4.3 Supercharged Chevy - Page 6 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Homeoboxter · 11-02-2020, 07:04 PM

Yeah, looks sharp! I loved the belly pan solution, very genuine

Qingdao · 11-04-2020, 05:18 PM

Quote:

Originally Posted by Qingdao

This is what happens when you have the plug wires in the wrong spot and your engine says "CHECK YOUR TIMING" and you are like "F YOU I'm gonna pour more gas in the carb". Oh well I really shoulda clear coated that adaptor plate anyway.

Further in the saga of LISTEN TO WHAT YOUR ENGINE IS SAYING. LOL

Yeah, roots blowers don't allow for backflowing of gasses. Apparently I've been running on 5 cylinders ever since I first started the engine. LOL

I'm not mad, I'm actually impressed. That push rod made it through a rocker.

Oh well. In about an hour and a half I had both the heads off stripped and I'd ordered new headgaskets, rockers, and lifters. God I love this engine in this car, its like insanely easy to work on. Everything is so easy to fix and right there. Imagine having an engine on a permanent engine stand with 2 feet of room to work on either end; that's a SBC in a Porsche.

Qingdao · 11-09-2020, 03:09 PM

Ahhhh yeeeeah; She moves. BUT got some questions...

The DME apparently does NOT like this situation. The A/C doesn't click on because the computer doesn't think the engine is running (oh boy its running LOL). So I have to hard wire strait from the climate control box a wire to the A/C clutch. Does anybody here know off the top of their heads which wire kicks the A/C on?

Also, cause the computer is not getting all the info the cooling fans aren't coming on... Thats an easy enough solution. I'm just gonna get a thermo switch and hard wire them. Not really looking for an answer here; just sharing

And third problem. The Porsche designers didn't make the throttle cable long enough for an edelbrock carb. WHAT WERE THEY THINKING???!! LOL

Other than those issues... its fun. Just fun to be out of the garage finally. Even though I'm happiest when in the garage.

Homeoboxter · 11-10-2020, 08:20 PM

For the A/C: there are at least two points where you can hotwire the system: the A/C pump relay, and the A/C control unit. Based on the circuit diagram probably you can trick the control unit such that it thinks the engine is running. Do you have the Bentley service manual? I`m uploading the respective diagram here, just in case, I hope that`s allowed:

Hope that helps.

Homeoboxter · 11-10-2020, 08:24 PM

Hmm.. Looks like it got resized, I guess you can`t see the text. I can send it to you in the original size, that`s readable, lmk if you need it.

Qingdao · 11-11-2020, 05:54 PM

Quote:

Originally Posted by Homeoboxter

Hmm.. Looks like it got resized, I guess you can`t see the text. I can send it to you in the original size, that`s readable, lmk if you need it.

Got it.

I think I'm gonna try giving the crank angle sensor some voltage from the tach wire. I'm hoping that might trick the computer to think that the engine is running. I think that might cure what ails me.

If not I guess I've gotta wire stuff up.

Qingdao · 11-14-2020, 05:54 PM

Last image dump.. The body isn't gonna change much at this point so picture viewers can sign off now.

I have the "tuning top" on the car right now. It makes it soooooo much easier to make carb/timing or other tuning changes when the hatch isn't on the car.

OK sitrep I have cooling fans when the engine gets up to temp. The problem is the fans cool off the radiators... and the radiators are 2 meters from the sensor. Maybe some day in the future I'll wire up an electric water pump to turn on when the fans do. That way if I shut the car down the fans won't run FOREVER. ATM I wired them to turn off when key is in the off position.

There is NO power to the relay 2 box. I'm gonna try to hot wire the relay 2 box tomorrow. That might give me A/C voltage.

As for the tac... I'm still up in the air. I think I might honestly just get a Porsche CAS and glue a picup sensor to my flywheel. Kind of a jerry rig situation, but who cares.

Anyways, she is lookin suuuuuwweeeeeet. [You're supposed to read that with a good southern inflection]

PS: yeah, I know that right fender is fubar... the door is questionable.

Qingdao · 11-16-2020, 05:09 PM

The propane diffuser fits.

Qingdao · 11-22-2020, 03:12 PM

Too much compression... too much boost... Too much timing... not enough ring gap... not enough fuel...

Muy muy mallo...

Its all good though. I sorta clocked myself working on the boxsterado this time. It took all of 4 hours to get from running engine to pistons out. Granted I am a "professional" mechanic, but even by my standards thats a pretty easy engine to work on.

The washer machine looks good though

Well lesson learned; I got some deep dish pistons on order and I said to hell with it and ordered some Eagle H beam rods. Cause why not.

Qingdao · 11-26-2020, 04:15 PM

So, after some maths, I found out that my CR with the old pistons was about 11.1:1. TIDAK BAGUS!!! I mean I could run E85, but no, just no. I could have just run strait propane, but I like the versatility of gasoline. I mean when you are camping and you need to start a fire you just unplug the fuel line and BOOM instant fire. LOL

With the new pistons and eagle rods my CR should be about 9.7:1. Which IMPO is still kinda high for boost, but definitely doable with 93 octane.

I really wanted to be able to run like 87, but oh well.

Just gotta hone out the block and slap these buggers back in there.

Qingdao · 01-09-2021, 01:56 PM

So after 1000 miles I think this machine is about in its final form.

I ditched the hot air intake and made this cold ram air intake. I blocked off the original hole and made my own in where the top would normally sit. In theory this should shoot cold air from the side intake into the conic filter that feeds the carb. In reality it makes cool intake noises from the side of the car.

My fear of a VERY unbalanced plenum is put at ease a little bit by making this "gutter" to feed cylinder #6. Its just a piece of steel in a gutter shape that is bolted to the intake; then the piece is welded to the bolt. All the parts are larger than the intake runners so I'm not afraid it will get sucked into the engine. But it should help charge #6 as much as 1-5.

And lastly I finalized my A/C situation. I just jumped strait off the A/C cycling switch to a toggle switch to power my A/C compressor. I have a toggle switch to turn my A/C on; not too happy about that. BUT it works and cycles under pressure changes, and the HVAC works just as stock otherwise.

And after driving for a while now I can say its a hoot. Yall already know how spectacular the handling is, and the creature comforts are just as amazing as I remembered them to be. The car is not as powerful as I'd wanted, but much more than a stock boxster. Butt dyno measures 300hp at the wheels. More than a boxster S; which is plenty. If I really want more I can always put a shot of giggle gas on there; lord knows the IRON block will take it with stride.

Racer Boy · 01-10-2021, 08:06 AM

Very cool! Thanks for the updates.

Homeoboxter · 01-10-2021, 10:35 AM

Pretty cool! Can we request a video of how it runs when you have the chance?

Qingdao · 01-10-2021, 03:56 PM

Quote:

Originally Posted by Homeoboxter

Pretty cool! Can we request a video of how it runs when you have the chance?

Can't figure out how to upload here. I mean I am a cave man running a carburetor LOL

I just noticed I hadn't made any update since the little detonation party I had in cylinder 3.

To fix that issue I got some deeeeeeeep dish pistons and some forged eagle con rods. Compression should be on the high side of 9.4:1. Before the compression was about 11.1:1; thats kind of a lot for 93 octane and 8psi of boost. There is a weee bit of detonation now; only after a good heat soaking on the highway. I might be able to dial the ignition timing back a hair and fix that. I might be investing in an ignition box to control timing a little better, but for now its good enough.

Fuel ratios are a little fat. 8:1 at wot... I'd like 10:1 but I wanna get the ignition sorted before I start pulling fuel out. This is my first roots blower, and from my experience so far the heat soak is real LOL. You do a few pulls and everything is super, then the intake gets warmer and warmer....

Homeoboxter · 01-12-2021, 07:10 AM

Just create a youtube account and upload your videos there, very straightforward.

Qingdao · 01-13-2021, 04:35 PM

Quote:

Originally Posted by Homeoboxter

Just create a youtube account and upload your videos there, very straightforward.

I know; to be honest its a lot of work for the 8 people interested. LOL

PM me your email I'll send you a video or two, but I'm gonna warn you my wife and I are TERRIBLE camera operators.

EDIT: oh and I think I'm just gonna live with the glowing headers at idle... I mean they don't seem to mind being that hot at idle, and if thats the ignition timing required to keep this thing from pinging then thats what it takes.

Homeoboxter · 01-14-2021, 03:48 PM

Haha, yeah, I hear you, PM sent.

piper6909 · 01-18-2021, 02:34 PM

Quote:

Originally Posted by Qingdao

EDIT: oh and I think I'm just gonna live with the glowing headers at idle... I mean they don't seem to mind being that hot at idle, and if thats the ignition timing required to keep this thing from pinging then thats what it takes.

Wouldn't too lean of a fuel mixture cause the headers to glow?

Qingdao · 01-18-2021, 04:01 PM

Quote:

Originally Posted by piper6909

Wouldn't too lean of a fuel mixture cause the headers to glow?

Yes, but in this case its timing related. I was trying to run a locked distributer using vacuum advance at idle retard enough to correct for the timing needed at WOT.

As of last night I've given up with that idea. I ordered an MSD boost retard control box. Supposedly it takes out 1, 2, or 3 degrees of timing per pound of boost made at the turn of a dial. It cost a pretty penny so I hope its worth it.

I was almost about to take the heads off and check which cylinders are pinging the hardest. I was under the impression that 1 & 3 were/are running harder than the rest due to the supercharger's location. I also wanted to maybe lower the compression some more. BUT I took a syringe and actually measured the dish of my new pistons. They are 18ml of dish; with a 4.120" X 0.040" HG, 64ml of head volume, and nominal deck to piston I should have about 9:1. Thats a lot lower than I was guessing at. Actually measuring things helps LOL

^^^ after that revelation I decided to buy a better ignition system; regardless of its astronomical cost.

Cost aside it is a really nice unit. It records boost pressures and timing maps. I might be able to get it to communicate with my LM-2 wide band system.

Qingdao · 01-27-2021, 05:25 PM

Oh yes, this is the ignition I shoulda been running from the get go. Totally tunable, I can adjust ignition on the fly with the retard nob. It lets me go full retard or just a little retarded.

I was full retard with the locked distributor; and we all know "you never go full retard". LOL

The MSD does provide LOADS of spark too. Doesn't really help much power wise, but starting is like 1 000 000 times faster.

I also gave my little box 'o' small blocks a nice hair cut.