.480"/280 cam and EFI intakes

[turbogrill]

Hi,

 

I a .480" lift and 280 duration Shadbolt M455 cam with a "street" ported N47 and cast pistons on my race car.

The head has some valve unshrouding and the bowl area cleaned up. No reshaping of ports or welding of chambers.

 

It seems like the general consensus is that the Stock EFI intake struggles on modifed engines, over 5500 RPM and it seems to struggle. 

This is mostly peoples opinions, the only real evidence I have seen is from a dyno plot from  z-ya

 

On 9/23/2015 at 1:32 PM, z-ya said:

Here is another one:

 

- L28 with flat top pistons

- Mild cam (460/280)

- No head work

- Header, 2.5" exhaust

- Dual throttle bodies with SU manifold

- Megasquirt with EDIS ignition

 

The dotted plot was with a stock 280Z intake manifold. So about 11HP gain with the dual throttle body setup.

 

 

 

After about 5500 the stock intakes struggle whilst the ITBs still makes torque.

 

This is a mild cam with no head work. With head work and aggressive cams the difference would be more?

 

But it seems like it's possible to make power using a modified EFI intake, lester001 is making power with a ported N42 intake. Even if Rebellos said he would make 50more hp (!) with ITB

 

On 7/31/2017 at 8:22 PM, harlest said:

Here's what I have:

 

1978 280z

Rebello Racing 3.2L Stroker

N42 block N42 head

Ported stock intake

360CC Injectors

60mm throtlebody

Pace Setter header 3-2-1

Adaptronics ECU

Z32 Trans (Hoke Adapter)

Infinity Diff 3:69

T3 Susp.

 

So, doing something about the stock EFI is probably a good idea. Home porting seems hard.

 

Are these my options?

 

1. Lonewolf stage 1, $125 (Port without cutting). 

2. Lonewolf stage 2, $325 (Port with cutting up).  

3. Lonewolf custom intake $700. (Stop making them?)

4. Custom intake with Blake flange, $300 + fabbing.

5. Jenvey ITB, $1600

6. Datsun Spritit ITB >$2000.

 

Seems like option 2 might be a good alternative if cast pistons are being used (<6500 RPM). ITB probably makes more sense on >7500 RPM engines?Also hard to tune.

 

Has anyone tried a hot cam with stock efi?

 

 

 

 

 

 

[Chickenman]

Almost the exact setup I have on my 280Z right now. L28, N47 head , F54 block with FT pistons. approx 10.5 CR. N42 Intake with 60mm Weber TB. MSA headers, 2.5" exhaust Cam is a bit of a Mystery. Engine builder was a bit secretive( don't know hwy ) . Was only told it was 280 degrees .480" lift. I've driven enough Z cars with the Shadbolt M445 to recognise it's characteristics

 

 Wel.. short story. Engine makes power like a SOB. Easily pulls HARD past 7,000 RPM. Had to put a Rev limiter on the danged thing. Surprisingly the stock ECU handles the large cam just fine, although I would suggest a true standalone ECU for it's adjustable, especially on a Race car.

 

But starts on first turn of the key every morning. Warms up fine. stable idle at 1,000 rpm , even though it is a pretty lumpy camshaft. I'm sure the compression help there. Gas mileage is fine. No driveability issues. Engine is a rocket. haven't had a chance to put it on a Dyno... too busy enjoying the car. But other experienced Z owners are surprised at the Power it has.

 

It's so good that I have a Haltech E11 sitting on the shelf for 3 years. I'm finally going to install it... because = I have it. But for day to day. It's not necessary. 

 

 Now, I'm not suggesting that everyone is going to have the same luck with their ECU. Mine is a bit of a Unicorn and it's working amazingly well. The factory AFM is NOT affected by the lumpy idle, and if you look at how the factory AFM idle circuit works you will see why. Idle air goes through a the mixture bypass on the AFM. Falpper does not fluctuate. I've wtached it with intake hose off and engine idling. Only weak point of the factory AFM is that it Tops out at around 4,500 RPM. On my car I do get a bit of a lean sport between 4,500 to 5,500. After that the ECU is on the WOT MAP , and at least on my ECU, it is rich enough to handle the engine Mods. But like I said... my ECU may be a bit of a Unicorn. Any aftermarket ECU like aan MS2 would completely solve the fueling issue though.

 

The N42 Intake Manifold. Yeah, the runners are small. ITB would make more power. But it's certainly not horrible. As I mentioned, my engine will spin HARD pat 7.000 rpm any day and evry day. And the mid range torque is awesome. It will do on a DD. 

[Chickenman]

BTW... the is an Option for an affordable ITB ( or Plenum ) setup from  local fabricator that we are trying to get into production. Byron Meston does a lot of fabrication for the Datsun community up in BC. He just built a new Machine shop... but is waiting for three phase power. 

 

Here's the thing. He has been sitting on literally a Pile of L-4 EFI custom built IR manifolds for well over 5 years. They are beautiful works of machine. He a great fabricator... but not so good at marketing. When the local Z community found out about these we went nuts. Because he can make the same thing for L-6 engines. He's just been too busy with work, family, other projects and building his new shop. He's waiting availability of a 3 Phase power unit for th shop.  

 

I'll post up link later to his L-4 manifolds . Hop on the band wagon and pester him to put the L-6 version  things into production. 

[Chickenman]

Here's the link on FB in Church of L. Plus some pictures of the L-4 manifolds.

 

https://www.facebook.com/groups/995586513795146/permalink/1826020180751771/

 

Edited July 12, 2018 by Chickenman

[Chickenman]

With gutted carbs as ITB's: 

[Chickenman]

With Plenum Option: 

[HuD 91gt]

Weber manifold with injector ports?

[turbogrill]

3 hours ago, Chickenman said:

Almost the exact setup I have on my 280Z right now. L28, N47 head , F54 block with FT pistons. approx 10.5 CR. N42 Intake with 60mm Weber TB. MSA headers, 2.5" exhaust Cam is a bit of a Mystery. Engine builder was a bit secretive( don't know hwy ) . Was only told it was 280 degrees .480" lift. I've driven enough Z cars with the Shadbolt M445 to recognise it's characteristics

 

 Wel.. short story. Engine makes power like a SOB. Easily pulls HARD past 7,000 RPM. Had to put a Rev limiter on the danged thing. Surprisingly the stock ECU handles the large cam just fine, although I would suggest a true standalone ECU for it's adjustable, especially on a Race car.

 

But starts on first turn of the key every morning. Warms up fine. stable idle at 1,000 rpm , even though it is a pretty lumpy camshaft. I'm sure the compression help there. Gas mileage is fine. No driveability issues. Engine is a rocket. haven't had a chance to put it on a Dyno... too busy enjoying the car. But other experienced Z owners are surprised at the Power it has.

 

It's so good that I have a Haltech E11 sitting on the shelf for 3 years. I'm finally going to install it... because = I have it. But for day to day. It's not necessary. 

 

 Now, I'm not suggesting that everyone is going to have the same luck with their ECU. Mine is a bit of a Unicorn and it's working amazingly well. The factory AFM is NOT affected by the lumpy idle, and if you look at how the factory AFM idle circuit works you will see why. Idle air goes through a the mixture bypass on the AFM. Falpper does not fluctuate. I've wtached it with intake hose off and engine idling. Only weak point of the factory AFM is that it Tops out at around 4,500 RPM. On my car I do get a bit of a lean sport between 4,500 to 5,500. After that the ECU is on the WOT MAP , and at least on my ECU, it is rich enough to handle the engine Mods. But like I said... my ECU may be a bit of a Unicorn. Any aftermarket ECU like aan MS2 would completely solve the fueling issue though.

 

The N42 Intake Manifold. Yeah, the runners are small. ITB would make more power. But it's certainly not horrible. As I mentioned, my engine will spin HARD pat 7.000 rpm any day and evry day. And the mid range torque is awesome. It will do on a DD. 

 

Maybe you have the Isky L480 grind? Exact same numbers. I think it's a little more aggressive than the Shadbolt M455, at least it has higher duration at 0.050".

 

Interesting that your stock EFI is working, are you running higher fuel pressure or something? Maybe the CHTS is broken so the ECU thinks it's -40 and adds a ton of fuel

That happened to me but it was undrivable, very rich.

 

I am running MS2 fuel only, have a trigger wheel but had some issues. I think my homemade bracket sucks so the hall sensor is to far away from the wheel.

Would there be a big benefit of running spark with MS as well?

 

Thanks for the tip regarding the manifolds! Looks very nice

 

 

 

Edited July 12, 2018 by turbogrill

[turbogrill]

1 hour ago, HuD 91gt said:

Weber manifold with injector ports?

 

So a carb intake manifold and fab something to fit a TB?

[Chickenman]

No tricks done to the factory Fuel system, other than fine tuning the AFM with a 4 Gas analyser. The Factory ECU has a fairly rich WOT base Map. It can usually handle the increased Fuel flow. Anything additional you need could be handled with an Adjustable FPR. But I didn't need one. After setting WOT fuel Pressure you can dial the midrange in with fine Tuning on the AFM. 

 

All brand new CTS aetc. My car EFI system is like new.  Even the wiring harness is in showroom condition. Bills Datsun Shoppe in Clackamas Oregon tuned the AFM and he has a lot of local L-28's running factory ECU's with Big Cams, headers exhaust etc. It all depends on what yo know. Helps if the ECU drifts a bit rich with age instead of a bit Lean. Like I said. 

[Chickenman]

2 hours ago, HuD 91gt said:

Weber manifold with injector ports?

 

No all new bespoke castings, but based on a Cannon Weber 45mm manifold I believe. It's all in the FB blog.  

[Chickenman]

Only marking on the back side of my Cam are the numbers 0650. It's an " A " Datsun core. 

[turbogrill]

On 7/12/2018 at 2:17 PM, Chickenman said:

 

No all new bespoke castings, but based on a Cannon Weber 45mm manifold I believe. It's all in the FB blog.  

 

What diameter is the intake at the head side? Same as the head? 

 

Stock head is about 34mm at the intake, the stock EFI diameter is 32mm.

 

I don't want to make the runners larger than the head input port.

[madkaw]

Running N42 intake with Isky 490/290. Makes power to redline. Actually wish it made more down lower. It almost seems like you have to get the air velocity up on these intakes to make power, but maybe just my set up. My triples hit harder down lower, but no bitching about the stock intake.

[madkaw]

On 7/12/2018 at 3:15 PM, Chickenman said:

No tricks done to the factory Fuel system, other than fine tuning the AFM with a 4 Gas analyser. The Factory ECU has a fairly rich WOT base Map. It can usually handle the increased Fuel flow. Anything additional you need could be handled with an Adjustable FPR. But I didn't need one. After setting WOT fuel Pressure you can dial the midrange in with fine Tuning on the AFM. 

 

All brand new CTS aetc. My car EFI system is like new.  Even the wiring harness is in showroom condition. Bills Datsun Shoppe in Clackamas Oregon tuned the AFM and he has a lot of local L-28's running factory ECU's with Big Cams, headers exhaust etc. It all depends on what yo know. Helps if the ECU drifts a bit rich with age instead of a bit Lean. Like I said. 

Have to chat about this sometime . I have this mint 77 that the owner wants more power, but stock EFI is solid.

[turbogrill]

1 hour ago, madkaw said:

Running N42 intake with Isky 490/290. Makes power to redline. Actually wish it made more down lower. It almost seems like you have to get the air velocity up on these intakes to make power, but maybe just my set up. My triples hit harder down lower, but no bitching about the stock intake.

 

Is that a stock intake? 

Do you have any head work done?

 

Been researching this like crazy and so much conflicting information.

 

Nice engine bay btw

Edited July 18, 2018 by turbogrill

[madkaw]

e-88 Head - shaved .050 , bigger valves , ported slightly . Yes that’s a stock N-42. 

[turbogrill]

1 hour ago, madkaw said:

e-88 Head - shaved .050 , bigger valves , ported slightly . Yes that’s a stock N-42. 

 

Got it! Thanks! Looks very clean.

 

Any dyno results?

[madkaw]

Not with the EFI- I was at 150 RWHP with the Mikunis and th butt dyno feels about the same