OMP TRS Seat Installation, Planted Seat Bracket
 

Posting this information hoping it will help someone else out there that is looking for or thinking about a seat for the 350Z track day car.

I decided a few months back it was time for a better seat for track days. After trying out a few different seats I decided on the OMP brand, and decided to go with their entry level TRS seat. It is not as comfortable as the HTE seat I tried, but for 1/3 the price of the HTE I don't expect it to be. I have not spent much time in it as I just fished the installation but so far I am pleased with the fit, comfort.

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I tried to read other peoples reviews, recommendations on what bases and seat brackets would work best. I chose the OMP side mount brackets (low mount version), as well as the Planted seat base (low version as well). I am 5' 10", wear 36" waist jeans, and 210 Lbs. I do not need to sit that low in the car to have clearance to the ceiling for my helmet. So I was just hoping that this combination of low mount side brackets and low mount seat base would keep me at stock seating height or maybe a little lower.

First installation attempt, I bolted the Planted seat bracket to the car to see how low it really did sit in the car. It bolted in nicely with everything lining up just fine. At first glance I was impressed with how low it sat in the car. However, I noticed that on rear, right hand side of the bracket instead of including a locate hole to accept the locate pin in the floor they built the bracket around it actually pushing the seat base up about 1 1/4" higher than it could be.

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I was not that concerned at the time so I proceeded to mount the OMP side brackets to the Planted seat base. I was surprised to learn that even though Planted claims their seat base works with several different seat suppliers, the OMP seat brackets did not line up to a single set of holes on the seat base. So, first challenge was figuring out what location to set the OMP brackets up at so I could drill the required holes to mount the seat brackets to the base. I found that the rear slotted center holes on the Planted seat base would work fine for the rear of the brackets, centering the seat directly behind the steering wheel. Once I fixed the seat brackets to the seat base in the rear using these center slots, I marked where on the seat base I needed to drill new holes to be able to bolt the seat bracket to the base in the front. My first set of holes had the seat about 1/2" to 1" closer to the steering wheel than I liked, so much later I went back and added two mores sets of holes (1/2" back and 1" back from first set) giving me 3 locations to choose from.

Once I had the OMP side brackets mounted to the Planted seat base, I noticed that the rear of the OMP seat bracket had 6 holes for adjusting height and seat angle. However, in the front there was only 2 two holes for selecting seat height the lowest of which still left almost 2 inches between the seat bottom and Planted seat base. So, I proceeded to mark and drill one more hole on each side giving me a total of 3 holes. I bolted the seat to the 3rd hole that I had just added and the second to lowest hole in the rear (seat would hit the base so could not use the lowest hole in the rear).

My first test fitting of the seat was actually not bad at all, the seat was centered behind the steering wheel, angle of the seat bottom was good and was only 1/2" or 1" closer to the steering wheel than I would like. I was able to take the car for a test drive like this and it was not bad, worst thing was that even though I was using the lowest possible settings on the OMP seat brackets, the seat was still 3/4" to 1" higher than my stock seating position.

After further inspection of the clearance between the rear section of the Planted seat base and the floor that is when I decided to cut the rear feet off of the Planted seat bracket. I was able to take 1/4" flat stock and weld on new rear tabs to set the seat bracket even closer to the floor, 1 1/4" closer actually. On the rear, right hand side I simply added a hole for the locate pin like Planted should have done in the first place. At the same time I also went ahead and added one more set of holes in the front side of the OMP side mount brackets to be able to lower the front of the seat another 1/2" as well.

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After these adjustments the seat now sits 1/2" - 3/4" lower than the stock seating position. This is using the 2nd set of lower holes I dded in the front and cutting off the 1 1/4" high rear tabs and replacing them with the flat tabs. If anything from this position I might adjust the seat up a notch or two but for now I will leave it as is.

One final note, the Planted seat bracket also comes with a tab on the right hand side to mount the factory seat belt buckle to.. All fine a dandy except that they made the tab too tall, You can get utilize the factory seat belt as you can see in the photo below, but they sure make it a PITA to buckle it on the other side. Later I will cut that tab off as well and weld on a shorter one so it is much easier to get the buckle through the sot and buckle the seat belt.

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Wow. You were way too happy to modify that bracket. I was pretty pissed when I went to install mine and found the same problems. I thought a $200 bracket should have been engineered right from the start.

Agreed, I paid $140 for the Planted seat base and agree completely it should have been designed correctly from the start. However, I have yet to find a single example of one that does fit correctly from the start for the 350Z. Do you have experience with one that does? That would be great info to share for those like me that were looking for one.

All I had to go from was all of the information I could find here searching, plus the experience of many at the track that told me to just have brackets custom made as most of these off the shelf seat bases, brackets never fit like they should. I have seen this 350Z Planted seat bracket recommended by a few senior members on here that appear to have a lot of track experience and hands on experience so I gave them a try. I posted my results so hopefully others can do the same or avoid them, their choice.

For me it did not cost anything to modify the seat base or brackets as I had access to the tools and scrap metal to make it the way I wanted it. Only took me a few hours to get it done. Now I am working on getting a custom roll bar installed and some harnesses. Hopefully will have that done in the next month or two, depending on when the shop can work me in to their schedule.

I haven't got experience with them but the Wedge Engineering brackets are supposed to work out of box on the 370 at least. I've been meaning to see how close the floors are on the two and see if I can temporarily use the seat from the 370 in my 350. (My guess is no) :

I wound up having a custom mount made myself. Good luck on the build though!

Thank you for the detailed writeup! Very helpful

I can speak from personal experience the floors in the 350 and 370 are way different. I just finished a 370Z Nismo track car build with some coworkers. We have the OMP HTE seat, OMP side brackets, and bought the OMP seat base for the 370Z. We had to modify the OMP base as well because it sat way too high in the 370Z.

Planted makes omp bases. They are the same thing. I'm gonna do this to mine. I was thinking bout it and now that I see this I'm going for it.

Nice write up. All very frustrating to me as I am 6'4", need a racing seat bad, and only barely have enough room in OEM seats. Anything taller or closer to the steering wheel and I will not fit.

Sounds like custom brackets might be in order for me. Where do you go for that sort of thing and how much would it cost?

I have a friend who welds and does fab work but I would not want to ask him to take this on because he is pretty busy with his own car ('67 Mustang Fastback). But, if I could get the materials, design the bracket and have everything cut and ready to go I wouldn't mind asking him to weld it together. What type of metal stock do you need for this job?

The Planted seat base is made from 3/16" thick steel. I mentioned that I used 1/4" for the new mounting tabs, but when I double checked it was 3/16" also. My seat mounted in the car is very rigid, such that I can grab the seat and rock the car via the seat with no visible movement of the seat assembly. If I was going to make my own I would say 3/16" is fine for the base material.

The set up I have is basically laying as flat as it can be and still using the stock mounting locations. In the rear the OMP seat is basically touching the seat base, I actually have one more slot of adjustment but can not use it because the seat will hit the base. This setup is about ~1" lower (hard to measure) than the stock seat. Like I mentioned it was ~1" higher, but cutting off those 1 1/4" rear mounting tabs and making them flat then sliding it back another 1/2" added some more vertical room since the base is on an incline (seat drops down as it slides back).

A friend of mine that also has a 2003 350Z track model test fit my seat this week. He had is OEM seat mounts lowered several years ago by a shop in CA. He thinks my OMP seat is about the same height as his lowered seat. In my car he has about 3" between his head and the ceiling losing about 1.5" when he wears a helmet. His legroom was ok but he said he might want to move it back another 1/2" if it was his seat. We concluded that for him he would probably want to go a different route and have the seat mounting area modified with custom brackets made to get a seat to sit even lower for him.

Thanks for posting this idea. Worked perfectly for my drivers side rail.

The pass side rail in crazy high up, took alot more work to get it low like the drivers side. Had to notch out the planted bracket on the sides and re-make all the mounts. Its on the floor now.

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Nice write up

Didn't you guys know, the more it costs, the worse it fits? Race car 101. lol. I made my own brackets for my Sparco Evo seats. It was a PITA, but it looks like the same difficulty as what you have, and I didn't spend any money on it.

Why use the side rails? The seat I'm looking at has mounting points both side and bottom. To save weight and possibly head room I was planning to mount my seat right to the base using the bottom seat holes. Did yours not have bottoms? Would it have been way to low?

Most FIA seats are side only, but you can get the seats lower with side mounts. Bottom mounts must be on top of the bracket, while sides can be as low or touching the actual seat bracket.

I'm looking at this seat now (which is bottom mount also) and corbeau forza sport. Both FIA and both have bottoms and side mounts. I understand they must be on top of the bracket but the side mounts have to sit on top also as everyone's shown. So you're gaining weight with the extra side bracket and I don't see it being lower since the bottom holes in the side bracket are still elevated above the base mount.

This is a steel frame seat that is still FIA approved. Composite shell seats can only be side mounted which I think may be what you are referring to. 2 different animals there.

I realize that.

You are correct about mounting of the side brackets, but the seat can go below / in-between the side brackets. Making it lower mounted than the bottom mounted version.

In my case I had both bottom and side mounts on my OMP TRS seats.

I went with the side mounts because the side mount brackets give you easy adjustments for adjusting height/tilt of the seat once you have the base mounted the way you want it. I have used the adjustable side mounts to change the height of both the front and rear of the seat a couple times following a couple different track days recently to see what seating position is the most comfortable for me on track.

I think I get it. So the bottom mounts are probably flush with the bottom of the seat but the side mounts with rails allow the seat bump to sit down in between the base hole which is lower than the bottom mounting holes? I guess it all just needs to be bought and tested with what works best for that person.