Doug Thorley Tri-Y Headers

[Keith2]

Brand: Doug Thorley Tri-T Headers
Price: $625 shipped
Purchased From: www.autoanything.com, and for the O2 chek engine light:
http://www.redlinemotive.com/store/megan-racing/megan-racing-check-engine-light-eliminator.asp


Installation: Moderate to Involved if your a novice such as myself.

Installation Time: About 8 hours including breaks and a trip to the parts store.

Any Installation Tips You Have: I found that using white out is an easy way to keep the steering shaft lined up once you remove the bolt and slide it out of the way. Loosen and tighten the header bolts from the outside in. Also, the driver's side O2 sensor very difficult to loosen with a ratchet and O2 sensor socket even after sparying it with penatrating spray. I unplugged the driver side front O2 sensor harness and pulled it off with the impact wrench outside of the car (seemed to be the eaiset way). Fortunatley, I had access to air tools which made it a lot eaiser to loosen. The way the passenger side O2 sensor is located is very tight so I had to drop the header and prop it up with a liitle stool under the car to work on it. If you are working with jack stands like I did you will have to remove the O2 sensor from the manifold because the harness is just in too tight of space to undo. It will hang just enough to get the impact gun in there to loosen it from the manifold. If you have an extra set of hands when bolting on the headers it makes it a lot better to line up the gasket and bolts instead of trying to hold the headers and do this. I did the driver's side by myself but had the extra help with bolting up the passenger side (much easier). The gaskets for the collectors takes a little elbow grease to remove from the factory manifolds.All in all just be patience with this job. If you don't do a lot of work on cars it can seem a bit overwelming at times. I found it easiest to just stop when I was getting frustrated instead of trying to force parts and end up breaking things.

Quality of Part: I would give quality a 10. They are very well packed and built. All the bolts and instucitons were supplied for the install.All the welds were very professional and the cermaic coating looked good as well.

Product Performance: Performance I will give an 8.5, for now, but only because I know they will be even better once I have a dyno tune and not just my cortex tuner. They do add a deeper tone to the exhaust but nothing that is real noticable under normal driving. However, if you get on the car a little it does wake and you notice that there is something that is not quite stock under the hood. I'm sure it will be more pronounced once I get my catback since the headers don't have any cats. For the seat of the pants feel I can really feel it the most out of the mods I have done so far. For the price of the headers it is worth the performance increase I feel. If I would have to guess I would say the car most likely picked up at least 25 whp. The dyno will tell very soon though.

Would you Recommend to Others: For someone that is looking for a good quality product that is sure to net great gains in peformance I would recommend these headers.

Any Other Comments: The car is really fun to drive now.:thumbsup: Pictures to come once I have time to take them.

[bbutler455]

I went to school on Keith and had a little easier time. I completely agree with the quality of these headers. Installed they look like right at home.
http://i225.photobucket.com/albums/dd216/bbutler455/DSCN2017.jpg

A few suggestions:
- unfasten the O2 sensors from the harness and leave them on the cat. Remove them after you remove the exhaust.
- you can't see the driver side o2 connection so remove the passenger side first so you see how to un-clip.
- the O2's may be galled when you remove so be prepared to chase the threads with a 18x 1.50 die, or use a file.
- my passenger side O2 cable was too short for the new headers so either buy an aftermarket O2 (longer cable) or splice 2" to the exisitng cable.
- you will need to drill out the dipstick spacer to fit the 10mm bolt
- you will need a 8 x 1.25 tap to clean the threads in the block becuase GM uses loc-tite.
- also, DON'T CLOSE THE TRUNK AFTER YOU DISCONNECT THE BATTERY (don't ask)

Possible problems:
- if you get a Stablizer Control Turned Off message - you broke a spark plug. Don't ask me how but it happened to both keith and I.


Performance:
OUTSTANDING! Before the VMS tune it was noticeable. After the tune it was smoother and much more powerful. There were not any check engine codes and I can't tell that the front cats are gone - no smell. I kept the stock mid-pipe and mufflers. Cruising around it sounds stronger but refined. When you put your foot in it I have no idea what it sounds like becuase I was too busy hanging on. Holy cr%p! With the VMS ECM and transmission tune it puts ALL the power to the road and absolutely leaps through the gears.

Like Keith, for $625 shipped and a day of my time (I go slow so I don't f&%k up too much) it was exactly what I wanted. My engine-bay looks like it should from the factory. Vararam, crazy paul radiator cover, and Doug Thorely Tr-Y's. Here is a picture of my engine.
http://i225.photobucket.com/albums/dd216/bbutler455/DSCN2014.jpg

This kind of refined performance is EXACTLY what I have been shooting for. This car is my Australian M5 BMW. And only car guys know about it. This is the last performance pontiac. The last of the Mohicans.

[TY2185]

This car is my Australian M5 BMW. And only car guys know about it. This is the last performance pontiac. The last of the Mohicans.

Nice write up and an even nicer quote:thumbsup:

[Keith2]

Brock, Yeah school was in session :boxing: No need to post any pictures since yours looks very nice and clean. VMS has a tune out for the headers? I might go that route if it seems to be running well for you. I know it feels pretty good with just the cortex tuner and can't wait to get a real tune for it...

[mtolivecracker]

Those shine beautifully!!! Love the placement of the logo too!!! Very stylish

[bbutler455]

Brock, Yeah school was in session :boxing: No need to post any pictures since yours looks very nice and clean. VMS has a tune out for the headers? I might go that route if it seems to be running well for you. I know it feels pretty good with just the cortex tuner and can't wait to get a real tune for it...

Keith, VMS sent me the tune for the Kooks LT headers and vararam. It seems to fit pretty good. They send you the program for your laptop and loan you the ECM cable. Then you download the file from your computer and email it to them. They tune it and send it back the next day. Upload it and Viola!

[StandFast85]

Do the Tri-Y's bolt to the stock mid-pipe?

[dukeofpg]

which of the 02 sensor eliminator did you use ? Straight or 90 degree? and do you need just one or two? Thanks

[bbutler455]

1. The headers bolt perfectly to the stock mid-pipe. You re-use the same doughnut gasket. It is a better-than-factory look and fit. AND my Pontiac dealer didn't have any problem doing warranty work after I did it. (If I blow the engine it will be a different story.)

2. You do not HAVE to use an O2 eliminator. If you get a check engine light (I didn't) it will be eliminated when you get your re-tune. On my car the O2 cable on the drivers side was 1/2" too short so a straight eliminator on that side would allow you to use the stock O2 cable without having to splice additional length.

[StandFast85]

Hm, these may be the headers I go with!

I wonder what effect some high-flow catalytic converters would have.

[GRRRR8]

AND my Pontiac dealer didn't have any problem doing warranty work after I did it. (If I blow the engine it will be a different story.)

They didnt say anything about voiding your emission warranty as you have no cats?

[jimmytt6]

Very nice..too bad I have emissions to go thru..
Please tell me were you got your red plug wires?? What type are they?
I have seen them on a couple of cars and can't get a answer on what
type of plug wires or who sells them...lol

thanks,

Jim




I went to school on Keith and had a little easier time. I completely agree with the quality of these headers. Installed they look like right at home.
http://i225.photobucket.com/albums/dd216/bbutler455/DSCN2017.jpg

A few suggestions:
- unfasten the O2 sensors from the harness and leave them on the cat. Remove them after you remove the exhaust.
- you can't see the driver side o2 connection so remove the passenger side first so you see how to un-clip.
- the O2's may be galled when you remove so be prepared to chase the threads with a 18x 1.50 die, or use a file.
- my passenger side O2 cable was too short for the new headers so either buy an aftermarket O2 (longer cable) or splice 2" to the exisitng cable.
- you will need to drill out the dipstick spacer to fit the 10mm bolt
- you will need a 8 x 1.25 tap to clean the threads in the block becuase GM uses loc-tite.
- also, DON'T CLOSE THE TRUNK AFTER YOU DISCONNECT THE BATTERY (don't ask)

Possible problems:
- if you get a Stablizer Control Turned Off message - you broke a spark plug. Don't ask me how but it happened to both keith and I.


Performance:
OUTSTANDING! Before the VMS tune it was noticeable. After the tune it was smoother and much more powerful. There were not any check engine codes and I can't tell that the front cats are gone - no smell. I kept the stock mid-pipe and mufflers. Cruising around it sounds stronger but refined. When you put your foot in it I have no idea what it sounds like becuase I was too busy hanging on. Holy cr%p! With the VMS ECM and transmission tune it puts ALL the power to the road and absolutely leaps through the gears.

Like Keith, for $625 shipped and a day of my time (I go slow so I don't f&%k up too much) it was exactly what I wanted. My engine-bay looks like it should from the factory. Vararam, crazy paul radiator cover, and Doug Thorely Tr-Y's. Here is a picture of my engine.
http://i225.photobucket.com/albums/dd216/bbutler455/DSCN2014.jpg

This kind of refined performance is EXACTLY what I have been shooting for. This car is my Australian M5 BMW. And only car guys know about it. This is the last performance pontiac. The last of the Mohicans.

[Keith2]

Jimmy, I'm not sure about Brock's plug wires but mine came from the factory with red ones. Maybe try the dealership...

[jimmytt6]

Really WTF..My 09 had these ugly black boot with gray wire..mm
I thought the red would look nice since I have the rare Liquid Red color..lol
Nice write up you guys did should help when I order my headers here in the
next month.
Guess I'll ask the dealer..I'm still waiting for my touch up paint.

Jim



Jimmy, I'm not sure about Brock's plug wires but mine came from the factory with red ones. Maybe try the dealership...

[shane]

i would love to see numbers on thsese

[Keith2]

i would love to see numbers on thsese

I was planning on dynoing once I ordered my VMS tune. I'm going to do the Superchips 93 tune pull then load up the VMS tune to compare the differences. Hope to have this done soon when I can break away from my work schedule. I will say the car is fun to drive with the mods I have right now.

[StandFast85]

I'm still very interested in these headers. You can't beat that price.

[johnh]

i would love to see numbers on thsese

http://www.g8board.com/forums/showthread.php?t=13775&highlight=thorley&page=5

[bbutler455]

1) Yes, the red plug wires are stock.

2) No, the pontiac dealer had no problems with my mods. They were careful to not screw up my VMS tune. There is an active hot rod pontiac club in Plano, TX - I think they are used to it. Also, this is Texas... nuff said.

I've been driving the Tri-Y, Vararam, VMS combination for two weeks and am glad I did not put an aftermarket exhaust on it. The Vararam intake gives more bass to the sound of the engine. The Tri-Y's transmit just enough of the unleased detonation sound waves to make the car sound dangerous.

My driving experience is that the car is so smooth and quick that it FEELS lighter. The slightest acceleration puts you way ahead of traffic. I am anxious to measure the MPG. It HAS to be more efficient. (Once I stop putting my foot in it)

I'll keep you posted

[StandFast85]

:woohoo:

[jimmytt6]

Nice..I think the Tri-Y headers and no cat would be a little too loud with my Borla cat-back for me atleast.

I wonder if just the 08's G8's came with the red plug wires or if Greg from Pace sells them



1) Yes, the red plug wires are stock.

2) No, the pontiac dealer had no problems with my mods. They were careful to not screw up my VMS tune. There is an active hot rod pontiac club in Plano, TX - I think they are used to it. Also, this is Texas... nuff said.

I've been driving the Tri-Y, Vararam, VMS combination for two weeks and am glad I did not put an aftermarket exhaust on it. The Vararam intake gives more bass to the sound of the engine. The Tri-Y's transmit just enough of the unleased detonation sound waves to make the car sound dangerous.

My driving experience is that the car is so smooth and quick that it FEELS lighter. The slightest acceleration puts you way ahead of traffic. I am anxious to measure the MPG. It HAS to be more efficient. (Once I stop putting my foot in it)

I'll keep you posted

[shane]

my 04 sierra came with red wires... some did some didnt..

my gto did and my g8 did...

back in the day with the truck guys the red ones were supposed to be better and actually ohmed lower

[jimmytt6]

thanks for the info..guess I try my local dealer but I'm sure they wont have a
clue if I can get them..


my 04 sierra came with red wires... some did some didnt..

my gto did and my g8 did...

back in the day with the truck guys the red ones were supposed to be better and actually ohmed lower

[StrykersG8]

Have these came back in stock yet?

[G8V8]

Nice..I think the Tri-Y headers and no cat would be a little too loud with my Borla cat-back for me atleast.

I wonder if just the 08's G8's came with the red plug wires or if Greg from Pace sells them

Mine are red too.

[Mlozano]

So do you guys think there's really a difference between these, kooks, or ARH Headers besides the price, performance wise?

[MGMG8GT]

I keep looking at these. As soon as I pay off some bills, I'll bet buying a set.

[GTeve]

Sound clips please!

And how do you think these will do with a cam and SC? compared to Kooks or ARH 1 7/8" obviously.

[StrykersG8]

Yes need a Video :D

[StandFast85]

What if I wanted to run cats with these headers? I'd have to get a shop to install them and mate them to my stock cat back right?

[BrentAdams646]

:woohoo: VIDEO! I'll be running DT Tri-Y's with no cats and Corsa cat-back so i'm interested to see what it sounds like.

[WhyteSS]

These headers are becoming a real option for myself.

[dandragonrage]

What if I wanted to run cats with these headers? I'd have to get a shop to install them and mate them to my stock cat back right?

Cats don't have to be integrated with headers. You can put a cat anywhere you want. They work better hot, though, so do put them as close as you can.

Personally, I think selling catted headers is stupid.

[justinss]

MD Speed has these on sale FYI

[StrykersG8]

Do you already have this on???? If so make a video :)


:woohoo: VIDEO! I'll be running DT Tri-Y's with no cats and Corsa cat-back so i'm interested to see what it sounds like.

[Blackrider]

I bought my set today.

[GTeve]

Must.....make......video!

[StandFast85]

Has anyone mentioned the fact that we need videos of this setup?

LOL

[StrykersG8]

Still no videos.... :*(

[ronbuick]

If I remember correctly,GM Performance Parts ones are red in color, the red does look good on your car, can not remember if mine are red or not. And those headers do look good and will be my next mod as well, after rebuilding the Turbo Buick motor I'm a little short of cash at the moment, still waiting for the stimulus money to get here


Ron

[VaderzV8]

Cats don't have to be integrated with headers. You can put a cat anywhere you want. They work better hot, though, so do put them as close as you can.

Personally, I think selling catted headers is stupid.

I know dumb question, but if you have emissions testing in your state you need cats...Right:uhm:

[dandragonrage]

I know dumb question, but if you have emissions testing in your state you need cats...Right:uhm:

Depends on how the emissions testing is done. If it's done just by OBD2 stuff then you can tune out the codes with HPTuners/EFILive. If it's done by a "sniffer" then you pretty much need them.

Please use them either way. Good cats do not notably restrict you, and I can always tell when I'm behind catless cars and it's incredibly annoying. Some people have no respect for fellow drivers. Very loud exhausts, running catless, etc. They all give car enthusiasts a bad name.

[VaderzV8]

so should I just get the Kooks Mid Length Header w/Cats already installed on them? http://marylandspeed.com/kooks-mid-length-header-wcats-1-78-20082009-pontiac-g8-gt-gxp-k6712-shorty-p-2418.html

[firebird400]

I went to school on Keith and had a little easier time. I completely agree with the quality of these headers. Installed they look like right at home.
http://i225.photobucket.com/albums/dd216/bbutler455/DSCN2017.jpg

A few suggestions:
- unfasten the O2 sensors from the harness and leave them on the cat. Remove them after you remove the exhaust.
- you can't see the driver side o2 connection so remove the passenger side first so you see how to un-clip.
- the O2's may be galled when you remove so be prepared to chase the threads with a 18x 1.50 die, or use a file.
- my passenger side O2 cable was too short for the new headers so either buy an aftermarket O2 (longer cable) or splice 2" to the exisitng cable.
- you will need to drill out the dipstick spacer to fit the 10mm bolt
- you will need a 8 x 1.25 tap to clean the threads in the block becuase GM uses loc-tite.
- also, DON'T CLOSE THE TRUNK AFTER YOU DISCONNECT THE BATTERY (don't ask)

Possible problems:
- if you get a Stablizer Control Turned Off message - you broke a spark plug. Don't ask me how but it happened to both keith and I.


Performance:
OUTSTANDING! Before the VMS tune it was noticeable. After the tune it was smoother and much more powerful. There were not any check engine codes and I can't tell that the front cats are gone - no smell. I kept the stock mid-pipe and mufflers. Cruising around it sounds stronger but refined. When you put your foot in it I have no idea what it sounds like becuase I was too busy hanging on. Holy cr%p! With the VMS ECM and transmission tune it puts ALL the power to the road and absolutely leaps through the gears.

Like Keith, for $625 shipped and a day of my time (I go slow so I don't f&%k up too much) it was exactly what I wanted. My engine-bay looks like it should from the factory. Vararam, crazy paul radiator cover, and Doug Thorely Tr-Y's. Here is a picture of my engine.
http://i225.photobucket.com/albums/dd216/bbutler455/DSCN2014.jpg

This kind of refined performance is EXACTLY what I have been shooting for. This car is my Australian M5 BMW. And only car guys know about it. This is the last performance pontiac. The last of the Mohicans.

Did you go with the 1 7/8 or 1 3/4? I am thinking of going with the Veraram intake; how do you like it? Are the Tr-Y's long tubes? What is the VMS tune? Where do I get it. Thanks for the help.

[Blackrider]

Did you go with the 1 7/8 or 1 3/4? I am thinking of going with the Veraram intake; how do you like it? Are the Tr-Y's long tubes? What is the VMS tune? Where do I get it. Thanks for the help.

The Tr-Y's are considered a long tube and only come in 1 3/4ths. The VMS tune is an Engine and Transmission tune from Vector Motor sports, you can find it at www.vectormotorsports.com.

[Steve@Vectormotorsports]

Nice install and great pics!

[crazygreek89]

I'm installing my DTs on Saturday. Will post pics and dyno results then.

[Thunder_PC]

Sorry If I missed this somewhere in the thread, but are these a direct bolt on for the 09.5's since they have the two added cats? Or is some modification needed?

[JAM]

Yes they will.

JAM

[crazygreek89]

Only reason I went with Doug Thorley besides the price was because they bolted up to the Borlas as well. That was my turn off with the Kooks and their stupid connector pipes for the Borla and Corsa.

[G8inItaly]

hey crazygreek89, how about that dyno? videos would be great too :)

[Mr louis]

So did the MIL Eliminater work?

[red870]

so do these headers make more power than a kooks header?

[MGM GT]

so do these headers make more power than a kooks header?

I dunno about if they make more/less/equal too, but they make enough to go 11's. ;)

[red870]

my point is if you were going to buy kooks because they have a reputation for being the best, would you change your mind and get these because of the equality in performance.

[dthornton8]

my point is if you were going to buy kooks because they have a reputation for being the best, would you change your mind and get these because of the equality in performance.

Do the Doug Thorley's make the same gains as the kooks or ARH without cats? One reasonthe doug thorley's make such good gains is because they don't have any cats right?