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Does anyone know the differences in the 04 SSR LS1 compared to the 04 GTO LS1? I know the SSR is about 290hp, 5.3L and the GTO is rated at 350hp, 5.7L.

So what is the difference? Cam, throttle body, compression/pistons. Were the heck is that 60 horse difference coming from!
 

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There is no replacement for displacement , bigger is better !
 
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HD-Fatboy said:
Does anyone know the differences in the 04 SSR LS1 compared to the 04 GTO LS1? I know the SSR is about 290hp, 5.3L and the GTO is rated at 350hp, 5.7L.

So what is the difference? Cam, throttle body, compression/pistons. Were the heck is that 60 horse difference coming from!
Well, first off, the 5.3 isn't an LS1 :lol The 5.3 (LM4, LM7, L59) is 325 cubic inches. The LS1 and LS6 are 346 cubic inches.

The LS1 uses better heads than the truck motors (4.8, 5.3, 6.0), as well as a more agressive cam. Why GM didn't put the LS1/LS6 into the 03/04 SSR is beyond me.

If you want to learn some technical on the GM GEN III engines, check out http://www.ls1tech.com (specifically the truck section for you guys).

The Gen III Small Block V8
RPO, Cubes, Bore x Stroke, and Liters

LR4, 293 cu/in, 3.779” x 3.268”, 4.8 Liters
LM4/LM7/L59, 325 cu/in, 3.779” x 3.622”, 5.3 Liters
LS1/LS6, 346 cu/in, 3.898” x 3.622”, 5.7 Liters
LQ4/LQ9, 364 cu/in, 4.000” x 3.622”, 6.0 Liters
 

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Discussion Starter #6
Thanks demonspeed, it helps to have a clear view. I'm not as up on the engines as I was as a teenager. :)
 
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HD-Fatboy said:
Thanks demonspeed, it helps to have a clear view. I'm not as up on the engines as I was as a teenager. :)
No problem. I love researching the GEN III/IV engines and anything that has an SS badge :thumbs
 

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No Replacement For Displacement

Boosted said:
Yes there is...It is called boost... :lol :lol
THEN WHY NOT BOOST BIGGER ENGINES :jester :leaving
 

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just curious, if the 05 SSRs have LS2 motors, then does that mean that aftermarket engine upgrades such as heads and cams for the C6 will fit on the 05 SSRs too?
 
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Daij said:
just curious, if the 05 SSRs have LS2 motors, then does that mean that aftermarket engine upgrades such as heads and cams for the C6 will fit on the 05 SSRs too?
Yup :cool
 

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A comment in the SSR book from one of the GM techncial guys answers the question about WHY they used the LM4 engine rather than a car performance engine:

The LM4 engine was engineered from the geto go to power a HEAVY vehicle that might also pull a trailer. The LS1 and LS6 engines were NOT, and the SSR development team did not have time to do the required testing and possible mods to ensure that those engines would work in a heavy versus lightweight vehcle.

Presumably, that testing WAS eventually done before the LS6 was dropped into the SSR for 05.

I drove an 05, and was underimpressed with the LOW speed performance in our heavy SSRs. This vehcile does not need PEAK horsepower, it needs LOW and MID range power, so that it can feel more nimble than it does aorund town.

Another way of addressing that is with even stiffer gearing, lilke a 4.11 versus the stock 3.73. I am serious. Talk to an automotive engineer.

Jim G
 

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JimGnitecki said:
A comment in the SSR book from one of the GM techncial guys answers the question about WHY they used the LM4 engine rather than a car performance engine:

The LM4 engine was engineered from the geto go to power a HEAVY vehicle that might also pull a trailer. The LS1 and LS6 engines were NOT, and the SSR development team did not have time to do the required testing and possible mods to ensure that those engines would work in a heavy versus lightweight vehcle.
Umm, cough...
.
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JimGnitecki said:
Presumably, that testing WAS eventually done before the LS6 was dropped into the SSR for 05.
...LS2...
JimGnitecki said:
I drove an 05, and was underimpressed with the LOW speed performance in our heavy SSRs. This vehcile does not need PEAK horsepower, it needs LOW and MID range power, so that it can feel more nimble than it does aorund town.

Another way of addressing that is with even stiffer gearing, lilke a 4.11 versus the stock 3.73. I am serious. Talk to an automotive engineer.
Jim, Underimpressed compared to what? The 03-04 is incredibly gutless. Hit the throttle hard in the 05 and it goes. Not like a C5 or C6 since it does weigh quite a bit more. Certainly a gear swap will improve low speed performance, but the gas pedal is the real key. :)
 

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I stand by my statements. This vehicle, being as heavy as it is, needs low and mid range power and torque more than it needs high rpm power, FOR NORMAL EVERYDAY DRIVING.

In the late 1970s, I owned a Lincoln Town Car with a 460 cu. in engine. At peak power, it made well under 200 hp, but it had LOTS of low and mid range power, because of the generous displacement and realistic gearing. It was a pleasure to drive because it felt responsive under normal everyday driving conditions.

Objectively, it was slower from 0 to 60 than an 04 SSR, but under every other driving condition, it felt much more "powerful" because of the shape of that engine power curve and the gearing.

I have modeled the 03-04 SSR in my computer performance modeling software (I run a web-based small business that offers a re-gearing service to owners of fast motorcycles and cars). It turns out that the SSR needs not a 4.11 axle, but rather a 4.56 (still only 2900 rpm at 80 mph). That gearing knocks o.75 second off the 0 to 60 time.

The reason for this rather spectacular improvement is the combination of a rather high rpm engine (our LM4 engine has its peak torque at 4000 rpm and peak power at 5500), and the EXTREMELY wide range of the automatic transmission, whose internal ratios range from 3,60 in 1st to 0.70 in overdrive. This is, as one gearing manufacturer describes it, "the widest range on the planet". It is definitely NOT a "performance" gear cluster.

It's not just the SSR that benefits. I spoke with a Corvette high performance shop yeterday in fact about gearing also, They are routinely doing C5 conversions to 3.73, and the owners of the cars, especially the ones who were initially skeptical, are loving the results.

The reason that regearing is so effective on many modern cars and bikes is that te factories are making the gearing VERY tall in order to artificially improve their emissions, noise, and EPA mileage scores. When you regear for sensible "real" everyday use, the results are often spectacularly good. In fact, besides performance improvements, do NOT assume you will lose gas mileage. On many vehicles, the mileage IMPROVES under REAL world conditions, because the original gearing is targeted at an artifical test procedure rather than real world.

I have lots of motorcycle clients who have sent me testimonials.

Jim G
 

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Jim G

Keep that pencil sharp Jim, I like seeing you calculate all this stuff out. I'm working on appearance know, but will follow with smart mods to performance after warranty.
 

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Posted By JimGnitecki
[The reason that regearing is so effective on many modern cars and bikes is that te factories are making the gearing VERY tall in order to artificially improve their emissions, noise, and EPA mileage scores]

My question is will this change make any differences when you need to have in inspected every year?
 

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No, it will not affect emission or safetyinspections, Emissions tests, where actually done, will be totally unaffected.

The only possible downsides are reduced fuel mileage (possibly, not positively) and more engine sound at cruise (NICE!!! NOT a downside!).

My Ducati S4 motorcycle is running 25% stiffer than stock gearing, with NO reduction in fuel mileage. In fact, I seem to be getting better mileage than stock bikes.

Jim G
 

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Jim,
I think the real reason the 5.3 was installed in the SSR is because it was already
certified for use for use in the long wheel base Trailblazer. Certification can sometimes
cost more than a million dollars, thats why they use the 6.0 now, its certified for use
in other vehicles. GM won't get a special engine certified just for SSRs, it to low
volume. Also with 4.56 gears the critical speed of the driveshaft is compromised at high
speeds, I think you should do some real world testing with your SSR and then let us know.
 

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Rick: Since the driveshaft must by definition be adequately balanced to handle AT LEAST the speed limit set by the computer (130 mph or so as I recall), its rpm at the highest speed I EV ER cruise, 80 mph, is still going to be only 4.56/3,73 x its rpm at 80 wth stock gearing , or about 22% higher, or about equal to 98 mph with stock gearing.

In addition, I drove the SSR at 60mph for short periods the last couple of days, in 3rd versus overdriive. Its rpm at 60 in 3rd is over 2600, and it felt absolutely smoooooth. The sound was a delight compared to the stock sound level and quality, but still very quiet. No apaprent change in engine temperature reading either, although I actually would expect the higher rpm to REDUCE any tendency to run hot, since the water is being circulated 22% faster in top gear (at city speeds, it doesn't make a difference - the tranny shifts at certain rpm points anyway).

Thanks for drawing attemtion to the driveshaft possibility though. Any other potential points of difficulty or undesirable effects, that you miht be aware of?

Jim G
 
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