If You Think The Z/28 Should Have a Free Revving, Normally Aspirated Smallblock ....
 

I posted a similar thread on GMI and sent it off to Mark Reuss, Al O. and others. Figured this would be a good place to discuss this as well.

My sources indicate that a 6th gen Z/28 is in development and it's powerplant would be the LT4. Sounds like GM may want to merge the Z/28 and ZL1 into one model in the same way that they have folded the ZR1 into the Z06.

To paraphrase Yogi Berra, this seems like deja vu all over again. Didn't we just go through this with the 5th gen? Many of us screamed and whined until they renamed the "Z28" the ZL1 and then as a bonus also got a really badass Z/28.

Personally, I'd like to see a "hot cammed" version of the LT1, with whatever changes are needed to support that, including the deletion of AFM for the Z/28. Maybe GM could share it with a Corvette model as well. It would be a direct competitor to the flat plane 5.2L in the GT350 and GT350R.

Save the LT4 for a different model.

What say you?

I've suggested all along that an LT2 (or whatever) could be done.

GM has already shown a paradigm breaking move with the LF4 for the ATS-V. That is if the LF3 stays in production for the CTS V-sport and XTS V-sport as is. All we need is a 10% bump from the LT1 and you've got a 500 plus HP engine. The issue will be if it's a low volume hand built engine like the LS7 and LS9 and the LS3 with the dry sump. That gets pricey in a hurry. But I don't think the LF4 is hand built for being low volume.

The same people you wrote your letter to were the ones that made the late decision to make the Z/28 a REAL Z/28, a NA car. So there is ZERO convincing you needed to do there.

I would suggest your sources are not necessarily fully or completely informed. I think the Gen 6 is the most buttoned up program to date. I'm just skeptical of anyone claiming GM employees are sharing anything right now.

Now is it possible the they combine the ZL1 and Z/28? Yep. I would suggest the difference would be chassis, CC brakes and tires with some light weighting to make the difference if they do. The ZL1 becomes the "street" flavor and the Z/28 becomes the "track" flavor of the Hi Performance engine Gen 6 car.

But when they announce the Gen 6, don't expect to have this laid out for us. It won't be. GM will milk that with one or more separate announcements.

I occasionally post on GMI under the same handle but can't remeber if I posted in your thread.

I would do an upgraded LT1, similar to the LS1 to LS6 but more so.

No AFM
Higher compression
CNC ported heads
7000 RPM redline
Tubular shorty headers
Dry Sump

GM made an to the LS from ~350 hp to 405 without changing displacement. I would like to see them match or exceed that increase if possible.

The LF3 to LF4 is a great analogy, similar to the LS1 to LS6. Personally, I'd be happy with that. It could give similar performance to the Gen IV LS7 at MUCH lower cost.

As far as my sources not being completely informed - yep certainly they may have gaps in their info. But this is about the time (pre-production), we started the crusade against a supercharged Z/28 on the 5th gen, and it took until a short period, right before the ZL1 intro, for Mark, Al and others to make that decision. I figure we can use the same strategy again...and no time like the present :)

Here is a great article i came across showing the outcome of a cam swap in a gen V lt1

http://www.superchevy.com/how-to/eng...p/viewall.html

The final results on a chassis dyno was 424 TQ/4900rpm and 471 HP/6100rpm at the wheels. This was with bigger cam, upgraded valve springs, headers, CAI and a tune, all while retaining AFM which is impressive.

I think this would be a great combination for the next z28, keep it Naturally Aspirated!

I just wonder if eliminating AFM would give a more lusty, revvier personality. It would certainly lighten and simplify the valvetrain.

It would lighten the valvetrain for sure, and assuming the z28 will be a lower volume car, fuel economy numbers won't be as important

My worry is that they've set precedent with the Track Focussed Z06 going SCed. So a reminder can't hurt. Just keep in mind the LS7 existed and it was only a decision to continue it in the Camaro. What we are hoping for is an engine that doesn't exist which costs $$$ to develop.

I think that if they do it it will be a Z/28 and Grand Sport engine......or Zora.

Exactly. I have the same concern about the Z06's precedent. And even if my info isn't 100% complete, it couldn't hurt to get the ball rolling.....just in case.

Ah, the Zora. I'm excited to see what that might be all about. And what kind of motor would Zora Arkus-Duntov want for his Corvette? Probably EXACTLY the one I'd want for my Z/28. :thumbup:

So, do you think the Zora rumors have merit? Wouldn't the Zora need more hp than a naturally aspirated engine can produce? If it is mid engine, that would leave room for twin turbos.

I hope GM builds a Grand Sport and Z/28 but I haven't heard any rumors of a GS. Not to mention the Z06 and Z51 don't leave much of a price gap to fit it in.

http://upload.wikimedia.org/wikipedi...kus-Duntov.jpg

According to my psychic medium, Zora says go with a non-AFM, hot cammed, LT1. ;)

Maybe call it the"Special Performance LT6" and reserve it for the Camaro Z/28 and Corvette Zora. Flat plane whaat?

Supercharging the coming Z28 would be a great way to show 1 of 2 things.

The naturally aspirated pushrod engine has maxed out it's potential due to emmisions regulation. Or

Go xxxx yourselves camaro-enthusiasts.. We build. You buy!


I will be amazed at the foolishnes if GM choose the second option. It would however give me the final push to move away from GM knowing they dont care anyhow.

Well GM trademarked it. Could be a ruse....could be the C8........or could be a no holds barred low weight tack-nastic C7.

I think it's relevant, and here's why.

http://www.motortrend.com/future/fut...gt_first_look/

for what GM has done lately in the performance realm, they don't want to be second best to Ford or Fiat.