We normally do engine dyno before installing but the time frame for the next race made us skip that step. Sorry for the non fiero chassis dyno, but its an F23 LZ4 setup that could be done in a fiero, minus the exact header configuration Stock 140k mile bottom end with an MS3x computer for full SFI. It has the wot-tech big race cam and VVT delete kit, 75mm TB, ported heads and manifolds, thinner head gaskets for quench, and custom headers.

Good stuff!
How much head and intake work was done?

(I posted in your thread on Farcebook but, of course, it's disappeared from my view. It's why I like the Forum so much.)

Edit - What would you estimate the drivetrain loss to be, through an F23?
I've been attempting to talk myself into proceeding with my LQ1 swap, but with these kinds of numbers, I'm having a hard time not switching to an LZ4 or LZ9.

[This message has been edited by Raydar (edited 10-09-2025).]

Facebook does the same to my personal account. I like to keep any details that matter to myself when it comes to port work, but I also want to make it clear that it didn't take a lot of effort on the heads (besides testing on a flowbench a lot). I think there is more to gain, based on the flowbench testing, but now its finding the point where we lose power.

Dan figures 310 at the crank and id hope its over 300. We haven't done an engine dyno to chassis dyno comparison to get the losses figured out yet.

LQ1 belt tensioner has been discontinued for quite some time now. It is going to be hard to keep those on the road without that available:/

quote Originally posted by WOT-Tech: ... LQ1 belt tensioner has been discontinued for quite some time now. It is going to be hard to keep those on the road without that available:/

Thanks for your response. Regarding the head work, I get it.

The belt tensioner is not likely going to be an issue - at least for a while. I have a newly rebuilt (albeit about 5 years ago - still on the dolly) engine, as well as a crate engine. Maybe even a spare tensioner. I know I have a spare belt.
Just the PITA of shoe-horning it into the car, especially hacking the hinge box, and notchback decklid, to get everything to fit, when the LZ4/LZ9 is so much more compact and... flexible?

Here's a question that is more back on track, to the original topic...
That LZ4 already seems to make more power than the NA LQ1 is realistically capable of. (I don't care anything about boost, at this point.)
I was leaning towards an LZ9. But would the shorter stroke of the LZ4 be more suitable? Or usable?
Thinking cam bearing spacers and ~270-280 cam, with either one. Obviously VVT delete.
Probably mostly stock, otherwise, except for a larger TB and matching TB neck on the upper intake.
(I had really good luck with a cammed iron head 3.4, but I'm not looking to do that kind of work to this one. Had $6-700, just in head porting, back in 2005 or so.)

The car is an 88 base coupe. Trans will be a Cavalier-geared F23. (3.94).

Have you any thoughts?

[This message has been edited by Raydar (edited 10-20-2025).]

LZ4 for anyone not trying to replace the pistons. You can't get the quench right without pistons in an LZ9 but you just need .040" mls gaskets to get it where it needs to be in the LZ4. 2:1 rod stroke ratio is a nice to have as well. LZ9 would be better for a heavier vehicle, something that tows or climbs over rocks. If you wanted torque galore and not go over 6k, its a great option.

I'd be interested to see what one of these could do in a car with a different intake. the stock intakes aren't a terrible design, but I think they leave alot on the table for a max effort build.

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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

I invited Lou Dias to trash me in my own thread, he refused. sorry. if he trashes your thread going after me. I tried.