Has anyone done this before and if so what does it take to do this? I have a 1988 and want to get rid of the system.

 

I have a 1988 Corvette and all my emissions equipment is on the car and working. I can get 30 mpg and still have the A/C on.

A lot of folks try to remove the emissions equipment on Corvettes for some reason or the other but performance gains are minimal without new software for your ECM.

Why do you feel compelled to remove the equipment that makes the car run cleaner and perform better? You can remove all the parts you want but the engine itself is the reason it can't make any power over 4500 rpm. To do any serious modifications in search of horsepower on an L98 and the first thing is get rid of the entire intake as the runners are a bit too long.

There are many posts on gaining power on the L98 C4's. There is always some guy who wants 500 hp out of the L98 Corvette. Without spending a lot of money it won't happen. The best answer is to buy a newer Corvette that already makes the power. The C4 Corvette is a well designed Corvette and a blast to drive when maintained properly. I have a C3 with its 427 for scaring myself silly and the C4 for fun driving. The C4 is a great car but these older Corvettes require regular maintenance to be drive-able. You are dealing with a 32 year old Corvette that came with some cool features.

If I were new to a Corvette the first thing I would do is get to know the "Corvette" as they are all different. This is YOUR Corvette and you need to slowly come up to speed with it. A Corvette can be a fearsome animal in the hands of a careless person. The 1988 C4 has the better brakes than the years before it. Do you have a set of the Factory Service Manuals for your 1988 Corvette?The factory manuals are by year so be sure you get the set for the 1988 C4 How about a fuel pressure gauge? get one of those as well.

If you were determined to remove the emissions equipment you will need a set of the FSM's. Helms publishes the set and they were ~$90 for the set or you can find them on fleabay on a DVD.

To improve on this engine you need to "Know" it first.

Get the old beast working like she did in her prime and it might surprise you! It IS a Corvette after all!

 

While emissions equipment most definitely makes the car run CLEANER....it doesn't make it run BETTER.


You can removed the smog pump and install a dummy pulley available from a variety of places, then cap the A.I.R. manifolds that are connected to your exhaust manifolds. You can remove the cats, if you'd like. Both of these changes will increase power. You can remove the EGR valve and cap the intake, but that will likely cause pinging under some operating conditions and won't change performance at all. EGR doesn't function at open throttle settings.

 

The removal of any of the emissions equipment will make your Corvette illegal to drive on any public highways.

After removing the factory stock catalytic converter and replacing it with a newer design "High Flow" unit I was able to break into the 30 mpg range. That is with a 700R4 and a stock engine with the high flow catalytic converter and chambered exhaust system with a 3.07 rear end.

Removing or disabling the EGR (completely) can make the engine run hotter and potentially ping. It will require you to buy a better grade of gasoline to compensate. The only way to properly remove the EGR is to remove it from the code that operates the Corvette. Otherwise the higher temperatures will make your emissions go up.

Here in Virginia they now test your catalytic converter to see if it was gutted by measuring the temperatures of the catalytic converter. If they are the same temp as the nearby exhaust system then they are gutted, it is easy to test.

I do understand the "Need for Speed" so I modified a non emissions controlled Corvette with the 427 to start with. I love going fast in a Big block Corvette. If I wanted some serious power I would not start with a C4, there are C5 and C6's out there on the used market. I see Z06 Corvettes for less than $10k on Craigslist. There are some powerful Corvettes out there that are "light years" better than the C4's. The newer suspension and engines are nothing short of amazing.

You are allowed to do whatever you want to your Corvette. I am not trying to be a party pooper or anything. The performance of my L98 was down when I bought the Corvette, turned out to be a defective knock sensor keeping the engine from hurting itself by retarding the timing. This is why I suggest getting to "Know" your Corvette before making any modifications. After I replaced the knock sensor it was a different Corvette altogether. It will light up the tires now where it could not earlier.

I hope that the Corvette is able to meet your "need for speed" down the road.

 

Yep. Speeding is illegal too. You never do that though, right? How about rolling through a stop sign? That's illagal. Or rolling through a right on red? Illegal. Park yourself in the left lane? Illegal. You've never done any of that? OP isn't looking for legal advice, I don't think. I'm all "illegal" with my Kart...no one seems to care though....



No, it will not do that. The operating temp fo teh engine will not change in a meaningful or noticeable way w/o an EGR.


Wrong, also. You are right that removing the EGR may cause pinging (I already said that, above), but your understanding of "EGR" is clearly, off. Regardless of "how" you remove the EGR, it's going to cause emissions (NOX) to go up; you're increasing combustion temps and that is the condition where NOX is produced. "Removing it (EGR) from the code" is not going to change that. Likewise, regardless of whether you remove EGR or not, at any throttle setting over ~1/2 throttle, EGR is out of the equation either way. It only functions during high vacuum conditions (cruising).

 

Check local laws, that is not true in all locations. Some areas, once a car reaches a certain age it no longer has to pass an emission inspection.

 

The EGR definitely has no control over operating temp. We have beat thermostats, radiators, pumps, and fans to death in other threads. Those control operating temps. They will be more than capable of handling a removed EGR without changing the operating temps for sure.

However, what is does do is bring up the combustion temps.


I think this is where @ctmccloskey got that statement from, just stated it improperly.

 

One benefit is that EGR removal really cleans up the front of the engine.

Capping the damn tube on passenger side eases access to the front spark plugs.

Disabling EGR helps clean up intake air (except for PCV contamination) which may help keep intake valves a bit cleaner.

 

I have finally decided to dump my A.I.R. pump,diverter valve and hoses so i can more easily route my new fuel line and wiring harness. I have a neat delete pulley with chrome brackets to replace the pump. No pre-cats but a set of hi-flow cats
[img] [/img]

 

Tpi forever!!!

 

What are you trying to achieve? Before we can properly adviser you, we kinda need to know what you are trying to do.