Catless to catted tune changes

[DJKuehn]

I recently purchased a FiST with lots of mods. I absolutely love it in every way except for the catless stench. From what I've read, it seems like going catless is more for sound and doesn't effect the power much until you get to crazy high output. So I'm considering swapping the downpipe back to stock or a catted aftermarket.

Here's the catch... I know absolutely nothing about the tune. I've driven stock FiSTs and this is a TOTALLY different car. Even with R888Rs on front, I have to be really gentle with the throttle through 2nd gear and sometimes even into 3rd or it just spins. I have no dyno data, but if stock is 200ish, then my mk1 foot dyno tells me this is easily 250. I'm both picky and very mechanically inclined as I build fast things for a living (not cars). The previous owner seems to have done everything "right." Everything I have inspected was done with quality parts and a quality installation. The mods I know about I stuck in my signature, but again, I know nothing about the tune and do not have a tuner.

So here are my questions:
1. Since this thing currently runs beautifully like a swiss watch, how much effect will changing the downpipe have?
2. I do not know what changes with a tune when going catless. If I went back to a catted pipe without touching the tune what would happen? I'm guessing the O2 sensor will be an issue.
3. Do I need to buy an Accessport or equivalent? And if so, can the existing tune be saved and tweaked?

 

[Erick_V]

Going from catless to catted isn't an issue. I did the same and was told by my tuner it was fine and no adjustment was necessary, didn't notice a difference when I was retuned almost a year later. Also, is it possible that the PO left the tune on the car? Can't imagine spinning R888's in 2nd on a stock tune that much if any, unless they're heat cycled like crazy. I'm on RT660's with FBO and E30 and I can still spin 2nd if there isn't any heat in the tires. The stock tune can't be adjusted. You would need an Accessport to make any adjustments. You could lower front tire pressure and see if that helps

 

[DJKuehn]

Going from catless to catted isn't an issue. I did the same and was told by my tuner it was fine and no adjustment was necessary, didn't notice a difference when I was retuned almost a year later. Also, is it possible that the PO left the tune on the car? Can't imagine spinning R888's in 2nd on a stock tune that much if any, unless they're heat cycled like crazy. I'm on RT660's with FBO and E30 and I can still spin 2nd if there isn't any heat in the tires. The stock tune can't be adjusted. You would need an Accessport to make any adjustments. You could lower front tire pressure and see if that helps

I am as certain as I can be that the POs tune was left on the car. However, I found this at a random local lot in Indianapolis and the last registration was in Arizona. I have no idea who the previous owner was, but if they left the tuner itself in the car, it disappeared before I got it.

I know these tires have an extremely short lifespan (100 treadwear!) but they look fairly new. And yes I can easily break them loose on good dry pavement anywhere in 2nd gear. What's amazing is that with all the suspension mods there is zero wheel hop and the torque steer isn't bad considering the power. But you absolutely have to roll the throttle in as you accelerate or they just spin. I thought for sure that the turbo must have been upgraded, but when I got it up on the lift it looked stock.

 

[Lays]

I have R888R as well, they have to be very hot to grip. Otherwise they spin real bad. Normal spirited driving isn't enough to get enough heat in em to grip. You really have to beat the shit out of em.

 

[M-Sport fan]

I thought for sure that the turbo must have been upgraded, but when I got it up on the lift it looked stock.

It could be a hybrid turbo, as they are about as 'stock/factory appearing' as is possible (same exact outside frame/housing).

But, most remove a costly item like that before sale and sell it separately, unless they just did not want to be bothered, or did not have a functioning OEM factory one to replace it with.

 

[DJKuehn]

It could be a hybrid turbo, as they are about as 'stock/factory appearing' as is possible (same exact outside frame/housing).

But, most remove a costly item like that before sale and sell it separately, unless they just did not want to be bothered, or did not have a functioning OEM factory one to replace it with.

Last night I went ahead and ordered one of the 3" catted downpipes from Whoosh since it sounds like I can swap it directly without messing with anything else. While there I saw their hybrid turbos and wondered if I needed to do a closer inspection. Is there any good way to tell without taking it apart? I would assume the builder would stick there own ID tag or logo on it somewhere. All I did last time I was underneath was look at the part number.

Even at really low RPMs (2000ish) if I give it WOT I can clearly feel the turbo kick in with very little lag time. At any speed a momentary down and up on the pedal off gives a huge blowoff hiss. I wrote that off as normal due to the whoosh valve, but the general feel of the turbo feels suspiciously non-stock to me. Does any of this sound normal?

Granted, apples and oranges, but my usual daily driver for the past ten years has been an F-150 with the 3.5 twin turbo. Insane power once it spins up and kicks in, but there is a lot of lag time (several seconds) before that happens and it is not very obvious until you get some RPM (3000+). The Fiesta is less than a second of lag and super obvious at almost any RPM.

 

[Jabbit]

That's the reason people love this car, spool is so quick. If you take off your intake and take a picture of the compressor wheel inside the turbo, that would be an easy way to tell if it's stock or a hybrid. It's tough to see though because of the intake elbow so if you have a small camera or something to put down there that would work.

 

[dhminer]

Switching DP you definitely don’t need to mess with the tune but eventually you’re going to want an accessport anyways I’m sure.

The hybrids use a stock frame so you’d never know it’s a hybrid unless you take off the turbo inlet like Jabbit said above which is a huge PITA. Borescope would probably do it. I have a borescope and a stock turbo lying around. Hit me up if you want to take a peek, I’m just up the road in Carmel.

 

[DJKuehn]

Cool, thanks guys. I have a long scope so next time I have a chance I'll take a look and post a pic here. If I can't get in the easy way I'll try to take a look when I swap the downpipe.

 

[M-Sport fan]

That's the reason people love this car, spool is so quick. If you take off your intake and take a picture of the compressor wheel inside the turbo, that would be an easy way to tell if it's stock or a hybrid. It's tough to see though because of the intake elbow so if you have a small camera or something to put down there that would work.

^^^THIS is the only way to tell without full disassembly.

 

[Lays]

Curious why you smell exhaust in the car, I'm catless and I never have a smell in the car, and barely anything outside the car as well.

I wonder if you have a potential exhaust leak somewhere?