My 2.7l rebuild and tuning project

[CarreraEvo]

Originally Posted by brianjames1

Great thread-
I have a 75 carerra roller in search of an engine. Thinking of buying a core 2.7
Thoughts on a newb with strong mech background doing a rebuild ?

The mag cases can be made to work, but if you don't have it already, I'd definitely get a 3.0 or later, if I were you.

Making the 2.7 mag work is a lot of work, and it'll never be as strong as a 3.0.

The reason I did mine was, that I already had the engine.

[CarreraEvo]

Originally Posted by jpnovak

Your torque dip at 2100 rpm is likely too rich. your 1600/1900rpm columns have a large jump in delivered fuel. This is an artifact of tip-in fueling on take-off.

Now that you have a torque curve you need to rescale your fuel table to add an RPM column at 2200rpm. Take away (or average the 4500/5100) a higher rpm column where your torque is flat.

This will give you resolution to improve your tuning as you ramp in torque.

Also, scale your load rows to match your engines total vacuum. Shift rows to add more resolution between 85-100kPa to better match your ITBs. use a datalog to set your lowest row at MAP-min value and scale accordingly.

Thanks for your advice!
I'll get on to that asap - which is in 5 months, winter has arrived here
I was thinking of something like: 1300-1500-1800-2100-2500, where I remove 4500. 3900-5100 are fairly similar.
How how does that sound?

[CarreraEvo]

Originally Posted by winders

What is the displacement of this engine? What headers did you use?

It's a 2.7 engine with 10.5 compression.
I'm using the stock '74 headers, which is the same as SSI, I think.

[winders]

Originally Posted by CarreraEvo

It's a 2.7 engine with 10.5 compression.
I'm using the stock '74 headers, which is the same as SSI, I think.

So you are saying you are getting 271 HP at the wheels from this 2.7 build?

[CarreraEvo]

Originally Posted by winders

So you are saying you are getting 271 HP at the wheels from this 2.7 build?

Not at the wheels - as I understand it the dyno meassures the transmission loss when it coasts down after the run. Once it’s down to about starting speed, it subtracts the losses and you get engine hp.

[winders]

271 HP at the crank is a little optimistic for that build especially at 7000 RPM. What correction factor did the dyno software apply?

[CarreraEvo]

Originally Posted by winders

271 HP at the crank is a little optimistic for that build especially at 7000 RPM. What correction factor did the dyno software apply?

I don't have the dyno graph with me, but there is a "EOF k = -0.6%".
Other than that, I don't know.

But I tend to agree, 271HP is a lot - I was pleasently surprised

But in the end, it's just a number.

[brianjames1]

Originally Posted by CarreraEvo

The mag cases can be made to work, but if you don't have it already, I'd definitely get a 3.0 or later, if I were you.

Making the 2.7 mag work is a lot of work, and it'll never be as strong as a 3.0.

The reason I did mine was, that I already had the engine.

Ill look for a 3.0 or 3.2 many thanks

[gandeesinla]

Congrats on your rebuild, very clean and incredible outcome. I have single TB 3.2 MS1 EFI setup on my rebuilt 3.0 but I want to go ITB and those ITBs seem to be the ticket for max flow. Can you describe the fabricating to make the filters fit the trumpets? Did you seal the plate to trumpet interface or use some sort of gasket? It looks really clean overall. -cheers

[CarreraEvo]

Originally Posted by gandeesinla

Congrats on your rebuild, very clean and incredible outcome. I have single TB 3.2 MS1 EFI setup on my rebuilt 3.0 but I want to go ITB and those ITBs seem to be the ticket for max flow. Can you describe the fabricating to make the filters fit the trumpets? Did you seal the plate to trumpet interface or use some sort of gasket? It looks really clean overall. -cheers

Hi
The filters from Pipercross came with a bottom plate with no holes.
So I made 3 holes about 8mm larger in diameter than the trumpets. Then I used sliced silicone tubes as gaskets.
I installed 4 studs from each of the ITBs to keep the plate in place.
I’ll look for a photo.

[CarreraEvo]

Pic of filter plate

[Hcarraro]

Nice work. Thanks for sharing.

Henry

[Ginger77]

Great build! I was wondering how you got the Bosch PWM idle air valve hooked up. The wires, I suppose, go to the MS as described in the manual. But how did you hook up the air hoses?

[CarreraEvo]

Originally Posted by Ginger77

Great build! I was wondering how you got the Bosch PWM idle air valve hooked up. The wires, I suppose, go to the MS as described in the manual. But how did you hook up the air hoses?

I’ll hook up the PC and look for in a bit 😀

[Ginger77]

I don't think the answer is in the PC unless you're looking for photos. I literally mean how did you hook up the mechanical side of the valve? Not the electrical wires.



The idle valve blows air but into where? I get the principal with a regular injection intake boot. But I don't see how it works with us using filter or stacks.

[CarreraEvo]

Originally Posted by Ginger77

I don't think the answer is in the PC unless you're looking for photos. I literally mean how did you hook up the mechanical side of the valve? Not the electrical wires.



The idle valve blows air but into where? I get the principal with a regular injection intake boot. But I don't see how it works with us using filter or stacks.

It was indeed photos I was looking for.

Basically I run a hose from each TB to a plenum, a single hose from the plenum to the idle valve and a single hose from idle valve to the right side air box.

Below are the two best photos I could find. It looks as if the hose from idle valve to air box is not fitted in the below photos.
If it doesn't make sense, I can snap some better photos for you?

[BURN-BROS]

Outstanding build! Peak HP @7k plus should net 100hp/liter. Looks like yours is healthy. If you can figure fuel lbs/hr for your build, you can verify the Dyno results. Also, if you can get the injector quantity per cycle, that would work as well.

[Mark Ennis]

Where did you source you wiring harness

[CarreraEvo]

Originally Posted by Mark Ennis

Where did you source you wiring harness

I made it myself 😎

[mikedsilva]

Nice result, very impressive results.