Can Am LS7
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Discussion

Bebs

Original Poster:

3,033 posts

310 months

Monday 3rd September 2007
quotequote all
Danish friend of mine collected his Can AM LS7 from the factory this weekend.
I had a brief run on Sunday before he went on his way back to the home land.
My oh my.. that IS quick. I don't think I have quite seen a speedo needle work its way round like a rev counter before yikes

Comparing with several runs out with Ted in the factory demonstrators over the years - I must say the LS7 route does seem far more sophisticated. Very smooth with a big almighty push. However, running on the motorway at moderate speeds it did seem to have quite a high gearing needing 3000 RPMs. I would have thought that engine is more than capable of cruising at 2000.

The car was factory buildt and I gather they did 400 miles of testing as this was one of the first LS7s coming out of the factory? Very well put together clap

my own mota seemed a bit 'comfy'.. and err.. slow after that weeping


fastco

75 posts

260 months

Monday 3rd September 2007
quotequote all
Hello...yes those LS7 are smooth and produce decent BHP..and torque..but @ higher RPM's not a ton 0 torque @ 2000 RPM
Here is a print out of an old school Chevy 406 we dyno'd last week for Ken's CAN-AM...this beast pumped out 405 ft lbs torque @ 2900 RPM , 456 ft lbs @ 4800 RPM , & 457 BHP @ 5500 RPM. Check out the nice flat torque curve....
Cruise'n in 6 th gear @ high 1800 to 2200 RPM @ 60/70 MPH should'nt be a problem...gota love old school..
[URL=http://good-times.webshots.com/photo/2375327120087216316dmMoBU][/URL]

Cheers! Dr,Dee

Seasider

12,728 posts

278 months

Monday 3rd September 2007
quotequote all
Bebs said:
my own mota seemed a bit 'comfy'.. and err.. slow after that weeping
Shouldn't suprise you really Bebs wink

jschwartz

836 posts

287 months

Monday 3rd September 2007
quotequote all
I have to disagree with the statement reagarding LS7 torque.
I made 485 lbs ft at 2100 rpm with a slightly modded LS7 last week.
The rpm at highway speeds is dependent on the transaxle and gearing used. I've got a .67 top gear in mine, brings it down in the 2200 range at the speeds I cruise at.

LuckyP

6,243 posts

254 months

Monday 3rd September 2007
quotequote all
jschwartz said:
I have to disagree with the statement reagarding LS7 torque.
I made 485 lbs ft at 2100 rpm with a slightly modded LS7 last week.
The rpm at highway speeds is dependent on the transaxle and gearing used. I've got a .67 top gear in mine, brings it down in the 2200 range at the speeds I cruise at.
Is .67 your 5th or 6th? ie.which 5 or 6spd? Very interested to know what your 4th or 5th is.

Cheers

Pete


Builder

1,225 posts

271 months

Monday 3rd September 2007
quotequote all
fastco said:
...this beast pumped out 405 ft lbs torque @ 2900 RPM, 456 ft lbs @ 4800 RPM, & 457 BHP @ 5500 RPM.
This dyno sheet is from a bone stock LS7 with a good tune:


Bebs

Original Poster:

3,033 posts

310 months

Monday 3rd September 2007
quotequote all
jschwartz said:
I have to disagree with the statement reagarding LS7 torque.
I made 485 lbs ft at 2100 rpm with a slightly modded LS7 last week.
The rpm at highway speeds is dependent on the transaxle and gearing used. I've got a .67 top gear in mine, brings it down in the 2200 range at the speeds I cruise at.
I gather its a stock LS7 producing 'around' 550 BHP. Perhaps he needs to look into different gearing then yes

Bebs

Original Poster:

3,033 posts

310 months

Monday 3rd September 2007
quotequote all
Seasider said:
Bebs said:
my own mota seemed a bit 'comfy'.. and err.. slow after that weeping
Shouldn't suprise you really Bebs wink
Looks who's talking yikes


hehe

Edited by Bebs on Monday 3rd September 18:52

jschwartz

836 posts

287 months

Tuesday 4th September 2007
quotequote all
[quote=LuckyP
Is .67 your 5th or 6th? ie.which 5 or 6spd? Very interested to know what your 4th or 5th is.
Cheers
Pete

[/quote]
4th is .97, 5th is .68 in my case, we also use .68 ratio in the 6 speed GT2 and 996tt box, which have .92 5th.
Jeff

Edited by jschwartz on Tuesday 4th September 02:46


Edited by jschwartz on Tuesday 4th September 02:47

LuckyP

6,243 posts

254 months

Tuesday 4th September 2007
quotequote all
jschwartz said:
LuckyP said:
Is .67 your 5th or 6th? ie.which 5 or 6spd? Very interested to know what your 4th or 5th is.
Cheers
Pete
4th is .97, 5th is .68 in my case, we also use .68 ratio in the 6 speed GT2 and 996tt box, which have .92 5th.
Jeff
Well Jeff, just looked my PHII ratios up and I too have 4th 0.967 and 5th at 0.688.

How do you find the drop from 5th to 4th and at what RPM do you do change for maximum acceleration?

I find that ar 7000 I change and it goes right down to 5,200 and then just bogs down. My BHP and torque I suppose?




Edited by LuckyP on Tuesday 4th September 14:44

jschwartz

836 posts

287 months

Wednesday 5th September 2007
quotequote all
I change at 6500, drops right in my torque peak rpm, Perfect!
No bog.

crafty

2,291 posts

266 months

Wednesday 5th September 2007
quotequote all
jschwartz said:
I change at 6500, drops right in my torque peak rpm, Perfect!
No bog.
.... just wheelspin?






...only bog is in passenger's underwear.

Edited by crafty on Wednesday 5th September 05:06

fastco

75 posts

260 months

Wednesday 5th September 2007
quotequote all
jschwartz said:
I have to disagree with the statement reagarding LS7 torque.
I made 485 lbs ft at 2100 rpm with a slightly modded LS7 last week.
The rpm at highway speeds is dependent on the transaxle and gearing used. I've got a .67 top gear in mine, brings it down in the 2200 range at the speeds I cruise at.
Yes those #'s are impressive...my mistake here ..was think'n LS5 & 6's engine spec.
Those techy LS7 do come @ a price...
Sample US price crate engine.
egStreet Package Includes
Dry Sump Oiling System-8 Quart Reservoir
Flywheel or Flexplate
Starter
Block hugger headers
(Starting at) *****
$18,900.00
But there is still something good to say about old school SBC engines price
..460 BHP @ 9000 USD..add 1,000 or so to that.& bata boom 550+ easy BHP..
My 1 pence/ 2cents..... Dr,Dee

crafty

2,291 posts

266 months

Wednesday 5th September 2007
quotequote all
^^^^...... but it's still a SBC.

Sorry Dr Dee.... but I have to have a little rant here....

With all due respect I don't think you can compare the SBC to the LS engine.

Your USD10K SBC may have similar HP and TQ, but it wont match an LS7 for reliability, weight, fuel economy, oil-tightness, temperament at low speeds, running temperature, emissions.... or cool factor.

I also assume that in your 10K package you are starting with a reconditioned block, probably steel, and using a carb.

I dont think you should really be trying to compare the two - esp when it looks like you are trying to sell your package on the basis that it is "equal to" an LS7.


Sorry for the rant, but it seems that the only time you chip in here is to have a plug... and usually by trying to sell a SBC against an LS engine. There's people on here looking for good info on engines, who in the main are building an Ultima because they can afford to (and want to) have the best. In my mind offering an SBC as an "equivalent" to an LS7 is misleading.... and not really the right thing to do on a thread about a factory LS7 installation.


<rantmode: off>

Edited by crafty on Wednesday 5th September 05:56

andygtt

8,345 posts

293 months

Wednesday 5th September 2007
quotequote all
I know people are protective of the old SBC, its an increadable engine with mind blowing power... but it does run like 60/70's engine with all the flaws that craft mentions.

The LS engines however have all the plus points of the old SBC (power, noise etc) without the drawbacks which is an enormous step forward.

I also agree with Crafty and it is the rules that you do not advertise on the forums but in the clasifieds.

LuckyP

6,243 posts

254 months

Wednesday 5th September 2007
quotequote all
jschwartz said:
I change at 6500, drops right in my torque peak rpm, Perfect!
No bog.
That'll be the extra 500 horses and torques you have goin' on then!!

That makes me feel better........not!! Ta though.

fastco

75 posts

260 months

Wednesday 5th September 2007
quotequote all
crafty said:
^^^^...... but it's still a SBC.

Sorry Dr Dee.... but I have to have a little rant here....

With all due respect I don't think you can compare the SBC to the LS engine.

Your USD10K SBC may have similar HP and TQ, but it wont match an LS7 for reliability, weight, fuel economy, oil-tightness, temperament at low speeds, running temperature, emissions.... or cool factor.

I also assume that in your 10K package you are starting with a reconditioned block, probably steel, and using a carb.

I dont think you should really be trying to compare the two - esp when it looks like you are trying to sell your package on the basis that it is "equal to" an LS7.


Sorry for the rant, but it seems that the only time you chip in here is to have a plug... and usually by trying to sell a SBC against an LS engine. There's people on here looking for good info on engines, who in the main are building an Ultima because they can afford to (and want to) have the best. In my mind offering an SBC as an "equivalent" to an LS7 is misleading.... and not really the right thing to do on a thread about a factory LS7 installation.


<rantmode: off>

Edited by crafty on Wednesday 5th September 05:56
Hello Craft.. i do hear you sir ..and ofcourse repect all opinons as i stated i did make an error here inregards to LS7 VS old school SBC..& meant not to misleed anyone.
I do not agree with your statement in regards to the old SBC
reliabilty..we have no issues with any , run'n temps @ 460+ BHP are steady @ 180/190F..not sure what that is in C
as we all know the 1st by product of BHP is heat and we must address this with proper engine and cooling system and modifications ,eg high flow pumps ,block deck coolant flow mods
to heads , ally heads ofcourse ,high flow pumps,proper oil pan
and scalvage and windage , oil coolers, coolant additive such as Red-Line wetter and - 20 below heat transfer agent, high flow thermostat , proper heat range plugs , A/F set @ 12.7 to 13:1 ratios, elect fan rated @ 2800 to 3200 CFM..these mods control any engine heat build up.
The use of 100% full synthetic motor also reduces engine temps.
Fuel economy is in the range of 24 to 28 MPG ..depending on right foot pressure ofcourse.
Emmissions are very repectable with ignition amps & iridium plugs and elect FI systems and properly calibrated carbs.
I say why not compare old school & new school just for fun..as you say some want new school this is true..but some want old school with modern tech upgrades and seem happy with the results..as i say some like chocolate some like strawberry it all tastes good.
As far as post'n only to plug & flag wave'not so.read my posts
and info ...always happy to toss my 1 pence 2 cents of advice into the hat to help a fellow out.
In the end was just compare'n old to new & wished not to offend or misleed anyone..sorry if i came cross that way.
I'm also i'm not 100% stuck in the stone age and do play with FI systems with decent results..huge BHP gains no, reliabilty gains? MPG gains hummmm a tad improvement @ cruise speeds..do they look trick..yes do they wipe the floor with carb'd engines no.

Again IMO....
Cheers! regards Dr,Dee

EG: STONE AGE
[URL=http://good-times.webshots.com/photo/2382253660087216316qSgzQO][/URL]

AFTER I ESCAPED FROM THE TIME TUNNEL
[URL=http://home-and-garden.webshots.com/photo/2368518320087216316CEqiAF][/URL]



Edited by fastco on Wednesday 5th September 13:04


Edited by fastco on Wednesday 5th September 13:07


Edited by fastco on Tuesday 18th September 17:48

andygtt

8,345 posts

293 months

Wednesday 5th September 2007
quotequote all
Fuel economy of 24mph? even sedate cruising never saw 20mpg in my carbed Ultima (average 13mph) and I had mine dyno'd twice so the fueling was spot on and it was only a little more powerful than your example, it also had huge gearing.....
the cooling issues are that the cooling in the Ultima is marginal and if it idles at more than 1000rpm then it will boil..... with a carbed SBC you have to keep on top of the idle as it does move, but on an LS it will always be spot on and thus potentially more reliable.
This can be address with bespoke rads fans ect (as high flow water pumps are the norm) is this what you have done in the Ultimas you have installed your engines in?

As for cost, a friend has recently just rebuilt an LS1 with a mix of brand new bits from LS1's, LS2 etc to deliver approx 450bhp and he's spent less than £4k including the ecu and original engine... of cause as he's in the UK he will have to fit cat's.

fastco

75 posts

260 months

Thursday 6th September 2007
quotequote all
andygtt said:
Fuel economy of 24mph? even sedate cruising never saw 20mpg in my carbed Ultima (average 13mph) and I had mine dyno'd twice so the fueling was spot on and it was only a little more powerful than your example, it also had huge gearing.....
the cooling issues are that the cooling in the Ultima is marginal and if it idles at more than 1000rpm then it will boil..... with a carbed SBC you have to keep on top of the idle as it does move, but on an LS it will always be spot on and thus potentially more reliable.
This can be address with bespoke rads fans ect (as high flow water pumps are the norm) is this what you have done in the Ultimas you have installed your engines in?

As for cost, a friend has recently just rebuilt an LS1 with a mix of brand new bits from LS1's, LS2 etc to deliver approx 450bhp and he's spent less than £4k including the ecu and original engine... of cause as he's in the UK he will have to fit cat's.
Hello sir... not sure why your MPG is very low.. on street driven engines we use vaccum secondary carbs not double pump type..these carbs are full trick with vac secondary control system...as far as idle goes 800 to 850 is the norm with idle mods ofcourse... 0 complaints of over heating.. adding proper fan & cooling mod & agents to cooling system works.
GM here in the USA are dump'n all there LS1 engine dirt cheap
and a good value for those wish'n to go that route....but yes cats must be used... 1970 era SBC blocks need only a visual test for SVA cert... nice.
Regards Dr,Dee

GTRCLIVE

4,193 posts

312 months

Thursday 6th September 2007
quotequote all



GM here in the USA are dump'n all there LS1 engine dirt cheap



are they where ???