1,600 pounds and LS power!! Brunton M-spec

[Cobra 498]

why do i have the feeling that thing would like some downforce...

410 Sprint car wings front and rear would hook that brute up, just put smaller equal size end plates on.

[subtlez28]

Hi Shaun,
looks like Euro Lotus 7
Will be killer if you autoX
Very cool project !
Black steel wheel looks like Nascar style, very nice choice imho
Very nice
Gil

Thanks Gill.

Correct, this is a Lotus 7 replica of sorts.

why do i have the feeling that thing would like some downforce...

Because you are a wise man. That is already on the agenda for next year. Some existing fast track cars like mine with LS engines need the wings.

410 Sprint car wings front and rear would hook that brute up, just put smaller equal size end plates on.

Funny you should say that. The LS3 Stalker that inspired me to build one had a sprint car like wing (and a former sprint car driver).

[subtlez28]

I've been a bit neglectful of my build thread. Sadly, I am not yet racing the car, but I have made some progress of late.

One day, for inspiration I slapped on the hood and some of my magnetic racing numbers (that will be of no use to me on the fiberglass and aluminum skin).

The bad news is the classic hood, does not clear the pushrod suspension...

A racer friend of mine came up from Chicago to align the car with me. So down from the tables!

This one is fuzzy, because I took it quickly with my cell phone. He was more than a little nervous about me stepping back for a photo op at this point!

Down safe and sound, time for a fun (giant wheel-stand) photo!


Got it aligned, but... I chose the middle height points for the control arms. With the oil pan being the low point... I could not run over a 2x4 laid flat with my 23" race tires... Doh, one step forward, two steps back seems my pace...

So, I had to take the whole suspension off and go to the highest (lowest pick up points - still not very high) settings. Now I need another alignment....

I was inspired by having my number on the car, so I had the side panels vinyl wrapped and added the 228 placards and "AR" for my class (A-Race).


Then I installed the side pipes and see they are a little close for comfort to the vinyl. I bent out the passenger side as it had even less clearance. Time will tell. I'll keep a fire extinguisher handy when I start her up! May need some heat wrap. Open for suggestion here.

As you can see, we also started the wiring. Since I decided to keep the air intake on the shelf, my battery placement was compromised. I wanted it under hood to avoid extra safety equipment. The solve was to recess it into the shelf, and actually bolt it to the passenger side of the trans tunnel. I used an Odyssey battery and their aluminum box. I suggest you go direct with them, they were a pleasure to deal with and give a great direct price!
http://www.odysseybatteries.com/main...ccessories.htm
I'll get a pic of that up when I finish up the wiring.

I went with Speedhut's new CAN-bus style controls that pick up signal from the ECU, eliminating the need for extra sending units. I also ponied up for the GPS speedo. It has all kinds of cool toys like 1/4 mile times, 0-60, etc and will not be effected by differing street and track tire sizes. I chose to have the fuel gauge in the speedo. This should be cool watching one go rapidly down, while the other climbs! You can fully customize your set up. I went yellow. Hey, they look good on a Ferrari, and more importantly should be easy to see.

The blue tape was to protect the dash panel, but may have to stay. I dig the contrast!

Another friend of mine, who happens to be both a car nut and engineer has been invaluable with the electrical. Starting from scratch with just a painless T-bucket kit was a bit overwhelming.

So, as per past practice, another issue bit me. We added the radiator and struggled a lot to build hoses to fit the tight chassis. After paying for a bunch of AN stuff that would not clear, we ended up with heavy duty industrial hydraulic type stuff. The local industrial hose shop was a huge help. We filled it up with Evans water-less coolant. I come back from a few days of vacation and find some coolant on the floor. Just a couple drips mind you, but more than I would expect with all new parts... There was a pin hole near the welds on the tabs.


After I quite sobbing, I tried epoxying it. However, not wanting to take 2 steps back, I tried to do it in place with out draining the coolant. That didn't work. The coolant made it's way through the epoxy and formed a new pin hole... twice! Today we drained the coolant, wire wheeled off the epoxy (Quick Steel) and re-did it without coolant. That seems to be holding. Wish me luck!

[subtlez28]

IT LIVES!!!!!

https://www.youtube.com/watch?v=sobX..._kMmdjWGE23FAQ

Just need to tie ups some electrical stuff, fit some body work, and get it aligned!

Lets go racing!

[CruizinKev]

oh nice!!!

[subtlez28]

So, I had the car running... I somehow resisted the urge to street drive it... But Friday I trailered it to an empty lot and drove it a bit. What a thrill! I was very happy with everything, really. I loaded the car on the trailer under it's own power. The LS engine, T-56, LS7 clutch, and Speartech harness all did their jobs flawlessly.

I do not have the rad fan wired yet, and only had the catch can zip tied in. The only issue I had was the catch can leaking a bit. Have to solve that by Saturday and get the hood on it. It is time to go racing!!

https://www.youtube.com/watch?v=DXXW74z_GX0

The lot was freshly sealed, and I didn't want to get in to much trouble, so I took it easy. I still managed to get asked to leave. Damn Hot Rodders! It felt about like driving in the rain traction wise. I cannot wait to hit the road course!

[andrewb70]

So, I had the car running... I somehow resisted the urge to street drive it... But Friday I trailered it to an empty lot and drove it a bit. What a thrill! I was very happy with everything, really. I loaded the car on the trailer under it's own power. The LS engine, T-56, LS7 clutch, and Speartech harness all did their jobs flawlessly.

I do not have the rad fan wired yet, and only had the catch can zip tied in. The only issue I had was the catch can leaking a bit. Have to solve that by Saturday and get the hood on it. It is time to go racing!!

https://www.youtube.com/watch?v=DXXW74z_GX0

The lot was freshly sealed, and I didn't want to get in to much trouble, so I took it easy. I still managed to get asked to leave. Damn Hot Rodders! It felt about like driving in the rain traction wise. I cannot wait to hit the road course!

Pretty awesome Shaun!

You need a lightweight clutch in that thing, that will really make it up!

Andrew

[Tig]

Its alive bwahahahaaa.

Man that is awesome. Looks and sounds amazing.
Did read somewhere that it has 500whp? Good lord that must be a blast to drive.
Lookin forward to seeing you get a deeper into that go pedal.

[Gil]

Come on, It's not an oval track car. Turn clockwise now !

This beast is awesome, beatiful work !

Gil

[FRENCHBLUE72]

Very nice any track time yet?

[subtlez28]

Pretty awesome Shaun!

You need a lightweight clutch in that thing, that will really make it up!

Andrew

Thanks! Yes, if I hadn't already had the LS7 set up... Should be hella reliable though!

Its alive bwahahahaaa.

Man that is awesome. Looks and sounds amazing.
Did read somewhere that it has 500whp? Good lord that must be a blast to drive.
Lookin forward to seeing you get a deeper into that go pedal.

Should be north of 500 flywheel horsepower, based on similar combos out there. I'd like to do a chassis tune to get a number. Maybe over the winter.

Come on, It's not an oval track car. Turn clockwise now !

This beast is awesome, beatiful work !

Gil

LOL, I got kicked out before I could try...

[dangina]

love the car and would love to build one someday - looks good in black!

[subtlez28]

So, bad news first. We got rained out on last Friday night, so we didn't get to run down the drag strip. Times are coming though, I promise!

That was actually ok, as I worked on the car until after midnight (before the road course) fitting the hood and tying up last minute things. I ran without the rear body work.

Good news: perfect weather on Saturday for our High Speed Autocross. As expected, even though this was literally the first time I dove it other than rolling around the parking lot, I found the confidence to push it right away! The car is obviously capable and surprisingly forgiving.

It was the third fastest car there, behind a heavily modded GTR (no real hope of catching him), and a LS swapped - well sorted and moded Datson 240Z (driven by a very skilled and experienced driver).

The form of racing I do is called High Speed Autocross. We run on ~2 mile road courses, from a stop, one lap for time (no cones).

http://www.mcscc.org/autocross.php

The car ran a 1:19.760. To put that into perspective, my fastest time with my old 02 Z-28 was 1:25.809, and I ran a 1:24.839 with a 2012 ZL-1 (580 HP Camaro).

I have some video. I will edit and put something together when time allows. Though it does not capture the excitement as it looks pretty low drama with slicks.

This thing hauled. Enough power on tap to light the tires in 4th gear meant busying myself with shifting much was not needed. It also helped me keep the rpms down for the maiden voyage (don't think I was taking it too easy though).

Going ~130 mph with no windshield was quite the rush! I know better understand the chin strap as the wind wanted to rip it off my head!

I absolutely love the manual steering! I finally understand what the car review guys mean when they say they can feel what the tire is doing through the wheel! I am strongly considering a move to manual brakes for the same reason.

As far as teething issues, there were only a couple. I discovered another pin hole in my passenger side header (at a factory weld...).

With the 23" slicks, I ran the track in 4th and 5th gear (needed 5th). I think I will move to taller slicks. Shifting into overdrive (5th) was not as speedy as the other gears. And the vague CTS-V shifter might not be helping that. Just stuff to refine.

I also started experiencing a bit of front brake lock up in fast corners (like the 130 mph one at the end of the front straight). Not so much at weight transfer. I'm used to ABS cars, but that wasn't my mistake. It happened late in the braking. The proportioning valve is already allowing full pressure to the rear, so that isn't the issue. I may try a more aggressive rear compound and taller slicks for the next event.

Long term I think I will go with race style manual brakes with split masters and a balance bar.

Another issue was temp. According to my Speedhut CAN-BUS (reading through the OBDII diagnostic port) my LS (stock 195 thermostat and water-pump) was running 210-220 moving and as much as 240 sitting still. Not sure if this is normal with the Evans waterless coolant, the gauge is off, or if the fan is just not able to keep up (puller). I may swap to a larger, pusher fan.

I'm rambling a bit. I look forward to any feedback or conversation on my results.

[subtlez28]

The right lane trap mph was not working. Lets see who can guess what number I am...

I went to a test and tune Weds with some friends.

I spent the first couple hours trying to diagnose a no-charging issue. Ultimately I gave up, charge it w jumper cables, pushed it through staging and made a run. Oddly after the run it started charging so I made a few passes.

I swapped out my 23" Hoosiers for some 25.5s. Not only do they look bad @$$, they allow me to run higher speed in fourth, avoiding using overdrive like I had to at BHF.

I ran 17 psi. I imagine it would have liked less pressure for drag racing, but really not what the tires are for. I also passed on the burn out since I am having issues with reverse...

My friend took a decent video that I will try to post soon. You can hear the poor Hoosiers begging for traction pretty much the whole way. I really couldn't go full throttle in 2nd (the gear I launch in) without burning off the tires. Third was also touchy.

I was short shifting an bit, which might explain the lower than expected trap speed.

Point being there is plenty left in it!

I also did a low speed autocross. It was in an oval track and infield, so it was pretty tight. Not ideal for such a powerful car. It also tended to push badly in low speed corners. I think this is a scrub issue, as the 15's I am running require spacers, so they are not optimal offset wise.

I also experienced front lock up again (running the 23"s).

I have one more high speed event in October. I am hoping the taller slicks help. I do not have time to do much with the brakes before then.

The off season will be the time for brake and oiling revisions.

[HellPhish89]

how to hook up ~670hp per ton... hmm... time for taller tires..lol.

[chevyz240]

This is a pretty cool, bare bones type of car! It's hard to beat the power to weight ratio! I had a similar Seven replica, it had a 4 liter BMW V8 with a centrifugal blower. 420 horses and 1850 lbs dry weight. Does your car really weigh 1600 lbs?





Driving video: https://www.youtube.com/watch?v=FJAZlsxYJq4

[subtlez28]

Sorry, I did not see this reply earlier. I'm told the Brunton Demo car with an Iron 5.3 weighs 1600. I have not scaled my car but hope for less with the aluminum block 6.2. Though I do run a heavy clutch and steel wheels. So it may be a wash.



I will post an actual weight soon I hope!

[subtlez28]

So, I've been a little neglectful of updates to my build. Over the winter I had to pull the car basically entirely apart. I had to have the T-56 repaired. That meant pulling the engine, which meant pulling the interior, bodywork, steering , exhaust and part of the front suspension.

The good news was with the engine, shelf, scuttle, and side panel out of the way, I was set to update an area I was not entirely happy with (brakes and pedals).

After much thought I took a chance on Wilwood's dedicated pedal set up. I felt this was an area worthy of improvement. Firstly, I was experiencing front brake lock up that I could not work out with the adjustable proportioning valve (limiting pressure to the rear). I was also skeptical of the need for power brakes on the car. I was already in love with the manual steering, and wanted similar feel and feedback in the brakes. I also like the spartan nature and effort required to hustle the car around.

Anyway, I probably should have taken better pics of the original set up. I was never truly satisfied with the pedal placement. Original set up included a Wilwood pedal for clutch, another for brake, and a custom set up from Brunton to allow a lot of accelerator pedal travel to actuate the "fly by wire" pedal/sensor, that was mounted up on the shelf. Their set up worked, just like I said, room for improvement.

Here is the Wilwood pedal set up. It looks and feels more race car now!

I did have to move the pedals rearward to clear the trio. I moved the seat back to compensate, and am overall happier.

The main draw was going to manual brakes, and divorced two master cylinders for the front and rear brakes. This also allowed for a balance bar to further tune the bias. Willwood's tech line guy was extremely helpful! At his recommendation I went with a 3/4" front and 7/8" rear master cylinder. I kept the original wildwood master cylinder for the clutch (in fact we kept the hydraulics in tact with the motor pulled to avoid the pain of bleeding again). Engine out allowed for much easier brake line modification as the brake masters (Wilwoods new mini masters) were on the floor rather than the shelf.

I relocated the accelerator pedal for the LS engine harness to under the shelf also. We were able to work out a ratio that allows 6" of accelerator pedal travel. A must to modulate the arguably overkill (no such thing) power level.

[subtlez28]

Part of my brake upgrade also called for a cool kit I found at Flyin' Miata. They machine Wilwood 4 pots to accept an integrated emergency brake. This was a double score as I wanted more brake power, and the OEM Miata calipers oriented the emergency brake toward the tub of the car. The FM kit had the brake cable run straight toward the inside (perpendicular to the rotor).


I am impressed with the machine work on the kit. I was also able to upgrade to the slightly larger (but still cheap) Miata "sport" rotors.


The pretty purple anodizing didn't really fit my style, so I rattle canned them black quick prior to installation:


I also took the chance to install some longer ARP wheel studs. They went in with the hub in place (there is a relief cut out) which was a huge relief (see what I did there?!). I also needed the longer studs. I have to run a 13mm spacer on the front and rear to get the steel wheels to clear the beefy Wilwood calipers.


I am now running Wilwood BP20 pads front and rear. So far so good. No issues with fade whatsoever (during 20 minute HPDE sessions). Gotta love light cars!

[subtlez28]

Another off season add on was to add some oil control. I had not yet noticed an issue, but guys with fast C6 vettes and another Stalker owner have found the limits of the Corvette pan's baffling. Improved Racing makes a set up to help with this. I figured it was cheap insurance. I considered an Accusump (in fact I have a whole set up I purchased for another LS racer), but for now I want to avoid the complication and room it would consume.

Of course I put off the undesirable task of dropping the pan until the day before my first event of the year (an HPDE at Blackhawk Farms).

The Improved Racing baffle can be purchased with a crank scraper/windage tray for the 6.2.



While I was at it I squirted the white cowl black w Plasti-dip (love that stuff) and threw on the seat covers (I raced it last year with bare aluminum seats). Looking sinister!



I completed my first HPDE on Saturday. I had not done an HPDE before because I thought I would miss having the competition of lap times (like the full course HSAX - Time Attacks I do). I am hooked! Tons of lap time for the money, and passing is addictive!!!

I then competed in the HSAX at Blackhawk Farms on the following Monday (Memorial Day). I set fast time of day (admittedly the crazy fast cars from the club weren't there like the 1,000 HP GT-R, LS swapped Datson or race ready Evo)!! A friend snapped a pic of another friend of mine (and alignment guy) who co-drove (I was #228, he was #288 ). This time he didn't embarrass me by setting a faster time (in my car), like he did in a low speed autocross last fall...