This simple mod gave us 5 horsepower for free

The 3.5-liter 2GR-FE V6 that will soon find a home in our 1991 Toyota MR2 Turbo (which will, of course, no longer be a turbo, but we’ll probably leave the badge on just the same) is a fairly high-spec powerplant as delivered from the factory.

[What does it take to swap a V6 into a Toyo…

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I recently had a talk with Ed Senf, tuner to the stars, about some head porting–specifically involving a Miata.

His answer was something like: "Yeah, I don't know what kind of voodoo they performed over there, but the dyno numbers looked just amazing."

Polishing the intake tract is more likely to hurt than help on any random engine, polishing tends to help more on the exhaust side.

Following this closely. I feel like every V6 swap blows up the minute it hits the track

Those bumps look a lot like the ones in the exhaust ports of the last generation small block Ford pushrod V8. They were also a low hanging fruit for a little port work. 
 

I have to wonder, after looking at the title for an easy 5 hp, who else thought this would be the recommendation?

calteg said:

Following this closely. I feel like every V6 swap blows up the minute it hits the track

There may still be some PTSD over at GRM HQ about the Camry experiment.

#4 will astound you.

This is worth an easy 23 kilowatts.

In reply to GameboyRMH :  We used to do port work on our 2-stroke motocross bikes and finished by polishing the exhaust side and bead blasting the intake side to create a slightly rough surface. We got serious HP boosts. 

You forgot to add: "and you won't believe what happens next!"

Keith Tanner said:

calteg said:

Following this closely. I feel like every V6 swap blows up the minute it hits the track

There may still be some PTSD over at GRM HQ about the Camry experiment.

That was a different V6, and supposedly the 2GR FE solves a lot of the issues that one did. It was actually so sensitive to starvations that it once wiped a bearing while being jacked up.

Even so, we're taking a lot of extra precautions, like baffling, an oil drainback from the PCV and a Moroso pressure acuumulator, whch I think just arrived on the UPS truck. Gotta run out to the street and see. Be right back.

In reply to JG Pasterjak :

So, anything good from the brown truck? 

In reply to David S. Wallens :

I think he's run away from home 

Nice big box from Moroso. Very pleased.

rssmithiq said:

In reply to GameboyRMH :  We used to do port work on our 2-stroke motocross bikes and finished by polishing the exhaust side and bead blasting the intake side to create a slightly rough surface. We got serious HP boosts. 

Turbulent flow on the intake tract improves fuel atomization, or that is what my geeky friends who understand this stuff say.

Keith Tanner said:

calteg said:

Following this closely. I feel like every V6 swap blows up the minute it hits the track

There may still be some PTSD over at GRM HQ about the Camry experiment.

I feel this build is the redemption arc that the v6 camry swap needs.

In reply to CrustyRedXpress :

Then they need to swap a 2gr into a gen 3/4 Camry and wipe the floor on track 

Bookmarked and added to the to-do list for the Free Europa.

Drop the pan & clean the oil system. PCV opening is too small & low mileage engines will gunk up. Thats why your Camry expired. You need a "nicsly broken in" engine of about 180,000 miles. Quote from parts guy when buying front cam cover gasket for my Camry.

Toebra said:

rssmithiq said:

In reply to GameboyRMH :  We used to do port work on our 2-stroke motocross bikes and finished by polishing the exhaust side and bead blasting the intake side to create a slightly rough surface. We got serious HP boosts. 

Turbulent flow on the intake tract improves fuel atomization, or that is what my geeky friends who understand this stuff say.

I know this is why you don't polish a carbed intake, but what about EFI?  Still some benefit from turbulence?

In reply to Toebra :

Surely it must be true. Remember all the intake-side "swirl generators" that were all over in the 1990s and that amounted to a PC fan that would sit inside air cleaner neck?

You could even buy them alongside the fuel rail magnets.

In reply to Floating Doc (Forum Supporter) :

I assumed it was a 4" exhaust tip.

Mr_Asa said:

Toebra said:

rssmithiq said:

In reply to GameboyRMH :  We used to do port work on our 2-stroke motocross bikes and finished by polishing the exhaust side and bead blasting the intake side to create a slightly rough surface. We got serious HP boosts. 

Turbulent flow on the intake tract improves fuel atomization, or that is what my geeky friends who understand this stuff say.

I know this is why you don't polish a carbed intake, but what about EFI?  Still some benefit from turbulence?

Turbulence isn't the right word for what's going on in the intake port. Because a "turbulent" air flow port is very poor quality air (and fuel) getting into the cylinder.

Smooth flow that keeps/promotes fuel atomization is what we're after. That starts with getting rid of turbulence (herky-jerky air movement) because while the air and fuel both have mass, the fuel has more. So if the air is changing directions the fuel might not stay with it and can fall out of suspension.

The purpose of roughing up the intake port finish is to create a larger boundary layer. Bigger boundary layer acts like a support. The boundary layer air is moving slower and rolling along like a tire down the road. Higher speed air in the port (and fuel)  moves over the top of the boundary layer. This separation promotes keeping fuel suspended vs it latching onto the surface and running down the wall, ad which point it won't re-atomize (due to surface tension).

"This simple mod gave us 5 horsepower"

Makes me think of the old J.C. Whitney catalog - just about every part they sold was guaranteed to gain 5 or 10 or 20 horsepower.    When I used to page through it as a kid, I wondered if it was cumulative, and if you bought every part it would increase your horsepower by hundreds and hundreds.

5 more HP.