zip tie mod
Thread Starter
Drifting
Joined: Nov 2014
Posts: 1,977
Likes: 109
From: Switzerland
zip tie mod
as this comes up regularly:
i was doing some logging on a stock configuration/tune and so just for the hell of it i took of the lid of the air box. i checked map at 3000 and 6000 rpm.
well, what do you know, without the mod i lost 0.5 kpa and with the mod i lost 2 kpa. (i was loggging at 10 hz. the data is fluctuating by about +/- 1 kpa. i used a moving average and thats what i got.) conclusion: the effect is zero. your engine doesnt need more air than goes through the smal holes in the lid.
this also nicely shows you dont need a larger throttle body, maf or some "cold air intake" contraption. (iat was at ambient, btw.)
i was doing some logging on a stock configuration/tune and so just for the hell of it i took of the lid of the air box. i checked map at 3000 and 6000 rpm.
well, what do you know, without the mod i lost 0.5 kpa and with the mod i lost 2 kpa. (i was loggging at 10 hz. the data is fluctuating by about +/- 1 kpa. i used a moving average and thats what i got.) conclusion: the effect is zero. your engine doesnt need more air than goes through the smal holes in the lid.
this also nicely shows you dont need a larger throttle body, maf or some "cold air intake" contraption. (iat was at ambient, btw.)
Racer
Joined: Jan 2020
Posts: 275
Likes: 39
love it. I did the same thing after installing an aftermarket air filter assembly. No change in the data. The only reason I installed is my oem box kept popping open and got a deal on the aftermarket piece. Thanks for the science! Just to note the system I installed was not "cold air" or "ram air" so that could be a different analysis.
edit, aslo my car is stock
edit, aslo my car is stock
Drifting
Joined: Mar 2018
Posts: 1,365
Likes: 414
From: New Jersey
as this comes up regularly:
i was doing some logging on a stock configuration/tune and so just for the hell of it i took of the lid of the air box. i checked map at 3000 and 6000 rpm.
well, what do you know, without the mod i lost 0.5 kpa and with the mod i lost 2 kpa. (i was loggging at 10 hz. the data is fluctuating by about +/- 1 kpa. i used a moving average and thats what i got.) conclusion: the effect is zero. your engine doesnt need more air than goes through the smal holes in the lid.
this also nicely shows you dont need a larger throttle body, maf or some "cold air intake" contraption. (iat was at ambient, btw.)
i was doing some logging on a stock configuration/tune and so just for the hell of it i took of the lid of the air box. i checked map at 3000 and 6000 rpm.
well, what do you know, without the mod i lost 0.5 kpa and with the mod i lost 2 kpa. (i was loggging at 10 hz. the data is fluctuating by about +/- 1 kpa. i used a moving average and thats what i got.) conclusion: the effect is zero. your engine doesnt need more air than goes through the smal holes in the lid.
this also nicely shows you dont need a larger throttle body, maf or some "cold air intake" contraption. (iat was at ambient, btw.)
Race Director
Joined: Sep 1999
Posts: 12,435
Likes: 916
From: CONCORD NC
As far as I know I did the first "zip tie mod" in the fall of 1998. you must remember there were ZERO aftermarket parts for the C5, and I was a young engineer playing with a new car. I don't remember all of the data, but I had a rudimentary OBD setup (Autotap) and saw a small pressure AND/OR temperature improvement of the incoming air. Again, no high flow filters, no aftermarket exhausts, nothing....just winging it.
Shortly after, people started chopping up their radiator shrouds and ruining their cooling systems in search of a few HP. I haven't had a street Corvette in Decades, but I definitely enjoyed playing with that car. it was extremely capable and led to me building many dedicated races cars after that!
I'm pretty sure I did a write up for the C5 registry on that mod, and lowering my first C5 back in that era.
Shortly after, people started chopping up their radiator shrouds and ruining their cooling systems in search of a few HP. I haven't had a street Corvette in Decades, but I definitely enjoyed playing with that car. it was extremely capable and led to me building many dedicated races cars after that!
I'm pretty sure I did a write up for the C5 registry on that mod, and lowering my first C5 back in that era.
Safety Car
Joined: Mar 2003
Posts: 4,524
Likes: 372
From: Philadelphia PA
Don’t you need headers, maybe exhaust, and a tune to accommodate a zip tie mod?
That’s like putting a k&n filter in and think you’re getting more horsepower.
Granted I did that on my c4 cuz k&ns were cool back then.
That’s like putting a k&n filter in and think you’re getting more horsepower.
Granted I did that on my c4 cuz k&ns were cool back then.
Thread Starter
Drifting
Joined: Nov 2014
Posts: 1,977
Likes: 109
From: Switzerland
cutting the plastic is even more useless as you destroy an original part and now ingest air not separated from the hot radiator. (i dont think you get warmer air when the car is moving fast but you might if its not.)
almost all intake stuff out there is just misleading the "consumer". not so long ago i figured the ecs dongle on the novi 1500 might be a restriction. i lowered the rad a bit and made myself a piece that had an intake area 2.5 times larger in the bend. effect was exactly zero.
almost all intake stuff out there is just misleading the "consumer". not so long ago i figured the ecs dongle on the novi 1500 might be a restriction. i lowered the rad a bit and made myself a piece that had an intake area 2.5 times larger in the bend. effect was exactly zero.
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Drifting
Joined: Jan 2008
Posts: 1,722
Likes: 138
From: Florida
St. Jude Donor '09
cutting the plastic is even more useless as you destroy an original part and now ingest air not separated from the hot radiator. (i dont think you get warmer air when the car is moving fast but you might if its not.) almost all intake stuff out there is just misleading the "consumer".
Team Owner
Joined: Oct 1999
Posts: 31,976
Likes: 487
From: Guinness Its whats for B'fast JAWGA
CI 3-4-5-9 Veteran
I've witnessed the mod gain a few hp on the dyno multiple times. Logging at cruise I wouldn't expect much of a change.
As with most bolt ons you really need more than just one for the results to snowball.
As with most bolt ons you really need more than just one for the results to snowball.
Last edited by 93Polo; Jan 9, 2023 at 03:18 PM.
Burning Brakes
Joined: Mar 2014
Posts: 807
Likes: 239
I believe cutting the shroud and reversing the filter to be exposed to air from below the shroud, has been dubbed the “Fliptie Mod”. Also the statement that it ingests air not separated from the radiator is false. The radiator is behind the exposed filter and both are exposed to air not heated from the engine compartment as in just doing the Ziptie Mod. The LS 1 in stock configuration is adequately provided all necessary air flow with the stock air cleaner assembly in the stock location. However, it will respond positively to a cooler air charge. Thus exposing the motor to external ambient air, which in most cases is much less than engine compartment temps, will increase power. To what degree depends on operating conditions and ambient air temp. So, in my humble opinion, the Fliptie mod is a worthwhile no cost mod while the Fliptie Mod serves no practical purpose for the reasons cited above. 🙂
Last edited by norcalace; Jan 12, 2023 at 07:36 AM.
Safety Car
Joined: Jan 2012
Posts: 3,956
Likes: 520
From: Da U.P.
Norcalace is right. All the air in the shroud is untainted ambient air. The air behind the radiator is preheated. If you do the fliptie and actually seal it up there should be no adverse effects on engine cooling. Not everyone takes the time to seal the box properly to the shroud, left to flop around the 2 don't line up very well.
Burning Brakes
Joined: Mar 2014
Posts: 807
Likes: 239
Uh the area ahead of the radiator where the stock air cleaner assembly lives is exposed to the atmosphere surrounding the engine. There is a 2-3 inch gap between the radiator cover and the underside of the hood.
Safety Car
Joined: Jan 2012
Posts: 3,956
Likes: 520
From: Da U.P.
I misread your post, agreed that in stock configuration there is cooler air to be found and benefitted from.
Burning Brakes
Joined: Mar 2014
Posts: 807
Likes: 239
I’ll try to take some next time it’s up on the jack. Too low to get my big head under there. I’m running the OEM Delco filter so it’s just a rectangle of pleated white paper. And no I’m not concerned about water intrusion. You’d have to drive into a 12” deep body of water, at speed, to even have a chance of that happening.
Moderator
Joined: Apr 2002
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