L92 Longblock + LSA Supercharger - Build Advice
 

So I just bought a L92 long block, only 9k miles on it. I am on some type of budget so I don't want to dump tons of money in that I don't need to for my goals. I want 650-700 crank for a street car, rare track days (road or 1/4). It's a 72 Camaro pro-touring so I don't want the "cheapest" build that hurts resale haha.

So with this combo can I just keep the stock VVT cam and still make my goals? I'm thinking overdrive balancer pulley from Texas Speed (that's a no brainer since I need to swap out the balancer anyways), maybe stock pulley on blower. Given the compression is 10.5 I think this should bring it up to 12-13 lbs of boost and be about as much as I want/need?

I'll use the ZL1 lid and a LS7 throttle body, mid length swap headers (for ground clearance).

So do I need a cam, should I just use a LS9 and drop VVT for ease of tuning? After springs and VVT delete that's about $450 (unless I can use LS6 or similar GM springs?). An upgraded VVT based cam/springs seems to cost at least $700?

Any injector recommendations, best bang for buck? I also will need a harness/ecm/tune. Thinking the LSA or 9 kit from GMPP with a good tune, anyone know one in Det area?

I also posted on ls1tech, but know there's some real good engine guys here.

Title edited - Cam chosen...looking for other advice later in thread. Went with a BTR stage III cam and VVT delete.

I think ~625-650HP is a more realistic goal with what you have to work with. Compression is a little high to expect 10-12 psig boost with pump gas. Issue will be have to retard timing so much to suppress detonation at those boost levels that will likely make less power than lower boost and better optimized spark.

LPE GT9 cam works great in LSA's and LS9's and should work great with what you have as well (just need to check piston-to-valve clearance with higher CR pistons).

CNC porting of heads helps as well (depending on budget).

If running LSA supercharger, just buy the LSA GMPP kit - includes everything needed.

GMPP LSA FEAD (Front End Accessory Drive) can be purchased as well (fully validated OEM accessory drive).

Injector Dynamics ID725 injectors. Not cheap - but best injectors I've found.

Thomson Automotive in Wixom if you are looking for location in Detroit area to get this work done.

Dave

Personally, I would retain the vvt. The more aggressive of the vvt cams available from comp cams is actually very comparable to the LS9 cam.

LSA: 198/216 .480/.480
LS9: 211/230 .562/.558
Comp vvt cam: 218/222 .566/.578

All with a ~114 split.

I think the benefits of the vvt would be worth keeping.

Mixed bag here - depends on your goals.

With HP desired, will not make it even close with these milder cams. Running a more aggressive cam with VVT requires a phase limiter to prevent piston to valve clearance issues. Once you do that, benefits of VVT are greatly diminished.

This is a dual-equal VVT as well (single cam) - not a DOHC or even cam-in-cam (ala Viper). Benefits of VVT are already not nearly as good with dual-equal.

VVT benefits include dilution (for FE and emissions) as well as broadening TQ band. Seeking these power levels means FE is not a top priority. Going in an older car - so emissions not an issue. The need to broaden TQ band on a positive displacement SC engine is also not an issue. Depending on front end clearance, VVT hardware requires truck FEAD (front end accessory drive) or at least spacing further away from block. And more s**t = more s**t that breaks.

I love VVT - especially with DOHC - but need for it in this application I'd question.

Dave

The OP's mentioned power goals are right around the LS9's listed power. So, I was assuming that a comparable cam to the LS9 cam could get him where he wants to be, and the vvt would help improve driveability.

Even a limited cam phaser should still provide noticeable gains in driving a 600+rwhp vehicle on the street, right?

From my very limited understanding, people seldomly install/ lock in more than 4° advance or retard in their cam anyways, so if the vvt, even in its limited state with the more aggressive cam, only offers a plus or minus 4° difference, isn't that still going to help?

Or am I missing something entirely? It wouldn't be the first time. Probably won't be the last, either.

To the OP,

Mikels/Dave knows these motors really well. Listen to what he has to say. He could also build it for you, too.

Dave,
Why don't you embed a link to your website in your signature?

Thanks for all the insight everyone.

From what I've been reading the gains w/ a cam and tune even w/ the limiter are still huge, up to 100 hp w/ TSP's cam. Sounds like quite a bit is actually in the tune itself.

Budget is a concern, not to mention part of my fun in this is the challenge of getting the most from the least if that makes sense.

Dave, an LSA motor w/ less compression and simlar boost makes 650 pretty regularly, and that cam I understand to be very mild.

The L92 compression is quite similar to an LS3 (slightly lower actually). I read (on camaro5, etc) of many of them running 12, with quite a few in 13-15 lbs on 93 with no problems. They're making 650+ rear wheel at 12ish pretty easy.

So with the added benefit of VVT, I am now leaning towards actualy the stock cam and 12 lbs of boost, LS7 throttle body and a good tune. I think w/ a cam change I'm going to exceed power goals, as NA that would make 500 ish. Of course I could just do a cam and less boost, but what's the fun in that and it's not efficient $ wise, as then I"m in $800 for cam/springs etc to get the same output.

From what I've been learning on VVT (even w/ the limiter) it makes an awesome torque curve, so adding in the supercharger can only make it better haha. So even if I don't make my goal of 700 crank, which I still think I will, the power under the curve will make it a complete grin machine...well except for the tire costs haha.

Dave I was thinking the GMPP harness kit w/ a tune might be best. I'm going to run the modified CTS-V accessory drive from GM that puts the alternator up high in a vette position for clearance on the bottom. I am trying to determine if the L99 water pump which clears the VVT stuff will work with the CTS V FEAD. Looks like the water pumps due to lack of actual rib/edging are most flexible on belt placement at least.

Reading it seems you are pretty familiar with Thomson, do you know if they can tune for VVT well? If I had the dough I'd just have them be building from scratch for me, especially after seeing the LS7 short block/LS9 screw setups going in at sled alley haha!

I was also thinking that a thicker head gasket could take a little compression out.

So new head gasket, stock cam, 12 lbs boost and good tune would be the most cost effective formula in my mind. However if for some reason this still wouldn't make good power of course I can just change the cam.

Next up in cost is LS9 cam/springs, head gasket, 12 lbs boost etc, which would probably make more than plenty of power for me, just lose the novelty of VVT/boosted engine. Looks like it's about $450 more (after VVT delete parts).

I'd really like to run 12 lbs due to the Texas Speed balancer pulley, if I need a new pulley I'd like to pay for one that also increases performance vs stock ("free power" if you will since I need a part anyways).

All out then would be a new aggressive VVT cam, limiter, thicker gasket and 12 lbs. I think this would exceed my power goals (limited by $$$ for corresponding upgrades), and be most expensive build of just the engine.

The vvt and blower combination just makes sense to me, as well. Granted, I do not have any actual experience with boosting LS motors, so it's probably best to listen to the man with real knowledge on this topic.

The price of the vvt delete parts, and the compatibility of the vvt timing cover with the blower accessory drive will be a huge determining factor. If the blower drive doesn't line up with the vvt cover, it's time to swap cams, and nix the vvt. If it lines up, then there's no reason to delete it, in my opinion. Assuming that the valve springs used with vvt can actually support boost. I don't know if the vvt requires special springs, or if they are stiff enough for 12psi.

Right, just seems dumb to throw away a good power making technology haha.

I'm a quick learner, but still have a lot to learn on all this. But given some simple math like 10 hp per lb of boost I think even a stock cam VVT setup plus 12 lbs gets me to my goal w/ a conservative tune for 93 octane. If I can lower my compression a bit even better. I know it will build heat if I beat on it on a road course for long, etc. Not really intended use though. I also think on stock LSA boost it won't make my power goal without a big cam, so this is the most $$ efficient way to get there.

I get the idea to "overbuild" and be bulletproof, but I also don't have a super expensive short block. I could spend $2k overbuilding a $2400 shortblock lol, or just hope I don't blow it up and if I do buy another and turn down the boost (or build that second one appropriately for more money). Not sure if that makes sense to anyone else, but it's my view on paying for warranty etc also. I'll take some risk I may have to spend more money in the future rather than for sure spend a decent portion of it up front.

Yes, the vvt is another system that can fail. But it is still robust enough to be on thousands of warranty covered vehicles. So I don't think that retaining the vvt makes your build any more or less bulletproof than it would be without it.

Plus, you already have it. If the blower accessory drive lines up with the vvt timing cover, then I say see what the stock vvt cam gets you with 12psi of boost.

I'm raising the BS flag very high for anyone 'realistically' making 650 RWHP with a 6.2L @ 12 psig even with cam & CNC heads. The math just doesn't support it. Neither does the dozens of SC engine combinations I've worked with.

An otherwise stock LSA with 12 psig will make 625 CRANK HP in my experience - but like I said, the lower compression allows better spark timing resulting in this power level. I've done many, many LS3's with same boost that will not clear 600 HP due to knock sensitivity with higher compression. An engine is a system - not just a pile of parts. All need to be considered together to optimize capability.

Remember - properly calibrated dyno's don't lie, but dyno operators do. And chassis dyno's are all over the place. Great for doing A vs B work - but horrid for absolute numbers. Changing your tire pressures can result in 20 HP (more with bias tires). Tell me the airflow rate and/or fuel flow rate and I can tell you how much power you can POTENTIALLY be making.

Thicker head gasket to lower compression - BAD idea! Ruin the quench in the chambers and make engine even more knock sensitive than it was with higher compression. Dished pistons for lower compression always keep quench of chamber for better flame front propagation.

Reason to run lower boost with cam and maybe CNC heads: Better adiabatic efficiency. You stated you want to road race this combination - not gonna happen with 12 psig on stock compression ratio. Well, at least not making full power for anything more than part of lap 1. Plot where you are asking SC to operate on compressor map and look at drive losses & adiabatic efficiency then figure out how many kW cooling system you'll need for not just engine, but intercooler as well. Best to optimize efficiency to get the power. Drag racers can get away with some crazy crap (and can run air-to-ice intercoolers) - but they have no duty-cycle to contend with like road racers or even Auto-X.

If you are running an LSA SC, why not run LSA CTSV accessory drive? I assume you are talking old (2004-2007) CTSV accessory drive - which means you are limited to 6-rib drive belt - for everything including SC (unless re-pulley everything to 8-rib - more $$). 6-rib will not drive the 1900 TVS SC without slipping @ 12 psig. There is a reason factory drive is 8-rib (and that is for SC alone).

Yes, VVT can broaden torque band. But with a positive displacement SC - you'll have all the torque band you'll need. Up to you - but I'd ditch it.

Yes Thomson can calibrate any of these combinations - I do most of their calibration work so I can answer that.

Matt @ Sled Alley does exceptional work - reason you see Mark's cars there frequently. He also has a '67 Camaro we did a 418 SC engine for that made great power. And an old Caddie with an LSA in it we did.

Dave

I can't vouch for their dyno's, hell could be just internet boasting of RWHP. Also likely they're tuned pretty "risky". I was more concerned on have they popped or not and how many miles... And I'd be doing rare HPDE's so not real road racing I'd say. I've read your threads on Mark's cars...I'm not at that level of use so my cooling will be much more street than track.

I just talked to Matt and recommended I talk to you actually and I mentioned I think I was already lol.

I am talking about the GMPP CTSV FEAD, there's a part number that puts the alternator up top like a vette but is otherwise the same. It's 8 rib for sure. http://paceperformance.com/i-1999062...em-w-o-ac.html

So I have access to the engineer for water pumps (we can all put together location and guess where I work haha) and unfortunately it's been years since he worked Gen IV stuff, but we determined that anything that definitely clears the VVT cover is truck spacing. However, he said there is sufficient material to possibly create clearance in the back of a CTS V pump, but we weren't sure how much needs to come out. I'm going to try and look at the math tomorrow. and see what's possible.

So assuming I can solve the water pump issues, but am stuck at 10.5 how much power would you guesstimate at stock LSA 9 lbs vs 12 (stock L92 heads, LS7 throttle body unless that's limiting too)? How about then with a LS9 cam and no VVT same two options? Which leads to what's the gain on dropping below 10 (or whatever's optimal) w/ dished pistons? I didn't want to take apart the short block but everything's about tradeoffs right?

Thanks again, sorry for so many questions... Just kinda wanted to figure out how to be "first" w VVT and FI, but if not worth it it's not worth it. Like I said if I had the dough a LS7/2.3 blower setup would be in the works haha.

Is the truck/ vvt water pump the only accessory that is out of alignment with the CTS-V/ LSA drive? If so...

Electric water pump. The end.

Yep, everything else would come out of the kit I linked above. The VVT cover sticks out further which is why the normal "car" pumps don't fit as cast. That's definitely an easier solution, hadn't thought of it I gues. thanks.

Waiting to see Dave's thoughts on the above, I'm definitely getting the feeling he's seeing no advantage to a VVT. Having owned a stock CTS-V I can attest there isn't a lack of torque w/ this PD blower on a 6.2... I just want to make more power than that haha.

I would imagine that the vvt would improve the driveability, no matter what. No, you don't need it on a positive displacement blower motor. You probably don't need a positive displacement blower motor, for that matter, either.

But things like blowers and boost in these applications make the driving experience more enjoyable. And wouldn't the vvt just make all that power a little bit easier to drive? Wouldn't it just be that much more enjoyable?

Except for maybe limiting the ultimate top end numbers, what disadvantage is there to keeping the vvt?

Would you be willing to not have 700hp at the crank, for a really easy to drive 650 crank horsepower engine?

That's the math I'm trying to figure out exactly, and what the costs are.

If I can get a really fun/responsive setup with stock L92 + LSA at stock boost with a good tune that could be the way to go. Otherwise I'll go w/ a LS9 cam and stock boost if that's best as that is a known quantity and affordable, not to mention I like using GM parts where possible haha.

Only bragging rights I'd want is to have more at the wheels then a buddy w/ a lingenfelter setup on his CTS-V...where is upgrade cost more than my engine will (not the whole swap). I am already confident I can outpower his Gallardo lol.

No matter what it will exceed my tires and driving ability for most situations... but since when do we care about that?

That's what I gathered from your previous posts. That's why I think that whatever power may come from sticking that LSA blower on your longblock, with your stock vvt cam, I think will be plenty fun.

It will be the cheapest route, as well. Stock vvt cam, LSA blower, and a good tune. Drive that, see if you have room for more boost or a bigger cam.

It's going to be a beast no matter what.

Realistically I think this is correct. Just don't want to leave a lot on the table if all it takes is a LS9 cam haha. So many variables though... All I know is I can't wait for good power I don't have to warm up for 5 minutes and gets 8 mpg!

Why not port the stock blower while you have it off? Also if you run a good heat exchanger to keep the charge cool shouldn't that help with stopping knock? And a water/meth injection system that maybe engages at 8psi with a 5 gal tank system so you can run 93 no problem? Just get a good system. maybe pick up a used blower cam thats vvt or non vvt, with new springs and dont forget to do the trunnion upgrade while your at it.

I thought about both, but it's extra $$ for a return beyond what I need I think. Trying to get the most for the least, doesn't need to be the biggest power motor out there though.

I've been doing more reading, and it seems like the more reputable tuners on the L99's (simlar vvt/compression motor in Camaro w/ auto) don't want to go above 9 lbs of boost either, and get 510ish RWHP on stock motor. Looks like w/ stock cam that's best I'd see as well w/ any safety.

Putting all this together then, I'm thinking dropping the VVT for a BTR stage 3 with new springs, stock LSA boost of 9 lbs and a good tune should get me to 650 crank at least? Stock balancer is cheaper than the Texas speed over drive so that helps fund the better cam.

Cool. It's good to have a game plan. Now stick to it and let us know how it turns out.

Save a couple pennies for an upgraded heat exchanger with a fan. Install the upgraded HX in place of the original, AND install the original lsa heat exchanger between the reservoir and the blower. You shouldn't need meth with two heat exchangers unless you are road racing it.

Thanks for all the input!

I'm planning on the ZL1 heat exchanger as it's bigger than the V's and pump (as well as SC cover as it's worth some flow/power) in front of the radiator. If it isn't sufficient for my needs I'll upgrade down the road, but given it works for the ZL1 which is a car that's probably capable of pushing much harder than my 72 (ridetech fronts/ GW springs out rear and Z51 brakes) I think it'll be good for my use.

I keep blowing my budget away... but trying to hold back where I can. Started w/ 10k for wheels/suspension/brakes, but since have added a TKO, seats, CF parts, and now a blown LS motor :ups:

Long block gets in this week and I'm picking up blower base unit this weekend...so it's starting to come together. Now time to buy a real torque wrench and read up on the actual work, this is my first foray into anything beyond easy bolt on stuff.

Thinking I'll talk w/ Dave about tuning once it's in car, hoping he'll chime back in here on the latest plan and guesstimate what it'll do haha.

The 67 Camaro that Dave is referring to is mine, but my LS418 with a LS9 is at 841 hp and 818 ft/lbs torque at 10.9 psi. We haven't tested at 15 psi, but you need to figure out your goals in your engine. I wanted long term reliabilty in my engine, so I have oil squirters in mine. Spend some time talking to Brian, and have him build you an engine for your goals. Just plan to spend the money!:G-Dub:

Jeff

That's a dream build haha. I've been tossing around how much trouble I want to take on as I'm not sure how usable the power will be. I assume you have it mini-tubbed, do you have any electronics for traction control or is it just your foot?

I'm trying to determine if I even need the blower if I don't mini-tub and run big tires, otherwise it'll just be a tire eater. I've only had fast cars w/ all the modern TC to help put it down.

If I keep the LSA 1.9 blower (which is in my garage taunting me) I'm thinking again to save cash to go w/ the LS9 cam, as it will make more than I probably need. I want to do the engine build my self over the next few months and have Thomson tune it. Part of the fun for me is building it myself, well until I run into trouble. I have awesome luck... just spent 4 days doing ridetech front suspension and new brakes, was supposed to do rear suspension and brakes too. End result is front suspension sitting on tires (evidently the springs they sent are too soft) and no rear work done as I couldn't get c clips off axle due to sheared pinion pin retainer. 2 steps forward and 3 steps back. :drowninga:

So I made some decisions...

Ordered the BTR pd supercharger stage 3 kit (springs/tit retainers/rods), their VVT delete kit, ARP head bolts, CTS- V FEAD and water pump and a bunch of other stuff. So good bye VVT.

I'm going to get the tanks inc tank with their 400 lph pump, any other input on fuel system? Thinking siemens deka injectors, not sure if I'll need a new line or just adapaters for the existing.

For radiator I'm going w/ a Griffin, either the combo w/ fans built in or I'll ad 4th gen camaro fans to save $200, anyone have any reason not to do either?

Sounds like you are running almost the same setup as me except I have 11.2 compression and forged pistons. I also set my fuel system up to run E85.

What kind of numbers do you make on E85, did you ever tune for 93 octane? I thought of going that route but figure whatever i can make on gas will be enough, there is E85 in MI but I'd also need to beef up the fuel system/injectors etc too.

No numbers yet. Its running but I have not been on the dyno yet. Hopefully soon.

Cool. What cam did you go with? I'd figure it should be pretty stout on E85 w/ that compression.

Mine started off as frame off restoration in 2005 in a friends garage, but I am doing updates to it. Matt is just tweaking my original build, but it is looking great so far. The engine bay was my idea, but my car is long term build. I had to park it for years to generate more cash, but hopefully it will be finished soon. Mark Stielow builds a new one each time, but I do Mods to mine. This is my first car that I bought in 1983. Yes, mini-tubbed. No electronic traction control other than Detroit locker. If I had to do over, then I would have built an LS7 427 with LS9.

Originally it was supposed to be the Harrop TVS2300, but it is in the for sale section. You will want more power, so at the minimum it should be at LS418. I have same heads as Hellfire. Radiator was a custom built one, but I plan to have a spare built by C&R racing. Cooling has to be well planned, and you can't buy off the shelf unit.

Jeff

I'm hoping to get this mostly done this summer and then enjoy it! I've managed that on a huge bike build (26 in front etc on a Street Glide) and haven't fiddled with my boat much, so once I get it good I can usually just enjoy my projects.

I went with a Griffin radiator with dual fans, seems to work well for most people. I'm not going to be able to go out and drive the wheels off on a track very often so my heating needs should be less. I agree after seeing the 7.0's w/ LS9 chargers at Sled Alley I was dreaming about one too haha.


I just bought the book "How to Build and Modify GM LS-Series Engines " to help with my build, anyone know of other good resources on putting this all together? I am trying to find an LSA specific assembly manual to get the torque, etc all right on the SC build, and figure out what else I need to buy to plumb it up.

I decided to give the BTR stage 3 a shot the same as you. What ecu are you going to run?

I'm figuring the GMPP LSA complete wiring kit, unless I can find a better looking aftermarket one that is just as complete for $1400ish, anyone have any ideas? Speartech is somehow $2600, even with injectors (which they don't identify) that's crazy.

Im running the holley HP EFI. The cable throttle body fits but I have not run the cable yet.