Jimmy-D

Well - I wanted to start this thread so we can openly discuss mods and the pros and cons of certain mods for those that have already experimented and those considering adding. I think most of these threads have been started by Vendors where it may be a little uncomfortable talking about their competition. In this thread I would encourage an open discussion. Vendors are more than welcome to participate or chime in but by no means should any Vendor take any thing personal if some thing pops up. For all one knows feedback, whether positive or negative, can help one understand more about their products and/or perceptions. I am sure some like one product more than another or maybe one is just more loyal to a certain Vendor/ brand. My intention is that it has been a little quiet right now in some of those threads and as my car is going to be delivered in 3 weeks; I would like to start thinking/planning on what I mods I want to consider. Also, many may have lots of questions that we can use this thread to try to get answers or some good feedback. I have found some of the other threads to be confusing and/or one-sided where my goal is to narrow down the best mods available to suit my needs-personally. And for each person that may be different but at least we can learn, discuss, and share our experience in one "go-to" thread.

jmartpr

Talking about engine mods....Right now if you talk about single mods I think headers from a reputable vendor is at the very top, long tube ones (from reputable vendor) will probably make more power...if you can get away with cat-less even better (not my case).
The exhaust can improve sound and add a few ponies but not much, but you do have to be careful from who you purchase the exhaust system. Weight savings can also be part of the exhaust system mod. This mod you could actually skip if you are happy with the stock sound and don't mid loosing those last ponies.


Air filters should be part of the TB/Plenum upgrade which should also go with some kind of ECU flash or ECU upgrade. IMO without the TB/Plenum/ECU upgrade they will do nothing. Right now there have been some reports of problems with upgraded TB but hopefully these will be solved as it's key to increase the size of the TB in order to make some decent increase in power and torque. A local tuner tested a COBB on his personal GT4....full stock....and on a mustang dyno they could only measure 1-2 HP increases, so probably not worth it if you at least haven't done the exhaust mods.

d00d

I wouldn't suggest aftermarket air filters.
All of the ones I can find are oiled, which can migrate and kill MAF sensors.
The GT4 has something other than a MAF sensor, so not sure these are susceptible to degrading from oil.
The stock air filters are a good size, so I don't see any need to go to a replacement that will let larger micron silica dust through that can damage cylinder walls.

I have the IPD plenum and 991 TB on order, and will buy the COBB tune and Cargraphic or Dundon long tube headers without catalysts at some point.

jmartpr

That sounds like a good mod plan for the GT4........I started the other way around with exhaust first.

d00d

I'm going to go with that white ceramic coating like you did, maybe do the exhaust too and see if I can remove the grill heat shields.

jmartpr

I also wanted to do at least the middle pipes for my Cargraphics exhausts system but I ended up just wrapping the pipes from the headers to the muffler connection with a thermal blanket insulation. At least I sleep better I have some kind of insulation like the factory OEM so I don't radiate too much heat into the rear shocks......dong the Swain coating would be the optimum thing to do.

ShakeNBake

What product did you use to do this? My headers are melting the harnesses for the O2 sensors.

jmartpr

Heatshield Products Armour Exhaust Heat Shield....you can cut them and fixed them to tubes with their stainless steel straps. But they do have some sleeving products for protection of harnesses/lines. Check their website......

TheGhost

what's the story with removing cats? i don't see how the cops or anyone would have anything to say? what are the gains?

jmartpr

You do gain a considerable amount of HP besides headers being cheaper.....down here you get fined plus you wont pass inspection...and I'm not swapping headers with manifold every year. Also my dealer is more friendly with mods if I don't removed emission parts from the car.....

TheGhost

How much is the gain roughly? I mean, how often does a GT4 need to pass inspections?

ShakeNBake

+1 Dealers don't seem to like illegal cars. Couple other (minor) issues when going catless. 1) It smells and a snowmobile. 2) The splatters brown "goo" all over the back of your car, and that goo is hard to get off. if you have a white car, it is a visible mist of brown. Not an issue if you keep your car clean, but if you are lazy, it will require a lot of help to come off.

TheGhost

But what about them GAINS?

jmartpr

I think you are looking at around an additional 10-15 hp

okie981

May be nothing more than a coincidence, but I think mod topics got pretty quiet on this forum when the "unintended throttle staying open" issue occurred on a car with an aftermarket tune...