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2004 CTS-V
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Discussion Starter #1
So I took my V down to Intune Motorsports in Saturday and spent the day with the owner, Scott. I can't even begin to tell you guys how awsome this guy is, and how good of a job he does.

Anyway, since I have an older style maggie with the 3'' pulley, I picked up a 2.8. Previously, with the stock maggie, gutted cats, and a tune, I made 398whp and 380something torque. This is on a very conservative mustang dyno. My initial base numbers were right around 300hp.

So we swapped pulleys (and I changed the fluid in my diff while he was working on a stock car), jerked the stock airbox assembly out of the car, and bolted up a new K&N cone filter Scott had laying around (which was intended for a cobra but fit perfectly!). I had the resonators cut off the car after his last tune, so after dialing in the drivability stuff, we hooked it up to the dyno.

It was a balmy 80 degrees in his shop, and we had driven around quite a bit working out some tuning issues. With a somewhat conservative tune I ended up putting down 418whp and 411wtq. While the peak numbers weren't that much different, at certain points in my run, there was an increase of 36whp and almost 40wtq. I'll post my new graph tomorrow. Unfortunately, I forgot to get Scott to print me one out that showed both runs for comparison sake.

Anyway, I can tell a nice difference in power. The blower is much louder now too, which is awsome. It reminds me of my old lightning now. I'm at 8.2 lbs of boost, so I don't think I'll be messing with the pulleys anymore. I'm extremely pleased with how my V performs now, and with the numbers I've put down. There's a shop right by the house with a dynojet, and I plan to go there maybe next weekend and see what kind of numbers I get. Scott said he wouldn't be surprised at all if I put down 475whp on a dynojet, considering how conservative his is.

Now, I've got to move on to cosmetic mods.... I tinted my fog lights and side markers today, and I've got a rear spoiler on the way. I'll get some pictures up soon.
 

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2016 ATS Premium 6-spd MT
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So, at this point, you've matched (very closely) what Magnuson claims for the power increase using their SC. That's great!

How's your SOTP dyno like it? What's next?
 

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Discussion Starter #3
Next is installing a spoiler and powdercoating the wheels.

As for performance mods, I may buy some headers, but more than likely, I'll just save up and eventually do a head/cam swap, along with pistons, rods, etc. I don't want to push the stock rotating assembly any harder than I am now.
 

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'06 Z06, '05 CTS-V 453rwhp/434rwtq (sold)
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8.2 lbs with a 2.8 pulley? Holy cow! That dyno does seem conservative.
 

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2016 ATS Premium 6-spd MT
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Next is installing a spoiler and powdercoating the wheels.

As for performance mods, I may buy some headers, but more than likely, I'll just save up and eventually do a head/cam swap, along with pistons, rods, etc. I don't want to push the stock rotating assembly any harder than I am now.
With headers, I'd bet you'd see a lowering of your boost AND a significant increase in rwhp. Install would be much less intrusive to the motor, too.
 

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'05 CTS-V, '00 SLS, 98 SLS, 89 Eldo, '80 Eldo
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Next is installing a spoiler and powdercoating the wheels.

As for performance mods, I may buy some headers, but more than likely, I'll just save up and eventually do a head/cam swap, along with pistons, rods, etc. I don't want to push the stock rotating assembly any harder than I am now.
With headers, I'd bet you'd see a lowering of your boost AND a significant increase in rwhp. Install would be much less intrusive to the motor, too.
I'm with Randy on the boost. I'd also like to see your torque numbers, if you get the headers.
 

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2016 ATS Premium 6-spd MT
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Honestly, with that kind of boost :eek:, it would seem that your Maggie is sure doing its job on supplying air, but that there's a restriction downstream. Again, my suspicion is that it's in the exhaust gases trying to get through those stock manifolds and also further downstream.

Here's mine:

 

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Discussion Starter #10
That's crazy! Our torque's the same, but your hp is wayyyyy higher than mine. Would exhaust make THAT much difference. I'm running the stock manifolds with gutted cats, no reasonator, and stock mufflers.
 

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id be very worried driving a stock ls6 with 8.2 lbs of boost....id lower that boost if you want that engine to last.
 

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Discussion Starter #13
Well, I'm looking for a set of headers right now, so that'll cure the boost issues.
 

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'06 Z06, '05 CTS-V 453rwhp/434rwtq (sold)
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id be very worried driving a stock ls6 with 8.2 lbs of boost....id lower that boost if you want that engine to last.
That boost is fine with a stock motor if the tune is right.

But the hp #s don't match the boost IMO.
 

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04 CTS-V with a little hp persuasion device
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If you cant get the air out, you wont have the hp on top end. Torque down low will be good but for up top, you need good flow. I can see were stock manifolds could hold you back.
 

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2016 ATS Premium 6-spd MT
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T.G., your torque starts dropping off at ~4800 RPM. Mine stays up there longer (my torque, not ... well, you know).

You need to allow those gases to exit. They're being bottled up as evidenced by your simply-to-die-for boost levels. Get headers and hi-flow cats, and your boost will be lowered, but your rwhp will increase.
 

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2005 Stealth Gray CTS-V, 2009 Black CTS-V
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So I took my V down to Intune Motorsports in Saturday and spent the day with the owner, Scott. I can't even begin to tell you guys how awsome this guy is, and how good of a job he does.

Anyway, since I have an older style maggie with the 3'' pulley, I picked up a 2.8. Previously, with the stock maggie, gutted cats, and a tune, I made 398whp and 380something torque. This is on a very conservative mustang dyno. My initial base numbers were right around 300hp.

So we swapped pulleys (and I changed the fluid in my diff while he was working on a stock car), jerked the stock airbox assembly out of the car, and bolted up a new K&N cone filter Scott had laying around (which was intended for a cobra but fit perfectly!). I had the resonators cut off the car after his last tune, so after dialing in the drivability stuff, we hooked it up to the dyno.

It was a balmy 80 degrees in his shop, and we had driven around quite a bit working out some tuning issues. With a somewhat conservative tune I ended up putting down 418whp and 411wtq. While the peak numbers weren't that much different, at certain points in my run, there was an increase of 36whp and almost 40wtq. I'll post my new graph tomorrow. Unfortunately, I forgot to get Scott to print me one out that showed both runs for comparison sake.

Anyway, I can tell a nice difference in power. The blower is much louder now too, which is awsome. It reminds me of my old lightning now. I'm at 8.2 lbs of boost, so I don't think I'll be messing with the pulleys anymore. I'm extremely pleased with how my V performs now, and with the numbers I've put down. There's a shop right by the house with a dynojet, and I plan to go there maybe next weekend and see what kind of numbers I get. Scott said he wouldn't be surprised at all if I put down 475whp on a dynojet, considering how conservative his is.

Now, I've got to move on to cosmetic mods.... I tinted my fog lights and side markers today, and I've got a rear spoiler on the way. I'll get some pictures up soon.
8.2 lbs of boost from a 2.8" pulley would be very good.

An increase of ~40 rwtq makes perfect sense, as I've not only seen that increase several times in other cars, I got ~40 myself when I went from a 3.0" to a 2.8" and also got another ~40 rwtq from the switch from a 2.8" to a 2.6" (which I then changed to an 8" crankshaft, which got me a shade more...). The entire rwtq cuve just shifts up when you do a pulley change---it's, by far, the single easiest change to feel it in the SOP.

~475 rwhp from a 2.8" pulley would be absolutely god-like and better than any numbers I've ever seen from a 2.8". ~475 rwhp is much more like a 2.6"/8" crankshaft pulley number. ~440-450 rwhp (~410 rwtq is very common as well) is about the average from a 2.8" pulley from across the US that I've seen.
 

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8.2 lbs of boost from a 2.8" pulley would be very good.

An increase of ~40 rwtq makes perfect sense, as I've not only seen that increase several times in other cars, I got ~40 myself when I went from a 3.0" to a 2.8" and also got another ~40 rwtq from the switch from a 2.8" to a 2.6" (which I then changed to an 8" crankshaft, which got me a shade more...). The entire rwtq cuve just shifts up when you do a pulley change---it's, by far, the single easiest change to feel it in the SOP.

~475 rwhp from a 2.8" pulley would be absolutely god-like and better than any numbers I've ever seen from a 2.8". ~475 rwhp is much more like a 2.6"/8" crankshaft pulley number. ~440-450 rwhp (~410 rwtq is very common as well) is about the average from a 2.8" pulley from across the US that I've seen.
Luna do you think the 2.6 pulley had anything to do with your failed bearings?

That's probably my #1 concern about putting the 2.6 pulley on right now.
 

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Luna do you think the 2.6 pulley had anything to do with your failed bearings?

That's probably my #1 concern about putting the 2.6 pulley on right now.
Very possible.

The part that still makes me raise an eyebrow to this day, however, was that I couldn't get past the logic that I was only truly spinning it faster than the 2.8" intended at higher RPMs (say, 6,200+). Below that, it isn't spinning any faster than what it was intended to. Since I babied the hell out of my car (I'm STILL on the original '05 diff for crying out loud...), it strikes me as strange that such few run-ups could make a significant impact.

What I truly enjoyed was just "torqueing" the heck out of the motor...you know what I mean, a good 1/2-3/4 throttle jab, just letting all that torque shove the car down the road effortlessly... :) I did that 50x more than WOT up to redline (or even past 6,200 RPM for that matter)...

As such, I'm honestly not sure. Many others are running 2.6" or 8" crankshaft pullies & I haven't read about a ton of issues, so who knows? I want to say yes, but it still doesn't pass the smell test. I'm thinking I was just unlucky... :rant2:

My biggest concern for going to a 2.6"/8" crankshaft pulley would be the pistons far before the bearings though...Bearings are a fairly easy fix as compared to the pistons...

Looking back, I honestly would NOT go to the 2.6"/8" crankshaft if I had the chance to do it all over again. Why? Well, it sure as heck is NOT because of the additional power...it's addictive as hell and you will NOT ever want to change back...WOW is all I can say about the difference.

The reason is because I got belt-slip from the 2.6" pulley. Since I was now addicted to the power, I just couldn't go back, so I went to the 8" crankshaft pulley, but then I spun two belts. Then, I went to an 8-rib setup across the board, which isn't exactly cheap and I made a stupid mistake which caused me to spin another belt (NOTE--the 3rd belt issue was 100% my fault for installing a improper air coupler). One of the key things I believe EVERY PERSON WITH A MAGGIE SHOULD INSTALL IS AN AIR COUPLER THAT CAN "FLEX." There were a few screws, especially one in particular, that would ALWAYS come loose on the air filter housing because the entire torque of the motor flexing was running "threw" the air cleaner housing for the simple fact that the air couplers do NOT allow for engine flex! Not providing customers with what I refer to as "correct" air couplers is one of the huge mistakes that Magnuson does...this should come STANDARD.

Well, what all this means is that it was one headache after another to make that final upgrade. Yes, I do finally think I had it solved, but it was such a frustrating journey that I wish I had just stayed at ~450rwhp/410 rwtq and been happy with that---it's still one hell of a ride...

This is to say nothing about just doing it "right" the first time out. I spent a lot of dough on making the stock LS6 perform at a level it wasn't really made for. What I SHOULD HAVE DONE was just yank the LS6, sell it, and just drop in an aftermarket motor that would blow the doors off of what I made for probably the same I ended up spending, but without the headaches and 10x the reliability & probably wouldn't have spent THAT much more...lol

If you are one of the lucky ones that can run a 2.6" pulley and not get belt slip, then I *MIGHT* consider going that route again, for that's an easy upgrade to do. If you get belt-slip, yeah, you can do a lot of changes to make it work, but it starts to get so expensive, why not just yank the stupid motor, sell it for some dough, and drop a motor in that will spank even a 2.6" maggied LS6 could ever do, with greater reliability
 

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so with a forged bottom end your saying a 2.6/8 is possible???:lildevil:
 
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