I wanted to share my review of the TopGear Catless headers on my 981 GT4 since I never found any mention of them. TopGear seems to have a big following with the 911 UK owners, but there's little to no mention about them here in the US, and I'm not quite sure why. They're a great option at an amazing price point.

From the photos they have listed on their website, TopGear's catless headers appear to a very similar design to another very popular producer of Porsche exhaust systems. This set of catless headers are made of 304 grade stainless steel and also come with a lifetime warranty.

I first contacted TopGear via email and dealt with Alexander who was extremely responsive. I wanted to confirm availability & fitment of their "decat headers" on the GT4. After a few emails back & forth, I decided to pull the trigger and place an order for them. I placed the order on Sunday evening and the well-packaged box arrived Wednesday via DHL. Guys, can we say that's some AMAZING shipping time? It literally crossed over the massive pond to my front door in 3 days (UK to Florida)!





Some pics of the headers & welds:
















Compared to stock header:




The TopGear headers do not come with any gaskets, bolts, o2 spacers, etc. I ordered new exhaust gaskets & header bolts from Suncoast and decided to get a set of J-style o2 spacers to prevent CE lights. I don't have a tune yet at this time, so I decided going with a o2 spacer in hopes of preventing a CE light in the meantime. You will need to make a quick trip to a hardware store to pick up some stainless steel bolts, nuts, & washers for the flange at the header to muffler.

The installation was extremely straightforward. I completed it in my garage on jackstands. If you have access to a lift and a helping set of hands, it'll go much easier. Overall, if you can change your oil, you should be able to handle this installation. The TopGear catless headers fitment was spot on. No issues with bolt holes not lining up or anything in that nature. Literally fit like an OE part. Factory header bolts were long enough and were torqued to 22lbs. I'll have to recheck them again after a few more heat cycles to make sure they're still torqued properly.





I've put on 150mi on them thus far with no issues. No strange exhaust rattles. No CE light. Only thing I've noticed is the ButtDyno says it pulls much harder, and my ears ring a little more from the glorious sound this GT4 now makes. ;-)

Since I was trying to find info and sound clips of this TopGear catless header and wasn't able to find any before purchasing, I decided I would take some sound clips before and after so others that might be shopping for headers can decide for themselves. Keep in mind I have the stock PSE valved system on the GT4. I personally feel this is the best setup for the GT4 - catless headers w/stock PSE valved exhaust. It's the best of both worlds, calm & collective when driving through the neighborhood, but screams like a race car when on it. Previous to this setup, I ran stock headers with Fabspeed Competition exhaust which sounded amazing at all times, but it was also obnoxiously loud when driving through my community. Click link for sound clips:

Overall, I am EXTREMELY satisfied with this set of TopGear catless headers for my 981 GT4. Best of all, they retail for almost half off the competitors!! Can’t beat that deal!

 

They look just like soul headers. Cant beat that price.

 

I wasn't going to be the one to say it... ;-) Supposedly some sources have said it's the exact same part, made in the same factory, just without the sandblasted finish & Porsche Tax. How true, who knows! Either way, I'm very satisfied with the part & service from TopGear. My wallet also thanks me as well!

 

Thanks for the illuminated writeup on the headers - sounds like a good deal for the money and great delivery service too.
Could you let me know the following:
A) Where did you get the J style O2 extenders from? I've not seen them here in Australia and the TopGear site says you "may" need them to prevent CEL's..
B) Did you have to lengthen the O2 cable to fit ?
C) Could you have used the original bolts to mount the header flange, or do you have to use longer bolts (thicker flange)?
Good to know you have not had any CEL's illuminate on the dash too.

 

A)I got my set through Ebay, Any catless header will eventually cause a CE light. Only a tune will fully eliminate the chance of getting that code, but the spacers will help prevent them. It's not 100% though since some people have reported CE lights even with spacers. It all just depends on how sensitive your ECU is. I ordered these specifically: O2 Spacers
B) I disconnected the O2 sensors when installing and removed them from their factory mounting point clips. After it was reinstalled, I just had to refit them onto the mounting clips. No need to actually extend the wires, it's just adjusting where they mount on the clips.
C) Yes, I used the factory header bolts (got new ones directly from Porsche). Although the flange was thicker, I was able to use factory bolts just fine.

 

Great write up!

 

Thanks for the clarifications re installation guidelines.

 

They look great and I've been looking at something for my 981 spyder but I'm either on the wrong website or doing something wrong as I can't find anything for a 2016 Boxster, let alone a spyder or GT4. Would love to know who much they cost...

Could you post the website? TIA

 

Here's the link to the exact ,15-model[Cayman]]headers. Unfortunately it looks like another RL member ended up getting the last one they had in stock. From my understanding, they have more coming though. Try emailing TopGear to find out what their ETA is and current shipped price. I dealt with Alexander (alex@topgear.co.uk) and he was very helpful.

 

That price is amazing, talk about even better bang for the buck going with headers

 

I'm surprised it is the same part for all the different 981's. I would have thought the GT4 and spyder ones would be a slightly larger diameter... guess I'll email them.

 

Thanks for your input, I’m going to pull the trigger on the 987.1 long tube headers by Topgear. Looks like base on the reviews, the Topgear headers for the price and build quality is comparable to Soul and Fabspeed. Btw, did you get any CEL with the O2 spacers post install?

 

Would you mind posting the part numbers of the gaskets/bolts etc.? Be nice a complete of bits so could imagine it as a 'kit'.

I wonder what kind of power you'd get with these and a tune?

 

Assuming they work just like Soul, you can look at dyno postings on the Soul site that compare HP and Torque on the same graph between Stock, Stock with tune, Catted header, catted header with Softronic Tune, and catless header with softronic, iirc. Very informative, not just the raw increases at max HP, but the shape of the curve, which is the more useful improvement IMO.

I went Soul Catted with Softronic and couldn't be happier.

And for the record, I'm not saying these TopGears are equivalent to Soul; just saying that you can get the info you're looking for on the Soul site for their products.

 

hi there sorry to revive this thread
but I am looking to replace the headers
Fabspeed was my option but then I read this thread and the quote shipped to my place is 1.2k
Fabspeed equivalent is 3k without cats and 4K with cats
I have a couple of questions for you,
1) did you ever have a CEL or your J style 02 spacers prevent that?
2) a smog visual inspection can see the catless configuration without lifting the car? California only plugs the computer now, no sniffer, so as long as you don’t have codes you pass, but I am not sure if the cats are visible with the car on the ground.
3) I read you had the racing exhaust from Fabspeed with stock headers and decided to swap the configuration. What was the reason? Too loud?
4) top gear also offers manifolds with HF cats, did you consider them to avoid the CEL possibility ? Or you think catless is a way better configuration?
thanks