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L67 Intercooled Oldsmobile Silhouette Minivan

W

Wes2k8

New member
I bought this L67 swapped Oldsmobile Silhouette a couple months ago, the price was good and it was just so weird that I couldn't pass it up. It was pretty quick as is with just a 2.5" downpipe and catback exhaust, but I couldn't leave it alone long. So I bought a stage 2 intercooler kit from ZZP, a smaller pulley and a cone intake. I also got the PCM done by Intense Racing. It took a little longer than expected, there isn't nearly as much room to work with in there than on a car. My dad was the genius behind putting it all together and I probably took years off his life with this project. But it's all together now minus the intercooler wiring. I know this isn't a grand prix but the powertrain stuff all is and I'm sure someone here will appreciate it.

Anyways, here is the van.


1rnhvC6.jpg


Here's what the engine bay looked like when I bought it:

eLwxhYQ.jpg


Here is a little front mount action:

XK7wx2g.jpg



And here is my favorite part, the thing actually running tonight, with the intercooler mounted.


I'll try and get some better pictures and videos tomorrow when it is completely finished, I'm super excited.
 


would headers even fit in there? I have a silhouette i never thought all that would fit in there not that i would put another penny into that pile mommy missile of mine...its funny tho. i 2nd the tune your gona want to do that be for you get squirrely in that 7 seat beast.
 
Scottydoggs said:
http://www.grandprixforums.net/threads/38297-I-introduce-the-quot-Man-van-quot-!-*now-with-vids* i found this way to easy lol

you have a tuner? with a ic and pulley drop i hope you got headers as well. a tune would sure wake it up even more.
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I got a custom PCM done by Intense racing, but I don't have an actual tuner. I only dropped to a 3.5 pulley, so I think that will do fine for now. I know every engine is different but I really don't think their tune would be that outside the ballpark.

Either way, I plan on dropping to a 3.2 pulley, getting headers, larger injectors, and with that an actual dyno tune, or HP tuner next. So if I don't like the way it runs with this computer I'll just do that sooner than planned.
 


dyno tunes dont always go so well, cause most shops dont know how to tune these cars. be cheaper to buy a tuner then just hit the dyno for fun.

with your canned tune thats a good start, get a way to scan for KR and timing and fuel trims, then you can see how your running. run only 93 octane too.
 
Scottydoggs said:
dyno tunes dont always go so well, cause most shops dont know how to tune these cars. be cheaper to buy a tuner then just hit the dyno for fun.

with your canned tune thats a good start, get a way to scan for KR and timing and fuel trims, then you can see how your running. run only 93 octane too.
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I've never done any kind of tuning before, I'd definitely like to learn how though, that would be a great skill to have. You're probably right about getting it dyno tuned, I haven't found anybody who's experienced tuning these engines in my area through some searching,

I have an aeroforce scan gauge as well, so I can check for knock and fuel trims and I understand those decent enough. Before the I/C it had very little KR and the short term fuel trims were pretty normal, so if something is up it's probably related. I always run 93 too.

Oh and that Montana looks real clean! I've seen that van before in his youtube videos, they were the only ones I could find of this swap. Hopefully I can get mine looking that nice to go with the engine eventually.
 
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your off to a good start then.

short term mean nothing. its the long term fuel trim you want watch. when tuning your goal is to get it close to 0 wot, then like -5 or so idle and cruising.

neg is rich, pos is lean. on the rich side is better then the lean side.
 
So I drove it for the first time. She's definitely faster, and the supercharger whines like crazy with the intake on there. Best of all there was absolutely no KR, I need to test it when it's hotter out, but that is a good sign for now.

It did throw a P0300 code. Some googling shows its a misfire but I'm not really sure where to start with it. It has brand new autolite 104's gapped to .055 so I hope I could rule that out. I'm going to check the vacuum tomorrow, but it seemed to be around -17 to -20 when I checked it before the CEL came on.

Could it be related to the cat? When everything first got put back together fuel was pouring out the exhaust manifold because of two open injectors.
 
double check the plug wires, we all cross em up time to time. or just maybe yo cracked more then one plug installing them.

you replace them injectors? if it was pouring raw fuel out the dp, id do a oil change asap. that might have fouled the plugs too.
 


Scottydoggs said:
double check the plug wires, we all cross em up time to time. or just maybe yo cracked more then one plug installing them.

you replace them injectors? if it was pouring raw fuel out the dp, id do a oil change asap. that might have fouled the plugs too.
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I checked all the injectors and replaced the two that were stuck open, changed the oil, and changed all the spark plugs. The old spark plugs were crazy fouled and had huge gaps, I'm surprised it even ran. I tried to check all the plug wires today and I'm pretty sure they are correct but I'll definitely double check them tomorrow, however the van had plenty of power and sounded fine when giving it some throttle so I'm not sure if that is the culprit. It kind of sounds like there might be a little miss at idle, but smooths out when given some gas. It did this while the engine was stock as well though, but with no CEL, and it was a little less prominent because of the stock intake I think.

I guess I'll start by checking the plugs and all the plug wiring first tomorrow. Definitely possible one is cracked. Thanks for all the help and advice Scottydoggs, it's definitely appreciated.
 
could be a bad icm as well. the part under the coils. you can have them tested at autozone, but they also tend to test good when bad. new they are pricey, but used they are rather cheap 20 to 40. good junk yard pocket part.
 
did the cel ever flash when you floored it? that could be a clogged up cat. who knows if the down pipe is from the mini van or a gtp or what ever it came from. na engines tend to clog up cats more then the sc'ed engines.
 
Yeah the CEL was flashing after flooring it while driving, I floored it a few times before it came flashing on. Got home, cleared the code, revved it a little in the driveway, and it came flashing back in again.

The downpipe was done by an exhaust shop and it has what is probably an aftermarket cat in it. The exhaust then kind of continues into a cherry bomb muffler, which feeds directly into some other aftermarket muffler. It is certainly a creative set up.
 


thats fine, it replaces the res, does the same job, i ran one for many years myself.

back to the flashing, thats almost always either a bad cat, or misfires due to needing a tune up real bad. im sure it didnt flash before the ic install, so best to start with what you last touched. the plugs and wires.

you can shut them gaps to 0.50 if you like too. stock is 60 why they looked so damn huge.

if your plug socket does not have a foam insert, pull all the plugs look for cracks.
 
The new plugs were gapped to .055, the plugs that looked huge were the original plugs I pulled before installing these. The gap in those looked like it could be a legit 0.100. I haven't checked to see what is going on with these yet. I might try stepping them down more if none are cracked, but there is no foam insert in my plug wrench, and I'm really starting to think it's a cracked plug. One specifically in the back was really difficult to get to and it probably got cracked during all the messing around with it.
 
Wes2k8 said:
The new plugs were gapped to .055, the plugs that looked huge were the original plugs I pulled before installing these. The gap in those looked like it could be a legit 0.100. I haven't checked to see what is going on with these yet. I might try stepping them down more if none are cracked, but there is no foam insert in my plug wrench, and I'm really starting to think it's a cracked plug. One specifically in the back was really difficult to get to and it probably got cracked during all the messing around with it.
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id be willing to bet you cracked more then one to get a 300 code, thats multiple misfires. a proper socket will have foam inside and a nut at the top of it you use a wrench on it.

that rear plug thats blocked by the o2 sensor, that one i put the socket on the plug, then a 3 inch extension on the ratchet, then i can get just the tip of the extension in the socket and break it free, then remove by hand. install the same way. thread it in by hand, then hit with the socket to make tight.
 
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