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Discussion Starter · #1 ·
I've been debating doing this for a long long time, and I think I'm finally going to do it.

This will be a LONG LONG term project, I expect it to take several years to be completed properly.

Here is the gameplan

1967 396 Chevelle SS (I really only want a body, frame, and a VIN)

- LS3 Based 396cid engine
- DIT Twin Turbo Kit
- T56
- 8.8 IRS from 03/04 Cobra
- Full G8 Interior, electrical, abs, a/c, etc swap
- Coilover Suspension

The list goes on but this is a general outline of what I had planned.

On one hand I'm excited because it will be what I always wanted, comfort performance, and reliability of a brand new car with the styling of a classic. On the other hand I think its kind of a sacralidge to put the newer interior into the classic car...
 

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That sounds great but you better change your name to "Moneybags" or "Moneytoburn" for that kinda project...once it is done then you can change it back to "nomoney"...
Good luck and keep us posted...
 

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Just FYI, most guys pull the 8.8 IRS out of the cobras cause they break them.
 

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There are a few factors at play with the guys yanking 8.8's out of Mustang Cobras...

First factor is the mounting of the differential is very substandard. The mounting points are designed to be compact rather than to provide a stable base. This in turn causes a small amount of vibration isolation cushion to allow a fairly large movement of the differential. Compare with how the differential is mounted in late model Vettes.

The next factor is the dynamics of tire traction. Tires provide the most traction just before they break free. Thus as you increase torque into the tire it grips and the soft vibration isolators compress further and further until the tire breaks loose. Then since less torque is being transferred (less traction) the vibration isolators relax.

If this was all that happened there might not be a problem. But the final and fatal factor is when these affects become harmonic and oscillate in the phenomenom known as wheel hop. Not unlike valve float, wheel hop can literally shake things apart. One of the common weak points is the mount in the rear differential case that gets pulled out of the case. Half shafts have also been known to be weak links.

Also do not underestimate the ******* engineering aspect of all this. Many of these guys do not give a hoot about how the car goes around corners. They only want to run the fastest 1/4 mile. So for them simple is always better. Tried and true is understood. So they are pretty quick to grab a solid axle since they are a bolt in and very easy to come by.

My DD started out with a solid axle and I converted it to the 8.8 IRS. The IRS can be decent depending on your expectations. In general I avoid wheel spin because they usually hop, wet or dry. It does track much better than the solid axle ever did and the lower roll center allows for improved roll stiffness and balance between front/rear roll stiffness. It does feel better.

With the subframe design it may be a simple fabrication to convert to as well.
 

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Discussion Starter · #7 ·
Just FYI, most guys pull the 8.8 IRS out of the cobras cause they break them.
I am VERY familiar with the 8.8 IRS, I work with a guy who has a shop that builds Cobras out here.

We have several 10 second and a few single digit IRS cobras.

Thanks for the heads up though.
 

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Didn't mean any disrespect, you seem like you've done your homework. Sounds like a great build, looking forward to seeing it completed!
 

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Discussion Starter · #10 ·
Didn't mean any disrespect, you seem like you've done your homework. Sounds like a great build, looking forward to seeing it completed!
none taken, i appreciate the heads up. I'm sure there are many things about this car that I am not familiar with...
 

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I love the LS engines but Im not sold on this combo

- LS3 Based 396cid engine
Factory PCM for the LS3 are not ready for twin turbo land
GM changed the VE programing so the VE tables are very very hard to crack
The Injector tables end at 63lb this is bad news for big power
Even the big dogs are still running MAFs on these
unless they have a stand alone FAST / EFI system

LS1 1999 - 2004 harness with an LSX race block and custom twin turbos is the best way to go IMHO.
Real Time Tuner Suite in HPTuners with 4 channel i/o Datalogger
on the fly spark and VE tables on a 2 or 3 bar boost reference tune with the factory PCM!!!
The 99-04 PCM is OBD2 not CAN like the LS2 and up cars!!!
Also you get a real throttle cable out of the deal not a servo!!!!
And you can run the Interceptor OBD2 scan gauges to display everything on one or two digital gauges!!!

http://www.aeroforcetech.com/products_analogic.html

second choice would be a LS3 with a pullied up Magnacharger and a MAF
That will make 550 rear wheel all day long
easy to maintain, no boost leaks, clean engine bay, easy install, cool blower sound ect...

- T56
Normal T56 will not handle this power level in any way.
We have a car we built at our shop makes 800+RW
ended up with a Tranzilla with straight cut cryod gears
3 different big dog clutches in 1500 miles.
800+ just destroys tires and drive line parts
and does wierd stuff like broken 5 & 6 gear!!!


- 8.8 IRS from 03/04 Cobra
GM 12 Bolt, Dana 60, Ford 9" for my money!
IRS is bad news at 396 LS3 TT power levels.
Get ready for Big dog custom axles, ring and pinion ect.
This is not Thunderbird JunkYard IRS territory

IRS is bad news at 800+ IMHO
Down shifts at 90+ MPH require corrective steering input while driving in a straight line!!!
Toe, Camber, Caster, Ride height all migrate with the application of power.
Solid Bushings will not resolve this only band aid it.

Solid axles w/ 5link or 3link setups running a Wolfcarft or Jonny joint style zero lash bushing have
zero problem going straight even with shag nasty 2 gear kick downs on high stall the auto cars :)


- Full G8 Interior, electrical, abs, a/c, etc swap
Good luck with the ABS plumbing and tone wheel sensors.
Metric brake lines = nasty parts quest.

Personally,
I love a Hydroboost > distro > rear prop valve > c5/c6 fronts & late modle Impala rears.
Your not going to get enough tire under the car to deal with that kind of stopping power!!!
ABS is calibrated for a specific gear and tire range as well.
This pic is my heart pumping a little to fast coming out of the straight section after 2x Monster Energy Drinks and no lunch.


- Coilover Suspension
How much is it going to weight?

that may be more than my $.02 worth
 

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Discussion Starter · #12 ·
Tad,

We have the newer (05+) PCM's running at over 1,000 RWHP (through a 6 speed) with a MAF still.

We also have T56's (and IRS's) holding 900 RWTQ on slicks in 4,000 pound cars, multiple cars. However I must admit I was toying with keeping the 6 speed auto. The car will be 90% a street car, which is why I considered the IRS (that and wanting to be different).

No offence, but I think the maggie (except the TVS series) is garbage.

I'm VERY confident in the modern parts and their abilities, its incorpirating them into the classic car that is "the unknown" area to me....
 

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Our shop G8 is holding 600RW with a bone stock A6.
They are fairly tough from what I have seen.
Puts the 4L60E to shame for durability.

The MAF table is huge on the LS3 PCMs thats the good news.
For spark tables I really love MAP vs TPS to be honest.
I'n not a big fan of the LS spark table architecture but it works.
air mass vs RPM..... bLeck....!

Ok now the big Question is ...
Your on post #4 and your sand bagging.

So....Whom is "We"?

And is "We" looking for a good LTx / LSx PCM tuner / Dyno Operator?
 

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Discussion Starter · #14 ·
"We" would be myself and some friends, one of which owns a shop here in Las Vegas.

My personal daily driver is only a 480 RWHP N/A L76 (small displacement LS3) in a 05 GTO, but it does allright.

I love these motors, I am very confident with them and setting the car up, I think the issue will be mating the car with the technology available.
 

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what shop?
 

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From experience you might wanna rethink the G8 cluster. I personally spent months on a very trick Corvette GS clone that had a c6 dash in it. Getting it to work was only half the fun the other half was explaining to the customer that there was no way in hell to turn off all the error messages in the information center. Stuff like tire pressure warnings, AIRBAG WARNINGS, ABS, among others. As far as I know there is absolutley no way to remove this from the dash. It expects to hear messages from all other nodes in the vehicle (the dash is CAN) .

Without a BCM you wont even get the turnsignals working on that dash. And the dash itself turns on via a wake up message from the BCM and the PCM. Im looking at the schematic right now and the connector is VERY small. The cluster has 15 wires and a bunch of them are for the stereo of all things.

All in all I could list out at least 50 reasons wyh you dont wanna do that cluster and only 1 reason why you would. Id suggest taking the cluster housing and building in aftermarket gauges into it. The stock stuff will not work without ALOT of work. I do this everyday and I wouldnt do this project if you paid me 20k cause I wouldnt be able to make it work properly.
 

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Damn, 20K and still no budge? That's pretty loud and clear. I thought about using the the center console out of a G8. Looks good but the execution is where I'm hung up. Seems as though the console flows right up into the dash and in my case I wanted the dash and console to remain two seperate pieces and not appear a HUGE afterthought Still don't know if I'll do it though.

And hey, NOMONEY, I have to admit those G8 seats are mighty comfy too. Also considered those in my 65 although they aren't as readily available as the GTO seats.
 

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Discussion Starter · #19 ·
From experience you might wanna rethink the G8 cluster. I personally spent months on a very trick Corvette GS clone that had a c6 dash in it. Getting it to work was only half the fun the other half was explaining to the customer that there was no way in hell to turn off all the error messages in the information center. Stuff like tire pressure warnings, AIRBAG WARNINGS, ABS, among others. As far as I know there is absolutley no way to remove this from the dash. It expects to hear messages from all other nodes in the vehicle (the dash is CAN) .

Without a BCM you wont even get the turnsignals working on that dash. And the dash itself turns on via a wake up message from the BCM and the PCM. Im looking at the schematic right now and the connector is VERY small. The cluster has 15 wires and a bunch of them are for the stereo of all things.

All in all I could list out at least 50 reasons wyh you dont wanna do that cluster and only 1 reason why you would. Id suggest taking the cluster housing and building in aftermarket gauges into it. The stock stuff will not work without ALOT of work. I do this everyday and I wouldnt do this project if you paid me 20k cause I wouldnt be able to make it work properly.
If I'm pulling the wiring, PCM, BCM, etc from the G8, I don't see the issue other than fitment?
 

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If I'm pulling the wiring, PCM, BCM, etc from the G8, I don't see the issue other than fitment?
Let me make it fairly clear. The only way you will pull this idea off without spending and Im not exagerating here... at least 500-600 hrs of wiring and fabrication to make ALL of the systems operational, is to actually cut the floor out of your 67 and graft in the chassis of the G8 with the suspension, motor and trans, rear end, HVAC, BCM and all other devices.

Yes it can be done. Someone very recently one the Ridler award with a Rambler wagon sporting a Ferrari drivetrain. That would be easier than what you are proposing as far as electrical systems go.

Its not just making the plastic stuff mount into the car like trim, that will take a very long time but anyone with patience could do that and be okay (a pro would take a while ande look awesome). Its all those stupid little switches and modules to make work. Im talking very mundane stuff.

For example, suppose you do get the dash up and running as in turn on. Now we gotta make it work properly, and for me properly means it works like it came from the factory without any warning lights or stuff you "can live with". So we will make the ABS light turn off. For starters we gotta have the steering angle sensor, and the yaw sensors and the four wheel sensors and the EBCM (properly plumbed and wired) so now you got full on ABS that you gotta install just to turn off a damn warning message!!!

I wont get started on the Airbags lol.

As you can see the way I would do it would instantly turn into a MASSIVE bill at my shop.

NOW... There is a simpler way. Take the cluster apart. Remove the guts. Make a panel that fits inside the now empty cluster shell and have someone skilled in custom dash or yourself install some pretty gauges in there with warning lamps and maybe some trick electronics.. Install it in the plastic dash you made fit in the car and VOILA!! You know have a fully functioning dash board that looks like a G8 almost but costed you 1/1000th the amount of time and money you woulda spent otherwise.

Let me remind you I am speaking from EXPERIENCE and I will neverr go that route again. Pre- CAN cars are not the same and are easy to do, its any car powered by a GenIV motor that gets near impossible to do.

Im not trying to crush your dreams by sounding so pessimistic. Im hopefully saving you what would most likely end as an unfinished project that doesnt work. By using aftermeaket gauges INSIDE the factory cluster and just deleting that part of it, now all youre dealing with is a conventional LS swap. You dont need a BCM or all the multiple fuse panels. You dont need all the modules and crap that will weigh your car down by a ton and the very best you wont need to find a GM electrical foreman to help you figure everything out.

More or less I see something like this and it just screams of underestimating the scope of such a project. Its my business to help people through this part of a ccar build and by the time we get to the other side they are much more knowledgable to what is required. More or less if I wouldnt attempt this then you shouldnt attempt this.
 
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