1984 SD4 Resurrection

[FieroWanaBe1]

are you still planning on ITB's? I bet a tri-y header would work well on one of these.

Im still planning on ITBs based off busa throttles.
I will definitely be redoing the header, the one the car came with has 1.5" primaries, and i don't think that will be enough.

[FieroWanaBe1]

I think my first run at the intake will be to 3d print a test fit item from CF-Nylon I am curious how it will hold up being bolted to the cylinder head, I truly wonder how well these consumer 3D printer polymers compare to commercial molding nylons.

my back up plan would be a Lost PLA casting for the runners and weld them to a milled out plate for the port shape at the head interface.

[FieroWanaBe1]

I'm printing some runner geometries to flow test after the Iron Head is tested in the coming weeks.
my older first iterations is a shorter transition from 46mm ID to rectangle, and 30 Degree incline to the port.
The 2nd option is a 45 Degree incline with a full length 46mm ID to rectangle transition
and the 3d is 60 degree incline, with a lateral 30mm bend to bring the centerlines of the 45mm ID to 80mm Center to Center for the ports, this would allow the gen-1 'busa throttles to be used without modifications, this is the worst case outside runner, inners have a 15mm bend.

[The Dark Side of Will]

Intake is on the rear side of the engine? What fits under decklid and inside trunk wall?

[FieroWanaBe1]

The two barrel intake on the Iron head left only about 1" to the trunk wall with the Holley 4412, Room for the air cleaner to the Decklid didn't exist. Hence the previous owner's use of the large over the roof decklid scoop that held the 14" air cleaner on a 2" riser.
I intend to reuse the scoop to house an air filter, box and sectioning the decklid around the runners. I also plan lowering and rotating the engine some on the cradle, since I have a shallower dry sump pan now to replace the large Moroso pan.

[ericjon262]

are you still planning on ITB's? I bet a tri-y header would work well on one of these.

Im still planning on ITBs based off busa throttles.
I will definitely be redoing the header, the one the car came with has 1.5" primaries, and i don't think that will be enough.

that will be determined by the output of each cylinder. I'm starting to research more scientific header designs that match the tube closely to the port, and prevent reversion downstream of there with different collector and muffler designs. This might also be a great application for a stepped tube design as well.

The two barrel intake on the Iron head left only about 1" to the trunk wall with the Holley 4412, Room for the air cleaner to the Decklid didn't exist. Hence the previous owner's use of the large over the roof decklid scoop that held the 14" air cleaner on a 2" riser.
I intend to reuse the scoop to house an air filter, box and sectioning the decklid around the runners. I also plan lowering and rotating the engine some on the cradle, since I have a shallower dry sump pan now to replace the large Moroso pan.

I had considered going dry sump and lowering my engine at one point. When I started looking at it, the only effective way to get the engine significantly lower involved massive modifications to the transmission, because my transmission case is flush with the bottom of the oil pan. The F23 case is also very close to the cradle as well, I'm not sure about other transmissions.

Just food for thought.

[FieroWanaBe1]

that will be determined by the output of each cylinder. I'm starting to research more scientific header designs that match the tube closely to the port, and prevent reversion downstream of there with different collector and muffler designs. This might also be a great application for a stepped tube design as well.

I will most likely go with a stepped long tube design, the '801 has much larger ports than earlier SD4 heads, and the '801 is closer in cross section to 1 3/4" than 1 1/2". The Hooker header the car came with was a short 4-2-1 design, with a square port at the header flange and 1 1/2" OD, I believe designed to go into the D port of the original SD4 Head and rely and the tube port mismatch for anti reversion. The '322 iron head originally installed has a port shape I haven't seen on any other SD4 head in pictures I found on the internet, It is much more compressed in height. I feel that the exhaust port the biggest power limiting factor with the iron '322 head, followed by the port floor heights relative to the valve. The good thing is there is a lot of meat to port the exhaust further. The '801 head has a much taller exhaust port, and a radius similar in feel to how LS ports are designed. I don't think half of a 500HP+ 6.0L, or a 250HP 3.0L would like a 1.5" primary, much like LS motors don't typically perform well with 1 1/2" OD headers.
Its my understanding, and opinion, that for the collector to be of use as resonance-well, you need to include your downstream exhaust in the collector length and sizing, and muffler as an expansion chamber, Engine masters on MotorTrend has some interesting Dyno tests on this, and other header theories.

I had considered going dry sump and lowering my engine at one point. When I started looking at it, the only effective way to get the engine significantly lower involved massive modifications to the transmission, because my transmission case is flush with the bottom of the oil pan. The F23 case is also very close to the cradle as well, I'm not sure about other transmissions.

Lowering the drivetrain in itself is limited, but that is also why I would like to rotate the engine around the Axle centerline, similar to the IMSA cars, although they are less constrained being a true tube-space frame design. The primary benefit would be greater room in the bay for a straighter intake runner path to the valve head.

I think I am still leaning towards the V6 four speed with the 4.10 final. I have enough parts to build 2, but I also have 1 getrag and a spare F40. I think the LQ1 I built will get the getrag, and the LS4 can have a spare F40. The 4 speed has the smallest case, and if I remember I should be able to move it around enough to move top of the engine forward a fair amount, I played with the concept a little once with just a transmission on a cradle.

[ericjon262]

Engine masters is pretty good, however some of the later episodes have started to get kinda bland IMO. I'm honestly starting to lose interest in MTOD more and more, too many shows that aren't really that great. I will say, I'm pretty impressed with Alex Taylor, on Hot Rod Garage, I was expecting her to be more of an "eye candy" host than a builder, so her coming in and ripping apart a transmission and talking about it in a intelligent sounding manner was fairly impressive to me, granted, I don't know alot about automatic transmissions, so it could have been bullshit...

I have a book here at the house called "Scientific design of intakes and exhausts", it's an old publication, but the principles of the operations should still be valid. in it, they describe two primary styles of header design, "Interference" and "Independence" Independence being a 4-1 style, with each tube making the trip to one collector, and Interference being more like a tri-y design. In this particular book, it is claimed that an interference header almost always boosts low end, with minimal effect on top end, and in some instances beating a 4-1 or independence header. most of this discussion was on 4 cylinder engines, crossplane V8's tended to lose top end on an interference header due to the banks not firing even. because you can match the cylinders together with a interference design, I would imagine your results would be a bit better than a 4-1, not that a 4-1 would be bad.

I look forward to seeing what you come up with, I enjoy making headers, I plan to make a really cool set for my Suburban when I put the big block in.

[FieroWanaBe1]

This thread should be renamed to 1984 SD4 Resurrection, since I care much more about the motor than the car it's in, although, the owner did install Koni's, a rear swaybar, and it is lowered a bit, to try to help the car handle better.

Did some test mock up with the Suzuki throttles.

These are Gen 1 GSXR1300 throttles, They may be too small for the application as is. Some Measurements:
They start at a 50mm bore, and neck down to a 42mm at the base of the manifold connection. The rubber for the manifold is sized for a 47mm connection. I should be able to bore the throttle bases open to 45mm, I'm not sure if that is still a large enough opening.
The SD4 port opening, unported, is 34mm x 54mm, that is 2.84 sq-in, and the '801 head lacks the pinch point of must 2 valve head designs, leaving the throat as the primary restriction, a theoretical 90% throat diameter at the valve, for a 2.1 valve with a 5/16 stem, is 1.89", with an area of 2.72 sq-in, I'll say this would be the maximum port area possible after porting.
A 42mm Dia bore only has an area of 2.14 sq-in
A 45mm Dia bore only has an area 2.47 sq-in
A 50mm Dia bore has an area of 3.04 sq-in

It's obvious to me suzuki tapers the throttle body for venturi effect at the point of fuel injection to increase atomization. If I bore they throttles to 45, I will reduce the effect, but most likely benefit from a restriction upstream of the port, But a full 50mm bore would require new blades, Hilborn sells throttle blades for around $30, do they fit these Kehin Throttles? Doubtfull, but maybe they could be made to work?
My alternative is some Chinesium DCOE pattern 50mm throttles from Amazon, more money and work than the Hyabusa units, but cheaper than anything else out there at $130 for a two barrel unit. I may just get one to look at up close.

The measurements with the '801 head on stock mounts are:
11" to the firewall, and 5.5" to the base of the deck "vents" (solid units on the car currently)

I will most likely ditch the dogbone and mount, but the 'busa 80mm center to center spacing could clear it, the 60 degree up turn provides adequate clearance from the trunk wall. 45 may fit, but 30 doesn't look hopeful.
Looking at my stance as the car sits, that axles point slightly upward, I could rotate the engine a little forward on the crank center to raise the axle centerline, gain some clearance and ever so slightly shift engine weight forward.

[The Dark Side of Will]

Mark the welding rod V12 guy is using 6 sets of Honda RC51 (IIRC) throttles on his engine precisely because all the four cylinder ITB sets he looked at were too small

[FieroWanaBe1]

https://racehead.com.au/designing-perfo ... uld-i-use/
from this recommendation a 42mm throttle would be for a 280hp 4 cylinder @70HP/cyl
I will need to flow test the 'busa body as well to be sure they actually produce decent flow to even compare this data.
even a 500HP V8 would use 42mm throttles, however no 2 Valve V8 intake I have ever seen run that small of a throttle.

Using Richard Holdener's theory that an LS V8 has the power potential using 2 times the port flow, a 4 cylinder would have 1 times.
if my target is 260-280 Flywheel Horsepower, I need the head to flow 280 cfm at least at .600 lift. Probably achievable, but not by me, maybe 250-270, the throttle bodies should flow at least 330-380 cfm if they fall within 120-140% of cylinder flow, their 45mm would be the best fit according to the recommendation.

https://www.efihardware.com/products/9/ ... mm-to-48mm

Their sizing would indicate the 48mm units are about good for 260HP

DCOE 45mm and 48mm throttle bodies are 90$ on Amazon.

[FieroWanaBe1]

More comparative Data:

From Wallace Racing Calcs:
Estimate Throttle Blade Diameter For Individual Runner Intake
Enter Engine CID:
181
RPM (at Max HP?):
7300
The Throttle Blade Diameter is 61.97 mm
The Throttle Blade Diameter is 2.44 inches

The HP for your Cylinder Head Flow of 260
is 267 with a RPM Range of 5,987 to 7,487
for your engine size of 181 CID

Kinsler '801 intake advertises a 2.5" throttle, judging by the IMS GTP-L photo, this is the intake they ran on that motor, 365HP+ on race gas, at 2.7L
https://youtu.be/-Hman0a3QQw?t=1005

Probably a little extreme for a car with a street transmission.

[FieroWanaBe1]

Ran PipeMax using the smallest solid roller cam from Lunati, A Isky Cam may be a better choice, less extreme lift, more available in the software recommended lift range and with a 1.55 rocker, they have the largest selection dedicated SD4 grinds I have seen, maybe they can even make a hydraulic roller grind, Cam specs don't effect many calcs in the software though.

- Induction System Tuned Lengths - ( Cylinder Head Port + Manifold Runner )
3rd Harmonic= 12.615 (ProStock or Comp SheetMetal Intake • best overall HP )
Plenum Runner Average Recommended Entry Area = 3.036 Sq.Inch
Maximum Plenum Volume CC = 2970.1 ( typically for Tunnel Ram Intakes )
--- Cross-Sectional Areas at various Intake Port Velocities (@ 28 in.) ---
128 FPS at Intake Valve Curtain Area= 4.638 sq.in. at .703 Lift
172 FPS at Intake Valve OD Area and at Convergence Lift = .525
212 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 2.806 sq.in.
--- 7000 RPM Intake Cross-sectional areas in Square Inches ---
300 FPS CSA= 1.981 Smallest Port CSA ( Hi Velocity FPS • good TQ and HP )
285 FPS CSA= 2.085 Smallest Port CSA ( very good TQ and HP combination )
260 FPS CSA= 2.285 Recommended average Intake Port CSA (very good TQ and HP)
235 FPS CSA= 2.529 Largest recommended Intake Port Gasket Entry area CSA
Note : these are calculated average Port cross-sectional areas and FPS
--- Cross-Sectional Areas at various Exhaust Port Velocities (@ 28 in.) ---
127 FPS at Exhaust Valve Curtain Area= 3.483 sq.in. at .693 Lift
219 FPS at Exhaust Valve OD Area and at Convergence Lift = .400
271 FPS 90% PerCent Rule Seat-Throat Velocity CSA= 1.629 sq.in. at 7000 RPM
--- 7000 RPM Exhaust Cross-sectional areas in Square Inches ---
265 FPS CSA= 1.664 Recommended average Exhaust Port CSA
250 FPS CSA= 1.764 Recommended average Exhaust Port gasket area
240 FPS CSA= 1.837 Recommended largest Exhaust Port gasket area
Note : these are calculated average Port cross-sectional areas and FPS
--- Single Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
Diameter= 1.977 to 2.102 Total Length= 28.7 to 31.2 inches long
--- 2-Step Primary Pipe Specs --- ( Mid-Range TQ to Higher RPM Horsepower )
1st Step Dia. inches= 1.977 Length= 9.6 to 10.8
2nd Step Dia. inches= 2.102 Length= 19.1 to 20.4
--- Conventional Straight Tube Collector Specs ---
( TQ ) Diameter= 3.308 to 3.558 Best Length= 16.2 and also 32.3 inches
( HP ) Diameter= 3.558 to 4.058 Best Length= 16.2 and also 8.1 inches
--- Megaphone Collector Specs ---( Diffuser or Diverging Cone Shape )---
( TQ ) Diameter= 2.558 taper to 3.558 Best Length= 16.2 or 32.3 inches
( HP ) Diameter= 2.808 taper to 3.808 Best Length= 16.2 or 32.3 inches
H-Pipe= 16.2 X-Pipe= 64.6 distance behind end of Primary Tube ends
-- Total Exhaust System Tuned Lengths (Primary ends to TailPipe end) --
Best HP/TQ Tuned Collector Lengths= 16.2 , 32.3 , 64.6 , 129.2 inches long
Worst HP/TQ Loss Collector Lengths= 24.2 , 48.5 , 96.9 , 193.8 inches long
Note=> measured from where the Primary Pipes end inside the Collector to
the point the Collector or tailpipe exits into the atmosphere.
Note-> all Pipe Diameters are OD and based-off .0625 inch Pipe thickness

[Shaun41178(2)]

Call kinsler. See if they got one of those intakes laying around.

[FieroWanaBe1]

Kinsler emailed back:
Discontinued.

[FieroWanaBe1]

I bought 4 of the 48mm bore DCOE pattern throttle bodies.
They seem nice. Straight bore at 48mm, sealed shafts on the on the outsides, idle bleed adjustments, mounting studs, orings, and fuel rails included. All for $89. They do offer 50mm units for $135.

[The Dark Side of Will]

Are those from Kinsler?

[FieroWanaBe1]

Not Kinsler.
Amazon, mega alibaba/wish.com vibes.
https://a.co/d/bInukYR

[FieroWanaBe1]

I also purchased an electric vacuum pump for the brakes on the car.
GM 20804130, interchanges with Standard Motor Product AIP30. Amazon has stock as of 10/19/23 for $108, beating all other prices.
https://a.co/d/dTTTHbC
The GM model is branded Hella, Made in Mexico by Buehler Motor Inc.
These pump are used in many applications:

CADILLAC CTS 2010-2014
CADILLAC SRX 2010-2016
CHEVROLET CAMARO 2010-2016
CHEVROLET CAPTIVA SPORT 2012-2015
CHEVROLET EQUINOX 2010-2017
CHEVROLET IMPALA 2012-2013
CHEVROLET IMPALA LIMITED 2014-2016
GMC TERRAIN 2010-2017
HYUNDAI GENESIS COUPE 2010-2016
JEEP WRANGLER 2012-2019
JEEP WRANGLER JK 2018
PONTIAC SOLSTICE 2007-2009
SATURN ASTRA 2008
SATURN SKY 2007-2010
SUBARU CROSSTREK 2016
SUBARU FORESTER 2014-2018
SUBARU WRX 2015-2019
SUBARU WRX STI 2016-2019
SUBARU XV CROSSTREK 2014-2015

I also bought a vacuum switch for relay control. https://www.newark.com/multicomp/psf109 ... dp/24R7147
This switch seems pretty common to use with TCC lockup control, and a few commented on amazon for use with brake booster pumps.

[The Dark Side of Will]

I also purchased an electric vacuum pump for the brakes on the car.
GM 20804130, interchanges with Standard Motor Product AIP30. Amazon has stock as of 10/19/23 for $108, beating all other prices.
https://a.co/d/dTTTHbC
The GM model is branded Hella, Made in Mexico by Buehler Motor Inc.
These pump are used in many applications:

CADILLAC CTS 2010-2014
CADILLAC SRX 2010-2016
CHEVROLET CAMARO 2010-2016
CHEVROLET CAPTIVA SPORT 2012-2015
CHEVROLET EQUINOX 2010-2017
CHEVROLET IMPALA 2012-2013
CHEVROLET IMPALA LIMITED 2014-2016
GMC TERRAIN 2010-2017
HYUNDAI GENESIS COUPE 2010-2016
JEEP WRANGLER 2012-2019
JEEP WRANGLER JK 2018
PONTIAC SOLSTICE 2007-2009
SATURN ASTRA 2008
SATURN SKY 2007-2010
SUBARU CROSSTREK 2016
SUBARU FORESTER 2014-2018
SUBARU WRX 2015-2019
SUBARU WRX STI 2016-2019
SUBARU XV CROSSTREK 2014-2015

I also bought a vacuum switch for relay control. https://www.newark.com/multicomp/psf109 ... dp/24R7147
This switch seems pretty common to use with TCC lockup control, and a few commented on amazon for use with brake booster pumps.

I would wire up a manual switch to bypass the vacuum switch, in case the vacuum switch has problems. That's not such a big deal for TCC lockup, but could be a big deal if you suddenly don't have brake boost. Also, if you're at a track day and your boost starts to go away through a corner or two, you want to be able to hit a switch to get it back.

What does GM use as the feedback mechanism? BB pressure sensor?