[Lt1z]

What is the max RPM you typically pulley the LS9 superchargers to?
I have a 9.55/2.65 on there now which will be overspinning it at high RPM.
I'm guessing it will make peak power at 66-6800 but will be able to rev much higher if necessary.

I'm planning E85 & a chiller to keep the air as dense as possible.
Cam is mid 230's/upper 240's on a 120 with .630/.600 lift.

Unfortunately, compression is only 9.25:1 as I did not want to excessively mill the heads or change pistons, which would have required a custom piston due to the odd length rods & pin size.
Once that process started, things would have escalated to a different rotating assembly, then different block, then a different charger, killing the budget part of this build.

I really only started this build due to the good deal I got on the engine & I must now resist the urge to get too out of control.

On most ZR1 I use a 2.35/14% which would be just over 24000 rpm at 6800

Your pulley combo would put you at 24500 at 6800 ish.

Cam sounds like a BTR 3 or very similar

 

[Lonnies Performance]

Lonnie, I just caught up with this today. What did you do with my truck?? All kidding aside, another great project, done correctly.

Your truck... it's not for sale yet lol.

I just re-did the front suspension for more travel as I could not get it to hook.
The pro-touring front suspension had just under 3" of droop, which I increased to 6" with high angle ball joints, spacers & altered sway bar brackets.
Hopefully I can get it to work without switching to drag type springs... at least with coil overs it is easy to swap without disconnecting a ball joint or removing the tires.

Also planning to drop the rear gear to a 3.54 so I can finish the 1/4 mi. in 4th gear.
Possibly converting to E85 as well.

Thanks for the compliment...I'm just rebuilding this car since I took the engine out of it for my S10.
It has been apart for 2 years in my garage.

On most ZR1 I use a 2.35/14% which would be just over 24000 rpm at 6800

Your pulley combo would put you at 24500 at 6800 ish.

Cam sounds like a BTR 3 or very similar.

Lingenfelter suggests limiting speed to 23000 for endurance applications, but I could not find a max rpm listed anywhere.

A 14% ZR1 lower is 8.53 & with a 2.35 upper, it is a 3.63 ratio.

I incorrectly listed my upper as a 2.65, but it is actually a 2.6".
My 9.55/2.6 is a 3.67 ratio.... so about 25,000 at 6800rpm.
Should I be worried?

I got the lower pulley & balancer from a friend when he traded in his ZL1 Camaro.
That was my gift for returning it to stock, so I was hoping to use it if possible.

As for cams, it is between a BTR 3 & 4.
I had a new in box BTR4 but thought it was a little too big for my liking.

 

[Lt1z]

You can always slow it down a little. DSX will make you custom size lowers to bolt onto either ATI or IW dampers. A race ported LS9 2300 spinning 24K rpm will make 20-21 psi on a decently cammed 376-377.

 

[Lonnies Performance]

You can always slow it down a little. DSX will make you custom size lowers to bolt onto either ATI or IW dampers. A race ported LS9 2300 spinning 24K rpm will make 20-21 psi on a decently cammed 376-377.

20-21 is more than I expected. Thanks for the info.
I'll look into some different lowers... they seem to be similar in price to replacement upper pulleys despite the larger size.


Things have progressed pretty well so far...

I picked up a few more measuring tools to assist with the assembly.
These came in handy for all the clearances & verifying what the machine shop did.

Also here are a few pictures of some of the parts used.

I have a few photos of the Frankenstein heads that I'll post tomorrow.

 

[Lonnies Performance]

Here are some photos of the M-Series heads.

I also had some issues with the head studs.

Due to the larger size, the head bolt holes were reamed for the 12mm studs.
I figured all was well until I went to install them.
The washers were too large of an OD to clear the spot faced area on the heads.

I ended up turning them down in the lathe.

The next issue was the studs are too long & I needed a second set of washers...
Summit then gets more money & I end up buying more stuff just to get free shipping.

A trunnion upgrade was in order also.
I had considered aftermarket rockers, but I was not sure it was worth the added cost.

 

[MeanMike]

I assume you’re using ls9 accessories and maybe you already know this, but iirc you’ll have clearance issues with the alternator to valve cover especially if you go aftermarket covers. My friend did trick flow heads and roller rockers that required thicker gaskets on his zr1 and had to space the alternator up.

 

[Lonnies Performance]

Actually, I converted the engine to LS3 Vette accessories with an add on LSA supercharger drive kit.
I used a special offset blower pulley to align with the LSA lower pulley.

The 10 rib ZR1 accessories are nearly unobtainable & do not play well with other items in my Firebird.

 

[Lonnies Performance]

I made some more progress & it is starting to look like an engine now.

I am going to fully assemble the engine & trans with all accessories before putting it in the car.
You can put on a set of headers & spark plugs in 10 minutes when the car is not in the way.

Currently routing all the wiring on the engine.
Unfortunately, the Holley wiring harness needs modified to match up with all the supercharger parts & accessories.
Air temp & MAP on opposite sides etc.

 

[Bluecoupe]

Actually, I converted the engine to LS3 Vette accessories with an add on LSA supercharger drive kit.
I used a special offset blower pulley to align with the LSA lower pulley.

The 10 rib ZR1 accessories are nearly unobtainable & do not play well with other items in my Firebird.

Can you let us know where you obtained the LSA supercharger drive kit?

 

[Lonnies Performance]

LSX Concepts for the drive system... they now also make an 8 & 10-rib system with a spring-loaded tensioner instead of the manual setup shown.

The LS9 blower required a custom offset upper pulley to align with the LSA pulley offset.

 

[Bluecoupe]

Thanks Lonnie.

 

[Lonnies Performance]

I'm still making progress.

Engine is back in the cradle.

Flywheel is mounted. Think GM could fit 1 more bolt on the flywheel?

Finding a 9-bolt flywheel for an auto (especially one that was available) was interesting since GM never made a ZR1 automatic.
JW performance custom drilled a blank & had it out to me in about 2 days... excellent service from them.

Don't worry about the pilot bearing... I have since removed it.

I picked up my Rossler 4L80E 2 days ago.
Another great company to deal with...
Carl (the owner) took the time to answer all my questions & even sat down with me to chat for a few minutes.
I was very impressed with all the custom components they make in house.

 

[Lonnies Performance]

It is now back in the car....

I have just over 5/16" clearance to the hood at the front corner.

Now comes all the fitting & adjusting everything for clearance.
I have a bunch of wiring to neaten up & to get the Holley harness inside the car.

One coil is against the heater box & will need relocated slightly.

Wiper motor is pressed against the supercharger ... I already shortened the mounting feet 1/2" before installing the engine.
Now I cut the corner off the cover exposing the electronics, so I have to fabricate some new items.

The throttle body will not fit in the present location... I'm thinking of mounting it in front of the alternator on a 90 elbow.

Transmission clears although very close to the floor, but the pan is closer to the ground than I would like.

 

[SecondhandV]

I just wanted to let you know that I am really enjoying this build. Your work does make me feel bad about the hack job I did on the LS swap in my Wagoneer though haha.

 

[Lonnies Performance]

Thanks for the feedback... it helps keep me motivated.

I'm at the stage of the project where the fun has worn off & it is becoming a job to finish.
I see huge list of fitment issues, which are a challenge (that I somewhat enjoy), but also consume so much time.

I think I have my wiper motor clearance issue solved.
I cut the feet off on the motor & moved the bushings up to gain 1/2" more clearance... this was the limit without cutting the firewall.

I had to remount the bushings with 10/32 set screws.

Unfortunately, it's still not enough...

I cut through the cover & now have just enough clearance.

Now I have to rebuild the corner as close to the electronics as possible.
I'm planning to use some epoxy or window urethane, which I can sand, shape & paint afterwards.

I got my Strange chromoly pinion yoke yesterday & can now measure for driveshaft length.

Tomorrow, my trans & engine oil coolers will arrive so I can mount them & make a list of plumbing components needed.

My next clearance problem will be getting the engine positioned exactly where it clears everything.
Currently the left header is 3/16" from the lower control arm mount & the coils are tight to the heater box on the right.
Common sense says move engine to the right a slight amount, but the trans is very close to the floor on the right already.

Height is also a problem...
Trans pan is too close to the ground (about 3"), but I only have 5/16" from the hood to charger on the right side.
I want to raise the trans, for a better driveline angle, but it will hit the floor, If I lower the engine, the ground clearance gets worse.
I'm going to try lowering the k-member away from the body a little (maybe 3/8"), giving me more hood clearance & leveling the driveline.... even if it raises the car slightly.