3100 build up, supercharger, best recepie?

[Michaelx]

My General questions and your advice please:

I have a 1998 Malibu and it has the 3100. I am not unfamiliar with performance and own several different cars and cycles. I have decided that once Autumn gets here that this car will be my winter project and I have been looking around WOT tech and reading and absorbing information pertinent to my car and its setup. What I know for certain is that I want to keep the configuration of the drive accessories (air conditioner) as they are, and to supercharge the engine.

I am planning a total build. WOT tech has an array of insight to their cylinder heads and manifold swaps, cams and throttle bodies, fasteners and crankshaft scrapers, etc etc. I've owned a lot of different cars that I've gotten deep into, in the past, factory turbocharged and natural. What I remember from my Supra was lower compression pistons, somewhere in the range of 6.5 to 1 versus 8.0 to 1 for the non turbo. I know the principle behind it and couldn't find lower compression pistons for the 3100. Would you or wouldn't you go that way if you were putting a vortech kit on it with 6-8 Lbs of boost? What type of injectors would yield more fuel flow? Brand and CFM? Given the specs of the vortech and its off idle boost to around 3K, how radical would you go with a camshaft?

I saw Hedder flanges and so forth, bottom end is pretty much a given and ARP has all the part #'s I need as well as head studs and good head gaskets are available, but what about the tranny? I can't find anything on it on the web, and I assume that built for high torque this engine could snap unhardened shafts, blow clutch packs, etc. Are there any MSD coil packs for the 3100? I see them available for the 3800 and described to be exactly the same physically.

I am also curious which other displacements will fit in where this 3100 sits now, I don't play fantasy football and so the real world cost of building and supercharging a 3100 are, well, real. The cost of a junkyard engine would be less that practically EVERY performance part from WOT so it would be an injustice to the car itself if it could have had a 3400 (like building a Chevrolet 305 because you didn't know the 350 or 400 would bolt up). I have read that there is a 3400/3500 hybrid and a 3500 which is a totally different engine/setup. Is this hybrid like a Chevrolet stroker motor, I.E. 383, 377 ? Are there any poly mounts for the 3100? Higher stall torque converters?

I am new to the forum and want to know what you all have done with your cars. I have a couple of months left before autumn and it is my request that thru the forum, combined knowledge, sources, and experience I can draft a blueprint for what this car will come to be.

[bszopi]

First off, welcome to the site!! I'll touch on a couple of your questions, although I won't dive deep into them right now.

1. CR ratio - For low levels of boost (8psi and less), stock compression of 9.5:1 is fine. With proper tuning (which needs to be done regardless), you could potentially even go slightly higher.
2. Tranny - Definitely a MAJOR area to focus on. These engines can actually make a real decent amount of power, as seen by several members cars, but the trannies are always the weak link.
3. Don't bother with aftermarket coil packs. They fail more often then not on these engines, and the stock ones are something GM actually did right.
4. 3400 is basically a direct swap with the 3100, and a 3500 is as well, but it just needs a couple extra items to make it work (mainly a external crank trigger).

As far as what people have done, check out the Garage. I'm sure more people will chime in though.

[robertisaar]

joseph upson is a VERY good example of stock compression(9.8:1) making good boost on a 3900...

and the GM DIS coils are awesome, all of the aftermarket coils seem to crap out LONG before the stockers do, without any kind of performance benefit either.

[Michaelx]

Bszopi,

The tranny, is there a shop that does a core and rebuild for it? Or, is it more of a source parts and kits and bring to a reputable transmission shop job? I suspected the transmission wouldn't hold much power, and I have also read that the gearing is tuned for horsepower, and not torque, and as such, you-tube video's I've seen are plastered with ugly comment wars about the video's poster's car not being any faster than stock from 50-70 mph acceleration sprints that they shot and posted, waste of $3K,etc.. and replies which state the car has much more off the line torque and needs tuning, etc. You can really hear the supercharger whine though.

The 3400 is a direct drop in? Are their any adaptations or mods needed at all? Are their certain years or generations which will or will not cross-mount? What is the difference between the 3100/3400 and 3500? There are comments about the 3500 being a superior low dollar swap because of the base horsepower it makes.

Are their any automatic transmission swaps which can be advised too?

[bszopi]

There are a couple of shops that are good, but I'd have to look them up again. But for the most part, you'd probably be better off sourcing components and either doing it or having it done.

As far as the 3400 being a direct replacement, basically yes. http://3x00swap.com/ On there, there is a guide about swapping a 3100 for a 3400. It is based more for the earlier 3100s (94-95), but most of the basics still apply.

Here is a great thread about the differences of the 3500 to the previous blocks - http://60degreev6.com/forum/showthre...ight=3500+pics