Need advice on 300 build

Hey yall

im new to the group and have found tons of info that has turned me away from doing a V8 swap. a little back ground I have a 1992 single cab short bed f150 with the famous 300 efi. Im currently in the process of tearing the motor down to rebuild its been sitting for about 4 years due to a snapped radius arm. iv read a lot of topics on turbo builds for these motors and it has peaked my interest in this. Im sure this has been asked a million and one times but I cant seem to find what im looking for so any help would be greatly appreciated!! my question is

1) how do I size the correct turbo for my application along with waste gate size?

2) iv understood ill need to do a MS style set up so what MS would be best?

3) how do I understand the sized injectors that will work well with the size turbo I use?

any other pointers and advice would be greatly appreciated. This is kind of a build that im doing in dedication to my father that never got the chance. so im sharring this build with my younger brother. so in that aspect id like it to be streetable and fun. thanks a lot guys :beer: :beer:
 
To better answer your questions we need to know: power goals, how the truck will be used, and how budget minded the build is.
 
The truck will be used as a street and off road truck. I'm not really worried about budget because I'm re doing the entire truck I'm doing the 4x4 sas swapping rear ends new paint new interior etc. power wise I was looking for 400 to 500 torque and atleast 300 horse. I'd like to set 2 to 4K towards the motor and essentials if that's helps anything
 
To answer your first questions
A Ball park figure for turbo sizing is, it take about 1 lb of air per minute to make 10 HP. The actual figure depends on the engine BSFC and the A/F ratio but again this is ball park.
If you want 300 hp then the turbo compressor must flow at least 30 lbs/min of air.

If the stock engine makes 150 hp then it if you double the air density it should make 300 hp.
At sea level the air pressure is 14.7 psi so if you compress the air another 14.7 psi it should have twice the density providing the temp of the compressed air remains the same.
However at a pressure ratio of 2 the turbo compressor raises the air temp about 165 degrees (depending on the turbo efficiency) and you need an intercooler to reduce the air temp.
In reality using an air to air intercooler with a 50% efficiency, it takes about 18 additional psi to double the power on a 300 six.
That is a pressure ratio of (14.7 + 18)/14.7 or about 2.2

You are now looking for a turbocharger that can flow 30 lbs/min at a pressure ratio of 2.2
Looking at a few turbocharger compressor maps shows turbos with 47 - 49 mm diameter inducer compressor wheels to be a close match.

Injector size = HP X BSFC/ # of injectors x max injector duty cycle

HP = 300
BSFC = .60 for a turbocharged engine
Number of injectors = 6
Max duty cycle is usually around 80%

(300 x .6)/ 6 X .8 = 37.5 lbs/hr
Round up to the next available injector size.

Paul
 
That's exactly what iv been trying to figure out but couldn't find a detailed explanation on how to figure numbers for what I need or want. I appreciate it!
 
Wastegate:
As the boost is regulated at a lower level, the wastegate has to dump more exhaust so wastegate size has to be considered at the lowest boost level that might be used.
In our above case at 5 lbs of boost the calculator shoes a wastegate size of 25MM needed so the very common external 38MM wastegate will work just fine.

On the EFI 300 the exhaust and intake manifolds are a big improvement over the early log style which leaves the cylinder head as the restriction.
Consider that each cylinder is 50 cu inches and would be the equivalent of a 400 cid V8 using a stock head that flows only around 100 CFM on the intake port.
The engine volumetric efficiency falls off dramatically after 3500 rpm.
As you use longer duration street application cams to try to make more power, the midrange power increases but the torque peak is still between 2000 and 2500 and the power peak between 3000 and 3500.
The stock head chokes the engine

If you want to make power using a lot less boost, the head needs a larger intake valve and attention to the bowl area around the valve guide along with similar work on the exhaust side.
A 1.94" intake valve and 1.6" exhaust produces good results.
If the head flow is improved then less boost to make the target power translates to lower intake air temps with less problems with detonation, ignition timing and gas octane requirements.
It also increases the amount of power available if you want to turn up the boost.

An interesting side note:
I talked to several companies about a cam for a turbo 300 project with the focus on midrange power up to 4500 rpm using a mildly ported head.
Jones suggested a 204/204 on a 114 LSA, Crower 210/213 112 LSA and Comp 220/220 112 LSA. After some discussion Comp was willing to come down closer to the Crower specs.
What's interesting is, in a 300 six you probably couldn't tell the difference in power between the 3 cams in a gas turbo application so all 3 suppliers are good in their recommendations.

There is a much bigger difference in spool time and power band due to the A/R ratio of the turbine housing along with running a larger turbo than needed to get the job done.
For a 300 six if you are looking at making a lot of torque just off idle without concern for power above 4000 rpm then turbine housing A/R ratios in the .60 range works well.
If the focus is more on HP above 4000 rpm then A/R ratios in the .80 to .96 have far less exhaust restriction and will be far more efficient. You will just have to wait a little longer to get boost.
Some like the longer response time in that the power increase is not so sudden making the power more controllable especially on wet roads.
 
that was very help especially on cams. sorry its taken awhile to respond iv been working none stop lately. I have never used Crower or jones im sure I can look up and do some research I haven't ever had a problem from comp but iv also never used their product in a incline engine. im focusing more on torque than on horsepower tho the more horse the better. as of right now I can get my hands on a couple turbos for free one from a 04 cummins common rail. an old chevy diesel and I have another turbo that needs a rebuild off a old 6bt cummins. I haven't checked sizes or anything or really researched much on these turbos available. I was finally able to find turboB and another build I believe JonL or something like that. I will be getting the stock head ported and polished to help. I was looking in to cams and came up empty till I saw your post so it was very helpful at the right time! I appreciate all the help explaining the turbo system! any advice on the mega squirt set up? iv seen that this seems to be some what a pain to get set up properly? best rout to take in that aspect?
 
The do it yourself Mega Squirt system is popular because of the money savings however the user has a greater responsibility to make it work.
That's why there are so many MS forums for help.

My choice for a fully integrated system would be the Holley HP EFI.
The 550-605N universal kit would cover the 300 six.
https://www.holley.com/products/fuel_sy ... s/550-605N
The 550-605N kit is more expensive than the 550-605 because it uses the NTK O2 sensor which is better suited for boosted application than the Bosch O2 sensor in the 550-605.
Add Ford TFI Ignition Harness #558-305
 
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