The Official 1HD-T/FT Fuel Pump Mod Tuning Thread (5 Viewers)

[mudgudgeon]

Are the pins all the same profile? Or are there different profiles available like I've seen for the Cummins pumps? What does that cap do that the OEM one doesn't?

Looks like they do 5 different pins.
I don't think the top cap doors a lot that can't be done with the stock cap, maybe simplifies mods a little.

One interesting thing to note on the trundles pins is the tapered grind starts from the very bottom of the pin.
On stock pins, the grind starts 5-6mm up the pin. One thing limiting how much travel is available on stock pins is the pin bottoming out in the pump housing. Having the taper start at the bottom of the pin helps this

 

[Douglas S]

The cap is taller to allow more movement of the pin. However, they usually use a custom spring and shims to eliminate the star wheel. I ordered one pin, 8mm. You can order an individual pin or the tuner pack with one of each. The mm measurement is how much material is left in the pin. The lower the number the more fuel. I chose the least aggressive because I can always grind it deeper and leave my stock pin alone. He said you can also remove the pin and install varying diameter drill bits and cap off the boost line to determine the amount of depth the following pin needs to move to hit your target AFR at full boost. I guess the profile is all the same, just the depth is different.

For reference $1.4 NZD = $1 USD

Do you use the 10.9 or 11.9mm pins?

 

[mudgudgeon]

Do you use the 10.9 or 11.9mm pins?

You need 10.9 diameter pin to fit the stock denso boost compensator housing

 

[troopie]

I've been looking at the cap and the pins for a while now. I think i'll just order the full set and see what happens.

 

[vwluv10338]

I ordered the 10.9mm pin. Also ordered a Moonlight fab air box last night and is scheduled to land in the USA on Monday

 

[vwluv10338]

I've been looking at the cap and the pins for a while now. I think i'll just order the full set and see what happens.

He mentioned if you want you can pull and rod and cap off the boost line. Install varying diameter drill bits to set your max boost fuel. Use the bit diameter to see how far you need the following pin to move at max boost and then order the pin with the correct max depth of cut.

 

[mudgudgeon]

The pics of the trundles pins look like the taper grind is is unpolished. I'd be interested to know if it's the case

 

[troopie]

I like the cap for the bling factor alone So if it increases the travel and makes tuning a little easier that's an added bonus...

The drill bit way sounds good, although i'm afraid i'll screw something up. I do have access to 10mm stainless rod so i can experiment some with some grinding and then order a rod that comes close to what i need and go from there.

It's a good thing i'm not in a hurry so i can steal ideas here.

 

[SeaJay]

I ordered the 10.9mm pin. Also ordered a Moonlight fab air box last night and is scheduled to land in the USA on Monday

you will like the airbox, I replaced my xxi one with a moonlight airbox a few months ago. Ordered a set of pins and a cap today

 

[vwluv10338]

you will like the airbox, I replaced my xxi one with a moonlight airbox a few months ago. Ordered a set of pins and a cap today

The box definitely has a bit of engine drone at 2000 rpms but it's not bad with the window up. It didn't seem to increase my initial spool time like I had hoped but I think it makes a difference over 15psi. It seems like my time to spool from 15 to 20 has been reduced and it's easier to hit. Before it would spool to 18 unless I really mashed the pedal. Now it hits 20 easily. Was it expense and not as much difference in drivability as the money spent on my turbo, yes, but I'm still glad I bought it and I think it will make more of a difference with my intercooler installed so I can really play with the fuel. My pin and cap have been in shipping for two weeks. They finally hit CA but it's taken forever.

 

[VK3FHDJ]

Seajay I'd be interested to see comparison betweeb the Trundle cap and the ADS spacer

 

[SeaJay]

Seajay I'd be interested to see comparison betweeb the Trundle cap and the ADS spacer

I'll put some pics up when I can, the Trundle gear is still in transit from NZ

 

[SeaJay]

 

[SeaJay]

 

[IanB]

View attachment 1579416

That looks pretty sexy.

Can you get a socket on those back boost compensator lid bolts, or do you need to use a wrench? Is the lid threaded then? Which profile pin did you start with?

 

[SeaJay]

I didn't try a socket, used a 10mm wrench. I did have to trim off the unused threaded mounting point on the inlet manifold just above the air line fitting. I put the pin with the deepest cut in first, after chamfering the bottom first. Seems a bit too fuelled judging by the smoke, I will have to connect the AFR gauge and see what's going on

 

[mudgudgeon]

Nice.
How polished is the ground surface of the taper?

Can you post a pic of this?

 

[loucaojr]

View attachment 1579266

Hi,

Where did you get that spacer?

Cheers

 

[vwluv10338]

Nice.
How polished is the ground surface of the taper?

Can you post a pic of this?

I only bought one pin, the least fueling. I figured I could always cut it deeper. Here is the ramp. It's pretty smooth but could be better. It's not rough enough to catch a fingernail.

 

[IanB]

I didn't try a socket, used a 10mm wrench. I did have to trim off the unused threaded mounting point on the inlet manifold just above the air line fitting. I put the pin with the deepest cut in first, after chamfering the bottom first. Seems a bit too fuelled judging by the smoke, I will have to connect the AFR gauge and see what's going on

These pin grinds look to be all linear? As in a straight grind, not a curved grind?