Hoping these will solve my low powerband... - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

RealQuick · 11-01-2016, 11:24 AM

As you recall I have been to the dyno 3 times previously... each time making progress, but trying to resolve issues. I run 93 octane and 100% meth.

Car has heads/cam (in N/A form peak power was at 6200-6300rpm).

Car now has Huron Seed Single Turbo kit with PTE 7675 with 3" DP into dual 2.5" exhaust.

Dyno sessions:
1st time - burnt plug wire but made (8-10psi) 608rwhp/571rwtq and making peak power between 5800-6000rpm

2nd time - burnt three plug wires but made (655rwhp/725rwtq) with boost falling off from 15psi to 11psi and making peak power @ between 5200-5600rpm (flat spot)

3rd time - car ran great but made (703rwhp/762rwtq) with boost falling off from 16psi to 12psi and making peakpower again between 5200-5600rpm

In my mind, there is a restriction, so i have done two things:
1) removed the 5.5 long conical air filter.
2) Added electric cutouts

As far as #1, I know it helped as my street logs show less boost falling off up top.

What does everyone think about the cutouts... I couldnt find a spot for them on the downpipe due to the WB O2 location, so they are on the peipes where the old bullet mufflers used to be (currently connects the the Huron Speed Y-pipe).

What kind of gains you think i would see with these two mods?

jeff657756 · 11-01-2016, 11:55 AM

I'm interested in the results.

bayarea408 · 11-01-2016, 11:56 AM

i use the same turbo, same kit. I planned on putting a single 3" cutout right at the end of the first downpipe pipe after the turbo. I got lazy and just decided to dump it right there under the front of the driver seat with a turn down, Boost comes on IMMEDIATELY. Running cutouts that far back i dont think will yield that great of a gain its still going through a neck down 2.5".

What plug wires did you end up using? After a few trials with custom plug wires, and stock plug wires i ended up following what was recommended and bought the PCM of NC wires and they fit perfect.

RealQuick · 11-01-2016, 02:20 PM

Quote:

Originally Posted by bayarea408

i use the same turbo, same kit. I planned on putting a single 3" cutout right at the end of the first downpipe pipe after the turbo. I got lazy and just decided to dump it right there under the front of the driver seat with a turn down, Boost comes on IMMEDIATELY. Running cutouts that far back i dont think will yield that great of a gain its still going through a neck down 2.5".

What plug wires did you end up using? After a few trials with custom plug wires, and stock plug wires i ended up following what was recommended and bought the PCM of NC wires and they fit perfect.

I didnt want to put it on the single DP because it might play havoc with the wideband. Hopefully I see an improvement. The nice part is with the flip of a switch I can make back to back runs and see if the cutouts helped.

Oh, and taylor 10.4mm wires with 45 degree boots.

1KillerSS · 11-01-2016, 03:49 PM

Quote:

Originally Posted by RealQuick

What does everyone think about the cutouts... I couldnt find a spot for them on the downpipe due to the WB O2 location, so they are on the peipes where the old bullet mufflers used to be (currently connects the the Huron Speed Y-pipe).

What kind of gains you think i would see with these two mods?

Cutouts are good for 30 to 40whp from what I have seen. However what cought my attention is the boost fall off, I would resolve that before I start chasing other things. Also, you could relocate your O2 sensor bungs.

RealQuick · 11-01-2016, 07:57 PM

Quote:

Originally Posted by 1KillerSS

Cutouts are good for 30 to 40whp from what I have seen. However what cought my attention is the boost fall off, I would resolve that before I start chasing other things. Also, you could relocate your O2 sensor bungs.

I think I resolved a lot of the boost issue by ditching the filter. A good sign of restriction is when these motors make more tq than hp... Not to mention peak power being so low (which nets less power than tq).

Ls1408cp · 11-02-2016, 11:37 AM

I think this kit around 700 needs a cutout to not kill topend. I plan on doing one on the dp right next to the rear of the engine. I plan on having a built shortblock by spring I'm hoping to get around 900rwhp.

RealQuick · 11-02-2016, 11:47 AM

Quote:

Originally Posted by Ls1408cp

I think this kit around 700 needs a cutout to not kill topend. I plan on doing one on the dp right next to the rear of the engine. I plan on having a built shortblock by spring I'm hoping to get around 900rwhp.

I agree.

I think 900rwhp is gonna be tough to hit with a 7675. You plan on using a 88mm?

Here are the installed pics. I still need to mount and wire the switch within the cockpit.

Trackman · 11-02-2016, 09:26 PM

The 76/75 made 900rw on my little 4.6. The trouble with it is the exhaust turbine chokes it and creates to much back pressure. You might be getting valve float.

fif_gen_powa · 11-02-2016, 10:04 PM

Cutouts look good and will certainly help along with not running a filter as well. At the end of the day the 3" downpipe is the bottle neck. 3" can only move x amount of air no matter how big a turbo is before it or how free flowing the exhaust is after it. Think of the guys with twins or SC guys running long tube headers most are working with two 3" collectors abilty to move twice the amount of exhaust flow

Curious to see results for reference I just made 816 on 15psi but waste gate is dumped to atmosphere, which IMO is another big problem being recirculated in an already small downpipe.

SeaCompiler · 11-02-2016, 11:45 PM

I am considering putting in a single 4" exhaust connected directly from my downpipe around where the O2 bung exists and running it straight to the rear axle before branching off to two x 3 inch pipes for exit. I wonder if that would be just as good as a cutout without all the weight of cutouts and dual exhaust?

RealQuick · 11-03-2016, 07:53 AM

Quote:

Originally Posted by Trackman

The 76/75 made 900rw on my little 4.6. The trouble with it is the exhaust turbine chokes it and creates to much back pressure. You might be getting valve float.

I hope it isn't valve float... But something to check. Advanced Inductions set up the heads knowing it was going on a boosted vehicle, so hopefully there is some safety factor built into the installed height/seat pressure.

fif_gen_powa · 11-03-2016, 09:11 AM

Guys tap a pressure gauge to check if back pressure is excessive, I've seen it done both pre and post turbine

RealQuick · 11-03-2016, 09:24 AM

Quote:

Originally Posted by fif_gen_powa

Guys tap a pressure gauge to check if back pressure is excessive, I've seen it done both pre and post turbine

Yeah, winter project for sure. BTW, awesome numbers you made! Where is your peak power happening at?

11-02-2016, 11:37 AM	#7
Ls1408cp Drives: 14 1le turbo Join Date: Oct 2015 Location: Ofallon Mo Posts: 159	I think this kit around 700 needs a cutout to not kill topend. I plan on doing one on the dp right next to the rear of the engine. I plan on having a built shortblock by spring I'm hoping to get around 900rwhp. __________________ 2014 1LE 2SS/RS Huron Speed turbo kit

11-02-2016, 10:04 PM	#10
fif_gen_powa Drives: 2013 Camaro SS Turbo Join Date: Apr 2014 Location: South Florida Posts: 1,525	Cutouts look good and will certainly help along with not running a filter as well. At the end of the day the 3" downpipe is the bottle neck. 3" can only move x amount of air no matter how big a turbo is before it or how free flowing the exhaust is after it. Think of the guys with twins or SC guys running long tube headers most are working with two 3" collectors abilty to move twice the amount of exhaust flow Curious to see results for reference I just made 816 on 15psi but waste gate is dumped to atmosphere, which IMO is another big problem being recirculated in an already small downpipe. __________________ 388ci 91/104 Turbo TH400 8.3@164 https://instagram.com/turbo_ls3/

11-02-2016, 11:45 PM	#11
SeaCompiler ...not a marine biologist Drives: 2012 Camaro RY SS LS3 Join Date: Mar 2013 Location: Clarkesville, GA Posts: 752 View My Garage	I am considering putting in a single 4" exhaust connected directly from my downpipe around where the O2 bung exists and running it straight to the rear axle before branching off to two x 3 inch pipes for exit. I wonder if that would be just as good as a cutout without all the weight of cutouts and dual exhaust? __________________ Forged 416 stroker Turbocharged with Huron Speed with Cam Motion custom grind,Tuned by Vengeance, 8psi, 25% PowerBond UDP, Ported TB, shaved heads, LS9 gaskets, chromoly pushrods, BT trunnions & dual valve springs, IWIS, Might Mouse CC, SJM Line Lock,, MSD 2-Step, ZL1 Rear End, ZL1 spoiler, Strut Brace, ARP bolts, Skip shift elim, A-Pillar Gauges, FR Style 41 20X10, 3 inch exhaust, blackouts, Lowered, Custom badges, Hines vents,RPI fender vents, Technostalgia Tail Lights, Metra Kit, Pioneer stereo, Morimoto RGB Halos, "The Great Awakening" on gab.com

11-03-2016, 09:11 AM	#13
fif_gen_powa Drives: 2013 Camaro SS Turbo Join Date: Apr 2014 Location: South Florida Posts: 1,525	Guys tap a pressure gauge to check if back pressure is excessive, I've seen it done both pre and post turbine __________________ 388ci 91/104 Turbo TH400 8.3@164 https://instagram.com/turbo_ls3/

11-01-2016, 11:24 AM	#1
RealQuick Drives: 2010 Camaro 2SS M6 - Intake/Exhaust Join Date: Sep 2014 Location: Bridgewater Posts: 693	Hoping these will solve my low powerband... As you recall I have been to the dyno 3 times previously... each time making progress, but trying to resolve issues. I run 93 octane and 100% meth. Car has heads/cam (in N/A form peak power was at 6200-6300rpm). Car now has Huron Seed Single Turbo kit with PTE 7675 with 3" DP into dual 2.5" exhaust. Dyno sessions: 1st time - burnt plug wire but made (8-10psi) 608rwhp/571rwtq and making peak power between 5800-6000rpm 2nd time - burnt three plug wires but made (655rwhp/725rwtq) with boost falling off from 15psi to 11psi and making peak power @ between 5200-5600rpm (flat spot) 3rd time - car ran great but made (703rwhp/762rwtq) with boost falling off from 16psi to 12psi and making peakpower again between 5200-5600rpm In my mind, there is a restriction, so i have done two things: 1) removed the 5.5 long conical air filter. 2) Added electric cutouts As far as #1, I know it helped as my street logs show less boost falling off up top. What does everyone think about the cutouts... I couldnt find a spot for them on the downpipe due to the WB O2 location, so they are on the peipes where the old bullet mufflers used to be (currently connects the the Huron Speed Y-pipe). What kind of gains you think i would see with these two mods? Attached Images

11-01-2016, 11:55 AM	#2
jeff657756 Drives: 2014 SS 1LE Join Date: Apr 2014 Location: United States Posts: 660	I'm interested in the results.

11-01-2016, 11:56 AM	#3
bayarea408 Drives: T Join Date: Mar 2015 Location: CA Posts: 803	i use the same turbo, same kit. I planned on putting a single 3" cutout right at the end of the first downpipe pipe after the turbo. I got lazy and just decided to dump it right there under the front of the driver seat with a turn down, Boost comes on IMMEDIATELY. Running cutouts that far back i dont think will yield that great of a gain its still going through a neck down 2.5". What plug wires did you end up using? After a few trials with custom plug wires, and stock plug wires i ended up following what was recommended and bought the PCM of NC wires and they fit perfect.

11-02-2016, 09:26 PM	#9
Trackman Drives: 67RS Camaro ,Black 2013 ZL1 Join Date: Jun 2010 Location: Alberta Posts: 1,408	The 76/75 made 900rw on my little 4.6. The trouble with it is the exhaust turbine chokes it and creates to much back pressure. You might be getting valve float.