3.5.3.9 Air Intake and Fuel System Location Requirements

[raska]

All parts of the fuel storage and supply system, and all parts of the
engine air and fuel control systems (including the throttle or carburetor,
and the complete air intake system, including the air cleaner and any air
boxes) must lie within the surface defined by the top of the roll bar and
the outside edge of the four tires (see figure 8).

Any portion of the air intake system that is less than 350 mm (13.8
inches) above the ground must be protected by the same rules in Side
Impact Structure.


It shouldn't be a issue for us, since we have 2 plans for it (one would have the exhaust 'break' the rule the other wouldn't), but what do you guys think of this rule and a turbo? When does the "complete air intake system" stop? Is the full exhaust system part of this, or does it stop at the back plate of the compressor housing, or what? If it continues up to the air filter, and for maximum safeties sake, I would assume the complete intake included the full exhaust system, since any exhaust impact could effect the air intake.

[raska]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">All parts of the fuel storage and supply system, and all parts of the
engine air and fuel control systems (including the throttle or carburetor,
and the complete air intake system, including the air cleaner and any air
boxes) must lie within the surface defined by the top of the roll bar and
the outside edge of the four tires (see figure 8).

Any portion of the air intake system that is less than 350 mm (13.8
inches) above the ground must be protected by the same rules in Side
Impact Structure.
</div></BLOCKQUOTE>

It shouldn't be a issue for us, since we have 2 plans for it (one would have the exhaust 'break' the rule the other wouldn't), but what do you guys think of this rule and a turbo? When does the "complete air intake system" stop? Is the full exhaust system part of this, or does it stop at the back plate of the compressor housing, or what? If it continues up to the air filter, and for maximum safeties sake, I would assume the complete intake included the full exhaust system, since any exhaust impact could effect the air intake.

[Dave M]

It never states exhaust, nor does it imply it. The exit should be outside of the main structure for fumes and packaging. We havent run into any problems with this rule and exhaust. We have changed our intake to accomodate these rules though.

[Garlic]

Like Dave said, rule doesn't say anything about exhuast. There are different rules on height and rear protuberance for that.

[rjwoods77]

The whole intent of that rule is to make sure if you roll over, no part of the intake will rip off of bend that would shoot fuel up your canadian ass.So keep that in mind. The exhaust doesnt have to be like that but i wouldnt leave it to a judge to say " well if you roll over , your turbo will bend into your intake, rip it off...."

[raska]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rob Woods:
The whole intent of that rule is to make sure if you roll over, no part of the intake will rip off of bend that would shoot fuel up your canadian ass.So keep that in mind. The exhaust doesnt have to be like that but i wouldnt leave it to a judge to say " well if you roll over , your turbo will bend into your intake, rip it off...." </div></BLOCKQUOTE>

That's pretty much exactly why I asked this question because I realize the rule is in place to prevent damage to the intake system from roll over, or impact of any sort whether it be front cones or other. So the exhaust could have an effect on the intake system in a turbo car. You could bolt the turbo to the chassis, and claim that it will no longer have an effect on the intake, but bolting the throttle body to the chassis and having the air filter stick out is not acceptable, so I'm not sure if this would be either.

[rjwoods77]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by raska:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rob Woods:
The whole intent of that rule is to make sure if you roll over, no part of the intake will rip off of bend that would shoot fuel up your canadian ass.So keep that in mind. The exhaust doesnt have to be like that but i wouldnt leave it to a judge to say " well if you roll over , your turbo will bend into your intake, rip it off...." </div></BLOCKQUOTE>


It can stick out. Just not past the line between the top of the cage and the wheel ground contact. I see lots of people trying to "put the air filter in the air stream" to get clean air or a ram effect but I really think it is useless. Bolt the turbo to the frame and you will have one hot frame section.

That's pretty much exactly why I asked this question because I realize the rule is in place to prevent damage to the intake system from roll over, or impact of any sort whether it be front cones or other. So the exhaust could have an effect on the intake system in a turbo car. You could bolt the turbo to the chassis, and claim that it will no longer have an effect on the intake, but bolting the throttle body to the chassis and having the air filter stick out is not acceptable, so I'm not sure if this would be either. </div></BLOCKQUOTE>

[Buckingham]

In addition to the fuel leaking, the rule also is written to intend that if you rollover, the throttle won't get knocked off and let the engine go WOT.

[Alexandre D.]

I think it's also in case you hit a cone. A lot of teams use butterfly throttle body that are accessible from outside and it can be a major safety issue.

For us this rule is a major problem. Even if our admission is protected by a triangulated structure and not using a butterly, it's not inside our side impact structure and it's way below 350mm.

What if the air intake is behind the side impact structure? The rule is not exactly clear. I've sent a few questions about the rules to officials but I'm still waiting for answers.

Anyone has been more succesful than me?

[Matt Gignac]

I sent an email to the rules committee for a clarification to this rule as well. With our current setup, we'd be able to just raise it by approx 1 inch to meet the requirement of the rules, unless the compressor is considered part of the intake system (which I imagine it will probably be the case).

And also, the side impact rules specify that the tubes in question must be between both hoops... so how would we accomplish this behind the main hoop? This is another specification I asked for.

I'll post here any specifications I get.

Matt Gignac
McGill Racing Team

[Alexandre D.]

Anyone has news from the rule committee...? I've never dealt with them before, how does it take?

[Alexandre D.]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Dear Alexandre,

Your question is similar to one we got from Matt Gignac of McGill. So, we will give you the answer we gave Matt, and then answer your specific questions.

This was sent to Matt:
"Good questions. In answering them, we have to go back to the intent of this new rule, the third paragraph of 3.5.3.9. The Rules Committee has seen an increasing number of teams with their air intake systems running forward from the engine, down low alongside the driver, sometimes in a side pod, sometimes not, right in an area of potential side impact. If an impact into one of these systems should occur, we would immediately stand the chance of a rupture of the intake system downstream of the throttle body and an instant WOT. The Committee decided that the intake systems should either be out of the potential impact area or be protected. Hence this new rule.

Therefore, to answer your questions:
Question 1: Is the compressor is considered part of the intake system, and thus subject to the rules?
Answer 1: In so far as the turbo's compressor is a part of the air intake system and has ducting from the restrictor attached to it, AND acknowledging that the integrity of the joint between the ducting and the compressor must be maintained, the answer has to be "yes, the compressor is a part of the intake system and must comply with this rule."�

Question 2: Does the whole intake system have to be above the limit set, or if the intake centerline were above this height would be sufficient?
Answer 2: The answer to the first part of your question is "Yes. The whole intake system needs to be more than 350 mm above the ground to comply."� Having the centerline above this height is not sufficient. If the latter were allowed, one could theoretically have a component that is 600 mm in diameter which could take it to within 50 mm of the ground!

Question 3: If we were to keep the intake at its current height, but design a structure around the intake meeting side impact requirements, how far rearward would this structure have to go? Would it be acceptable if this structure were to double as the engine mounts at the front, or should we make it go back all the way to the rear sub-frame?
Answer 3: Sorry, without a detailed review of your design, we cannot answer this particular question. You may be able to answer this yourself based on the intent of the rule. If not, would you send us drawings or photos of your installation. From them we should be able to give you a better answer (we cannot promise). A quick look of the photos we have of your 2005 car doesn't give us any clues."�

Now your own questions where they are different.
Q 1: Must the air intake be in the SIS or in a structure serving similar goal for the air intake?
A 1: Yes. It must either be above or inside the SIS, or protected from side impact by a structure built to the same specifications. That is the intent of the rule.

Q 2: If a safety equivalency report must be made, what are the requirements? Integrity of the air intake during a side impact, integrity of the structure during a rollover, or something else?
A 2: Integrity during side impact. Integrity during a roll over is covered by the first paragraph of Rule 3.5.3.9 and Figure 8. Show equivalency to the SIS requirements given in 3.3.8. Nominally, 3 tubes of 1.00"� OD x 0.065"� wall.

Q 3: What if a part, or the whole intake, is behind the SIS?
A 3: If by "behind"� you mean rearwards, see the answer to Matt's question 3 # above.

Q 4: If I understand the goal of this rule correctly, I see very little problem with our current chassis as our air intake is well protected by a triangulated structure protecting it from rollover or cone impact. Unfortunately, it does not meet wall thickness and geometry requirements of the SIS.
A 4: The protection of the intake system on your 2005 car, as shown in the photo you attached, will almost suffice. The air cleaner and the throttle body are well protected. If you add one tube across the middle of the bay rearwards of the main roll hoop to protect the turbo compressor to inlet ducting junction, and make the tubing the correct size, you will meet the new rule.

Rules Committee,
FSAE
</div></BLOCKQUOTE>

[raska]

Thanks for posting that Alexandre. So although they don't spell out where the intake system begins and ends in terms of a turbocharger, the bottom line is, as the rules committee responded in your post, "Integrity during side impact" of the intake system is the intent of this rule. So I wouldn't want to show up with a design where a side impact of any part of the car (I'm mainly thinking of an exhaust-intake coupled system with a turbo) could have obviously consequences of the integrity of the intake system.

[Alexandre D.]

Yeah... well the rule is not really clear. With this answer, it's pretty clear that the turbo must be protected even if it's rearward the SIS. I would interpret it as a 1X0.065 protection too...

We're going to do some major chassis modifications that were planned for the 2007 car. It means that some senior design members will cut into some unessential projects... I wish they will apply this rule this year because I would be mad if they just let everyone pass the tech inspection because the rule is new.

While I totally agree with the intent of the rule, I think they might have gone too far. There are teams with totally unprotected admissions, no pods, no structure. This is extremely dangerous. A simple cone impact could mean WOT. But to require 0.065 tube everywhere may be a bit too much (at least for a single rule change).