Jake, would this be a good combination?

Guest · Post by **Guest** » Mon Jan 19, 2004 2:04 pm

I am considering many different possibilities on how I can rebuild the 2.0L in my 914. If I rebuilt the motor but bored out my stock cylinders to add the 96mm KB pistons and left all of the other specs stock (i.e., compression ratio, camshaft, all the d-jet components etc.), would this be a good combination as long as I increased the fuel pressure? I ran a simulation of this combination and I picked up 1hp and 5 ft*lbs of torque over stock ...

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Mon Jan 19, 2004 2:12 pm

toss that crappy cam and watch what happens...

Guest · Post by **Guest** » Mon Jan 19, 2004 4:06 pm

I ran another simulation and it seems that I would get more power by adding the Euro 94mm pistons with 8:1 c/r instead of the KB 96s at 7.6:1.

GDRBO · Post by **GDRBO** » Mon Jan 19, 2004 5:03 pm

try bumping the KBs to 8.5 and add a Webcam #73.

Guest · Post by **Guest** » Mon Jan 19, 2004 6:14 pm

GDRBO wrote:try bumping the KBs to 8.5 and add a Webcam #73.

Two more hp than the simulation with Euro pistons but five ft*lbs less torque. I'll most likely do a "stock" rebuild but with the Euro P/Cs. Looks like the engineers knew what they were doing when they designed the motor.

Guest · Post by **Guest** » Mon Jan 19, 2004 6:19 pm

Oops, I forgot to increase the bore to 96mm. Simulation shows 4 more hp and 1 ft*lb less torque. The d-jet is calibrated for 94 x 71, though.

raygreenwood · Post by **raygreenwood** » Mon Jan 19, 2004 9:35 pm

A simulation will show you nothing accurate with reference to D-jet...on a non-stock engine. The way in which D-jet tracks to the vacume signature of an engine...is not exactly the same as a MAP sensor. There are other variations and variables involved. Even the factory best settings were rather under-tuned. A simple bump to fuel pressure will give correct volume...but probably not correct throttle response.
D-jet is very capable of doing much better than stock, but many of the adjustments are subtle...and take a decent amount of testing. I can easily get 5 hp and about 3 ft lbs torque out of the bone stock 1.7 , with FI tuning alone. With tuning, fuel stabilization, mild porting, slightly larger valves and aweb #73...I can get about 20 hp more than stock. Ray

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Mon Jan 19, 2004 10:35 pm

Simulations are just that!

There is no replacement for doing it and dynoing it- OR doing it and driving it!

I simulate alot of things, over half of it don't work.

Guest · Post by **Guest** » Tue Jan 20, 2004 12:53 am

MASSIVE TYPE IV wrote:Simulations are just that!

There is no replacement for doing it and dynoing it- OR doing it and driving it!

I simulate alot of things, over half of it don't work.

Understood, but a simulation is a place to start. Jake, can you confirm (or deny) from your experience that adding, say, a Web 86 cam to an otherwise stock 914 2.0L motor (7.6:1 compression ratio etc.) would actually result in a decrease in hp and torque compared to the stock output?

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Tue Jan 20, 2004 5:12 am

I have done just that... Its not about HP all the time, or even torque!

I like a broad powerband, and the 86 gives that to a stock engine.

Guest · Post by **Guest** » Tue Jan 20, 2004 10:02 am

MASSIVE TYPE IV wrote:I have done just that... Its not about HP all the time, or even torque!

I like a broad powerband, and the 86 gives that to a stock engine.

How did the hp and torque change?