Twin Turbo Blow Through 300

AlphaZ

Well-known member
Supporter 2023
This is not a proposed project, it's a project I just finished, I had been documenting my progress on a different forum, I wanted to get on this one and put all the information I know about this project down on this forum for others to learn from my mistakes.
I will post again after work when I get more time to do this. Until then, a link to the exhaust noise! :D

[youtube]https://www.youtube.com/watch?v=LAy2bYZidRI[/youtube]
 
I haven't gotten boost going, I was dealing with the fuel pump sucking in rust from the tank. Couldn't get more than a couple miles. Just finished and took it to town tonight for a test run.
I'm waiting on a part for my throttle cable because at the moment I can only go part throttle, secondaries won't even open yet. But the turbos whistle like you wouldn't believe. Definitely gets attention from other people.
I've never tuned with an AFR Gauge before, I'm playing it very cautiously and watching it like a madman. I've been keeping it between 11:1 and 14:1. I'm curious as to what will happen when the methanol/water injection kicks in also.
I know I said I would have updated by now and put down all of the information I've learned, I need to wait til the weekend so I can take the time and sort through everything.
 
I know from tuning megasquirt how time consuming that can be. I like to play things safe and dial them in slowly. I've never tuned a blow through carb before so I'm very interested to see how it works out for you. It sounds very nice in that video you posted, curious to see how those wrx turbos work out for you.
 
Took it cruising last night, I've got the throttle worked out where I can run 4psi of boost. Also filled my methanol tank.

Holy crap. It really pushes a guy into the seat.

Just 4psi is a whole lot of fun. I need to keep an eye on when it hits but I think it spools below 2000rpm.

People were driving by going "Farm Truck!". It's pretty obvious even when I can hear the turbo whistle echoing off buildings. I had a crowd of lookie loos checking out the engine when I parked it haha.

My throttle is set where the primaries are open and the secndaries are just cracked open.

I'm borrowing my mom's Go Pro today and I'll take a video as it sits until I get more throttle stuff in the mail.
 
Looking forward to that video for sure! I'm going to try a tp38 off a 94-97 powerstroke on my truck. Mustang guys say boost hits hard 2800-3200 with the huge 1.15 a/r. I bought a .84 a/r housing in an effort to get spool around 2000 we will see. If that doesn't work I might look into those wrx units your running. Wonder what back pressure will be like with those. What're your cam specs by the way? In the video sounds like it's got a little chop to it, that could just be my crappy phone speaker though.
 
From compcams, 212/212, 114deg LSA.

It has a smooth idle, no chop to it, when it raps out it sounds a little bit like a ricer. Good low-mid torque though.

Even without full throttle and 4psi, it'll squeal tires when it spools up in first gear.
 
Ok I'm going to attempt to compile everything...

Engine:
EFI 300/4.9L inline six Pulled from 1987 F-150
Rebuilt and bored .060” over
Hypereutectic pistons, 8.5:1 compression
ARP main bearing studs and line honed
crank straightened to within .002”
custom ground turbo cam from comp cams, Duration @ .050” is 212/212, Lift is .447/.447, LSA is 114
Steel cam gear
ARP head studs
Stellite high temperature valves (propane valves)
Crane Pedestal to stud rocker conversion kit
High volume oil pump
Heavy duty 300 head gasket, Felpro 1024.
Offenhauser Dual Plane intake manifold

Turbos:
2x TD04-13T turbochargers, Part Number: 49377-04300 and 14412AA360
The 04300 is the oem TD04 on the 02-04 WRX / 2.0L.

Fuel:
Old Holley 600cfm double pumper converted to blow-through by following Hangar18 instructions.
Aeromotive boost-referenced return-style fuel pressure regulator.
Snow Performance stage 1 Methanol/Water injection kit.

OKKKK Pictures.

One of the most frustrating issues I encountered was the main stud clearance to the oil pump. I had to have a spacer made and a longer oil pump shaft.
[image]http://cimg9.ibsrv.net/gimg/www.ford-trucks.com-vbulletin/2000x1124/80-20140813_184852_955e7da3d8c199410b78fb8e6c6a9019fc55e088.jpg[/image]
And this:
[image]http://cimg5.ibsrv.net/gimg/www.ford-trucks.com-vbulletin/2000x1124/80-20140813_184827_88997ea5f06f142377188b776cca469e66976118.jpg[/image]
It's something I never ran across while visiting forums and looking at what other members had to say.

Here's a mock up before all the piping:
[image]http://cimg8.ibsrv.net/gimg/www.ford-trucks.com-vbulletin/2000x1504/80-1471730742341_931114480_a47cf2ad1e4c420dfaadd204c7cfcd814197716a.jpg[/image]

This is what the hand-made headers look like before they were ceramic coated:
[image]http://cimg0.ibsrv.net/gimg/www.ford-trucks.com-vbulletin/2000x1504/80-1471731360158_1334533116_7d7d4d55bb2b986e3e7fdaba11e402cca80ad86f.jpg[/image]
The biggest struggle with making these was making sure I could get a ratchet in there and tighten my manifold bolts.

Here's the headers after Jet-Hot coated them:
[image]http://cimg1.ibsrv.net/gimg/www.ford-trucks.com-vbulletin/2000x1504/80-1476480532769_1323167798_efaee911c406a43241801f5253b038d8cf1edc44.jpg[/image]
Did a pretty slick job on it, it's kind of a sandpaper feel, it's their 2000F coating.
[image]http://cimg3.ibsrv.net/gimg/www.ford-trucks.com-vbulletin/2000x1504/80-14764806155291130188262_21ab590edb9a5fc778ab52ceab563f1f16288a19.jpg[/image]

And finally, here's the mock up when I fitted all the piping
[image]http://cimg4.ibsrv.net/gimg/www.ford-trucks.com-vbulletin/2000x1504/80-14765508696521411496810_b98c5bc58bcde9524840251aacd285419df5450b.jpg[/image]

I hope I got everything in one go, instead of adding more posts on additional info I'm going to edit this one and keep it all in one spot.
 
Just took a video, trying to figure out how to edit it.... I'll upload soon
 
Ok, sorry about the horrible audio and video quality, hopefully you can see what's up on there.
Rolling start, pretty much floored to 70mph.
I think I need a boost controller to raise the pressure, I'm supposing the wastegate is going partially open at WOT.

[youtube]https://youtu.be/qT2A4jaLd1Y[/youtube]
 
I'll have to watch that later on the computer, can't see much on my phone. Looking forward to seeing what it does with more boost! Looks like your running 13.0 afr ratio at 5psi, may need a jet change with more boost
 
Yea you'll need to watch at 1080 to see the needles, I'll do a better recording next time
 
Yes, it's very lean in boost. Shoot for no higher than high 11s AFR. The 13's and even 14+AFR you have in boost now is good for N/A, but dangerous in boost.
 
Well I got the lean spike out and have my boost set to 10psi.
Road raced a guy in the quarter, I don't have a time but I crossed the finish at around 95mph.
There's a few more improvements to make yet.
 
Your carb doesn't look like a mechanical secondary "double pumper" Holley, it looks like a normal vacuum secondary in the pictures. How is that working out?

I'm considering using an Edelbrock 500 I have. It seems like the modifications to it for boost should be very easy, especially under 15psi., as you wouldn't even need to swap to solid floats.

As for the main stud to oil pump clearance issue, I had seen where they ground the stud down flush with the nut and may have even taken some off the nut, then clearance the pump some with some grinding and it was enough to fit without a spacer.

You talk about using a throttle cable and I see you are using a Dual Port manifold with the carb turned. What did you use for a throttle cable setup on your truck? How did you get one installed with the stock pedal arm? I'd love to convert to one and turn my carb.

Also, what are you doing/using to control spark timing?

With a 95mph trap speed, as long as you had a decent launch and didn't just burn the tires down, it's good enough for mid to high 14's in the quarter. Not bad at all.

It's nice to see more people playing with boosting these engines!
 
guhfluh":17qfywoy said:
Your carb doesn't look like a mechanical secondary "double pumper" Holley, it looks like a normal vacuum secondary in the pictures. How is that working out?

I'm considering using an Edelbrock 500 I have. It seems like the modifications to it for boost should be very easy, especially under 15psi., as you wouldn't even need to swap to solid floats.

As for the main stud to oil pump clearance issue, I had seen where they ground the stud down flush with the nut and may have even taken some off the nut, then clearance the pump some with some grinding and it was enough to fit without a spacer.

You talk about using a throttle cable and I see you are using a Dual Port manifold with the carb turned. What did you use for a throttle cable setup on your truck? How did you get one installed with the stock pedal arm? I'd love to convert to one and turn my carb.

Also, what are you doing/using to control spark timing?

With a 95mph trap speed, as long as you had a decent launch and didn't just burn the tires down, it's good enough for mid to high 14's in the quarter. Not bad at all.

It's nice to see more people playing with boosting these engines!

That was just a 390 holley vacuum secondary I was using to mock up everything to make sure stuff cleared. I was waiting on gaskets for the dp at the time.

I never looked into using an edelbrock for blow through, I've kind of been holley ever since I started doing this performance stuff.

I'll take a picture of how I have my throttle set up, it's a little mickey mouse but it works. As they say, if it works, it ain't stupid. haha.

I got a regular vacuum advance dizzy, timed the static to 8-9deg, and left that like normal. I know that there's very differing opinions, but I have my vacuum advance hooked up to manifold vacuum. Partly because the carb is old enough it doesn't have a ported vacuum on it.

I got a MSD 6 BTM and it pulls timing when engine is under boost. When I started, I was pulling 2deg per psi. Now, it's a little colder and I'm a little braver so I'm only pulling 1deg per psi.
 
guhfluh":2w0oz34p said:
Yes, it's very lean in boost. Shoot for no higher than high 11s AFR. The 13's and even 14+AFR you have in boost now is good for N/A, but dangerous in boost.

:nod: ... More power when richer as well.
 
Yea, I forgot to post that I got the tuning taken care of, it's running richer like it's supposed to. Bumped my boost to 10 psi, I'm happy with where it's at right now.
Just doing some quarter miles lately to estimate horsepower. I don't know the error on those little calculators that use MPH/Weight on the quarter mile to estimate how much power it's making, but I'm hoping it'll get me in the ball park.

My current issue is keeping traction. I don't have the money to get a locker for the rear end. I've got the old Ford 3 speed in it and in first gear there's no chance of grip once it spools. In second gear it chirps a bit.

On wet pavement it's best to just keep my foot out of it, it'll lose traction in any gear once the pressure goes positive.
 
This calc is what I use, seems very accurate. It estimated 488hp flywheel for the v6 tbird, and it wheel dynoed at 452hp the next week.
http://www.wallaceracing.com/hpcalculatorquarter.php

My F100 sleeper (sold to my brother Will) still has a stock wore out locker that one wheel peeled all the time. Use traction bars and sticky tires and weight in the rear, and work on the suspension until it posi's on it own. When it does, the suspension is set up correctly.

Just before I pulled the 300 out, I had stock/street all terrain shot tires on it, and when boosted around 20 mph, it never broke them loose the way the truck is set up. Estimated 450+hp and 700tq at that time.

The F100 sleeper has 2.75 gears in it, and the v6 tbird started with 2.73's, ran this year with 3.08's, and will go back to 2.73's next year to help with traction.
 
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