From knowing nothing to having a Thunderbird supercharger on an m20b27i

[Ether-D]

Wait a minute, that north star-ed fiero was you, Will? Awesome.

Also, I decided to go ahead and try to mount up the new TB to the old u-turn for now. I've got about half of it done. Throttle cable stuff and tps calibration left to go.

[The Dark Side of Will]

My dad has a '75 Jaguar XJ6 with Chevy TPI V8, 4L60E trans and 3.31 gears. The TPI throttle cam was like the Thunderbird throttle cam you described... It was actually difficult to leave a stop light without chirping tires. He swapped the throttle body from a '90's LT1 that was identical except for a progressive throttle cam. The car was much easier to drive slowly and smoothly after that.
I had the same experience with my Caddy Northstar in my Fiero... The OBDI throttle body I had to use with my first engine computer had a pretty linear throttle cam. When I swapped to my current computer I had to install an OBDII throttle body, and it had a more progressive throttle cam. The car's much easier to drive slowly now also.

[Ether-D]

The factory m20b25 one is reduced at first and then increased as the plate opens (Saab one is the same). The ford one is about the same size as stock, but it has no increase or reduction, just a lever on a throttle plate. That's what I think the issue is.

[Victell]

I had always thought that BMW throttle body linkage was designed to have an exaggerated early throttle opening curve as to make the engine feel stronger. This would be the opposite of what you want. My guess is that the tbird throttle body is simply too large for your smaller engine so it has difficulty modulating lower-volume airflow.

These are my guesses and I could be completely wrong about all of it.

[Ether-D]

After some research, it's actually off of a 93-2000 saab 900 or 9-3 2.5l.

[Ether-D]

Update.

Well, It's been a couple months and almost 3000 miles on the setup. It is just doing wonderfully. There have been some broken parts here and there, but not a one with the supercharger or related hardware.

One thing that is going to have to be amended is the throttle body. It's the one off of the thunderbird and it is so unrefined. It is really annoying to drive very slowly (say you're in a pickup line at the elementary school). It just wants to jump the rpm up to 2500 when you roll onto the throttle from idle. It doesn't have a long enough lever on the TB to make it "school zone friendly".

You know how the m20 TB has some sort of fancy exponential lever business? That's what I need to get back. So I went to pullapart and found a very nice TB from some 20XX ish Saab somethinorother. It has "GM" on one side and "PIERBURG Germany" on the other. It has a really nice contour on the inside, intended to only let the initial bit of air go on one side of the butterfly. It also has the throttle plate exponential opening thingamabob, and bosch 3-wire TPS like I need. So I reckon I'm gonna whip up a new S/C intake u-turn/throttle body mount plate/by-pass valve dump hoopajoop and see if this Saab TB is as nice as it looks.

[Ether-D]

This afternoon...

[Ether-D]

All of that room under those hoods wasted...

And there's only like 3 or 4 vac hoses to move. That shit is small potatoes compared to the manifold fabrication. Plus, you need to learn where those hoses go and why. I learned a shit ton about those hoses.

[Q5Quint]

Quint, just make a damn manifold. It was not that hard. Use a table saw to cut the flange off, table saw again for the 1/4" plate aluminum and have joebob down in town weld it up for you. You know you can doit. Doit!

But... but..... I would have to move the throttle body and all those funky vac hoses wahhhhhhh.

I do actually have a spare intake manifold and a buddy with a tig setup for the aluminum, so I should really just stop being a pus about it.

I will flip a coin this weekend if I am in town and not picking up a damn turbo delorean.

The sad thing is I was kind of excited about the mad max hood.









All the cool kids do it!

[slammin.e28]

T-bird M90 isn't as common as the GM 3800 M90 either.

The real deal to get your hands on is the XJ6R M90. It's perfect, from and I6, for an I6, intercooled, etc.

Good luck finding one though.

[Ether-D]

The great thing about the gm incarnation is that it has the bypass valve built in. I'm gonna try to use one of those on supercharger 2.0.

[klodkrawler05]

for the better option in small M90 what about the t-bird M90?:


you can usually pick one up for around $100-200 off craigslist with all the brackets/hoses and such they're just not quite as common as the GTP model.

[Ether-D]

Quint, just make a damn manifold. It was not that hard. Use a table saw to cut the flange off, table saw again for the 1/4" plate aluminum and have joebob down in town weld it up for you. You know you can doit. Doit!

[Q5Quint]

It dont fit, I am so jelly.





After moving all the things around for hours, my conclusion is that in order to make the m90 not hit the intake manifold, and still get out of the way of the stock alternator, and still clear the brake cylinder.... you have to have the short snout.

If you move the alternator, it would likely fit. If you have a custom intake manifold, it would likely fit. If you have m62, or the older shorter snout m90, it will likely fit. However, the big m90 will just not squeeze in there normally. There is too much wasted space around the snout and intake side where it normally stretches across a long v-6. Some massaging might make it fit if you are a wizard.... but I am lazy and will likely just cut a hole in the hood.

Also: inspirational shoehorning on a jeep- http://www.colorado4x4.org/vbb/showt...XJ-4-0/page3od.

also hilarious videos: http://www.cherokeeforum.com/f67/fee...59922/index24/

If the m62 is adding 60hp to a jeep I would hope we could get atleast 60-70 out of the m90.

[Ether-D]

Ummm, that guy would not shut up. er something...