Trick Flow Series R to Box R Upper Intake Road Block

Noobz347 · Apr 2, 2026

Question:

Why does it have to be adjustable?

Habu135 · Apr 2, 2026

Noobz347 said:
Question:

Why does it have to be adjustable?

It's not necessarily a question of whether the FPR needs to be adjustable or not, it's more about clearing the underside of the Box R intake. I also want to keep as many of the existing parameters in place/not change much, because the car ran so well before.

Habu135 · Apr 2, 2026

My plan is to remove the existing Accufab adjustable FPR and see if the Box R will sit flat on the lower intake. Ill also check hood clearance and see if the existing throttle body and power pipe line up correctly with the flat resting/in place Box R. If all those potential problem areas check good, then I'll grind a relief in the upper plate between the #4 fuel injector and FPR connecting points. Then I'll gently bend the FPR plate down, reinstall the Accufab and check for clearance. I want to keep as many of the old parts and parameters in place so as to limit any post install bugs I'll have to resolve.

Noobz347 · Apr 2, 2026

Habu135 said:
It's not necessarily a question of whether the FPR needs to be adjustable or not, it's more about clearing the underside of the Box R intake. I also want to keep as many of the existing parameters in place/not change much, because the car ran so well before.

Use a regular ole Non-adjustable regulator and shave half of the vacuum connector off.

I do the same thing for my Kenne Bell.

Habu135 · Apr 2, 2026

I think it would be too close and still require some bending of the fuel pressure regulator plate. I have to make up for the approximate 3/8" gap and still have room for the vacuum line. The oem FPR is not all that much shorter than the Accufab.

Habu135 · Apr 2, 2026

Actually, comparing the two....the non adjustable does look quite a bit shorter.

TOOLOW91 · Apr 2, 2026

I think a tweak in that mounting pad and what you have will fit fine

Habu135 · Apr 2, 2026

TOOLOW91 said:
I think a tweak in that mounting pad and what you have will fit fine

Little tweak.

Habu135 · Apr 2, 2026

While I appreciate the ease of tweaking that plate a bit, the underside looks to be housing the return line (back right portion of the plate). Suggestions from anyone on how to make this option work?

Pic is pulled from Ebay.

Habu135 · Apr 2, 2026

Non adjustable fuel pressure regulator is WAY smaller.

rednotch · Apr 2, 2026

Habu135 said:
What clearance work will permit this oem style fuel pressure regulator to fit under the Box R?

Take a look at post #17. I'm out of ideas how this could work without a huge spacer between the upper and lower intakes which would then require a cowl induction hood.

He ground clearance into the intake, he also used a non adjustable stock unit. Its all in the link i posted just the pics he had up are dead. I've done it with standard adjuable with twaeking the rail and clearancing the upper just dont have pics or the car anymore. Yours is kirban, not accufab btw.

Habu135 · Apr 2, 2026

rednotch said:
He ground clearance into the intake, he also used a non adjustable stock unit. Its all in the link i posted just the pics he had up are dead. I've done it with standard adjuable with twaeking the rail and clearancing the upper just dont have pics or the car anymore. Yours is kirban, not accufab btw.

Ok, I see it now. His comment about grinding the intake was under a photo bucket ad.

What work did you personally do tweaking the rail?

Kirban. Thanks. Came with the car on the old setup. Good to know.

AeroCoupe · Apr 3, 2026

The Kirban's are tall compared to others. I run an Aeromotive FPR and never thought to take a picture of my Kirban and it side by side. The Kirban had an issue so I bought the Aeromotive because i could get my hands on it that day. Turned out to be the diaphragm so I bought a kit and its in the cabinet as a back up. Both clear on my Edelbock Performer RPM II so I just never thought to do the comparison.

Anyhow, back to your situation. I would tweak the rail and move on.

Habu135 · Apr 3, 2026

AeroCoupe said:
The Kirban's are tall compared to others. I run an Aeromotive FPR and never thought to take a picture of my Kirban and it side by side. The Kirban had an issue so I bought the Aeromotive because i could get my hands on it that day. Turned out to be the diaphragm so I bought a kit and its in the cabinet as a back up. Both clear on my Edelbock Performer RPM II so I just never thought to do the comparison.

Anyhow, back to your situation. I would tweak the rail and move on.

Any suggestions for tweaking the rail? A leak will result in an engine fire.

TOOLOW91 · Apr 3, 2026

Habu135 said:
Any suggestions for tweaking the rail? A leak will result in an engine fire

Put it in a vice and try to roll the pad down a little with some force

A little fuel leak while testing after Isn’t going to cause some instant fire all you’d have to do is prime the pump a few times before you start it to check for leaks.

I posted pictures from an old thread in here where a guy got that rail to move enough to clear the same kirban regulator by a mile on a box r

TOOLOW91 · Apr 7, 2026

Any progress ?

Habu135 · Apr 7, 2026

I brought my car to my local transmission shop on Monday. Despite swapping out the VSS o rings, I've had a slight transmission fluid leak which started shortly after the T-56 install. Turns out the wrong VSS was installed. I should get the car back leak free by today or tomorrow, and then will start on removing the upper intake and addressing the FPR.

Update: car is leak free and safe back in the garage.

Habu135 · Apr 25, 2026

Worked on getting the troublesome Box R upper to fit under my stock height fiberglass hood (sans cross bracing). I was able to remove the adjustable fuel pressure regulator to get the Box R to sit flat on the lower intake, but the hood won't close with the 1" aluminum Trick Flow mating plate. I utilized a 3/8" spacer which is the thinest that will work with the stock fuel line connectors which otherwise will rub the belly of the Box R. So I'll need to have the 1" aluminum plate milled down to 3/8", or even better 1/4", but also add 1/2" spacers between the frame and k member when I install a tubular k member which will create problems of its own. Maximum Motorsports references these here:

Some considerations when installing spacers between the k-member and the chassis:
• Ground clearance may be reduced.
• The position of caster/camber plate strut shaft spacers may need changing to maintain the strut's proper compression travel and droop travel.
• Transmission mount may need modification to maintain proper driveline angles.
• Pinion angle may need to be adjusted to maintain proper driveline angles.
• Steering shaft will need to be extended slightly (easily accommodated by an MM telescoping steering shaft).
• Front suspension geometry may be altered, with possible consequences to the car's handling.
• A front-end alignment will be necessary.

All of this work is for what, 10-15 more horsepower in the high rpm range? I'm struggling with if it's even worth it.

AeroCoupe · Apr 25, 2026

If it is worth it then I would just put a 1-1/2" baby cowl hood on it and move on. All of that other crap is just a headache waiting to bite you in the ass. They do not look bad in my opinion but I may be a bit biased...

Habu135 · Apr 25, 2026

AeroCoupe said:
If it is worth it then I would just put a 1-1/2" baby cowl hood on it and move on. All of that other crap is just a headache waiting to bite you in the ass. They do not look bad in my opinion but I may be a bit biased...

I've tried very hard to keep the stock body lines and OEM look of the notchback. I was even surprised when I found a stock height fiberglass hood.

Trick Flow Series R to Box R Upper Intake Road Block

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Habu135

Habu135

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Habu135

Habu135

TOOLOW91

If you're the village idiot what's that make me?

Habu135

Habu135

Habu135

rednotch

I'd like to remain having one chocolate starfish

Habu135

AeroCoupe

lube between the nut and the face. I know my lubes

Habu135

TOOLOW91

If you're the village idiot what's that make me?

TOOLOW91

If you're the village idiot what's that make me?

Habu135

Habu135

AeroCoupe

lube between the nut and the face. I know my lubes

Habu135

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Trick Flow Series R to Box R Upper Intake Road Block

Stangnet Facilities Maint Tech... Er... Janitor

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If you're the village idiot what's that make me?

I'd like to remain having one chocolate starfish

lube between the nut and the face. I know my lubes

If you're the village idiot what's that make me?

If you're the village idiot what's that make me?

lube between the nut and the face. I know my lubes

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