Don Terrill’s Speed-Talk

90 hp @ 9300 RPM is just under 51 lb-ft. https://www.gixxer.com/threads/stock-k7-gsxr-600-dyno-graph-and-video-inside.316487/#lg=attachment_xfUid-1-1616609672&slide=0 That's a K7 GSXR600 ('06'-07ish), and @ 9300 it's making what....less than 40 lb-ft? Sure, there's some drivetrain loss there bu...

90 hp @ 9300 RPM is just under 51 lb-ft. https://www.gixxer.com/threads/stock-k7-gsxr-600-dyno-graph-and-video-inside.316487/#lg=attachment_xfUid-1-1616609672&slide=0 That's a K7 GSXR600 ('06'-07ish), and @ 9300 it's making what....less than 40 lb-ft? Sure, there's some drivetrain loss there but...

Just be careful, you're going to have a hard time making this engine live in a road race situation.

Cut apart a 2018+ Coyote plastic intake manifold. You're talking about a 7500 RPM engine making 84 lb-ft/L (SAE) through a full exhaust with cats and passing CA emissions. You'd be AMAZED how long the runners in these things are, and how ugly the plenum looks. They taper and have an elliptical runne...

Why have such a sharp turn? Why transition to round? If you're 3D printing parts there's no reason to go to round. Personally, I'd leave the narrow shape of the runner at the head intact and remove or eliminate the bend letting the runners cross. They do not need to terminate at the plenum perpendic...

Can anybody explain to me why dyno graphs sometimes show a spike when the throttle is closed? Logic would dictate that the reason this happens is that the throttle bore is too large or that the mixture is lean and when closing the throttle it provides a stronger signal to the carb, thereby enrichen...

This wasn't a very accurate test, I wouldn't read into this too much. The variables were not well controlled. To do this right you'd need an oil conditioning unit, a water conditioning unit, a complete intake air conditioning unit, and a dyno that uses an electric motor with at least two torque mete...

Now, if we're talking about just WOT MBT conditions, you could potentially make a case that this system in conjunction with VVT would be the ideal setup for maximizing MBT from say....2000-8000 RPM. That's the great part about this system, it has VVT built in. Not only does it decrease and increase...

Here's why changing duration is more important then changing lift and area, on a variable system. With today's technology, we can change a lot of parameters to make the engine more efficient. Timing, fuel, Intake and Exhaust centerlines, lift, duration, runner length, etc, but the one thing we're n...

I'm baffled as to why anyone would try to do a blow through carb. Get the Vortech carb box and be done with it.

EDIT: VVT is more important/useful for performance than any of the variable duration and lift systems, that's what the aftermarket should be trying to add to older engines. Not even close. Being able to reduce the duration, to control port velocity past the valve, is much more important then moving...

BMW's valvetronic is more effective. You can use it over a wider range and it allows you to throttle with the intake valve, reducing pumping loss. Way too complex, and doesn't really change seat duration, just lift and area. It effectively just changes rocker ratio. The problem with increasing rock...

BMW's valvetronic is more effective. You can use it over a wider range and it allows you to throttle with the intake valve, reducing pumping loss.

Yep, but no word on what happens with Lunati and Crane. It looks like they were not part of the deal. I have no idea how this is going to turn out, but history tells us that being bought out by a private equity firm, normally doesn't end well. This same private equity firm put a halt to Edelbrock d...

The Dark Side of Will wrote: ↑Wed Feb 05, 2020 11:57 am

LoganD wrote: ↑Wed Feb 05, 2020 9:36 am If you want US based, Moldex and Kellogg are no question the best for nitriding depth. I've had Moldex do 1mm depth.

Fancy meeting you here.

I've been here under various names for years!