Yeah, I saw that awhile ago, but didn't see much from the new owner since he sold it. I know he posts a bit on GPF, but I really don't get on there hardly ever. Good to see they've still got it going.

I assume the 620-640 is without spray? Any idea how big of a shot they plan to run? Either way, I know my setup couldnt touch those numbers due to the cam limitation. Next time the engine is out, I'm definitely changing cams, but it just isn't worth the effort to me right now.

Also, is PRJ still in the 3800 game? I thought I remember seeing stuff on clubgp awhile ago that he wasn't taking any new orders for custom parts. I also saw pretty much anything that wasn't a simple drop ship item was discontinued on his website.


So I got my bypass tube and inlet adapter to the machine shop today. After discussing with them the changes I wanted, it looks like it may be easier just to make one from scratch. They're going to run the numbers both way to get back to me by the end of next week. It'll definitely look a lot nicer machined out of 1 piece rather than having a bunch of welds and such.

 

I'm glad that you're still working on this bumpin. Can't wait to see more progress!

 

Prj is pretty much done, he is doing little side work but not really a business anymore. He took the Whipple car back as that was his build originally. Prj is suppose to build me axles but it's been a while now since we talked. I believe it's a direct port setup something like a 200 shot I believe not sure as i don't know a lot about nitrous. Yea greg posts on gpf a lot but that's about it. I have been to gregs house a few times, he is a good dude.

 

Well, two steps forward, one step back. I went ahead and built the last fuel line to connect the rear rail directly to the 2nd inlet on the regulator (on top). Not sure if I'll run it like this since it is a little ugly, but I'm thinking the extra pressurized fuel volume will help and I think that it will help both rails be closer to equal.

I got some more wiring done, but nothing real crazy.

The big downer was messing with wiring on the backside and noticing a big gap in the rear header at the crossover flange. There was a roughly 1/8" wide x 1.5" long gap where I could literally see into the crossover pipe. I thought I just had the crossover angled wrong when I installed it, so I pulled the crossover back out.

Turns out, it is impossible for the crossover on this set of headers to seal at the front and back crossover connections both. If I rotate the crossover to get a better seat on the back (until the pipe hits the egr tube), it doesn't quite get to the point of touching the donut all over, and it also unseats the front flange so I have a gap up there. See best case scenario:




Keep in mind, even in this miserable condition, the front has a nice sized gap into it.

I won't rehash the issue much since I discuss it in more depth in the header thread, but this is definitely a setback. Really shouldn't have to hack up a $900 set of headers to get them to fit (granted I bought them used, but still paid almost double what the ebay SLP knockoff headers go for). I really should've left my other headers on...

 

Have you tried turning it around?

 

Ouch man... That definitely sucks. Is it not round enough? I know you said something about using a pipe expander before...

I've got some brand new SSAC's that have 1.75" primaries, so when I get my truck's transmission fixed I'll be pulling the motor and pounding up the firewall - nobody around here will touch it. Until then, DDing the Monte!

 

Yep, that was the second thing I tried. It definitely doesn't go that way because that puts it going straight into the brake booster. The fit is certainly close with them this way, but unfortunately close doesn't really cut it when you're trying to seal exhaust up.


Nope, that only applies to the SLP style knockoffs with slip fit pipes (I guess to an extent the Pacesetters too where they used to have a large mismatch in diameters). I did have to use the expander on my DPPs to round the tubes out better.

With these stupid flange setups, the connecting pipes basically look like the end of a trumpet- flared out at the end. Then you've got a 'donut' gasket that is just a ring with an angle on each side to butt up to the 'trumpet' ends to seal them together.

The upside of this type of setup is that it's supposed to be more resistant to angle mismatch issues because the two flared ends don't have to be pointing directly at each other to seal. However, it can't help you in a case like this, where the pipes are offset. Even with the most extreme angle I can get on the crossover, it still doesn't put the outlet close enough inline with the rear header inlet.

I think I'm going to weld extra metal onto the 'trumpet' part of the crossover to bring it in contact around that side of the flange. I estimate only having to add 1/4" to 3/8" more material to get it in contact. The only thing I want to make sure of is that directly opposite that area on the donut- across the diameter, is touching the inside of the pipe to still seal. I can't see whether its touching the inside or not because it's open towards the firewall.

If that doesn't work, I think plan B is to cut the crossover in half, bolt both flanges up, and then weld it back together. I'll admit I'm not real crazy about doing that because it'll probably look like crap, and will kill resale value on the headers.

Sweet, should be fun- good luck!

 

Man the things that should be so simple are sometimes the ones that are the real p.i.a.. Totally a bad product to miss sealing as far as it did. As you mentioned it appears even the previous owner had the same leak. Poor quality control that day. Well at least you have the what for with to polish this turd and make it work. So sorry for you, your fortunate to have detected this before everything was all buttoned up and melted a few wires or possibly even worse. Best of luck MacGyvering your way out of this predicament. Now go pick up all the wrenches you threw after you saw this.

 

New TB adapter design is done, just need to cut it now.



Whipple BBV mounts to the side, and the holes beneath it are going to be tapped for barbs for vacuum lines (brake booster, PCV, etc).

 

Awesome work!!