NOTa2_4 wrote:this is why you need to be paying attention to other things i have the stock rear monifold and down pipe on my car so with the engine in its proper place headers should fit but you are working backwards. if the headers don't work you buy the ZZP ported manifolds and make a custom down pipe on my car headers should fit as my exhaust is W body from the engine to the cat
the subframe gets in the way its not the fact the engine is sitting in the wrong spot i have a stock rear on my car with a custom down pipe the problem was the headers that i was trying the downpipe was part of the header
Cut the downpipe off the header and weld a flange (or better yet, v-band)... your going to have to go custom, I know this because I am in the same boat, cutting the downpipe off and using my modified ZZP downpipe.
i have stock manifold and stock down pipe and my subframe is not in the way i moved my an inch forward. stock 2.4 DP follows the same bends as the 3800 DP.
i would just build your own anyways i prefer to build my stuff then buy it. its easier to make it do what you want it to do when you make it
JBO since July 30, 2001
I had to modify my ZZP downpipe, I cut 2" out of it if I remember because it was too tight, but it is 3", perhaps that is the reason, but now it fits perfect between the firewall and the subframe.
3" is definatly a tigther fit its even tight over the rear trailing arm assembly
JBO since July 30, 2001
i did full mandrel bent exhaust on mine this winter and is a hell of a fit of the rearend and by the gas tank
Right now I have a 2.5" cat back so I probably wont change it for a while. The only thing I might do is run a cutout sh!ts and giggles. However if I do decide to go for more than 300 WHP then I will upgrade to 3". Although I do plan on doing the rear IRS swap as well so I dont know if that will get me anymore clearance or not. I am going to pick up the SSAutoChrome headers because they are stainless and only run 300+shipping. I will likely get a local shop to fab me up a down pipe if the original doesnt fit.
Whats up people?
Rear IRS solves a lot of clearance issues for exhaust piping... I had no problems at all running 2.5", and when I upgrade to 3" all the way later this year, it will be a breeze. Probably the only difficult part is where to put the muffler!!
I had no issues fitting my 3" in the rear section... guess I got lucky. (I am lowered too!) Muffler I went a little different though, camaro style with 2 exits, it works for me and sounds good.
the 90 i used in the rear wasnt the tightest im pretty sure that why i had a lil issue
What do you guys think of this subframe design?
Whats up people?
The rear peace is useless and more than likely in the way since obviously the stock subframe must be used. The front bracing that goes from the vertical to the horizontal bars, they might be okay, just depends on your location of the rest of the subframe, your going to have to build the subframe around the motor and see where you have clearance, and where you do not, the vertical bars are inbetween the frame rails? If so are they infront or inplace of the stock upper rad support? The stock rad won't work if they are inbetween, there is VERY little room there. Other than that, it's fine.
I will take pictures of my design and post them once I finish it up.
Quicklilcav I designed it to be nice and strong. I will be using the GTP rad which is way to big for the stock location so I will put mounting tabs on the new sub frame. This is why there is a bar across the bottom. As for mounting straight to the rails, it should be strong enough built like this. all the mounting points should be all on the new subframe which is plenty strong enough to handle the torque that i will be throwing at it. I have mounting points top and bottom to where the rad support is which should be strong enough to hold the weight of the engine/trans since there shouldn't be much torque on these points
Like Isaak said I will have to build it around the engine so this is a rough guideline but I think a winning design. It should also be easy to remove by unbolting 12 bolts and sliding out if i need too.
Whats up people?
what isaak said that rear piece is useless and will give you nothing but problems when trying to replace the oil pan gaskets that the 3800 goes through ever so often.
i cut the rad support out and reinforced what was there because the vertical part would need long angles supports that will interfier with the motor placement as they will have to go atleast half way up
go to the the 3800SC post in the 3rd gen section or my post subject MY 99 ZED you will see how i built mine to run upper dogbones
that top bar MUST be tied into the rad support we have as its connects the right side of the car to the left if you cut out the stock rad support and put that in with out tieing it together YOU WILL TWIST THE FRONT END TO RAT SH*T. i would just ditch that idea entirly
JBO since July 30, 2001
1 thing i forgot YOU WANNA MAKE THAT THING REMOVEABLE
yikes man you will want aluminum my subframe is steel and is heavy as fawk and yours will be double the steel you angel supports WONT WORK will tell you that right now too big just looked at my car NOT GONNA HAPPEN
biuld the lower put the motor in the build the top but you HAVE TO tie it in from right to left
JBO since July 30, 2001
If you want it removeable and still strong, make your lower motor mounts as strong as possible, nothing is overkill in that area. Again, that rear bar won't work, once you have the engine in you will then see how little room you have as far as clearance goes, unless ofcourse you want to romove the engine every time you want to service it.
I will post up pics of my new upper dog bone/rad support brace as soon as it get's welded in, I have supports going from the rad support to the strut towers, completely removable with just 2 half inch bolts holding each in place I have nothing but lower motor mounts in right now and it doesn't bend at all, but I thought once I get racing, things will tweak/break, these engines have a lot of torque, breaking the tires loose at 50mph is quite easy I've come to realize.
Do things right the first time, you won't be sorry.
Mine's removeable... but the engine/transmission weight is on the sides from the stock frame rails. My donor was a Park Ave Ultra, so it's mounted differently than the Grand Prix GTP.. not sure about the Bonneville. Here's a few old pics:
The subframe extension:
Here's what the stock mounting points looked like in the Park Ave:
I just modified them a bit to work on the J-body frame as it's narrower. Otherwise... the weight is handled off the sides, the front and rear mounts in the car handle the torque from the motor trying to move back and forth (but they're so stiff... it doesn't move a bit..)
my lower is the exact same as lenko but i have my 5spd trans mount on it and my lower engine mount as i used a w body mounting not C body
JBO since July 30, 2001
My lower is exactly the same as well.......... I don't think that is a coincidence, just proves that it works! Although we all have different mounts one way or another.
Has anyone tried this swap in a 2003+ cavalier would it be the same as the other cavys?
i have the same lower as well
GODZILLA
since you can take the front end off any 3rd gen and swap them around i would imagine its pretty much the same. they just use different body panels. i would need a closer look 03+ though
Whats up people?
javis hildebrand wrote:GODZILLA
since you can take the front end off any 3rd gen and swap them around i would imagine its pretty much the same. they just use different body panels. i would need a closer look 03+ though
yeah i am pretty sure it will be about the same, maybe the wiring is a little different
I wouldn't know . . . will have to let some one who knows a little more about the 03+ answer that one
I do know however that the 00-02 wiring should work with the 04 impala SS pcm
Whats up people?
