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Discussion Starter · #1 ·
After years of dreaming and planning, I finally put the car in to have some fun things installed! I had already done 1 3/4" headers, 100cel cats and twin 3" exhaust with an OTR and tune back in 2017 which had the car making (allegedly) 407rwhp. I originally bought and fitted that exhaust system 2nd hand off a dude who had used them for years prior. I'd managed a best of 12.71 @112mph 1.914 60ft. I figured since my extended warranty was running out this month that it was time to execute my plan.

I'd already decided on the Harrop 2300 FDFI, but my plan was/is to have things setup conservatively because I do take the car to the strip, and also to a handful of track days/autocross events each year and I wanted a reliable setup. For this reason the builder and I decided to run with the stock LS3 cam, and include some extra supporting mods to help look after the engine. We decided to keep the target power below the 600rwhp mark.

The car has now been fitted out with the following:

1 7/8" ceramic coat headers
Brand new stainless twin 3" catback exhaust
Brand new 100cel high flow cats
Custom 3L surge tank (stealth install)
2 Bosch 044 fuel pumps (1 currently inactive)
Harrop 2300 FDFI kit setup to run 9psi
Custom 4L intercooler reservoir
SAAS .5L catch can

Interestingly the workshop I took it to have this work done baselined the car in its previous setup to read 364rwhp, I assume this is simply due to being a different dyno from the last place i took it to, knowing that they all read differently.

Anyways I picked the car up last week, and what a difference! The thing is so torquey and drives super nice on the street. I took the liberty of installing brand new 285 wide MPSS tyres on the rear and am glad I did because the car made a healthy 575rwhp! Picked up 50rwhp at 1500rpm and it stepped away throughout the rev range, extending to 211rwhp ahead at peak. I knew it was going to be a decent increase but wow! It pulls tremendously now.

I had the opportunity to test it out properly at a roll racing event at Barbagallo Raceway in Perth last Friday. I'm using the Torque Pro app with a Bluetooth OBDII reader to monitor vitals. I still need to setup oil temp, but intake temps looked decent over the night. Never saw anything higher than around 25'C above ambient, however, it was only 1/8th mile racing, revving out 3rd gear.

Some footage can be viewed here:


The car goes and sounds fantastic! Anyone sitting on the fence about going FI, its totally worth it!


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Tank under the spare is a nice touch. I like it. Enjoy!
 

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Nice clean install. I like that it looks like it could have come that way from the factory. If I could have spent the money, I would have done a Magnuson supercharger on my car. I can't bring myself to do an LSA supercharger due to a previous bad experience in not using a bolt-on kit.
 

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LSA is a great option. Factory parts.

But the Harrop, and the readily available SLP kits (if they still sell them) with the revised internals compared to the last gen - can be had for a bargain.

Looks great, one of my favorite wheel styles [and I am a bit biased]. Nice work!
 

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Discussion Starter · #8 ·
Sounds tough Dan. Did your tuner say what the standard LS3 fuel pump was capable of supporting power wise? Bosch pump sounds good, but x 2 seems like overkill if your never gonna turn it right up?
Cheers!

Standard fuel pump good for 550 - 600rwhp ish is what I gathered. The reason I upgraded is because I wanted a surge tank to combat fuel starvation I was experiencing under lateral G's on the track, specifically right-handers. Lean fuelling conditions are a big no no for force fed engines and I didn't wanna risk it.

The second pump is there ready to go for when I inevitability take things further with the engine in the future ;)

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Discussion Starter · #10 · (Edited)
Time for an update. It's been 14 months, 12,000km, 13 track events and 3 oil changes since the LS3 was supercharged. It appears I am now joining the group of people who have killed an LS3...

I was always wary of running at the 570whp level and pushing reasonably hard at track days. I consider myself to be a driver with 'mechanical sympathy' though and always treat my gear nicely and try to look after things. But, things do wear out and especially once you add boost and track days to the equation, the service life of standard engines drops dramatically.

I was participating in Powercruise, a car enthusiast event which goes over 3 days where you can take your car, load up with passengers and do what you're not allowed to on the street. Burnouts, cruising, roll racing, drifting, it's a super fun weekend and this is the second one I've done supercharged. I got through most of day one and the car was going strong, oil temps below 120°C and vitals all good.

Unfortunately towards the end of the day the car suddenly started running on 7 cylinders and backfiring under part throttle so I backed right off and pulled off the track straight away to investigate. Upon lifting the hood, I was greeted with an ominous loud tick which I first thought could be lifter tick. I pulled the rocker covers to see if it was something in the top end, but alas everything looked ok. So I flatbedded the car home. The plugs got pulled next and it was discovered that the plug from cylinder 6 was squished and the end had aluminium pressed into it. At this stage my own ability to fix was exhausted, so I flatbedded the car to my builder and he suggested that given the information, the rings had butted under heat and nipped the top ring land on that piston.

This was confirmed once the engine was pulled and head removed. I had always planned on someday upgrading the stock bottom end of the LS3 with stronger parts but just not so soon. Since this was now required, those plans have been brought forward. The plan is to go to a 4 inch stroker crank and build a stout 416ci stroker, retaining the LS3 block. Callies Compstar crank, scat H beams, SRP pistons, clevite bearings, ARP studs and all the proper block treatments for this level of build. Heads will be upgraded to PRC for their extra deck thickness (I know my block doesn't allow for a 6 bolt head). Clutch will be updated to a twin plate for the extra torque. Keeping the same Harrop FDFI 2300 sc but upgrading to an 8 rib drive. Fuel and exhaust already done (twin 044s / surge tank). The main thing I'm going for is reliability so I'm not shooting for ridiculous power levels here, but it will be a step up from the 570whp.

This update is not to worry you guys with stock LS3's. I've seen people run at 640whp on 12psi on their stock LS3's and they've been fine for years. YMMV is the main point. Once you go force fed, service life of the engine is decreased, and by how much is a dice roll.

I'll keep this thread updated, right now the engine is being torn down and block sent for machining. Expected turn around time from here is about 4 weeks.


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Mistakenly made myself @Rhousenator when I'm already @RoushSenator. Only had 2 Fords both Stock. Both would be appreciated by Aussies, XW Windsor V8, FPVF6 sedans. By comparison I went with the LS9 Bottom end no chance to stroke without revising piston oil cooling.

Its also an Aussie joke but one of our states Victoria, is lead by a Dan a polarising strong leader. So our Dan is lucky he is states away. Usage impacts costs. Since completion to boost with a built bottom end mine has been driven to work in no traffic Canberra and toured around Australia with wife and kids, and has only required routine servicing. Family has two other cars (atm) and two drivers and usage is spread across them. Dan has had appropriate competition use. That's a great way to spend time that I don't have (fortunately).
 

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Hi Dan, any updates from the work shop? 416 forged, 2nd fuel pump waiting and blown, waiting for the update.
 

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Discussion Starter · #17 ·
Update time! So quite a bit has happened in the past few weeks and the plan has adapted somewhat.

The LS3 block was stripped and sent to the machine shop for all the various treatments, but the process got halted very shortly after honing bore #6 when they discovered a crack in the bore. So there was more damage than previously thought!

After some discussion and decision making, we decided against re-sleeving the LS3 block, instead opting for a brand new aftermarket number. The LSX iron block was unavailable at the time so we decided to go with the next available option, being the Dart SHP LS Next Pro (iron). The plan was to use the same 4" stroke callies compstar crank, but we'd make a bit more use of the new block's potential by going to a 4.125" bore, making the 427ci. The pistons had to be reordered, and the 4" pistons that were already arrived would be used on another engine later on. The Dart block will of course accept the 6 bolt heads now as well, further adding to the strength of the new engine.

Camshaft choice was made next, my main requirements being drivability and a smoother idle. Something in the 22x 23x with lift under .600 and a wider LSA would be designed, leaving the technical details to the builder as he tailors each custom cam he designs to suit the combination.

I've chosen to upgrade to an 8 rib drive system for the Harrop blower to help with belt slip as we'll be spinning the blower harder to feed the bigger engine. Another item being upgraded is the sway bars, this is more opportune as it's an easier job while the engine is out.

Fortunately the Dart block requires less machining than LSX so less time and expense will be lost in that process. As it stands right now, to my knowledge the engine will be assembled this week, and the main item holding us up is the clutch. The company that manufactures them was completely snowed under with orders right when we were ordering and we were told it could be up to a 6 week wait. So once the clutch arrives, the car can get reassembled and engine break in / tuning can be done.

At this stage I'm hopeful of a 2020 delivery but we shall see. I'll keep updating this thread as I find out more. I really miss driving it but am fairly excited with how things have developed, so very much looking forward to a whole different animal when I get it back!

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An appropriate build for a Commander. I wasn't surprised the ring butted LS3 block was damaged. It had a good run. Of all the blocks Dart would have to be up there. With the larger bore you can have the larger intake valves, of the 6 bolt heads. You have a huge amount of power pre boost any way. I think in Australia these one off builds can take time, (parts) but may be not at your work shop. You'll have a lot of power to put down from a built engine.
 

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Discussion Starter · #19 ·
Cheers RoushSenator, I'm not shooting for huge power this time around, we just want a stout and reliable package for the track stuff I do. It is however, future proofed for if the power bug bites again later on ;)

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