LT2 intake primary cat removed v4 Big Knock Performance

Kerry · 02-25-2021, 09:26 PM

Just a heads up that if you have the lt2 intake with primay cats removed when the car coast a little in v4 then step on the gas slightly normal driveing gets huge knock like 8 deg retard. All stock car and tune. Turn off v4 problem completly goes away.

Removed cats not a lot of difference in feel and 0-60 and 100 might have done just a little better. There was no loss of power in low end. It felt to my butt dyno improved every where.

I then added the lt2 intake. Picked up .2 in 0 to 60 and 1.2 seconds to 100. Impressive!! Air denesty went from -500 before parts test to 600 + wth the mods so. This is a bone stock car with stock tune. afr went slightly richer from the normal 12.5 to about 12.3. It does have the nitto 2 305 35s. Stock 275s are well junk.

Then in normal driveing was getting the crazy big knock when doing the v4 stuff. Also makes a different noise when it goes into v4. Like a baffeling sound. the v4 valves closeing no doubt cause it would go very quite even when I use the foerenz thing to open the valves. With cats you do not hear that sound.

Turned v4 off and all knock completly went away. I would say NOT fake. So just a heads up from my experience.

After i put on the lt2 when I hit it felt much stronger.

Edit I mis spoke on the times
0-60 stock 4.1 to 100 9.7. Thats with the nitto 2 stock tires are about 4.5 lots of spin. This is all useing launch control default settings for consistancey.
Gutted primary cats 4 and 9.6 that could be just run difference. Their was no loss in bottom end.
LT2 3.8 and 8.8 still impressive and noticeable stronger.
Then stock stage 2 procharger was 3.6 and 7.6 thats the 1.2 second. Opps. Showing 6.5 pds at stock shift point.

Also with those mods my injecter was going near 7 micro second or what ever and rail pressure was dropping to 1800 psi. So defentaly more air flow and out of fuel with the base procharger. I will get the meth working before I run it any more and get the duty cycle down.

Trochoidal · 02-25-2021, 10:30 PM

Good feedback. Did you have stock or ported LT1 before doing the swap?

Kerry · 02-26-2021, 03:13 AM

Stock

Kerry · 02-26-2021, 03:31 AM

Question with primary cats removed it is some louder. Not crazy but some. What would happen if I removed the secondary. Would power go up? How much Louder? 10% 30?

Pendelton · 02-26-2021, 05:47 PM

Did you stock the LT1 before the trade?

02-25-2021, 09:26 PM	#1
Kerry Drives: 2019 2SS Camaro Join Date: Apr 2012 Location: Al Posts: 828	LT2 intake primary cat removed v4 Big Knock Performance Just a heads up that if you have the lt2 intake with primay cats removed when the car coast a little in v4 then step on the gas slightly normal driveing gets huge knock like 8 deg retard. All stock car and tune. Turn off v4 problem completly goes away. Removed cats not a lot of difference in feel and 0-60 and 100 might have done just a little better. There was no loss of power in low end. It felt to my butt dyno improved every where. I then added the lt2 intake. Picked up .2 in 0 to 60 and 1.2 seconds to 100. Impressive!! Air denesty went from -500 before parts test to 600 + wth the mods so. This is a bone stock car with stock tune. afr went slightly richer from the normal 12.5 to about 12.3. It does have the nitto 2 305 35s. Stock 275s are well junk. Then in normal driveing was getting the crazy big knock when doing the v4 stuff. Also makes a different noise when it goes into v4. Like a baffeling sound. the v4 valves closeing no doubt cause it would go very quite even when I use the foerenz thing to open the valves. With cats you do not hear that sound. Turned v4 off and all knock completly went away. I would say NOT fake. So just a heads up from my experience. After i put on the lt2 when I hit it felt much stronger. Edit I mis spoke on the times 0-60 stock 4.1 to 100 9.7. Thats with the nitto 2 stock tires are about 4.5 lots of spin. This is all useing launch control default settings for consistancey. Gutted primary cats 4 and 9.6 that could be just run difference. Their was no loss in bottom end. LT2 3.8 and 8.8 still impressive and noticeable stronger. Then stock stage 2 procharger was 3.6 and 7.6 thats the 1.2 second. Opps. Showing 6.5 pds at stock shift point. Also with those mods my injecter was going near 7 micro second or what ever and rail pressure was dropping to 1800 psi. So defentaly more air flow and out of fuel with the base procharger. I will get the meth working before I run it any more and get the duty cycle down. Last edited by Kerry; 02-26-2021 at 03:24 AM.

02-25-2021, 10:30 PM	#2
Trochoidal Drives: 2017 Camaro 2SS A8 Join Date: May 2019 Location: USA Posts: 1,656	Good feedback. Did you have stock or ported LT1 before doing the swap? __________________ Roto-Fab w/sound tube delete, Katech ported TB, Pray IM, Velossa, DD side markers, DSX FF, UPR Catch can, Halo brace, My custom vent gauge pod Originally Posted by arpad_m - “Aww, yet another oil thread with almost the same question in the OP“

02-26-2021, 03:13 AM	#3
Kerry Drives: 2019 2SS Camaro Join Date: Apr 2012 Location: Al Posts: 828	Stock

02-26-2021, 03:31 AM	#4
Kerry Drives: 2019 2SS Camaro Join Date: Apr 2012 Location: Al Posts: 828	Question with primary cats removed it is some louder. Not crazy but some. What would happen if I removed the secondary. Would power go up? How much Louder? 10% 30?

02-26-2021, 05:47 PM	#5
Pendelton Drives: Camaro 2017 Join Date: Dec 2020 Location: Florida Posts: 16	Did you stock the LT1 before the trade?

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