Replacing Main Cat with Cutout - But I have a question
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Replacing Main Cat with Cutout - But I have a question
I have a 1995 sc400 that it a project car. My goal for the car is to have a weekend toy. I'm wanting to install some cutouts that I have laying around the garage on this vehicle. I noticed that the Main Cat is the same diameter and length as my cutout.
If I were to get the right size flanges (is that the right word) welded on to each end of the cutout to bolt directly in place of the main cats (angled correctly for clearance and aimed towards the ground), would I have any problems with the ECU and/or O2 readings?
I noticed an O2 sensor before the cat and one after the cat. I was wondering if a cutout in this location would cause problems with the ECU and in turn...the car's performance. I'm not concerned about the emissions aspect, I'm concerned with the ECU's O2 readings and the pre and post cat points causing the ECU to reduce fuel and etc. I do have a AEM UEGO gauge that will be installed on a cutout to monitor AFR's (okay okay and to have a cool gauge in the car).
Here are some pictures of what I'm working with:
Another question is.... how do you remove the bolts from the cat to the exhaust manifold.... do you remove the nut with the red arrow(or is that welded on the flange) or do you remove the stud part with the green arrow.
And to answer all comments or questions... I know it will sound similar to this:
http://video.google.com/videoplay?do...2295100282509#
If I were to get the right size flanges (is that the right word) welded on to each end of the cutout to bolt directly in place of the main cats (angled correctly for clearance and aimed towards the ground), would I have any problems with the ECU and/or O2 readings?
I noticed an O2 sensor before the cat and one after the cat. I was wondering if a cutout in this location would cause problems with the ECU and in turn...the car's performance. I'm not concerned about the emissions aspect, I'm concerned with the ECU's O2 readings and the pre and post cat points causing the ECU to reduce fuel and etc. I do have a AEM UEGO gauge that will be installed on a cutout to monitor AFR's (okay okay and to have a cool gauge in the car).
Here are some pictures of what I'm working with:
Another question is.... how do you remove the bolts from the cat to the exhaust manifold.... do you remove the nut with the red arrow(or is that welded on the flange) or do you remove the stud part with the green arrow.
And to answer all comments or questions... I know it will sound similar to this:
http://video.google.com/videoplay?do...2295100282509#
#2
I've always wondered how the car would affected if I removed all 3 cats when doing my exhaust. Edit: As far as check engine lights and A/F ratios go.
I live in Florida, too, so yeah... **** emissions.
I live in Florida, too, so yeah... **** emissions.
Last edited by MarcusMIA; 10-17-09 at 07:46 PM.
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I figure worse case scenerio, I'll get the flanges made and mounted on the cutout pipe and install it to see how it sounds.... Unfortunately I have to be patient since I'm rebuilding the engine.
The reason I'm trying it this route is so I can keep the stock exhaust appearance (save money) but get the performance and loud noise from the cutout.
I'm also building the car so I have a reason to put these on:
The reason I'm trying it this route is so I can keep the stock exhaust appearance (save money) but get the performance and loud noise from the cutout.
I'm also building the car so I have a reason to put these on:
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Are you sure They are actually a 1/2 inch shorter than the wheels I have on there now. There is no rubbing though.
I think the offset could be a little better though... so if that is what you were referring to, then I see what you are saying.... Can't ask for too much on a 27x10-15. Especially when I only spent $35 on them. I do plan on new rubber, but these have a few passes left in them.
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#9
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On the OBD1 cars (including 95), the ECU won't care about the sensor readings. Will only throw a CEL if the sensor is unplugged. Even then it is a heater code and not a code for the actual sensor.
I have headers on mine with no cats at all and I don't have problems. The front sensors are the ones the ECU uses to determine AF.
KC
Oh and, you better do allot of "building" to justify putting on those slicks.
I have headers on mine with no cats at all and I don't have problems. The front sensors are the ones the ECU uses to determine AF.
KC
Oh and, you better do allot of "building" to justify putting on those slicks.
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On the OBD1 cars (including 95), the ECU won't care about the sensor readings. Will only throw a CEL if the sensor is unplugged. Even then it is a heater code and not a code for the actual sensor.
I have headers on mine with no cats at all and I don't have problems. The front sensors are the ones the ECU uses to determine AF.
KC
Oh and, you better do allot of "building" to justify putting on those slicks.
I have headers on mine with no cats at all and I don't have problems. The front sensors are the ones the ECU uses to determine AF.
KC
Oh and, you better do allot of "building" to justify putting on those slicks.
So with that said, KC you rock.
I already have one car that I race at the strip. I actually bought these slicks for that car. It's not crazy fast, but it does low 12's at the strip all day on street tires and 11's on borrowed slicks. I'm working on 10's once I turn the boost up. It's only running the 6.5 psi pulley.
I recently moved to an area that has an 1/8 mile track near by. I'm building this car to launch on spray (I sell kits and install them through my company) and to throw a big shot at it. I'm currently building up the internals to support the juice. I kinda have a little competition going with a rival business owner. I agree with these being a little overkill, but they will let me launch a big shot.
I'm really excited about this build because I got my wife working with me on it. She wanted to race, but doesn't want to race a stick shift. So this car is more for her to race around with... Unless I blow it up first lol.
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I would leave the sensors in place, or move them if needed. Won't hurt anything having them there and then no CEL. That's how mine is. The front sensors are in my headers and the rear sensors are maybe a foot back from them in the pipe.
I have seen a few 1uz's with NOS. The engine seems to respond very well to it. You very well may need those tires depending on the size of shot your planning on. I would highly recommend looking into an LSD.
Your lucky your wife want to race. Wish I could say the same. But, be aware that the auto transmission is the week link in the drivetrain. I killed second gear in a transmission just a week or two ago and now killed my converter. Looking into building up one or buying a built one myself.
KC
I have seen a few 1uz's with NOS. The engine seems to respond very well to it. You very well may need those tires depending on the size of shot your planning on. I would highly recommend looking into an LSD.
Your lucky your wife want to race. Wish I could say the same. But, be aware that the auto transmission is the week link in the drivetrain. I killed second gear in a transmission just a week or two ago and now killed my converter. Looking into building up one or buying a built one myself.
KC
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I would leave the sensors in place, or move them if needed. Won't hurt anything having them there and then no CEL. That's how mine is. The front sensors are in my headers and the rear sensors are maybe a foot back from them in the pipe.
I have seen a few 1uz's with NOS. The engine seems to respond very well to it. You very well may need those tires depending on the size of shot your planning on. I would highly recommend looking into an LSD.
Your lucky your wife want to race. Wish I could say the same. But, be aware that the auto transmission is the week link in the drivetrain. I killed second gear in a transmission just a week or two ago and now killed my converter. Looking into building up one or buying a built one myself.
KC
I have seen a few 1uz's with NOS. The engine seems to respond very well to it. You very well may need those tires depending on the size of shot your planning on. I would highly recommend looking into an LSD.
Your lucky your wife want to race. Wish I could say the same. But, be aware that the auto transmission is the week link in the drivetrain. I killed second gear in a transmission just a week or two ago and now killed my converter. Looking into building up one or buying a built one myself.
KC
I've seen a few SC's on here using nitrous, but it seems like most are using a dry setup. I'm keeping my eye out for one of the supra differentials with the LSD in it already. I know it may be impossible, but I'm patiently waiting for one that isn't going to cost me $600-$900. I saw your thread about your TC troubles. I've got one coming from Lextreme, so we'll see if that can hold up. They claim to handle anything under 600hp. I don't see myself going up that high on this setup.
Thanks for the heads up on the tranny. I guess one takes it for granted when it's paired up with an engine that can hold a lot of power. I'll have to start researching where the weak points are. I might have to call Darin from Titan Motorsports since I'm sure he's gone through many of them in those sick Supra's he puts out. I used to see him at the tracks a lot when I was living in Orlando, FL.
I've been very fortunate to turn my wife that hates cars to one that loves them. Fortunately she's good looking too
Last edited by Anti-Venom; 10-18-09 at 09:43 AM.
#13
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I've often thought about adding a 50 shot to mine but that's probably asking for trouble. LOL. I have seen a few wet ones, the engine really seems to like it.
Depending on what happens with PI and how it goes racing on the stock converter, I may end up getting a Lextreme unit. I wonder if the guy he uses can rebuild the PI unit.
I bought my LSD from Nero at Titian. I just bought the center Torsen unit and bolted it into my stock rear. Very easy job. There is one trans / diff combo Supra that the Torsen unit is a direct swap for the open SC400 diff. I can't remember, you'll have to research but it is possible. I think I got it for $350-$400? Keep in mind that a complete Supra pumpkin will have a different gear ratio, I think most of them are a higher gear which won't help you much in the 1/8 mile. I also know it's possible to use the 4.27 gear from the Supra but I don't know any of the details.
Let's see a pic of the wifey....kidding. Mine is good looking too just not into the car thing, maybe once the kids get older.
KC
Depending on what happens with PI and how it goes racing on the stock converter, I may end up getting a Lextreme unit. I wonder if the guy he uses can rebuild the PI unit.
I bought my LSD from Nero at Titian. I just bought the center Torsen unit and bolted it into my stock rear. Very easy job. There is one trans / diff combo Supra that the Torsen unit is a direct swap for the open SC400 diff. I can't remember, you'll have to research but it is possible. I think I got it for $350-$400? Keep in mind that a complete Supra pumpkin will have a different gear ratio, I think most of them are a higher gear which won't help you much in the 1/8 mile. I also know it's possible to use the 4.27 gear from the Supra but I don't know any of the details.
Let's see a pic of the wifey....kidding. Mine is good looking too just not into the car thing, maybe once the kids get older.
KC
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I thought the stock auto on the 1995 sc400 was already using 4.27 gears.
I'll check Titan's website.... I may just keep it simple and go your route if you did it for under $400. I haven't messed with LSD's before... so it will be all new territory for me. I think that is why I have been looking at the whole pumpkin. I'm thinking that I will just give it a shot and install the LSD on my own since you say it isn't extremely difficult.
I don't have a picture to attach at the moment.... but she's got a similar look to Dannica Patrick.
I'll check Titan's website.... I may just keep it simple and go your route if you did it for under $400. I haven't messed with LSD's before... so it will be all new territory for me. I think that is why I have been looking at the whole pumpkin. I'm thinking that I will just give it a shot and install the LSD on my own since you say it isn't extremely difficult.
I don't have a picture to attach at the moment.... but she's got a similar look to Dannica Patrick.