Easy enough then, thanks for responding. Not sure what shop this is but they replaced the 2.3 units with some 2.9's making the 1075 more like a 1200.

[youtube]watch?v=-RF3krHbGdw[/youtube]

What's a 2.3 or 2.9 Unit??? By the way... That motor doesn't sound too good at the end of that tape....

The 1075's are no where near out of blower. There is no need to replace the 2.3's. I have used 2.3L quads in the past to make well over 1400 hp. The biggest hurdle is the ecm. Both the 850 and 1075 have an electronic boost bypass that controls the boost. The only way to increase the boost is by programming it into the ecm. You can change the pulleys all you want and it won't help unless you get into the ecm. That is why I said to get the ecm from the 1075 to put on your 850.
By the way, the Merc 1200's use the same 2.3 L quads as the 850 and 1075.
Eddie

I didn't think so either. What was the last number you saw?

The blower size, as Youngs would say and probably has already, the stock engines come with 2.3L blowers. This compant replaced the stock ones with a pair of 2.9L Whipple units.

I kinda figured as much, thats how it is with the Roe blowers on Vipers where you can only physically mod so far until the rest is finished electronicly.
Even more so then I'd imagine with the 2.9 units and reprogramming the ecm you'd be able to go 1500+ without too much fuss.

The stock 2.3's are actually very near capacity because of the bypass system. They're turning just over 14,000 at stock peak engine rpm which was the mfg's max rpm.

We pickup 150-hp by lowering blower speed with the larger SC's. Just upgrading to the 1075 cam, pulley, belt, springs and PCM upgrade would be a world of difference.

The stock motors we tested made 1053hp in stock trim. With our large SC's, it made 1240hp on pump gas, then made 1375 on race gas.

The motor is fine on the high RPM, thats what they sound like at 6000+.

We rebuild the factory SC's, which should be done around 250 hours on 1075's. We also have more efficient 2.3 liters and the larger 2.9 liters.

Here's an image of the Mercury 850/1075sci with our 2.3L. This is in one of the Statements.
http://i62.photobucket.com/albums/h9...4/IMG_6631.jpg

Here's our 2.9 liter sc package, with our new upgraded belt system that fits all 850/1075/1200.

http://i62.photobucket.com/albums/h9...4/DSC00250.jpg

http://i62.photobucket.com/albums/h9...4/DSC00164.jpg