Jump to content
HybridZ
Ben280

280z FP Build

Recommended Posts

I have no doubt it will hold up.  What I meant is to take it to the next level it's going to require some changes.  A big one I haven't seen anyone try yet is reducing the front scrub radius using struts.  I'm cheating and using a-arms.  Look at what BMW does with dual lower ball joints.  Or Ford and GM with a strut that has an articulated upright on the end (superstrut).  Technology has moved on, fortunately in prepared you can bring your car up to date.  That's what it's going to take to take the fight to Gorman's Porsche or some of the other cars.  As they say the first few seconds are easy.  It's those last few tenths that get very hard.

 

Ahhhh yes, I see what your saying. Yes the Montgomery/O'Gorman car is a mighty foe, don't think anybody besides Kiesel has been as dominant in a class. There was one guy in FP running a SLA front end and I wish I got a better view of it. Might be a good time to go back to school and get an engineering degree!

Share this post


Link to post
Share on other sites

Halloween update! Been progressing slowly, everything is out of the car and ready to slowly start coming back together. I noticed a small leak out of one corner of the fuel cell, and needed to investigate. Got everything apart and pressurized the bladder. Sprayed throughly with soapy water and couldn't find anything. I suspect one of the fittings wasn't tight and fuel could leak out in between the bladder and steel cell. While the cell was out it is a good chance to investigate my fuel starve issue. I've been using a ford focus SVT fuel basket, which has a small built in surge tank. I think the pickups were clogged and it wasn't refilling the tank, because at free flow the pump was pretty weak. Took about 15 minutes to fill a 5 gallon jug... I jumped the gun and was looking at new pumps, but decided I should flow test the pump outside of the fuel basket. Night and day difference, was able to do a gallon in 45 seconds, so just under a 255gph pump. Looks like that will be staying with the car. I ordered a Holley Hydramat to replace the teeny factory pickup. It's a 3x15" version, and should let me run below 6 gallons in the cell pretty easily.

 

Working on my "To-Order" list so I can get everything headed back into the car! Right now it looks like a new shifter assembly for the 240sx trans, velocity stacks and a filter. 

Share this post


Link to post
Share on other sites

Oh man, where to start! Left you guys hanging here, and months later the car is back together and running! Lots of stuff happened with no photos, but I’ll try to give you the high points.

 

We left off when the original 2.8 had blown up and I had found a new engine. A 13.8:1 Rebello auto-x engine in a friends car and 240sx transmission was going to make an excellent upgrade to this machine!

 

JCfcgRN.jpg

 

XvuOEgO.jpg

 

A big fixture of this rebuild was the ITB’s! Thanks to the HybridZ classified section, I scored a set of OER ITB’s that used the FC RX-7 injectors that I was using already. I had to get ahold of a new manifold, and sourced a Kameari unit from a yahoo Japan auction. Once I had that piece I was able to get runner lengths and found that the 75mm Techno Toy velocity stacks were going to give me a good powerband with optimal induction wave at 5500rpm.

 

m8VEJcC.jpg

 

bSDKKvO.jpg

 

My excitement to blow up the new engine by not running filters was super minimal, so I was off to find a good filter scenario that would with with the fuel rail. Most of the traditional carb filters have interference issues with the rail, and I didn’t want to run the sock filters that most ITB’s require. ITG is a top name in the filter game, but their traditional filters weren’t going to work. Luckily some searching revealed that they make a “Sausage” style filter, which is curved for a more clearance. I also found a company in the UK called Reverie that makes carbon airboxes for formula cars. Fortunately for me, lots of the stuff they make fits on inline 6 formula cars, so I was able to pair up a couple custom UK pieces to keep this engine rolling!

 

krZDDKo.jpg

 

Also had to figure out getting MAP signal from the ITB’s. The Megasquirt ITB tuning mode uses MAP pressure up to a certain percentage, then switches to AlphaN/TPS position. I got ahold of a vacuum log/accumulator that I can run all 6 ITB’s into, and get a good MAP signal up to about 30-35% throttle.

 

IDQ2vUi.jpg

 

Was also able to spend some time working on the exterior and maximize my aero allowances! Rules say I get 10” of spoiler, so I’m taking everything I can get! Using NASCAR truck spoiler adjustment rods, pretty excited about how it turned out. Also added Techno Toy Tuning tow points for ease of recovery! Not that prepared cars ever break down ;)

 

KNw9pv1.jpg

 

Finally got the whole rig running over the weekend, and it’s idling nicely! Syncing the ITB’s was an essential step, needed to get a snail gauge on it and get everything working well.

https://youtu.be/MS7ahQA511E

Share this post


Link to post
Share on other sites

I've been looking at buying that same Reverie item - I imagine the quality of quite good? The price is certainly very fair right now with the exchange rate!

 

Really like the look of the sausage filter too. I bet it makes it much easier to maneuver the filter on and off, while also giving more clearance.

 

Great job!

Share this post


Link to post
Share on other sites

The Reverie piece is really nice. My one issue is that the #1 and #6 stacks sit really close to the edge, and on mine I had to file down the inner radius to get them to sit flat. As a general work of caution with it, make sure you have a way to get to the velocity stack hardware! I had to use allen button heads with a ball ended allen wrench.

 

The sausage filter is awesome and very easy to fit! I'm excited to do an on/off dyno run with the filter. 

Share this post


Link to post
Share on other sites

Thanks for the info!  Clearance shouldn't present too much of a problem - the EFI Hardware air horns I use have a separate flange, and then a set screw holds the horn into place once slid in.  Solves some mounting headaches.  Right now I have an ITG Megaflow JC100/65 mounted onto a grommet secured backplate.  Your solution is tidier and more secure though!

post-29570-0-17499600-1486526661_thumb.jpg

post-29570-0-82626400-1486526859_thumb.jpg

Share this post


Link to post
Share on other sites

Man been a while since I updated. Must be having too much fun racing to post here. For those who don't know, following BrokenJawRacing on instagram and facebook will get you SLIGHTLY more frequent updates, and sometimes a video if I can manage it. 

 

Since we last hung out, well, lots has happened. Firstly, got the car tuned with the ITB's. English Racing in Camas WA has been my go-to shop for this for the past couple years, and they did a great job getting it set up out of the box. Put down 223whp and 200tq. For comparison, we popped off the filter and picked up 4hp and 3tq, but I think the longevity of the motor is more important than a pretty minor HP gain. 

 

First couple events of the year were wet, so we couldn't even make use of all the power. The car did earn a new nickname while it was wearing some street tires, and now has a "hovercraft mode" if it gets too wet outside. First dry event that we had with even a slightly warm/grippy tire and we broke the u-joints in the drivers side halfshaft. These were recently rebuilt with good MOOG joints, so I was a little disappointed that they failed so soon. It was a good excuse to buy the Wolf Creek Racing CV kit, especially considering the next event was in California on even grippier concrete. 

IMG_8526.JPG.a709d046992ec1b0623a32c5866c473d.JPG

Hovercraft mode with some 15x6.5" 240sx SE wheels on the car

IMG_8529.thumb.JPG.250a727bc1a86f9215170cd632d4db00.JPG

Dry weather = broken u-joints

IMG_8592.thumb.JPG.7717475029f9f038eeba4d141f65c4db.JPG

Futofab kit, mmmmmmmm shiny

 

The Crows Landing event was a lot of fun, if a bit stressful. Had some early issues with the tune, since I was finally able to run at wide open, I found that the tune was loading up and dumping way too much fuel into the car. Once we leaned it out it ran great. The ITB's are funny, and require a fair bit of maintenance to keep optimal, particularly as weather/barometric pressures change. Also ran into a fuel pickup issue, where the fuel cell foam caused the holley hydramat to sit on top of the fuel when its around 3 gallons. Once all those got figured out, it was just a matter of running the course and keeping up with a very fast XP field. 

 

IMG_8669.thumb.JPG.0318e4fb434d13c1496833d9b99ea6cc.JPG

Crows Landing NASA Test Facility. Best concrete on the west coast

 

The rest of the season went pretty smoothly. Sticky, hard throttle cable got replaced with a custom Pegasus piece, perpetual tuning and fiddling with the ECU and ITB's, it will be interesting to see where the car sits when I bring it in for its annual baseline this winter! The Packwood NT and ProSolo were a lot of fun, did well at the tour, managed to hang onto the back of what I think is the car to beat nationally in the class. The Pro was fun on its own, didn't place well, but the R2 category is one of the hardest classes IMO. 

 

IMG_8949.thumb.JPG.5a52fe0d2f6a280cf413e7086ae2fc61.JPG

Fixing the throttle cable at the Packwood ProSolo, with the PRE Evo behind us.

IMG_8948.thumb.JPG.4854e3bf503d235c716c962975511fa8.JPG

More of the field for the ProSolo, K swapped Lotus and FD RX-7 with a monster turbo. The FD driver has been a national champ more than once with that car.

 

This winter has been "light" on the upgrades, compared to the past two years. The major outline is to change out the Arizona Z Car struts for Koni double adjustables, and build a new exhaust. Lots of other little maintenance projects and cleanup as well, but those are the highlights. Excited to get the car back on the ground soon, and see where these changes put me! 

Share this post


Link to post
Share on other sites
On 1/5/2018 at 5:31 PM, seattlejester said:

Yay an update!

 

Have you had any problems with the foam deteriorating in the fuel cell? Hope to see you out at the autocross this year!

 

 

So far, I haven't had any issues with the fuel cell foam. However, I have only used clear 92 and VP 110 gas. When I spoke to the people over at Fuel Safe, they said that any ethanol content at all would cause problems.

 

I'm trying to get up to one or more of the Bremerton events this year, although we had an event at the end of last year at Packwood where myself, zredbaron and JonMortensen were in attendance! Need to coordinate a big Z autox weekend at some point. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×