How to gut your primary cats (Dyno results to come soon)
09-24-14, 09:27 PM
#121
You know, I don't want to add fuel to the fire here... but I honestly think that a gutted cat with stock headers isn't going to be the limiting factor. I think the CATS are the limiting factor. I had a hard time believing it, but running the stock intake vs. a stock intake with NO air filter proved that the intake wasn't the limiting factor. I really don't think the two pipes aren't the bottleneck but the cats. The next restrictive portion being the exhaust or intake valves.
There is only one way to prove it. Either caymandive or I (we have put HUNDREDS of trips down the strip documenting DA and mods along the way) would have to put gutted cats back on and run the track a hundred times on various days and analyze the data. BUT, I don't want to spend a thousand bucks of labor to put stock headers back on and spend a few days on the track to potentially find out that I'm wrong and then spend another thousand to either put full stock headers or PPE headers back on. That's a 2 thousand dollar experiment plus time for me. PLUS, I'm keeping the stock headers in case I fail emissions next year!
There is only one way to prove it. Either caymandive or I (we have put HUNDREDS of trips down the strip documenting DA and mods along the way) would have to put gutted cats back on and run the track a hundred times on various days and analyze the data. BUT, I don't want to spend a thousand bucks of labor to put stock headers back on and spend a few days on the track to potentially find out that I'm wrong and then spend another thousand to either put full stock headers or PPE headers back on. That's a 2 thousand dollar experiment plus time for me. PLUS, I'm keeping the stock headers in case I fail emissions next year!
09-25-14, 06:25 AM
#122
no there is another way to prove it - a dyno, like how everyone else proves power gains. Why are we still on the idea of quantifying power gain mods on a drag strip and not a dyno? Way too many variables and its not conclusive.
Even the RCF has a new header design over the ISF. Its a four to one design, similar to the PPE headers. And its probably one of the reasons why it has 50 more hp over the ISF in addition to other changes.
Even the RCF has a new header design over the ISF. Its a four to one design, similar to the PPE headers. And its probably one of the reasons why it has 50 more hp over the ISF in addition to other changes.
09-25-14, 06:27 AM
#123
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Dynos are known to be variable. Trapspeed never lies and doesn't depend on driver skill.
09-25-14, 08:10 AM
#124
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Trap speed is variable too. Unless like toothdoc said, gutted cats are installed on a documented car, it's not going to prove much. There's header cars trapping from 115-120+ depending on da, weight, wheel/tire, etc. That's a huge gap.
Best case would be like toothdoc said and have one of them go to gutted cats. Alternatively if we had someone with numerous runs on stock manifolds, and then gutted them, we'd atleast know the increase in trap.
Doing a baseline dyno, installing gutted cats, and getting it back on the same dyno will tell us how much power they're worth. However it won't really tell us what that translates in the real world.
Problem is, let's say hypothetically, headers add 30whp. Let's say gutted cats add 20whp. It's such a small difference, the actual real world improvement on the track, in a 3500lb car is going to be pretty small. So it then will come down to is spending $2k worth it to YOU for 10whp and say potentially 1mph trap.
I wouldn't be surprised if gutted cats added 90% of the benefit of headers.
Best case would be like toothdoc said and have one of them go to gutted cats. Alternatively if we had someone with numerous runs on stock manifolds, and then gutted them, we'd atleast know the increase in trap.
Doing a baseline dyno, installing gutted cats, and getting it back on the same dyno will tell us how much power they're worth. However it won't really tell us what that translates in the real world.
Problem is, let's say hypothetically, headers add 30whp. Let's say gutted cats add 20whp. It's such a small difference, the actual real world improvement on the track, in a 3500lb car is going to be pretty small. So it then will come down to is spending $2k worth it to YOU for 10whp and say potentially 1mph trap.
I wouldn't be surprised if gutted cats added 90% of the benefit of headers.
Last edited by Cronic; 09-25-14 at 08:17 AM.
09-25-14, 08:20 AM
#125
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I didnt have a dyno done prior to installation, so it really wont do a whole lot at this point for proving gains. Its going to snow in another month or so here, so the car will be used sparingly. (My DD, but I live a few blocks from work and will be walking)
Side note.. O2 spacer is still doing its job! Two cold starts and around 30km driven.
Side note.. O2 spacer is still doing its job! Two cold starts and around 30km driven.
09-25-14, 09:17 AM
#126
Dynos are variable
ET are variable
Trap speed is not, its gunna do what its gunna do
but everyone wants to hear Dyno #'s and ET. those will give you an idea of where you are at but the real performance comes from adjusting your car to get the highest MPH, then the other 2 will follow.
If you do not believe me take your car to a dyno and put it on look at the torque, then go to another dyno the same day and run it again and look at the torque. my guess is that the 2 numbers will be different. MPH at the 1/4 mile will be damn near identical.
With all that said we all know a stock IS F will dyno anywhere fron mid 350's to mid 370 HP (depending on the dyno) to the tires. MGordo go Dyno it so we all can see what it makes now and we could have an idea.
Oh and since we are on the dyno subject, I see a lot of vids of IS F's being run in the wrong gear, mainly 4th gear, thats wrong it needs to be dyno'd in 6th gear. I have the gear ratio's handy if there is any questions about that. So here they are.
1 - 4.60:1
2 - 2.72:1
3 - 1.86:1
4 - 1.46:1
5 - 1.23:1
6 - 1.00:1
7 - 0.82:1
8 - 0.69:1
Last edited by v8sten; 09-25-14 at 09:44 AM.
09-25-14, 10:43 AM
#127
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. MGordo go Dyno it so we all can see what it makes now and we could have an idea.
Oh and since we are on the dyno subject, I see a lot of vids of IS F's being run in the wrong gear, mainly 4th gear, thats wrong it needs to be dyno'd in 6th gear. I have the gear ratio's handy if there is any questions about that. So here they are.
1 - 4.60:1
2 - 2.72:1
3 - 1.86:1
4 - 1.46:1
5 - 1.23:1
6 - 1.00:1
7 - 0.82:1
8 - 0.69:1
Oh and since we are on the dyno subject, I see a lot of vids of IS F's being run in the wrong gear, mainly 4th gear, thats wrong it needs to be dyno'd in 6th gear. I have the gear ratio's handy if there is any questions about that. So here they are.
1 - 4.60:1
2 - 2.72:1
3 - 1.86:1
4 - 1.46:1
5 - 1.23:1
6 - 1.00:1
7 - 0.82:1
8 - 0.69:1
To add in the dyno discussion, I am at nearly 3500ft above sea level not taking into consideration any density adjustments.. Certainly wont see the numbers you guys would at sea level.
09-25-14, 12:10 PM
#128
09-25-14, 12:36 PM
#129
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10-01-14, 07:55 AM
#133
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Well had the CEL and VSC come on yesterday.. P0430 and P0420.
Unless its something else, it looks like the O2 spacers arent working. Luckily I have a bluetooth ODBII dongle and that android Torque app, makes it nice and easy to clear codes. Guess it could be time to go to the Sikky or PPE conditioners... Are there other tests I can do to make sure thats the issue?
Unless its something else, it looks like the O2 spacers arent working. Luckily I have a bluetooth ODBII dongle and that android Torque app, makes it nice and easy to clear codes. Guess it could be time to go to the Sikky or PPE conditioners... Are there other tests I can do to make sure thats the issue?
10-01-14, 10:33 AM
#134
mgordo,
what about o2 spacers that are "catted"
http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html
http://www.redlineperformance.co.nz/...with-mini-cat/
novel uses something similar to the 2nd one
what about o2 spacers that are "catted"
http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html
http://www.redlineperformance.co.nz/...with-mini-cat/
novel uses something similar to the 2nd one
Last edited by imp0rted1; 10-01-14 at 10:40 AM.
10-01-14, 10:46 AM
#135
Okay... so I just got a baseline dyno on my completely stock 2012 IS-F Yesterday.
It was DynoJet, put down 348whp.
I was going to do PPE headers first then redyno but I'm VERY tempted to gut my cats and do a STOCK, GUTTED CATS, PPE Header comparison to put this discussion to rest...
Should be pretty accurate since all will be done on the same exact dyno.
I'm just afraid I won't be able to source a another set of factory headers if I chose to go back to stock..
It was DynoJet, put down 348whp.
I was going to do PPE headers first then redyno but I'm VERY tempted to gut my cats and do a STOCK, GUTTED CATS, PPE Header comparison to put this discussion to rest...
Should be pretty accurate since all will be done on the same exact dyno.
I'm just afraid I won't be able to source a another set of factory headers if I chose to go back to stock..