Hissing/rattle from 3.5-4k RPM after OFT - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

illmatic_frs · 09-24-2015, 12:33 AM

Hey guys
Running Stage 1 program on the OFT. I have a TRD catback. After 1 tank of gas I've noticed its very nice, open and smooth. Sounds a lot better too.

However from 3.5-4k RPM I notice what sounds like a rattling from under the hood. It's so short in duration thats almost like a hissing sound...

Any thoughts on what this could be? Is it a boxer thing? Airflow changes? Should I be concerned? Any ideas on how I could investigate/check it out further?

Much obliged gents...

Wayno · 09-24-2015, 12:50 AM

AVCS. all vendors do it for stg1 to reduce the dip

Shady195 · 09-24-2015, 10:01 AM

AS stated, its the cam timing. Tuners make it very aggressive to help with the dip. It's a resonance, nothing serious or anything to worry about.

illmatic_frs · 09-24-2015, 11:36 AM

Excellent. thanks for the confirmation
I actually like the sound.. Very addictive :-)

Sent from my HTC One M9 using Tapatalk

kch · 09-24-2015, 11:39 AM

Quote:

Originally Posted by illmatic_frs

Excellent. thanks for the confirmation
I actually like the sound.. Very addictive :-)

Sent from my HTC One M9 using Tapatalk

To expand on the previous answers, the tunes for EL headers (including stock with the OFT stg1) will have that aggressive cam profile. Tunes for UEL headers don't make that noise.

illmatic_frs · 09-24-2015, 11:41 AM

Ahh Ok good to know.

Will gladly exchange the 2 seconds of resonance for some o dat UEL gurgle ;-)

Sent from my HTC One M9 using Tapatalk

Griever423 · 09-25-2015, 09:03 PM

Quote:

Originally Posted by kch

To expand on the previous answers, the tunes for EL headers (including stock with the OFT stg1) will have that aggressive cam profile. Tunes for UEL headers don't make that noise.

The UEL tunes absolutely make the same noise. Mine does it right at the same RPM the OP mentioned. Emails to Shiv confirmed this. Running OFH and OFT.

Basically it's nothing to worry about. It's pretty annoying though.

kch · 09-28-2015, 12:19 PM

Quote:

Originally Posted by Griever423

The UEL tunes absolutely make the same noise. Mine does it right at the same RPM the OP mentioned. Emails to Shiv confirmed this. Running OFH and OFT.

Basically it's nothing to worry about. It's pretty annoying though.

Weird. I had the noise when i was on stg1 with stock header, but now that I'm on stg2 with a catless UEL, the noise is gone.

Griever423 · 09-30-2015, 10:52 PM

Quote:

Originally Posted by kch

Weird. I had the noise when i was on stg1 with stock header, but now that I'm on stg2 with a catless UEL, the noise is gone.

I'm not running an OP or catback. Maybe it's just more audible since there isn't as much noise?

steve99 · 10-01-2015, 12:43 AM

Quote:

Originally Posted by Griever423

The UEL tunes absolutely make the same noise. Mine does it right at the same RPM the OP mentioned. Emails to Shiv confirmed this. Running OFH and OFT.

Basically it's nothing to worry about. It's pretty annoying though.

I would check you actually running the UEL tune as the cam timing are different in the UEL tune so it should not make the raspy noise arround 4000.like the EL header tune or stage 1 tune.

The noise may also be the overpipe or some other exhaust component loose or hitting on subframe or skid plate or plug up the sound tube

breadcrumbz · 10-01-2015, 01:59 AM

I've been running stage 1 oft tune for about half a tank and haven't noticed any noise difference in my nameless axleback. Only difference I can feel is maybe a little smoother 1st gear. Will the car and exhaust be feel and sound smoother after a full tank?? Also, the dead pedal effect is still slightly there, but not as bad as right after a fresh flash.

Griever423 · 10-01-2015, 11:53 PM

Quote:

Originally Posted by steve99

I would check you actually running the UEL tune as the cam timing are different in the UEL tune so it should not make the raspy noise arround 4000.like the EL header tune or stage 1 tune.

The noise may also be the overpipe or some other exhaust component loose or hitting on subframe or skid plate or plug up the sound tube

I have wondered about the rattle. Maybe it's time to get the car back up on the lift.

themajesticone · 10-02-2015, 12:04 AM

There's a snake in your boots

Griever423 · 10-02-2015, 10:18 PM

Quote:

Originally Posted by steve99

I would check you actually running the UEL tune as the cam timing are different in the UEL tune so it should not make the raspy noise arround 4000.like the EL header tune or stage 1 tune.

The noise may also be the overpipe or some other exhaust component loose or hitting on subframe or skid plate or plug up the sound tube

Checked last night and it is the UEL stg 2 tune. Running the Grimmspeed intake so no sound tube. The noise is definitely metallic in sound. There is some hissing noise too but normal for an aftermarket header from what I can tell. The metallic rasp is what bothers me. It's pretty loud. It's noticeable upon acceleration but VERY noticeable upon decel.

09-24-2015, 12:33 AM	#1
illmatic_frs Senior Member Join Date: Oct 2014 Drives: n/a Location: GTA Posts: 157 Thanks: 105 Thanked 55 Times in 42 Posts Mentioned: 3 Post(s) Tagged: 0 Thread(s)	Hissing/rattle from 3.5-4k RPM after OFT Hey guys Running Stage 1 program on the OFT. I have a TRD catback. After 1 tank of gas I've noticed its very nice, open and smooth. Sounds a lot better too. However from 3.5-4k RPM I notice what sounds like a rattling from under the hood. It's so short in duration thats almost like a hissing sound... Any thoughts on what this could be? Is it a boxer thing? Airflow changes? Should I be concerned? Any ideas on how I could investigate/check it out further? Much obliged gents...

09-24-2015, 12:50 AM	#2
Wayno Senior Member Join Date: Apr 2014 Drives: Toyota 86 GTS Location: Australia Posts: 1,129 Thanks: 453 Thanked 895 Times in 424 Posts Mentioned: 211 Post(s) Tagged: 0 Thread(s)	AVCS. all vendors do it for stg1 to reduce the dip __________________ rom downloads, information and examples Toyota 86 GTS OFT - Guide To Dialling In OTS Base Tune OFT - Example Alternate Maps for AT, 98RON, E85, MAF Scales

10-02-2015, 12:04 AM	#13
themajesticone Senior Member Join Date: Jun 2014 Drives: '13 UM86 Location: Bay Area, California Posts: 406 Thanks: 338 Thanked 176 Times in 112 Posts Mentioned: 4 Post(s) Tagged: 0 Thread(s)	There's a snake in your boots __________________ JRSC C30 91 oct \| JDL UEL Header \| Tomei Overpipe \| Milltek Front Pipe \| Milltek Catback \| SPL LCA v2 \| FA 500 v5 Coilovers 6k/7k \| SPC Front Camber Bolts \| Enkei RPF1 17x9 +35 \| 245/40 Michelin Pilot Super Sport

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09-24-2015, 10:01 AM	#3
Shady195 Senior Member Join Date: Jun 2014 Drives: '13 10 Series FRS #1203 Location: Albany, NY Posts: 850 Thanks: 7 Thanked 386 Times in 221 Posts Mentioned: 5 Post(s) Tagged: 0 Thread(s)	AS stated, its the cam timing. Tuners make it very aggressive to help with the dip. It's a resonance, nothing serious or anything to worry about.

09-24-2015, 11:36 AM	#4
illmatic_frs Senior Member Join Date: Oct 2014 Drives: n/a Location: GTA Posts: 157 Thanks: 105 Thanked 55 Times in 42 Posts Mentioned: 3 Post(s) Tagged: 0 Thread(s)	Excellent. thanks for the confirmation I actually like the sound.. Very addictive :-) Sent from my HTC One M9 using Tapatalk

09-24-2015, 11:41 AM	#6
illmatic_frs Senior Member Join Date: Oct 2014 Drives: n/a Location: GTA Posts: 157 Thanks: 105 Thanked 55 Times in 42 Posts Mentioned: 3 Post(s) Tagged: 0 Thread(s)	Ahh Ok good to know. Will gladly exchange the 2 seconds of resonance for some o dat UEL gurgle ;-) Sent from my HTC One M9 using Tapatalk

10-01-2015, 01:59 AM	#11
breadcrumbz Member Join Date: Dec 2014 Drives: 2013 FR-S 6MT Location: SoCal Posts: 66 Thanks: 25 Thanked 23 Times in 11 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	I've been running stage 1 oft tune for about half a tank and haven't noticed any noise difference in my nameless axleback. Only difference I can feel is maybe a little smoother 1st gear. Will the car and exhaust be feel and sound smoother after a full tank?? Also, the dead pedal effect is still slightly there, but not as bad as right after a fresh flash.

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