I was watching an episode of Detroit Muscle on YouTube.

Found Here:

In this episode, they took an '01 Z06 to the dyno and pulled 337 horse at the wheels stock. They added Summit Racing heads, cam, lifters, springs, and fuel injectors, then topped it off with Hooker Black Heart exhaust complete with headers. When they went back to the dyno, they pushed 446 at the wheels, which I figure put them at about 485 at the crank.

I have been trying to research whether or not an LS1 has the same or similar rotating assembly as the LS6, and if I made this exact same bolt on upgrade would I see 440-450 at the wheels, too? If I remember right, the Z06 has 3.90s where I have 3.43s, so I don't know if that changes the dyno numbers. Has anyone built their LS1 and had this kind of experience?

I'm not looking for crazy 550rwhp or boost.. just wanting to bring my tired LS1 up to date. It has 87,000 miles on it, has never been tracked, doesn't use oil, doesn't leak oil, and runs great. I want to stay that way and not have it cammed so hard it doesn't run. Are my expectations too much here?

 

Your goal of 440-450 whp is possible with the LS1.

I've seen over 420 whp with an LS1 with stock heads and stock injectors. Just a lot of cam, long tube headers (made for the car it was transplanted into) and an intake manifold upgrade. Seems like we also upgraded the bearings on the stock rocker arms, too. And obviously a good dyno tune for it when it was finished. That engine pulled over 400 ft. Lb. Of torque from about 2800 RPMs up, too, so it kicked hard even down pretty low in the revs.

With upgraded heads, your goal should be attainable, probably with a bit less cam than we used.

 

The LS1 and LS6 shortblock are nearly identical. The LS6 has larger windows below the sleeves the let air moving from pistons moving to flow around the block better. ‘01+ LS1 & LS6 both got the better rod bolts and intake manifold. After a certain point most LS1s came with LS6 blocks.

Everything they bolted onto the shortblock in that episode will bolt to your block and achieve the same results. In regards to the gearing… both transmissions have the same 1:1 ratio in 4th gear which is where dyno pulls are made in these cars. Being they both have the same rear gear (the Zo6 got shorter transmission gearing except 4th gear) the results should be the same (or nearly identical) on the same dyno on the same day.

 

But the LS6 has much better flowing heads, and more cam, more compression…

I am building a less aggressive direction than the OP, but will employ 4.10 gears. My LS1 is getting a cam motion cam, .584 lift, 117 centerline, 118/224 @ .50. Should be a good midrange cam for pulling from 3500-5500 with purpose. It’s A Z06 inspired split, with more lift and duration.

I have been looking for a set or 243’s for the cherry on the cake. They can be had for about $600 a pair. With a tune I’m expecting low 400’s whp. Yet, it should idle and cruise like stock.

The heads are the key here to making it all work.

 

^ yes the ls6 has better heads/cam from the factory but the question was referring to the episode linked in the 1st post.

that ls6 got Trickflow heads, cam, headers and axleback which an ‘01+ ls1 build identical to that ls6 would make pretty much identical power on the same dyno.

 

Yes.

Compression will be the only difference but it is minimal.

The Z06 has a 3.42 rear.

 

For sure. This video is long on camera and short on details. Another slant on the video’s concept also addressing a gear option.

 

The LS1 & LS6 compression differences are from the cylinder head chamber volume.

If both engines swap the same aftermarket heads the compression will be the same.

 

Much of the answer to your question can be found in one very important part of the definition of "built." That's the heads. You can port the LS1 heads all you want, by the best porter around. But that same head porter will get more power out of the ported LS6 heads. Lingenfelter used to have (and may still) a disclaimer on their head porting page that read simply 'LS6 numbers will be higher', when discussing ported OEM castings. If you go to better, aftermarket heads for your LS1, then everything changes, and the same heads and cam on the same block should yield same numbers.....

 

~Josh is correct. Further later LS1 had the same short block starting in '02 or '03.

 

Idle and cruise like stock with an extra 100 whp sounds like exactly where I want to be. With those 4.10s, will you still be able to get on it hard off the line? I have an older set of Michelin Pilot Sports on the back, and right at peak torque (around 4500 rpm) the left one breaks loose under hard acceleration and it can start fish-tailing. I learned quick not to punch it while doing a lane-change. Nearly did a 180 in a four lane highway...

With the 4.10s would you just need stickier tires?

 

Thanks for the response. If I did this, am I going to have emissions issues? I still have to pass Utah smog. I'd love to have these mods and an X-pipe. I should have included this concern in the original post.

 

Being an older LS1, do you see any issue with not building the bottom? I am a little nervous about adding the power and then having it spin a bearing or throw a rod? Another alternative I have been considering is waiting in line for a crate LS3 with the moderate cam, then swapping the whole engine and clutch at the same time. I don't see many places that offer one with the 24x reluctor, so I assume some converter can be purchased. However, this LS1 appears to be in great shape, and I don't want to just toss it or sell it cheap if it can be worked with. What do you think?

 

If it is a good running engine, I see no problem. I've turned over 450rwhp with a 100k mile short block.

 

Any LS engine I think can handle 500rwhp no matter what kind of config, the block itself is not the issue and 500 to the tires isn't enough to harm any well configured OEM bottom end. Keep in mind you can damage an engine easily with 300hp and keep it alive at 500hp using two completely different tuning approaches and setup configurations. HIgh cylinder pressure for example is possible to damage/detonate a piston at 280rwhp using a poor fuel quality and poor tuning. My perception is based on superior tuning and fuel quality, ideal configuration, minimum cylinder pressure, best torque integral, minimum timing.

The disparity between engines, blocks, girdle design, stability, etc... starts after 500rwhp usually regardless of displacement or manufacturer. The bottom end components begin to matter less, and the block design, structure support, main girdle, pan support, material thickness, raw weight, etc... begin to define power capability more than the internals themselves. I give example,

For example Toyota 3.0L 2jz-gte 1998 block can handle 700rwhp using OEM internals for 200,000 miles.
The stock LS1 cannot do that at 5.7L. What is the difference? Both use forged crank, cast piston, similar rod, I think. It isn't the piston, rod or crank that is weak, it is the block itself, crankshaft deflection, for example. The material thickness, girdle, and so forth define the power limitation, not the rotating assembly.
Another example: Truck engines 4.8L support ~1000rwhp from 2002 Chevy trucks just like a 2jz-gte Toyota engine because both use very thick materials, strong block, stability in the girdle support for crankshaft, etc... they use the same cast piston, forged crank, similar rod.
The displacement under those circumstances becomes meaningless and the block design and integrity of materials is the over-riding factor.
Stronger bottom end components won't help an engine surpass these limitations because the whole rotating assembly is dependent on the stability of the block and girdle design in the first place. An engine like LS1 isn't intended for 1000hp, it is meant to be lightweight, possibly high revving potential, a quick engine, not a powerful engine. An economical engine, not a high power engine.

 

I’m planning on 4.10s, but had 3.90s in my vert. I never had the handling/traction issues you mentioned. I did not try to leave hard from a stop because I didn’t want to melt expensive tires, and I learned the value of traction control and left it engaged.

More to your point, low gears deliver significantly more torque to the tires, so it’s easier to light them up. I’m more interested in rolling starts and shorts bursts on the street, or a handy on-ramp. Low gears and a midrange cam make a great combo for quickness, and loads of fun without creating a race profile build.

 

The answer is yes. You can absolutely build an LS1 to the same power levels as an LS6. The heads and cam profile is where the like for like power comes into play. In fact I have a set of WCCH ported 241s on my car now that bench flow tested better than my 243 heads. A set of AFR heads would be far superior to either stock head with maximum effort porting. As grinder mentions above.

I've personally had NA LS1s that put down 418rwhp (228/228/112 cam) and 428rwhp (232/236/113 cam) with ported 241s and stock 28lb injectors and stock LS1 TB with port work.

Having run 4.10s on two H/C/I setups on an LS1 C5 and 3.90s on a mostly stock LS1. I personally find the 4.10 being a better gear . With more cam and head you get more RPMs from the powerband. Which takes optimal advantage of the steaper gear. Plus the car will drive better at low speed with the gears. It also makes driving more fun as gear selection choices in variation are more fun (like 1-3, 2-4, 3-5 etc) The gear also makes 6th a pulling gear. Which is an added bonus.

If your mostly stock car is washing out the rear on hard acceleration your tires suck. Adding a 4.10 or a 3.90 with same said tires will make your car slower. Change the tire to a stickier compound and you'll put the power down with a gear swap. Although I'm back in a 3.42 diff... I have 200+ more rwhp now with a procharger and my car still puts the power down with Nitto R2 drag radials.

More power requires better tires. It's that simple. So upping the power or lowering the gear or both...tires make all the difference and a must have.

Your stock car with a stickier tire will in many cases outperform a modded C5 with run flats or an old hard compound.

You may find this read on LS6vsLS1 helpful:

https://help.summitracing.com/app/an...nd-ls6-engines

 

Thanks for weighing in here.
Summit offers a Trick Flow GenX kit they claim makes 505HP.
https://www.summitracing.com/search/...-ls1/year/1999
Out of stock until November..

I see others like Lethal Performance and Texas Speed have similar kits. I could probably find one if I spent the day shopping around. Do you think it really makes 500+? And how are they (or any of you guys) handling emissions?

Lol.. even on 3.42s I already skip gears, usually 1/3/5. With 4.10s I could go 1/4 like Chevrolet intended before bypassing the lock out! Ha-
I looked at the date code on those Pilots. It's 2015. Definitely time to replace them even though they have quite a bit of tread on them.
What do you think?

 

I would think you’d be close to their claimed 515 if you add headers and fast intake. But car to car things vary, without seeing a dyno graph I imagine they rev’d it a little higher than most would as well to get that number

 

In agreement with the above. What's missing from the description to reach 505hp is the reccomendation for Longtubes. I don't see this combo ever reaching 500hp without longtube headers. When I added Kooks with a Kooks offroad Xpipe to my H/C/I setup I netted 18rwhp. Which put me at 428rwhp.

Dyno comparisons have too many variables. In this case they had optimal conditions and an engine dyno. This setup is good for 425-435 rwhp in an MN6 c5. RWHP is all that matters.

As far as emissions is concerned I haven't had my C5 inspected in 16+ years. It will pass the sniffer but it won't pass the visual. If I get popped for no sticker...it just had the windshield replaced. Then I'll pay the $200 ticket.