exhaust upgrade

[chubbydog]

Hello my question is for my 89 vette. We are building a stroker moter for it and want to put headers, with no cat converters. The question is how to get rid of 02 sensors, or do you just tap them into new exhaust? ;help

 

[dogfish246]

Hello my question is for my 89 vette. We are building a stroker moter for it and want to put headers, with no cat converters. The question is how to get rid of 02 sensors, or do you just tap them into new exhaust? ;help

You put in O2 sensor simulators if you don't run cats...

 

[aklim]

What has that got to do with anything? I ran no cats for a while and had 02 sensor in it.

 

[Hib Halverson]

You put in O2 sensor simulators if you don't run cats...

O2S simulators are for the rear sensors on 96-up OBD2 engines.

The 89 L98 needs the OE sensors in the headers or the engine controls will not work right. Most headers you buy for that engine are going to have sensor bungs. Just take the sensor out of the stock manifolds or headpipes and put it in the headers.

 

[chubbydog]

Thank you for your help. one more question, there are two sensors, one upstream, one downstream by the cat. Do you need both?

 

[aklim]

Thank you for your help. one more question, there are two sensors, one upstream, one downstream by the cat. Do you need both?

There are?? I have a 91 and it is 1 sensor. I don't think you have 2 sensors.

 

[chubbydog]

ok thank you

 

[aklim]

You need the upstream one to control the engine. The downstream one is for monitoring the cat efficiency. Fortunately for you, the 89 DOES NOT HAVE downstream.

 

[WhalePirot]

want to put headers

Highly recommend coated headers.

 

[T.M.808]

I'm on my 2nd 89,there are no downstrean o2's. I have a true dual exhaust,no cats with flowmasters..I would definatly do a dual exhaust if i was you.

My c5 had downstream 02's that needed o2 sims.. not an 89 though.

 

[ZumZum]

I'm on my 2nd 89,there are no downstrean o2's. I have a true dual exhaust,no cats with flowmasters..I would definatly do a dual exhaust if i was you.

My c5 had downstream 02's that needed o2 sims.. not an 89 though.

I concur with the dual exhaust recommendation. I'd take it one step further and install an X-pipe with that.

 

[aklim]

I concur with the dual exhaust recommendation. I'd take it one step further and install an X-pipe with that.

Why? Has there been significant gain to true duals that will justify the effort and money? I ran my car with the exhaust disconnected from the collectors and didn't notice any gain to speak of.

 

[ZumZum]

Why? Has there been significant gain to true duals that will justify the effort and money? I ran my car with the exhaust disconnected from the collectors and didn't notice any gain to speak of.

Are you talking open headers? By not noticing any gain do you mean through the seat of the pants or are you talking track times or dyno numbers? It depends upon your engine combo, but I find it hard to believe there was no advantage to open headers compared to running a full exhaust.

For a street car running a full length exhaust system IMO there is an advantage to duals over a factory type single pipe. Two 2.5" pipes provide more area than even a single 3" pipe. Plus a X-pipe (or a H-pipe) between the duals provides an advantage over duals alone by using the exhaust pulses to help scavage the exhaust from each side. There's an article I found once on how a X-pipe works. I'll have to see if I can find it again.

 

[aklim]

Are you talking open headers? By not noticing any gain do you mean through the seat of the pants or are you talking track times or dyno numbers? It depends upon your engine combo, but I find it hard to believe there was no advantage to open headers compared to running a full exhaust.

For a street car running a full length exhaust system IMO there is an advantage to duals over a factory type single pipe. Two 2.5" pipes provide more area than even a single 3" pipe. Plus a X-pipe (or a H-pipe) between the duals provides an advantage over duals alone by using the exhaust pulses to help scavage the exhaust from each side. There's an article I found once on how a X-pipe works. I'll have to see if I can find it again.

I was on a track. I timed the run with the full exhaust on and then disconnected it, tied it down in the trunk and ran again. Average Times were about a few hundredths apart so there was very little difference.

I realize that but I would there be a significant difference in power? Does it matter how much flow you can have if you can't use it? I mean Whether you piss into a hose or a coke bottle, same flow rate.

 

[ZumZum]

I was on a track. I timed the run with the full exhaust on and then disconnected it, tied it down in the trunk and ran again. Average Times were about a few hundredths apart so there was very little difference.

I realize that but I would there be a significant difference in power? Does it matter how much flow you can have if you can't use it? I mean Whether you piss into a hose or a coke bottle, same flow rate.

Well, lol, to use your analogy: If you piss into a coke bottle it's the same flow, but eventually the coke bottle fills up and won't take any more flow. Not so with the hose.