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

[coolwelder62]

Very Cool.This thing will be a Monster on the track!!!!!!

[subtlez28]

Very Cool.This thing will be a Monster on the track!!!!!!

Thanks! Yes, I would love to get the build done and start scaring myself with it on the track and street!

We have made a small amount of progress since the last update. We installed the front suspension (again) and plumbed the brake lines:



It feels good to be permanently installing panels as apposed to the mock up stage.

I hope to make some more strides int he next couple days.

[subtlez28]

We've made some more headway, I will try to catch up.

We connected the aftermarket braided clutch lines to a factory style hydraulic throw out bearing (like an 02 Z28). Because I am using a CTS-V T-56, that came this a thicker, dual-mass flywheel, I had to space the through out bearing away from the trans. I used a piece from Katech (they are getting a lot of my $ on this build... ha). Hopefully everything works out, but I wont know for sure until I add fluid to the clutch hydraulics. I am avoiding adding any fluids now, in case things need to come apart again.


I also learned that the CTS-V T56 bell housing is longer than the F-body bell housing. We had to make room for the new hydraulic lines by nothing the CTS-V bell. This was pretty straight forward with the aluminum.


In other trans news, Brunton suggested removing the three bolt flange from the CTS-V T56 so a traditional slip yoke could be used. They also suggested I cut off the alignment dowel. I, wrongly assumed (possibly because I was told...) the output shaft would have the same spline count as an F-body unit, and the F-body rear seal would work if using a slip yoke. Wrong on both counts... The guys at Brunton are working on a custom drive shaft and seal.



I have also since learned the new Camaros also use this three bolt flange. Unfortunately, custom driveshafts are still kind of pricey for the flanges or require adaptors to use more traditional units. So, by converting to slip yoke, hopefully I am saving some money. More on this topic later.

We dropped the engine and trans back in. I finally opened the box for the custom rear CV axles from the Driveshaft shop.


I opted to have some new bearings pressed into the donor Miata rear spindles. I guess that was a good choice as the shop had difficulty getting them together. My rear suspension can now go on.


I noticed the other day that the hubs really fight being turned despite the fact there is no driveshaft connected. I'm guessing that may be the new bearings... Is that normal? I can turn them, but it requires some effort! The diff itself is new, but I couldn't really turn it until the axles were installed. I may have to pull some stuff apart and investigate...

With the engine in, we bolted up a header, and made up the steering linkage. This was big for me. I can now sit in the car, shift the trans, work the pedals (except accelerator, which isn't in yet) and turn the wheels!!


I picked up a pair of front tires and had them mounted up. It is great to see a wheel and tire on the car!


I intend to run a separate wheel/tire combo on the road course (15s and race tires). So, I have been contemplating running 17" drag radials on the back for the street...

I remember reading a few years back how guys were auto-crossing f-bodies on 315 drag radials front and rear (due to lack of availability of good 315s I think). I know the idea of the softer side wall would work against handling but I have a few thoughts on that.
1- This is a very light car so a softer sidewall wont be as big of a deal as a heavier muscle car.
2- I'll be finding 9 and 10/10ths cornering on track, but will likely keep it more civil on the street. And acceleration runs may be the more fun, and safe thing for street driving (and scaring passengers).
3- I will then have my drag combo to drive down to the 1/4 track for kicks.

I would like any feedback on that idea. Especially from guys running DRs on the street, and even more so if in a similarly light car.

I have not yet committed to the idea, but my thought is 275/40/17 drag radials since I already have 17x9" wheels.

[BuddyP]

That is going together so nice!

[pist0lpete]

Shaun as light as that car is I am not sure a softer sidewall is going to net you all that much anyways. Nitto makes a 555R2 with the same compound as the 555R but with stiffer sidewalls. Something to consider. Even the 555R's have pretty stiff sidewalls compared to a Mickey Thompson drag radial.

[subtlez28]

We've made some progress on the build. The slip yoke idea didn't work out for the CTS-V T-56, so that meant a new output shaft needed to be put in. Upgraded a couple things while they had it open, and found the unit to be in great condition. That is the silver lining. The trans was the only used part in the drive line so its nice to know all is well with it.

I found a T-56 specialist a couple hours north of me. I decided to hand deliver the trans to avoid any risk of damage in shipping. Since I was making the trip I also brought along a F-body T-56 I scored on Craigslist. I got such a deal on it I assumed it was messed up. However, more good news there. It was good inside, and so I upgraded it with steel 3-4 shift forks, pads and billet keys. Now I have a fresh T-56 for the next project (maybe my DD 2012 Colorado w the 5.3).



We worked on the rear suspension to get a the alignment close, and the settings right to get the shock travel where I wanted it. I purchased a few sets of suspension push rods to play around with length. I found out a big mail order circle track suspension place is like 20 minutes from me (Lefthander Chassis), so that made getting the parts easy.


We bled the brakes, and clutch hydraulics. It is starting to feel like a real car! I ponied up for some pretty parts. I really did not like the factory brackets for the coils. I guess it was to speed up production but on the early LS1s (97-98) the coils mounted directly to the valve covers, which were perimeter bolt. When they went center bolt they went to brackets. Anyway, I picked up some black Holley valve covers that have the bosses to mount the coils direct. I really like how they look.



Next I need to set up the DBW throttle pedal and the air intake. My plan is for the intake to go right back through the scuttle and be in the interior between the shelf and dash. I figure this will be direct, and shield it from debris, water and heat. I don't see a lot of guys doing this so I am up for any advice on why this isn't common.

[Mateospeed]

perhaps the intake inside idea isn't common because it defeats the purpose of the firewall - in the event of a backfire, or something similar, there's no longer a firewall between you and the intake path.

Whether this is a big enough concern to bother you is your choice, as are so many safety-related decisions in a build like this.

In other news, I really like the valve cover and coil mount idea - looks a helluva lot better than my coils on my LS1.

[subtlez28]

perhaps the intake inside idea isn't common because it defeats the purpose of the firewall - in the event of a backfire, or something similar, there's no longer a firewall between you and the intake path.

Whether this is a big enough concern to bother you is your choice, as are so many safety-related decisions in a build like this.

In other news, I really like the valve cover and coil mount idea - looks a helluva lot better than my coils on my LS1.

Hmmm. Honestly, I had overlooked that issue. I'm thinking it over. On the one hand I feel the thin aluminum that serves as the firewall offers little protection in the event of a fire. On the other hand, it would protect from say a short burst like a back fire.

I guess the oiled gauze air filter will offer limited protection... Which reminds me, why are paper cone type filters so hard to find?

[minendrews68]

Look out !!!!!!!!!!!!!!! I see a late night jaunt through the neighborhood in a "almost" finished ride! Just ask me how I know lol..............

This build is really looking good! The engineering seems to be flawless. I'm impressed.

Carl

[subtlez28]

Look out !!!!!!!!!!!!!!! I see a late night jaunt through the neighborhood in a "almost" finished ride! Just ask me how I know lol..............

This build is really looking good! The engineering seems to be flawless. I'm impressed.

Carl

Funny you should say that Carl...

I have decided to focus on getting the car track ready for an event in early May. I plan to work on the street legal and licensing side as the year goes on. In fact I just picked up some Hoosier Road Race Slicks yesterday. I only have 2 street tires (for mock up).

So the temptation to drive it before all the details are worked out will be very difficult to avoid...

[andrewb70]

Shaun...you sort of have a "get out of jail free" card....so I wouldn't worry about a spin around the block...LOL

I also wouldn't put the air filter inside. Aside from the possible fire hazard (you may never pass tech at any event), the noise of the air being sucked in will be deafening!

Andrew

[subtlez28]

Shaun...you sort of have a "get out of jail free" card....so I wouldn't worry about a spin around the block...LOL

I also wouldn't put the air filter inside. Aside from the possible fire hazard (you may never pass tech at any event), the noise of the air being sucked in will be deafening!

Andrew

Andrew

Now that is a truly terrifying thought! I can live with the risk of being burned, but if I showed up to race with a club I don't normally run with and got kicked out at tech, that would ruin my week!

This may be a deal breaker on my interior intake. I really do not mind the noise. Remember this thing will have side pipes. I had not considered tech.

Here is the main issue with running an elbow. I can only go pass side as the brakes take up the driver side. I had hoped/planned to run the battery on the passenger side again to avoid needless cut off switches and rule issues. I guess I will have to sink the battery into the shelf so the terminals are still engine side of the firewall.

Hmm.. I am glad I did not cut the hole yet!

[andrewb70]

Shaun,

I would double check the various tech rules, but I am pretty sure that running an intake inside the passenger compartment is a no-no...

Why put the battery so high up? Isn't there space somewhere in the back and down low?

Andrew

[parsonsj]

I am digging this build. And Brunton is 90 minutes from my house...

What a temptation!

[subtlez28]

Shaun,

I would double check the various tech rules, but I am pretty sure that running an intake inside the passenger compartment is a no-no...

Why put the battery so high up? Isn't there space somewhere in the back and down low?

Andrew

I will look into the rules of the club I run with but the issue is if I run w other clubs. Plus, honestly they put silencers on modern car intakes for a reason. The noise isn't all pleasant. I put a cold air kit on a V-8 Dakota I had. The intake sound was like I had a alternator bearing going out - unpleasant. That said, it will still be loud on the other side of a thin piece of aluminum.

I have already ordered an elbow.

There really is not a lot of places to put the battery. I could put it lower in the footwell on the passenger side, but again w/ various tech rules this requires an external shut off switch. I am going for simplicity. I think the compromise is to sink it somewhat into the footwell, but keep the terminals visible in the engine compartment.

I am digging this build. And Brunton is 90 minutes from my house...

What a temptation!

Thanks.

You should go take a ride with Scott at Brunton. These things are thrilling. Theirs had a bone stock 5.3 when I was down there and it was the quickest thing I had ever been in. It is hard to go faster for the money.

Tell them I sent you. I promised them some exposure. Its pretty cool to see an American owner/operator company succeed!

I cannot wait to have some performance numbers and video to share.

Side note: I just checked out your site. It reminded me I need to come up with a solution for venting my diff and fuel tank. I may be picking your brain soon.

[parsonsj]

Side note: I just checked out your site. It reminded me I need to come up with a solution for venting my diff and fuel tank. I may be picking your brain soon.

Give us a call anytime. We've got a new number: 888-216-6033.

[subtlez28]

I mentioned before about some trial and error on the driveshaft. My original stance was to use adaptors on both ends to keep the factory 3 bolt flanges on the CTS differential, and the CTS-V T-56. I figured we could use a driveshaft with a splined section in the middle to take up any movement and ease installation. I had just that kind of driveshaft on my last Jeep Rubicon project.

Well, after some lessons learned, we went with my original idea.

Here is the adaptor made for the T-56 flange:


Here is the shaft:


I asked for some input on running the intake. I liked the direct and literally straight forward (or backward in this case) route. I figured flow would be good, packaging would be clean, and dry air would be assured if the filter was on the cabin side of the cowl shelf.

However, a friend pointed out that it may cause me issue with some racing sanctioning bodies as it more or less defeats the idea of a firewall. Firstly I don't want to risk missing an event due to tech. Secondly the idea of a potential back-fire through the intake emitting fire directly into the cabin seems less than ideal.


In other news, I received my Diamond Racing wheels. Steel 15x10s with a spun rim. I went this route based on budget. I want to get the car to the track soon. The wheels are of great quality! Obviously steel is a bit heavy, but custom aluminum can come later. The wheels are 21 pounds a piece, the Hoosier 23x9.5x15 Road Race Radials are around 19 pounds. So figure about 40 pounds per corner. Bear in mind this was measured using a bathroom scale, so it could be off a bit.


The sun is coming through the window behind the car, but here is pic of the wheels on the car:


Another catch to using steel wheels is the lack of stand off from the wheel flange surface. Diamond racing told me this would be an issue, so it was no surprise. The problem is my brake set up is stock 10" Miata rotors with beefy Wilwood 4 pot calipers. So the caliper protrudes outward of the hub face, and since the rotor is so small, it is to near the center to allow the steel wheels gradual angle away to clear. No worries though. Nothing a spacer (15mm) and longer wheel studs cannot solve.

[andrewb70]

With your butt being 5 inches off the ground and no roof, you will feel like you're going 150mph while doing 35mph! Make sure you install the "fat guy" passenger seat option so I can get a ride!

Andrew

[Gil]

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

[HellPhish89]

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