1999 Firebird with custom M90 top swap

[Trannyman95]

Hey guys, I havent been on many forums for a while due to being swamped with work and family stuff going on but moved into a new location early last summer so I got to work on some custom projects when time permitted and finally got a supercharged top swap setup on a 99 Firebird. I also posted this on a few other forums but wanted to share on here as well. The car belongs to a good friend and has been bugging me for the past few years but I didnt have the space to commit the project since I planned to take a lot of time to do things right and make more down the road..... After doing this project and having things buttoned up Im not sure it is honestly worth the trouble due to the extensive time involved and the expense. Its not just a simple top swap by any means and I give a lot of credit to the guys that have attempted this project! The firewall was not modified in any way for this project and that was the goal. The AC and ABS are still in tact as well. I made custom trolleys for the engine and trans and dropped everything out the bottom and rolled it out as this made it much easier to freshin things up and reseal the badly leaking engine. I used L32 fuel rails and since this fuel rail is for a returnless system an L67 fuel rail regularor and tubing was used and plumbed into the fuel lines under the hood. There is a whole lot more I could talk about but wanted to share a bit of what I did for now. The car is running and has a rough starting point tune on it but it has snowed here all week so I havent been able to drive it yet and the roads arent the best here, nor are the tires on the car so I cant report with its performance yet but already doing a rwd L67 swap in my 86 Cutlass produced pretty awesome results for what I worked with engine wise. This engine is still the stock lower L36, L67 heads that were rebuilt, S1X blower cam, Pacesetter headers with 3" catback, and of course extensive blower work and port job. Excuse the stock drive by wire throttle body that is currently on the car, my plans took a huge turn south after diving into wiring as this setup was intended for an LS1 throttle body. When spring time rolls around the throttle body will be swapped out with a larger one from a truck and the supercharger pulley will be dropped, this is just starting point stuff on the car for now. I have tons of pics but pulled a few of the nicer ones to share online. Enjoy!

 

[Trannyman95]

 

[Pronto]

Wow! That's NICE!

 

[troGNman]

Awesome job and great attention to detail! I always wondered when somebody would setup a V6 Firebird with a blower.

I have a few questions if you don't mind.

1) auto or stick?
2) Is that a Ram Air setup from a WS6 car?
3) what is the rear axle ratio?

Keep up the good work!!

 

[Trannyman95]

Thanks guys!

The car is an auto and has a mildly built up 4L60E trans with a bit looser converter than stock. The stock torque converters in these cars are horrible and only foot-brake to about 1600rpm unless you get the performance option with higher gear ratio and then it stalls up a little higher. The converter that I used stalls at about 2400 rpm.

It is not a Ram Air WS6 hood but think it would be a nice upgrade and overall the car is in very nice shape so would look great on it.

I havent checked the rearend yet but commonly they either came with a 3.08 or 3.42 rear gear. The rearend made a bit of noise when I drove it in before working on it so its soon going to need some attention anyways. In my 86 L67 swap Cutlass I ran the 4L60E with 3.73s for a while and was an animal off the line and cut several low 1.6 60's with MT drag radials. I later switched to 3.23s for future plans to turbo and need the gear to make it through the traps and also because we take long road trips in the car now and then to car shows and 3.73s sing a bit more than I like a 70mph so dropping down that much made it a much nicer and quieter ride on the highway. It also didnt really kill my 60's, was still cutting high 1.6- low 1.7s. It now has a bit looser converter so it may offset the loss. These engines make a lot of instant low rpm torque and with the 3.06:1 first gear ratio of the 4L60E even with a lower gear ratio it still is very strong off the line.

 

[murphinator]

I planned to take a lot of time to do things right and make more down the road...]

great work as always Dave

you plan on making more of the TB on a tube mounts or modifying m90's to accept it ?

a friend of mine is about to do an L67 in a 64 chevy 2wd shortbed and may have interest in parts or plans/blueprints/templates to do it himself - he is pretty handy. I hope to do a rwd L67 at some point also as well as see more posts around the forums lately from people with interest in doing similar - it would be nice to be able to refer them to you for parts being so well respected in the 3800 community , proper storefront/website etc...

BTW I have many m90's from cars I part if you ever need any $100 ea. or anything else just ask...

 

[FlintBuick4Life]

Damn... that is awesome, nice work.

 

[Trannyman95]

Here is a finished pic with the intake tubing that I used. I had a few odds and ends left to finish up like the evap solenoid and line, pcv hose, and extending the iat wires and it is all complete now. I had a chance to drive the car around a little bit a few days ago and its feels pretty strong. It had old gas in the tank and I didnt have my wideband in so I didnt make any heavy throttle runs but did get about 60% in it a few times and was worth a smile or two so definately will be nice to get it back on the road once the weather allows and get the tune dialed in. I would like to try and take the car and dyno it or at least hit the track once it opens in April and I will report back with how it does.

 

[liquidh8]

That looks great! I would love to go for a ride in it, lol

 

[Goat]

damn makes me want to build one now.

 

[uniquesnd]

Is the 3800 v6 supercharged capable of high horsepower? Never thought of that engine as an option?

 

[murphinator]

Is the 3800 v6 supercharged capable of high horsepower? Never thought of that engine as an option?

the quickest stock block stock rotating assembly series 2/3 3800 has run 8.6 @159 (ZZ Performance)

there is a datsun pickup with a 3800 series 2/3 in australia in the high 7's @170 +

 

[Pronto]

Guess that settles that.

 

[GBGN1]

Nice work!!

 

[Street Lethal]

I'd like to see this project taken to the next level sometime in the future, maybe with twin superchargers. There are a few guys on some of the other boards who are experimenting with that concept on the F-Body's, but I'd love to see one on a 4th gen like above. To the OP, great work.... :smile:

 

[FlintBuick4Life]

WOW! That`s awesome.

 

[Onalky87]

Maybe it's just me but I think all that and the alt etc off one belt is s Lil much

 

[Street Lethal]

Maybe it's just me but I think all that and the alt etc off one belt is s Lil much....

Agreed. I'd feel much safer running belts similar to this twin supercharged Lightning....;

[youtube]http://www.youtube.com/watch?v=u6iQCWgrJec[/youtube]