aerodynamics

[madrabbit15]

Of course it is legal to cut the resonator off of the box. You dont even have to use the stock box, its ahead of the air/fuel meter and therefore what you do with it is FREE, as long as the air is coming from the stock location or from inside the engine compartment. If you were not allowed to remove the factory box and/or cut the resonator off, every single car that won the ARRC last year would have been disqualified.

[gran racing]

I probably didn't explain it right...

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Dave Gran
NER ITB #13
'87 Honda Prelude si

[charrbq]

Well, not all that won the ARRC would've been disqualified...at least one class was almost all carberated.

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Chris Harris
ITC Honda Civic

[bldn10]

It was the last generation - the one w/ the big rectangular headlights. I found this description of a popular "cold-air" intake system and it makes some interesting inferences:

"AEM original Cold Air and most Version2 (V2) induction systems relocate the filter outside of the engine compartment for a cooler intake charge, and our Short Ram systems are an economical underhood alternative to our Cold Air systems. We have found that inlet length plays a vital role in the power production of V2 systems and not all V2 induction systems relocate the filter outside of the engine compartment. In these cases, extensive temperature testing was performed to locate the filter in the coolest area of the engine compartment to achieve the lowest inlet temperatures possible."

Now, I understand that it is not the location of the filter that is determinitive, but this suggests that the OEM air does not come from the fender well.

For the benefit of the driver since this is at least a questionable mod and he might not be up on the ITCS, it was a NASA U.S. Touring Car Series Prelude at Mid-Ohio. He ran up front.


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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis

[zracre]

I think the point is that the air filter needs to reside in its origional location (engine compartment) and all air filter accessories and baffles may be removed ahead of the air metering device (on a honda that is the throttle body on some cars it is the mass air sensor) even though you remove the resonators and baffle tubes running all over the front of the car doesnt mean you can relocate the filter to one of these locations. the baffles are attached to the stock airbox, therefore as i read the rules i can remove them....at least thats the way i see it...

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Evan Darling
ITA Integra

[gran racing]

Since we're talking about this... Is it legal to remove a portion of the resonator box; essentially cut the box in 1/2? (The one that is located in the wheel well)

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Dave Gran
NER ITB #13
'87 Honda Prelude si

[zracre]

The way it is described to me...if it is part of the air filtration system (sound resonator box is designed into the air filter system to keep things quiet) it can go as long as it is not in between the air flow meter and the engine (hondas use air density so the throttle body is where the filter starts). I bring my stock air filter "system" with me just in case anyone has questions...fully assembled it is an interesting looking piece...

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Evan Darling
ITA Integra

[bldn10]

Evan, the way I interpret it is this: forward of the metering device you can do anything you want to the intake system but the source of the air has to be either in the engine compartment (which I define as aft of the radiator) or the stock location. Thus, forward of the metering device you can remove, replace, alter, or add any baffles, boxes, resonators, etc. That also means you can relocate the filter (which may or may not be at the end of the line). The only limitations are the source of the air and no "ram air." There is no express prohibition of "cold air" setups.

So, back to the car in question, the issue is whether that model Prelude in stock trim sources intake air from the fender well. If so, then I think what I saw is legal.

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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis

[Roy Dean]

just to set the record straight, zoo's (and my) swift gt(i) has what I believe is the worlds smallest radiator. It takes up maybe 1/3rd of the front of the engine compartment. The ac condenser goes in the other side, but again only takes about 1/3rd of the area. Non-ac equipped cars had no block off plates.

[specialtyautomo]

Acording to Suzuki's factory parts manual non a/c automatic cars had the block off plate for the a/c condensor. My car, which is an 89 came with a/c.I have been racing it since 2000. I also have Taylor Robertsons old car which is a 90 model, it has the block off plate as does two parts cars w/o a/c. Most of the plates rusted at the mounting points and were removed because of noise. I will call the dealer to see if the part number is still avail. They were only held by 3 bolts by the way.

[zracre]

Is that automatics only or does that hold true for manual tranny cars as well?

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Evan Darling
ITA Integra

[specialtyautomo]

It does not specify in the parts manual if it is for auto only. Of the 15 cars we have parted out, three were non a/c cars 2 autos 1 manual. the manual had evidence that one was once there, the 2 autos were still intack though very rusty. Taylors old car came with one installed when I purchased it. Most of the swift gt and gti's sold in the US were auto's. The a/c was a dealer install through adout 1992.

[Knestis]

It just seems massively unlikely that a modern car would come from the factory with the cooling compromised as much as would be the case, were there a huge hole next to the radiator. I don't believe that it's possible.

K

[Roy Dean]

I have never, ever, seen a non-ac car with a block off plate... however I do see that part in the parts book... 72531-60b00... suzukicarparts.com lists it for $32.58.

As for which were sold more in the US, they were most certainly NOT automatics. Of the 5 year (89-94) production for gt(i)'s in the US, the auto was available for only 2 years.

I have been running my 89 gti for 3 years with no overheating issues with the ac condenser removed (and no plate in it's place).... Well, i did have some nuisance overheating from a poorly plumbed heater core, but since fixing that I've been a-ok. I must stress again, this radiator is ludicrously small, and these are all aluminum engines.... overheating is not an issue.

[specialtyautomo]

hmmm. Stepped out, I still see 2 non a/c cars with auto's and the block off plates rusting away. You are correct about the years produced in auto's. I as told by an employee of Suzuki North America {who was very helpful with getting te race car off the ground untill he retired in 01} that the majority were auto's. He also stated that the 89{tub} is the lightest. That did not matter since we already had a low milage 89 to start with. Forgive me if I am wrong I was only quoting from my notes. I have no invetory numbers or sales figures to back up the number of auto's. I have never had an overheating issue with either car one with the block off plate,no oil cooler the other no plate but an oil cooler. Both cars seem to run around 175 to 190 on race days. Seems to be no water temp diff with or w/o.

[H5Civic]

Originally posted by bldn10@Jul 16 2005, 02:58 PM
So, back to the car in question, the issue is whether that model Prelude in stock trim sources intake air from the fender well. If so, then I think what I saw is legal.

This is the '99 Prelude that is prepped for ITS and raced by Brian Shanfeld of Honda of America R&D. I would think that if anyone would know whether or not the stock air box pulled air from the inner fender liner these guys would.
FWIW, I've seen an ITA CRX w/ this same setup, and would have fought me tooth and nail that the "bladder" that is in the stock air box goes thru the hole in lower fender well and therefore the stock air box pulls air from that location and it is legal. IANATI, so I'm not sure how legal it is or not, just a few instances where I've seen the same thing.

Just my $.02.

[bldn10]

Sam, I did not know whose car it was or what his background was - my query was posed mainly because it appeared that the car was a NASA Touring Car Series car getting its first SCCA tech inspection and that the owner simply might not be familiar w/ our rules. In other words, hypothetically, he might know that the stock car does not source air from there but not know that that would not be legal in SCCA. Sounds like it is indeed legal. Anyway, he was fast.