LS7 vs LS3-480 or 525

[Robert May Eng.]

These HP figures are completely meaningless without dyno sheets to see where and how the said HP`s are delivered. A 600hp torque monster could quite easily suffer a savage beating at the track by a well thought out and correctly geared 400hp combo. These elevated HP figures may also never actually hit the road if there are traction issues. There are many variable`s to consider and the extra cash spent hunting down the extra HP is sometimes better spent around the chassis.


Bob

 

[Alex]

I went with a 525 after getting dicked over by my first engine builder (HKE) .... ended up doing new heads to make better power. As provided the engine is kind of meh. Cam has nice lope to it, but it needs way more power....first thing Katech asked me when they built my current engine is why I didn't buy another 525, and my answer was - not enough power.

like Luke said, LS7s are notorious for dropped valves .... buy a built LS3 from a reputable builder.

W With miner tuning my understanding is that 580hp is obtainable,

Not unless minor tuning now means head swap/work

 

[Jack]

Alex, the ASA spec camshaft, springs/retainers & hardened pushrods will get it there.
All bolt-on's.

 

[Luke Lonberger]

Engine hp not wheel hp i'm assuming.

 

[Jack]

Engine hp not wheel hp i'm assuming.

Yes it is.

 

[Alex]

Alex, the ASA spec camshaft, springs/retainers & hardened pushrods will get it there.
All bolt-on's.

The 525 has the asa cam. You're not getting to 580-600hp from tuning or simple bolt ons (well, heads are bolt on, but I'm just considering exhaust, intake, etc..)

 

[Jack]

'Gotcha Alex!
You are right, the ASA cam is in the 525 engine. I was considering heads too but failed to mention in the previous post. They are readily available aftermarket parts.

 

[Stu Coleman]

Another nice affordable option is a stock Ls3. Install a set of valve springs, retainers, pushrods, and a LG G6X3 cam.

We are seeing 502 whp on a 2010 camaro. The SLC will make a bit more since there is less drivetrain loss.

It will also require dyno tuning, but any car like this should with their varying exhaust, intake, and fueling setups.

As Mike says above the ''The LS3 (480) has a slight 1st gear 'buck' to it but will still run smooth while under way at 30-60mph and at 1,500rpm!.

Thanks for the 'heads up' on the LG Cam Luke. Is this cam suitable and streetable for a manual car such as the SL-C?
- would it 'buck' around in 1st gear at low RPM's much worse than the LS3/480
- when cruising at anything under 2,000rpm would the LG Cam be jerky/buck around as you tried to coast along?

I've attached my first dyno on my car for others interests and please throw any comments my way...good or bad, the 292KW equates to circa 390RWHP.



cheers
Stu

 

[Luke Lonberger]

Doesn't seem bad. You could prob run it a little leaner to make up some power. Any idea on how much timing you are running?

Th LG G6x3 is a big cam. It has an agressive idle, and will be hard to drive at low rpm's unless it's tuned properly. We have tons of street guys that drive them, but then again we have been asked to remove cams before because the customer couldn't drive with it.

 

[Stu Coleman]

Thanks for the quick response Luke! The result was probably a bit low because the temp in the dyno room was 42 degrees C that day (107F)
Sorry, I have no idea how much timing it's running. The car will be tuned sometime in the near future and I'll find out the timing.
Yes I listened to some footage on youtube of the LM Cam...this lead to my questions.

Given the gearing on my SL-C (diff ration 3.36:1) and the fact it's mainly a street car (will see some track work) I think having big torque down low is more useable for the street, I imagine with the big LM Cam you would lose low down torque?

By the way I love the information shared on this forum, just awesome!

 

[Ken Mason]

How the car feels and dyno numbers are all well and good, but where are the comparative numbers? Lap times, skid pad g's, 0-60 or the quarter mile....at least something to make an apple to apple comparison. Are there any such numbers in existence for these drivetrains, or will the topic remain always open to speculation and opinionation?

 

[Alex]

'Gotcha Alex!
You are right, the ASA cam is in the 525 engine. I was considering heads too but failed to mention in the previous post. They are readily available aftermarket parts.

People who buy crate engines probably do so because they don't want to do stuff like heads/cam/etc...

I know I didn't.

If I'd known I would have just had Katech build me an engine back then.

Don't get me wrong, it's not a bad engine, it just needs more power than the as-provided package and it certainly isn't under-rated (as I read on ls1tech a lot of people thought it was under-rated).

 

[Justin]

How the car feels and dyno numbers are all well and good, but where are the comparative numbers? Lap times, skid pad g's, 0-60 or the quarter mile....at least something to make an apple to apple comparison. Are there any such numbers in existence for these drivetrains, or will the topic remain always open to speculation and opinionation?

It's like comparing apples to oranges to lemons to pears to...

Nearly every SLC that's been built has been built differently.

 

[Ken Roberts]

Why go with a generic cam when you can get one custom ground for your application. It doesn't cost that much more. You email him (Pat G) your car specs and intended use and he models the cam with expensive software programs. The cost is about $25.
I went with Pat G. His custom cam recommendations are highly regarded among the LS engine building crowd.

I chose LS3 heads and had them worked over by Advanced Induction. I used a LSA block for the piston oil squirters. It was dry sleeved to a 427 by ERL. The cam was modeled by Pat G and Competion Cams ground it. I used a Katech blue printed dry sump oil pump. All of this can be done for about $10000. Some where in between the cost of a LS3 crate motor and LS7 crate motor. The dry sleeve liners are ductile iron which is much better than stock gray iron. Also the liners are longer than LS7 liners for better strength. The piston oil squirters are a nice addition to keep the detonation down.

Don't be afraid to buy an assembled short block and bolt on some ls3 heads. An ASA cam just isn't designed for street use in my opinion.

 

[Luke Lonberger]

Those are some good points.

A big hp cam will usually sacrifice torque and low rpm drivability. You could focus on a milder cam but it will only put you around 470 whp.

 

[Jack]

Ken has a really good solution. The ASA cam is quite lumpy and has a very fast ramp rate. It does "sing" at higher RPM's and sounds great. Not the best choice for a street only car. A camshaft with around 110 to 112 degrees LSA is a lot smoother.

 

[Michael]

Thank you everyone. Some really good information here. I appreciate it.

I agree with Fran; Stock LS376/480 sounds like the ticket. I am wavering between the Graziano, Porsche G96/01, or G96/96 gear boxes.

I also have an opinion that 425 hp is probably the sweet spot for driving one of these cars on the street. I want it to FUN to drive, but not scare the hell out of my wife whenever we go places in it.

As stated, unless you are on the track a lot, and constantly pushing the car hard, then you're not likely to ever come close to maxing out the engine or transaxle. (Unless have burn out fetishes)...

I am not likely to spend much time at all on race tracks; maybe once to experience it and to say that I did... This will be a Street car that I can terrorize Charlotte interstates with... (Escort Passport 9500 ci will go into this car as well)!

I would think that if treated with some sensibility, these pieces can last for as long as you want them to.

Thanks guys for helping me keep my head right in terms of correct components for personal taste.

As suggested yesterday by a good friend (of mine and this forum), I can go this route and save the difference for interior tub and upholstery work.


Thanks again everyone.

Mike

 

[Jack]

Mike, good choice for a street car. Plenty of power when needed or wanted, torque is fantastic too. Save the money for dress up on the interior. Other option I would go for are the front fender vents. They are functional and look awesome!

 

[Howard Jones]

Beware of internet bench racing and hp discussions. 425hp is perfect. Leave it alone and enjoy a nice mild reliable engine. Be careful, 425Hp in a 2500 pound streetcar on street tires can really become a handful very quickly.

 

[Warren kreyer]

Big cubic inch, torque cam, Lower RPM = long lasting and power IMO. I am seeing 20mpg with my 690hp LS 441 very street friendly.