on average "across the entire power band"... (remember "area under the curve"??? )

Let&#39;s see... If a car makes 150hp in IT trim, and can gain a "small" 3% increase in HP, that&#39;s an additional 4.5hp... Spread that across the "entire power band"...

Those cars making 200hp... that&#39;s an additional 6hp...

In ITA, for example... 4.5hp is worth about 65lbs... 6lbs in ITS is good for around 75lbs...

ALL of which seems quite significant to me... And that&#39;s just ONE of the potential benefits of this new open ECU/Wiring rule... as well as just an "average" increase... What hidden gems are still waiting out there to be found... (Here is a hint... NEONs, HONDAs, etc...)


It&#39;s all "fair and balanced", however, because now EVERYONE "get&#39;s" to spend the $1,000+ to do it...

Perfect...

[shwah]

OK - guess I&#39;ll bite.

What I know about sequential injection is that it helps low rpm/idle smoothness, provides small improvement in emissions and economy, and provides very small if any power gain. It has been included in modern production cars for emissions and smoothness.

This is why I was asking if anyone had actual data about batch vs. sequential injection. At the engine speeds we compete at, we are in the meat of the &#39;load table&#39; for our engine. We are at our max duty cycle in terms of injector performance (typically 75-80%). This means that regardless of system, the injector is spraying away on a closed intake port for more time than an open one (what is the average valve open time for a stock cam - 180-220deg? out of a 720deg cycle). If you wanted to try to only spray on an open valve you would need larger than stock injectors to do so, which is not legal.

Basically I don&#39;t buy the claims that this will provide a significant (in racing lap time terms) gain to change from batch to sequential. Not unless we institute a 3000rpm rev limit for all competitors.
EDIT - you also gain the ability to tune the amount of fuel to each individual cylinder... this is the one are that in certain cases of badly balanced intake flow, it is conceivable to me that someone could gain power.

That is what I think, but I don&#39;t have real world numbers to back it up. Can someone chime in and correct me with data?

Of course all of this assumes that the car you are working with has a cam position sensor so that you can properly operate a sequential system.

[Eagle7]

At the engine speeds we compete at, we are in the meat of the &#39;load table&#39; for our engine. We are at our max duty cycle in terms of injector performance (typically 75-80%). This means that regardless of system, the injector is spraying away on a closed intake port for more time than an open one (what is the average valve open time for a stock cam - 180-220deg? out of a 720deg cycle). If you wanted to try to only spray on an open valve you would need larger than stock injectors to do so, which is not legal.

Basically I don&#39;t buy the claims that this will provide a significant (in racing lap time terms) gain to change from batch to sequential. Not unless we institute a 3000rpm rev limit for all competitors.[/b]

[Z3_GoCar]

Besides, as Jake and Josh have said all along, when the class realignment was performed the ECU was open, with only one caviot which was as long as it fit in the stock box and used the stock wire harness/connectors. The hp/torque potential was already adjusted for the difference between EFI and a carburetor. This changes nothing. The odd ball guys should welcome the toss of the stock motor harness. I know of one case where a guy totaled his Z3 because of a burned harness, and this is from a car less than ten years old. Now how about addressing the secondary and terterary computers? You know the computer that runs the ABS and brakes each wheel independantly to keep you out of a skid, operates the pyro&#39;s on the seat-belt tensioners, and fluffs the air-bag for you....

James

[Banzai240]

...when the class realignment was performed the ECU was open, with only one caviot which was as long as it fit in the stock box and used the stock wire harness/connectors. The hp/torque potential was already adjusted for the difference between EFI and a carburetor. This changes nothing. The odd ball guys should welcome the toss of the stock motor harness. [/b]

This is completely absurd, for any number of reasons already mentioned above...

That&#39;s a pretty damn big caviate, dude... The hp/torque potential was adjusted based on an optimized STOCK system... Now with the additional wiring and sensors that can be added, complete reprogramming of the injection sequencing, additional mapping, additional controls, etc... Ya... "nothing changes"...