Question about an Allante intake for 4.9? (Page 1/2)
Spadesluck FEB 27, 12:52 AM
Besides actually getting the lower/upper intake what else is needed to install this? Thanks in advance
Spadesluck FEB 27, 02:55 AM
Should also be noted, what year range am I looking for?
Reallybig FEB 27, 02:14 PM
Wiring harness might be different enough to warrant swapping. Also the fuel rails are different. Not sure if they are needed or if you could just use your regular 4.9 rail.
Raydar FEB 28, 10:34 PM
You need the 89 (I think) or later setup. Has to be from the 4.5. The 4.1 setup will "sort of" work, but the coolant passages are different, and may leak.
Be sure to get the upper and lower intake, throttle body spacer and throttle body.
You will also need the fuel rails, including (this is important) the fuel inlet fitting. It's an odd fitting that I've never seen anywhere else. The return line can utilize a regular hose barb.
Also, ask for the Allante steel rocker supports. They have to be removed from the Allante engine, anyway, in order to get the intake off. No reason they shouldn't be readily available.

Wiring is not difficult. You will need to extend the wires for a couple of sensors. (IAT, map, and TPS, I think.)
Also, the TPS is not wired as you would expect. The 4.9 TPS has the wiper on the center pin. The Allante TPS has the wiper on one of the end pins. You might have to experiment, to get it right.

You will have to change the IAT values in the chip. Otherwise it will run very rich. Also, the EGR is deleted.
If you have someone who can burn a chip, I can send you a working BIN file.

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Raydar
88 Formula IMSA Fastback. 4.9, NVG T550

Praise the Lowered!

Spadesluck MAR 01, 02:12 PM
Raydar, I may take you up on that offer when I get back stateside. As you already know I am activly trying to get the Allante stuff. I also plan on having Delta grind the cam. Just trying to round up parts that is the challenge right now.
Raydar MAR 01, 05:06 PM

quote
Originally posted by Spadesluck:

Raydar, I may take you up on that offer when I get back stateside. As you already know I am activly trying to get the Allante stuff. I also plan on having Delta grind the cam. Just trying to round up parts that is the challenge right now.



That's cool. Just let me know. My tune (such as it is) has the Allante fueling, spark and (removed) EGR tables imported into the 4.9 BIN. I think I may have made a correction to the Base Pulse Constant, since they both use essentially the same injectors. My BLM was running right around 127 (with 128 being ideal) so it's damn close.
Of course, the cam will require a bit of tweaking to make it run optimally. But I'm not even claiming that MINE runs optimally. Just that it runs decently and cleanly. It's never been dynoed.
Akcraig85 FEB 01, 07:22 AM
Does anyone have pictures of this fuel inlet fitting? I’m working with a salvage yard out of town trying to get these parts.
sourmash FEB 01, 08:21 AM
Being a rookie at seeing inside the valve covers of a 4.9, did some standard 4.9s get rocker bracing? Because I walked passed one in at a pick and pull (a standard Cadillac) and noticed something resembling rocker braces.
olejoedad FEB 01, 10:44 AM
All 4.9 engines have rocker braces.
There is a difference in the plate the rockers mount to that is under the rockers.
Most of the plates are cast aluminum, the Alante 4.5 used a steel plate.
Spadesluck APR 22, 01:08 AM

quote
Originally posted by sourmash:

Being a rookie at seeing inside the valve covers of a 4.9, did some standard 4.9s get rocker bracing? Because I walked passed one in at a pick and pull (a standard Cadillac) and noticed something resembling rocker braces.



I have the steel rockers I can take a picture of if you want?