jbradsd1, STH, cats and me.

[G8V8]

I was looking at the posts about the Kooks STH and cats and the great job jbradsd1 did explaining and testing and reporting. I have some questions.

In some earlier posts it was expressed that STH don't make much difference. The HP gains with stock cats was minimal.

The numbers jbradsd1 reported look better but the total HP increase with the STH, cats, CAI tune and HSRK are about the same as reported for just the Tune, CAI and HSRK. When he put the headers on first, he showed gains. then when he put the CAI, tune and HSRK on he showed more gains but, again, the total was close to those reported by VMS for the Tune and Roto-Fab alone.

jbradsd1 and I are running G8s with the same mods except for the STH and cats so I hoped our individual trips to the strip would shed some light. I don't have a UDP and don't think he does either.

I expected his to be faster than mine but it wasn't. My best was 13.262 @ 106.77, 60' @ 2.031 and his was 13.48 @ 105.23 with a 2.099 sec 60' time.

So.... can anything be drawn from this?

Are STH and cats worth $800+?

I think he and i are drag rookies (at least I know i am) so does that swamp out everything else?

I was in MD with 70* temps and low humidity. He was in FLA, humidity always high. Did negate any comparisons?

LTH are not in my future so I'm trying to decide where to best spend the next mod dollars. i don't have a lot to spend and want to get the most bang for the buck.

[wreckwriter]

You've already got the cheap and easy stuff. I would suggest you reconsider the LT headers if you want to see real performance gains for reasonable money.

[Andy@Livernois]

is there any reason LTH's aren't in the future? I would definatly reconsider if it were my car...

[jbradsh1]

G8V8: I'd add the following observations. 1. I don't understand myself why the car didn't put out a total of 55 rwhp. I mean 15 for the Shorties + high flow cats (which I observed myself while watching the Mustang dyno with Kirk at VMS) and then with the addition of the R-F, VMS tune, & hsrk you would get the 40 additional rwhp giving a grand total of 55 rwhp, would you not. 2. If what you want is performance and the sound or quiet isn't quite as important then do as everyone else is advising and go with the LT's. 3. Sound & quiet was more important than all out performance so I went with the Kooks shorties, which I am very, very happy with because the sound is even better than stock but only just a little louder. 4. I think I remember Kirk mentioning that the cars he's dyno'd have improved between 30-40 rwhp, not necessarily a full 40 all the time, with the R-F, hsrk, and his tune. 5. Maybe Kirk could shed some light on this. He seemed a little surprised also at the overall result, but he's had some time to think it over now and might have some input. Kirk, if you are reading this post, your input would be appreciated.

[jbradsh1]

Also, my car I believe has more low end and mid range torque now. What makes me think that? Well, for one thing, when I give the car 3/4 throttle or better in first gear it lays down a good patch when it shifts into second. Before these upgrades my car wouldn't begin to burn the tires at launch much less on the 1-2 shift!

[jbradsh1]

One last thing. I believe that my car responds better off the line by loading the transmission to about 1200 rpm at launch. I didn't do that on my 1/4 mile track runs after these upgrades, I just floored it from idle. Also, I really do think that with that technique and cooler temps + lower humidity I should run around 13.2 at 106 to 107. This is still about what you are running so I still can't explain the difference. Also the total for the Kooks shorties and high flow cats with installation labor was about $1200, for your information.

[GTPprix]

Guys you have to remember mods are not cumulative and as we've said before Long Tubes are the way to go on these cars...

[G8V8]

Thanks JB1 and Chris as well the others.

For reasons of warranty, local emission laws and inspections, tight money, the stock market, retirement in few years and my marrage, LTs probably are not going to happen.

I have enough set aside for a catback (Corso/Borla?) or STH & cats with the Catback being the safest, warranty and emission-wise. IF the STH and cats gave enough gain to warrant the risks, I could be tempted. If not, then the Corsa (Borla) MIGHT yield a little power and at least sound better than stock.

If the quiet Magnaflow turns out to not drone I would have enough for it and a UDP, maybe.

I'm not sure about the UDP for dealer reasons. It is not something I can pop off and on for visits, should i need something and not want them to see it "for future reference".

My goal, and it may not be possible given my constraints, is to touch the 12s. I think there is more to be had with what i have now by improving my launching skills and technique.

I thank you all.

[-Ray-]

Ed, my dealer installed my UDP.

[G8V8]

Ed, my dealer installed my UDP.

I was thinking about that. Also the G8 SLP FireHawk available through dealers has a CAI and UDP if not mistaken and the 3yr/36k remains intact.

Did the dealer buy the UDP or did you supply it?

[GTPprix]

Thanks JB1 and Chris as well the others.

For reasons of warranty, local emission laws and inspections, tight money, the stock market, retirement in few years and my marrage, LTs probably are not going to happen.

I have enough set aside for a catback (Corso/Borla?) or STH & cats with the Catback being the safest, warranty and emission-wise. IF the STH and cats gave enough gain to warrant the risks, I could be tempted. If not, then the Corsa (Borla) MIGHT yield a little power and at least sound better than stock.

If the quiet Magnaflow turns out to not drone I would have enough for it and a UDP, maybe.

I'm not sure about the UDP for dealer reasons. It is not something I can pop off and on for visits, should i need something and not want them to see it "for future reference".

My goal, and it may not be possible given my constraints, is to touch the 12s. I think there is more to be had with what i have now by improving my launching skills and technique.

I thank you all.

If thats the case, maybe save some money and do other mods honestly the Shorties so far havent really been worth it IMHO.

[-Ray-]

I was thinking about that. Also the G8 SLP FireHawk available through dealers has a CAI and UDP if not mistaken and the 3yr/36k remains intact.

Did the dealer buy the UDP or did you supply it?

I supplied. I bought it from Wretched Motorsports.

[wreckwriter]

Yea, even if your dealer will install mods don't even consider letting them source the mods. You'll be raped harshly; as a friend once said "your wallet will be ported".

[GTPprix]

Yea, even if your dealer will install mods don't even consider letting them source the mods. You'll be raped harshly; as a friend once said "your wallet will be ported".

dude thats the best line EVER!

[wreckwriter]

dude thats the best line EVER!

It's a really good one. You know that though since it's YOUR line :)

[G8V8]

That really is funny.

[GTPprix]

It's a really good one. You know that though since it's YOUR line :)

Yeah.. I know ;)

[wreckwriter]

Yeah.. I know ;)

It was classic and totally fit the situation we were discussing. I still laugh about it when it pops into my head (pretty much any time porting is mentioned).

[G8V8]

I've read the VMS and Dr. Dana Miller's post about Dr. M turning a 12.76 @108 with a 2.04 60' time. His G8 had the VMS tune, Roto-Fab CAI and MagnaFlo catback. This was run on the stock 18" tires and without a UDP, headers or new converter. Ambient temps were 68* with pretty low humidity. I think he also had the Grrrr8 mods.

I am missing the catback and am on stock 19" tires. My 60' was better by a little, 2.031 vs 2.04 sec.

So, I'm asking myself what is different, what do I need to do. Here is what I think. Please jump in if my head is where the sun don't shine.

1. Practice. I think of things I could have done better, like launch.

2. Manage heat better. My best run came when I had the shortest wait to stage. My ECT was 189* on that one. Don't know the IAT. On my worst run (I logged it) my ECT was 205* and my IAT was 143* as staged and dropped to 96* at the traps. I didn't know if I should shut down waiting in the lane between advancing moves. On 2 runs I was held just before the water box for at least 5 min as they, 1) rolled 2 funny cars ahead to run before me for 2 individual runs and 2) as they inspected the track for oil from a smoking run by the car ahead of me.
3. Get the rev limiter bumped up by VMS as they offered to do. I hit the limiter in normal and it never shifter to 4th. It just went flat through the traps. When in Manual 3rd, it felt stronger through the traps and didn't seem to hit the limiter even though i had a higher speed so I'm not sure how that happened. I'll get with VMS about that.
4. Did I say practice?
5. Think about catbacks (I need SOME sound).
6. Researrch any benefit with high flow cats if used on stock manifolds and a catback.
7. Investigate a dealer installed UDP.

What do you guys think?

[g8_795]

I've read the VMS and Dr. Dana Miller's post about Dr. M turning a 12.76 @108 with a 2.04 60' time. His G8 had the VMS tune, Roto-Fab CAI and MagnaFlo catback. This was run on the stock 18" tires and without a UDP, headers or new converter. Ambient temps were 68* with pretty low humidity. I think he also had the Grrrr8 mods.

I am missing the catback and am on stock 19" tires. My 60' was better by a little, 2.031 vs 2.04 sec.

So, I'm asking myself what is different, what do I need to do. Here is what I think. Please jump in if my head is where the sun don't shine.

1. Practice. I think of things I could have done better, like launch.

2. Manage heat better. My best run came when I had the shortest wait to stage. My ECT was 189* on that one. Don't know the IAT. On my worst run (I logged it) my ECT was 205* and my IAT was 143* as staged and dropped to 96* at the traps. I didn't know if I should shut down waiting in the lane between advancing moves. On 2 runs I was held just before the water box for at least 5 min as they, 1) rolled 2 funny cars ahead to run before me for 2 individual runs and 2) as they inspected the track for oil from a smoking run by the car ahead of me.
3. Get the rev limiter bumped up by VMS as they offered to do. I hit the limiter in normal and it never shifter to 4th. It just went flat through the traps. When in Manual 3rd, it felt stronger through the traps and didn't seem to hit the limiter even though i had a higher speed so I'm not sure how that happened. I'll get with VMS about that.
4. Did I say practice?
5. Think about catbacks (I need SOME sound).
6. Researrch any benefit with high flow cats if used on stock manifolds and a catback.
7. Investigate a dealer installed UDP.

What do you guys think?

I saw some idiot trying to sell his MF catbacks somewhere around here. Oh wait, I found the link: http://www.forum.grrrr8.net/showthread.php?t=1182

I think he even lives in NOVA? If you want to hear them or anything, let me know. :)

-Robert

[GTPprix]

I've read the VMS and Dr. Dana Miller's post about Dr. M turning a 12.76 @108 with a 2.04 60' time. His G8 had the VMS tune, Roto-Fab CAI and MagnaFlo catback. This was run on the stock 18" tires and without a UDP, headers or new converter. Ambient temps were 68* with pretty low humidity. I think he also had the Grrrr8 mods.

I am missing the catback and am on stock 19" tires. My 60' was better by a little, 2.031 vs 2.04 sec.

So, I'm asking myself what is different, what do I need to do. Here is what I think. Please jump in if my head is where the sun don't shine.

1. Practice. I think of things I could have done better, like launch.

2. Manage heat better. My best run came when I had the shortest wait to stage. My ECT was 189* on that one. Don't know the IAT. On my worst run (I logged it) my ECT was 205* and my IAT was 143* as staged and dropped to 96* at the traps. I didn't know if I should shut down waiting in the lane between advancing moves. On 2 runs I was held just before the water box for at least 5 min as they, 1) rolled 2 funny cars ahead to run before me for 2 individual runs and 2) as they inspected the track for oil from a smoking run by the car ahead of me.
3. Get the rev limiter bumped up by VMS as they offered to do. I hit the limiter in normal and it never shifter to 4th. It just went flat through the traps. When in Manual 3rd, it felt stronger through the traps and didn't seem to hit the limiter even though i had a higher speed so I'm not sure how that happened. I'll get with VMS about that.
4. Did I say practice?
5. Think about catbacks (I need SOME sound).
6. Researrch any benefit with high flow cats if used on stock manifolds and a catback.
7. Investigate a dealer installed UDP.

What do you guys think?


1. and 4. are biggies didnt you say it was your first time at the track IIRC if so you are off to a great start :)
2. This is by FAR the biggest change you'll see, wait till its in the 40's/50's that car will FLY!!!!!!
3. No sweat, just let us know!
6. Probably not worth it, shorties with Cats at that point will be more beneficial due to the way they are setup compared to stock.

[GeorgeInNePa]

I've read the VMS and Dr. Dana Miller's post about Dr. M turning a 12.76 @108 with a 2.04 60' time. His G8 had the VMS tune, Roto-Fab CAI and MagnaFlo catback. This was run on the stock 18" tires and without a UDP, headers or new converter. Ambient temps were 68* with pretty low humidity. I think he also had the Grrrr8 mods.

I am missing the catback and am on stock 19" tires. My 60' was better by a little, 2.031 vs 2.04 sec.

So, I'm asking myself what is different, what do I need to do. Here is what I think. Please jump in if my head is where the sun don't shine.

1. Practice. I think of things I could have done better, like launch.

2. Manage heat better. My best run came when I had the shortest wait to stage. My ECT was 189* on that one. Don't know the IAT. On my worst run (I logged it) my ECT was 205* and my IAT was 143* as staged and dropped to 96* at the traps. I didn't know if I should shut down waiting in the lane between advancing moves. On 2 runs I was held just before the water box for at least 5 min as they, 1) rolled 2 funny cars ahead to run before me for 2 individual runs and 2) as they inspected the track for oil from a smoking run by the car ahead of me.
3. Get the rev limiter bumped up by VMS as they offered to do. I hit the limiter in normal and it never shifter to 4th. It just went flat through the traps. When in Manual 3rd, it felt stronger through the traps and didn't seem to hit the limiter even though i had a higher speed so I'm not sure how that happened. I'll get with VMS about that.
4. Did I say practice?
5. Think about catbacks (I need SOME sound).
6. Researrch any benefit with high flow cats if used on stock manifolds and a catback.
7. Investigate a dealer installed UDP.

What do you guys think?

1. Yes, that will help. Find whether your car likes off idle, 1000, 1200 rpm launches. Find out what the best tire pressure is, front and rear, for your car. Start with Charlies recommendations and go up and down from there.

2. If you are not moving your car, it should NOT be running. If you are in the pits or the lanes, the hood is open.

3. What is the limiter set at now?

4. Yes

5. Think about longtube headers. Even if there are strict visual inspections in your state, there is ALWAYS a place that looks the other way. ;)

6. Probably not enough to offset the cost.

7. The UDP is worth the money.

ETA
I type too slow. LOL

[G8V8]

1. Yes, that will help. Find whether your car likes off idle, 1000, 1200 rpm launches. Find out what the best tire pressure is, front and rear, for your car. Start with Charlies recommendations and go up and down from there.

2. If you are not moving your car, it should NOT be running. If you are in the pits or the lanes, the hood is open.

3. What is the limiter set at now?

4. Yes

5. Think about longtube headers. Even if there are strict visual inspections in your state, there is ALWAYS a place that looks the other way. ;)

6. Probably not enough to offset the cost.

7. The UDP is worth the money.

ETA
I type too slow. LOL

1. Understood. For example, I left my tire pressures where they were for the drive there.
2. I realize that now.
3. I think 6300 rpm.
4. Yes.
5. I would love them.
6. I suspect that is true.
7. I agree.

Thanks,
Ed

[G8GTlawride]

G8V8: I'd add the following observations. 1. I don't understand myself why the car didn't put out a total of 55 rwhp. I mean 15 for the Shorties + high flow cats (which I observed myself while watching the Mustang dyno with Kirk at VMS) and then with the addition of the R-F, VMS tune, & hsrk you would get the 40 additional rwhp giving a grand total of 55 rwhp, would you not. 2. If what you want is performance and the sound or quiet isn't quite as important then do as everyone else is advising and go with the LT's. 3. Sound & quiet was more important than all out performance so I went with the Kooks shorties, which I am very, very happy with because the sound is even better than stock but only just a little louder. 4. I think I remember Kirk mentioning that the cars he's dyno'd have improved between 30-40 rwhp, not necessarily a full 40 all the time, with the R-F, hsrk, and his tune. 5. Maybe Kirk could shed some light on this. He seemed a little surprised also at the overall result, but he's had some time to think it over now and might have some input. Kirk, if you are reading this post, your input would be appreciated.

Long tubes are just "a little louder" as well and perform much better. Especially with the stock mufflers which do NOT lose any appreciable HP.

[jbradsh1]

I understand your point. But what convinced me to go with the shorties was that someone on a post mentioned that because the headers extend down under the floor of the car and of course so do the pipes that go from the headers to the back of the car, which are less muffled, i.e., no midway muffler or resonators, that the noise comes through from under the car to a greater extent, i.e., less quiet. I also like the sound from the resonators, mio!

[G8GTlawride]

I understand your point. But what convinced me to go with the shorties was that someone on a post mentioned that because the headers extend down under the floor of the car and of course so do the pipes that go from the headers to the back of the car, which are less muffled, i.e., no midway muffler or resonators, that the noise comes through from under the car to a greater extent, i.e., less quiet. I also like the sound from the resonators, mio!

Well, I don't know what to say without sounding mean and that is NOT my intention. But there were many many posts that all said the LT's were almost stock quiet with the stock mufflers. I had a horrendous noise in mine, but the pipes were hitting the cross brace. Once that was resolved the car is super quiet and SUPER quick.

[jbradsh1]

Hey, sounds great. What's not to like about our G8 GT's!