[770guy]

Well. My plan was to do a baseline dyno tune tomorrow but I have no patience.

Today I installed the catless downpipe and xpipe. Overall. It took about 3 hours but I didnt really get to focus on it the whole time.

It was not hard at all with one exception. I would not want to do it without a lift. Would have been a total pain in the butt. Everything fit great.

I have not cranked it because my ECU comes back from Cobb tuning tomorrow so I will throw that in and head to the dyno at 2pm est.

Also need to put the BMC filter in tomorrow.

Not really related to this section but all the stuff I put on it today.

Downpipe
Xpipe
Wheel spacers front and back (15mm & 7mm)

Here are a few pics. I'll take some more tomorrow and post dyno graph.

I wish I had taken a picture but **** someone needs to make a set of headers. The factory ones have a ton of restriction.

 

[Guaji]

Your tips look slightly different than mine.

 

[zagaone]

How did it go at the dyno? ?

 

[770guy]

Ok, so I have not dynoed yet. I went and the guy said that we may have an issue with PASM. I was in a bit of a hurry so I didnt mess with it. The concern is that with the back wheels spinning and front wheels not spinning that the car will not let it be in sport + or sport mode when dynoing. He has a buddy with porsche software that will put it in dyno mode. I have not really looked at the cobb tuner much but someone said it had a "dyno mode". I will check into that and go back for a dyno this week.

Feedback on the mods.

1. Exhaust is not too loud with cat bypass.
2. Does now have the exhaust smell since the cats gone. I experienced this with every single corvette or camaro I had taken the cats off. It is kinda like if you go out and use a gas blower in your driveway and later your hands smell like fumes, pretty much like that. It is not nearly as bad as my camaro and corvette were but then again it has half the amount of cylinders. It will smell wonderful once COBB comes out with some tunes for high octane gas.
3. Definite seat of the pants improvement with the tune and downpipe. I cant really tell how much though.
4. Exhaust sound awesome ,crackles allot on downshift in sport mode. When in regular mode its basically just how it was before.

I wish someone would hurry up and develop the following. If it takes more than a couple months I may just pay someone I used to deal with in the corvette world to build me a set of custom headers and a larger intercooler. An E85 or E98 tune is needed and hopefully will be coming soon.

Those braces everyone keeps talking about taking off under the car to change the exhaust. There is no problem taking them off. They are not adjustable. The bolts holes in them are not slotted and if you take them off as long as the bolts go back in you are fine.

I want to get this car to 600hp. I think its easily achievable with headers, tune for e85, better intercooler, air intake and more booost. I am hesitant to say it needs a bigger turbo for those numbers because I cant find anywhere that someone has done any of the mods I mentioned in the previous sentence.

PS. I dont give a **** about a warranty.

 

[johan]

Ok, so I have not dynoed yet. I went and the guy said that we may have an issue with PASM. I was in a bit of a hurry so I didnt mess with it. The concern is that with the back wheels spinning and front wheels not spinning that the car will not let it be in sport + or sport mode when dynoing. He has a buddy with porsche software that will put it in dyno mode. I have not really looked at the cobb tuner much but someone said it had a "dyno mode". I will check into that and go back for a dyno this week.

Feedback on the mods.

1. Exhaust is not too loud with cat bypass.
2. Does now have the exhaust smell since the cats gone. I experienced this with every single corvette or camaro I had taken the cats off. It is kinda like if you go out and use a gas blower in your driveway and later your hands smell like fumes, pretty much like that. It is not nearly as bad as my camaro and corvette were but then again it has half the amount of cylinders. It will smell wonderful once COBB comes out with some tunes for high octane gas.
3. Definite seat of the pants improvement with the tune and downpipe. I cant really tell how much though.
4. Exhaust sound awesome ,crackles allot on downshift in sport mode. When in regular mode its basically just how it was before.

I wish someone would hurry up and develop the following. If it takes more than a couple months I may just pay someone I used to deal with in the corvette world to build me a set of custom headers and a larger intercooler. An E85 or E98 tune is needed and hopefully will be coming soon.

Those braces everyone keeps talking about taking off under the car to change the exhaust. There is no problem taking them off. They are not adjustable. The bolts holes in them are not slotted and if you take them off as long as the bolts go back in you are fine.

I want to get this car to 600hp. I think its easily achievable with headers, tune for e85, better intercooler, air intake and more booost. I am hesitant to say it needs a bigger turbo for those numbers because I cant find anywhere that someone has done any of the mods I mentioned in the previous sentence.

PS. I dont give a **** about a warranty.

There is not much of a difference on a dyno between the different modes
Just a couple of Hp on different rpm:s


*edit*

 

[peaedvard]

Hi
Did you notice how much the boost have raised after the tune, mine tune raised it with 7-8psi.
Also did you notice any difference in the power band after going fully catless, on my last car who was a supercharged M3 i gained power on top, but lost some in the midrange, when i removed the cats.

 

[zagaone]

I wonder how much improvement hp/tq is really gained with this tune since my previous experience with turbo Porsche tunes (944t; 997tt and 991tts) is that you can right away feel the hp/tq increase. I’m surprised that you can not feel a significant improvement or I’m misunderstanding your post. The Cobb Accessport is supposed to give somewhere around 45-50hp/70-80 ft-pd of tq. That is 25% tq improvement which should be easily feel. Thanks

 

[don]

Man, you certainly don't muck about. Eagerly looking forward to the results.

So does your exhaust mod remove all cats or just the down pipe cat? I assume there is still a primary cat after the downpipe cat? Or does the 718 only have 1 cat?

That's interesting about the restrictive headers. I think Porsche definitely doesn't want to make this car too fast.

Just wondering if you've noticed any rubbing with the spacers on full lock or over bumps?

I assume you are on SPASM? Please post some stance photos.

Maybe you could do a water spray like the GT2 RS for the heat soak? Though I believe so far people have noticed the engine runs fairly cool as is.

 

[770guy]

Man, you certainly don't muck about. Eagerly looking forward to the results. /forum/images/718forum/smilies/tango_face_smile.png

So does your exhaust mod remove all cats or just the down pipe cat? I assume there is still a primary cat after the downpipe cat? Or does the 718 only have 1 cat?

That's interesting about the restrictive headers. I think Porsche definitely doesn't want to make this car too fast.

Just wondering if you've noticed any rubbing with the spacers on full lock or over bumps?

I assume you are on SPASM? Please post some stance photos.

Maybe you could do a water spray like the GT2 RS for the heat soak? Though I believe so far people have noticed the engine runs fairly cool as is.

Sorry but I have been traveling for business and just couldnt find the time to give a good reply.

1. There are no more catalysts. Exhaust manifold -> turbo -> PSE

The turbo sound is so prevalent now. It's awesome on a cold start.

2. Spacers havent caused any issues one bit. I drove it hard around town and not once had a rub.

3. Custom stainless exhaust manifold, e85 tune, gt2 rs intercooler setup...this thing would scream.

 

[zagaone]

What is the relevance of the GT2 RS intercooler setup. If it is the water spray part, I don't see how can that help the 718 close intercooler system. Ours is water/air cooling system contained within the intercooler so really nothing to spray. To apply this to the 718 engine will require a complete system redesign. I'm I missing something?

 

[rjm98119]

Today I installed the catless downpipe and xpipe. Overall. It took about 3 hours but I didnt really get to focus on it the whole time.

Not to totally hijack your thread (I say as I hijack your thread... at least the question is for you ): When you disconnected the existing cat, did you find anysort of metal gasket between the cat and turbo (and did the new pipe have one?), or did your cat mate flange-to-flange with the turbo, with nothing in between?


I ask b/c when I installed my Fabspeed turbo-back, there was nothing, but there's a recess in the cat's entry that suggests something should have been there. I puzzled on this initially, but didn't think much of it. However, I am ordering a new clamp for the cat-to-turbo b/c mine... had issues.



I notice all the Porsche diagrams and parts lists have a gasket pictured, with a part number. I ordered clamp and gasket, but wondering... did yours have one?

It was not hard at all with one exception. I would not want to do it without a lift. Would have been a total pain in the butt. Everything fit great.

There's some question, actually, as to whether you even *should* do it without a lift. If I read it right, the older 981 Service Manual states, in no uncertain terms, that if you "loosen the threaded fasteners" on the diagonal braces (which I had to remove to get the original cat/downpipe out), you're not supposed to have any weight on the wheels... and then says you need to get a re-alignment after doing so. Not sure I understand why, exactly, and not sure if it's the same on the 718's, b/c I can't find a manual. Doesn't look much different down there, from what I recall (having also had a 981).

 

[770guy]

Today I installed the catless downpipe and xpipe. Overall. It took about 3 hours but I didnt really get to focus on it the whole time.

Not to totally hijack your thread (I say as I hijack your thread... at least the question is for you /forum/images/718forum/smilies/tango_face_wink.png ? When you disconnected the existing cat, did you find anysort of metal gasket between the cat and turbo (and did the new pipe have one?), or did your cat mate flange-to-flange with the turbo, with nothing in between?


I ask b/c when I installed my Fabspeed turbo-back, there was nothing, but there's a recess in the cat's entry that suggests something should have been there. I puzzled on this initially, but didn't think much of it. However, I am ordering a new clamp for the cat-to-turbo b/c mine... had issues.



I notice all the Porsche diagrams and parts lists have a gasket pictured, with a part number. I ordered clamp and gasket, but wondering... did yours have one?

It was not hard at all with one exception. I would not want to do it without a lift. Would have been a total pain in the butt. Everything fit great.

There's some question, actually, as to whether you even *should* do it without a lift. If I read it right, the older 981 Service Manual states, in no uncertain terms, that if you "loosen the threaded fasteners" on the diagonal braces (which I had to remove to get the original cat/downpipe out), you're not supposed to have any weight on the wheels... and then says you need to get a re-alignment after doing so. Not sure I understand why, exactly, and not sure if it's the same on the 718's, b/c I can't find a manual. Doesn't look much different down there, from what I recall (having also had a 981).

Only a vband clamp. I did not see any sort of gasket at all. I had to make sure the two flanges seated well together. Once I got them squared up and tightened the clamp it was fine.

 

[770guy]

What is the relevance of the GT2 RS intercooler setup. If it is the water spray part, I don't see how can that help the 718 close intercooler system. Ours is water/air cooling system contained within the intercooler so really nothing to spray. To apply this to the 718 engine will require a complete system redesign. I'm I missing something?

I have not even put my eyes on the intercooler to even begin to figure that out. I didnt know they were different. I am going to get deeper into this thing as soon as I get some free time. Meanwhile I. Ordering anything that could bolt on. My workload wont slow down until January so maybe I'll have a couple weeks to take it apart and look at it.

I am not even sure of how bad the heat sink is on the current tune. I just know what I've been told by COBB.

 

[zagaone]

Got it. The intercooler in the 718 is a water/air system. The enclosed cooler seat next to the air filter housing with in and out feeders for water and air to do their thing. Like you i only know what Cobb’s has said about it being prone to heat soak pretty quick. Let’s hope someone figures something out very soon. In the meantime just Accessport and downpipe. I don’t think i will even bother replacing the oem air filter until maintenance is due.

 

[eric]

Hi 770Guy

The manufacturer says it comes with an integrated cat simulator. I can't see it from your pictures. Is it hidden inside the pipe or bung? So the CEL issue caused by O2 reading is taken care of without further requiring an ECU fix or work-around?

Was the installation straight forward? Any cutting, modifying needed? How much time and money do you think a shop would charge for a job like this?

Thanks.
Eric

 

[eric]

Hi 770Guy

The manufacturer says it comes with an integrated cat simulator. I can't see it from your pictures. Is it hidden inside the pipe or bung? So the CEL issue caused by O2 reading is taken care of without further requiring an ECU fix or work-around?

Was the installation straight forward? Any cutting, modifying needed? How much time and money do you think a shop would charge for a job like this?

Thanks.
Eric

Answering my own questions. It has cat just made for the O2 sensor, very nice! No CEL so far.

No cutting is needed and since it's divided into 2 pieces, an easy one.

The pipe needs to be broken-in initially at high temp bcoz of some coating (according to the installer). We pulled the beast hard and some white smoke burnt for a while and thats it.

The effect? Significant.

The sound? Beast.

 

[zagaone]

Well. My plan was to do a baseline dyno tune tomorrow but I have no patience.

Today I installed the catless downpipe and xpipe. Overall. It took about 3 hours but I didnt really get to focus on it the whole time.

It was not hard at all with one exception. I would not want to do it without a lift. Would have been a total pain in the butt. Everything fit great.

I have not cranked it because my ECU comes back from Cobb tuning tomorrow so I will throw that in and head to the dyno at 2pm est.

Also need to put the BMC filter in tomorrow.

Not really related to this section but all the stuff I put on it today.
Downpipe
Xpipe
Wheel spacers front and back (15mm & 7mm)

Here are a few pics. I'll take some more tomorrow and post dyno graph.

I wish I had taken a picture but **** someone needs to make a set of headers. The factory ones have a ton of restriction.

Did you finally got it dynoed? Results?

 

[nineball]

i'm curious about the lack of a cat. how exactly do you pass emissions tests with no catalytic converter? i see in your pics (thanks btw for them) there is a "pseudo-cat" for the O2 sensor but that obviously does nothing for what is coming out the end of the system to the atmosphere.

 

[Fosgate769]

I think it varies state to state, and maybe even depend on the inspection shop. In my experience I've never had someone actually do a visual inspection and they don't test the tailpipe. Since 1996 with OBD2 as long as there isn't a check engine light you are good to go. On vehicles with tuning support you can just disable the codes and they simply wont pop up. If the cat simulator works then that would do the same thing.

 

[nineball]

they still stick the test equipment into the tail pipes in ohio, so there is not way to remove a cat and get plates if the car is less than 25 years old.