Dan's Build

[Frank Clark]

Day 542
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... the tipping point for me was the cruising RPM at interstate speeds………at 80, the Corvette RPM is 2000. With the .76 the SLC it will be ~1800, and with the 1.038 ~2500....
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Not trying to sway anyone on which set of gears to get...

But everyone should keep in mind how their engine is cam'd vs a Corvette. *IF* you have a wild cam, and don't have ITBs, an 1800 rpm cruise would be a nightmare. It would buck and jerk, and the light weight of the SLC would probably make things worse.

I have no personal experience with the crate engines most are using (other than LS7), so I have no idea where their cams fall. But I have had a wild cam street car and it was unpleasant under 2200 rpm with light load.

Changing the gears in the Graz is a PITA, so hopefully everyone makes the right choice for themselves first time around!

 

[Mark Setter]

My Z06 has a big cam (Katech) in an LS7 and it HATES being below 2100. Bucks like crazy.

 

[Dan Carter]

I may be crazy, but can't see GM building a crate motor without providing drive ability warnings if the LS3 480 had low speed bucking issues. I don't think the cam is that radical.

I would guess the tranny would make no difference, so even in first at low RPM the car would buck if it has that temperament.

 

[Ed Davis]

Mark which cam do you have?
Ed

 

[Dan Carter]

Today was main body cradle day. Removed the aft cups, and created a portal from the front two.


Molded in a roof scoop to the engine bay and built a removable end piece to capture any water into a drain tube. I integrated filter material to prevent water from blowing into the engine bay in both the roof scoop and the tail scoops next to the rear window.


Had a problem with the predrilled door pin holes. I glassed over the multiple holes to start from scratch. One of the door pins had the bolt top ground down to allow the door to close. Since the only reason for the bolt head is to hold for tightening, I cut it off and created a 7/16 slot on the shaft. The shorter pins work better for my doors.


Took the car to my local AC place. After we found a few fittings that were not tight enough, they filled her up and now we have AC.


Had a continuous check engine light at the GM fuse box and no light at the cockpit repeater light. No codes. However, in the non-permanent memory several codes were discovered (P0689, 507,506, 121, 059 and 053). Discovered I had wired the repeater light wrong, corrected it and all codes vanished. Go figure.

 

[Dan Carter]

Worked over the holiday to cut access holes for 5/6 point harness into the seats. When cutting into the bottom for an anti-dive bet, you will find in the newer seats are two layers. Once cut, I filled in the gap to create an enclosed portal for the belts.


The edges were smoothed out anyplace a belt will touch to alleviate any chaffing. The seats will be upholstered once final fit is confirmed. I plan to paint the rear of the seats in a carbon fiber effect similar to the instrument panel and parts of the side doors panels.


I have the interior tub and side door panels. In an earlier fitment check, the passenger seat fit (barely) without interference with the door. I'm going to reconfirm, but I did cut some of the flanges off the side of the seats.


Note on the sides, I filled in the areas that supports the seats to the side rails and built a metal plate that goes into the insert inside the seats to allow for secure bolting.

 

[Mark Setter]

I have a Katech LS7 Torquer. They have two versions, and I don't know which one I have. Over 600hp.

 

[Scott Rowland]

My Z06 has a big cam (Katech) in an LS7 and it HATES being below 2100. Bucks like crazy.

Fuel injection should take all of the low rpm issues out of a big cam if tuned correctly. Low vacuum is not an issue since fuel is being injected and not have to be drawn in like a carb.
Typically what it is, is the area between 5%, and 0% throttle position. You must match this perfectly with the big spike in vacuum (not like idle, but think engine braking at 2,000rpm), to the slight loss of vacuum when at 5% or so. This transition takes a lot of street driving while tuning and is very timely. You can tune your engine to oem driveability with aftermarket ecu's, it just takes awhile to get all the areas flawless.
Most tuners mainly concentrate on the power numbers, and the real fine tuning is costly.
Or, you have too big of injectors and your resolution on them is muddy until higher rpms.

 

[Dan Carter]

I tried an alternative method to installing the door struts. My objective was to have the strut hold the door open, no assist, so any aid to open or close is secondary. The “J” hinge has a small threaded hole that accepts the strut ball stud. This hole swings in an arc from fully closed to fully open. I used a 10-inch strut (ball to ball) and swung an arc from the “J” ball stud along the vertical 2x6 cockpit frame first fully open and then fully closed positions. The intersection of the two arc is the point where the strut is fully extended for both open and closed door. The two arcs intersected on the lower main body 2x6 vertical on the outside of the cockpit. I ended up with a 150 lb strut to hold the door fully open with the RCR interior panel, Lexan window and the hippo ears attached. If you move along the door closed arc rather than the intersection, you can actually compress the strut some to add a positive force to the hinge ball if you wish. This configuration places no stress on the fiberglass and the only time the strut is compressed is during transition from open to closed. I’m going to add a small stiffener inside the door to take some of the load off the direct hinge contact point. To gain access I added an access panel as shown.

 

[Colin Dalzell]

I like the idea that there is little to no stress on the strut; but I can't quite picture where you attached the end of the strut. Is the new strut 10 inches ball to ball compressed or extended? Is the cutout directly over the attachment point? Thanks for providing this detail.
Colin

 

[Dan Carter]

The length of the strut can vary slightly (10 inch ball to ball worked nice), but will be restricted in length by any obstruction located at the bottom of the 2x6. I found Lift Support Depot had the sizes/weights I was looking for. 120 was too light, 150 is very strong but its what I'm using right now. I circled the location of the bottom ball stud location on the frame 2x6 by the drivers left knee. I will drill a hole on the back side to allow a nut to secure the stud better than just tapping the aluminum. As an experiment, I placed two studs along the 10 arc I created by swinging the strut from the J hinge ball stud with the door closed. I used non drying modeling clay to leave impressions to locate the arc and drill point. One stud location is the fully extended point for both open and closed (aka no stress on the ball studs, fully extended) and the other is along the arc to only put pressure on the door hinge while open. Both work, but some pressure does make the open door feel more secure but actually isn't any more secure than the fully extended strut. I like the zero configuration as the strut only compresses while in transition from open to closed. I could have made the access panel more to the side, but its a bit less obvious in this spot but still allows you to access the ball stud and in my case other things for servicing if ever needed.

 

[Dan Carter]

Two items worth sharing this week.

1. On my front nose section, it hits the door hingebolt enough that it was difficult to drop it into place. My solution was to move the aft pin locationforward away from the hinge and notch the front nose section to allow it topass by the hinge without any interference. (see picture)
2. Completed the mounting of a wing on a streettail. I used the larger “J” hinge andwelded a support brace for the vertical mounting brackets so all down force is transferredto the chassis. The verticals weremachined from 1-inch aluminum and secured at the top by a sleeve surroundingthe vertical with a plate beneath the fiberglass to spread forces. As you can see the wing travels with the bonnet.

 

[Dan Carter]

Finally got the Vette back in shape (I hope) so back on the SLC. My focus has was working the door openers, not a very exciting thing, but no less a challenge. I'm using the interior RCR door covers so mounting the interior door handles to match the contour of the interior panel was interesting. I chose to build connecting rods for both the interior and exterior connection to the latch.

Still trying to figure out how to configure the connections and modify the locks so I can lock the door from the outside and inside using the supplied Miata door locks. I plan to buy new exterior door handles as the ones I got were very used.

You can see the interior panel mounted to the door via feathered OEM style panel mounts. The door is not yet painted so its a bit of a mess.

 

[Dan Carter]

Here is another approach to mounting the Instrument panel. Instead of trying to glue a "shelf" to the windshield body contour, I built the feet shown in the drawing below and I will hide the glue mess with some liquid sound deadener. I used 4"set screws which will be cut to length and as you can see, the access holes in the IP are small and for me are not a concern cosmetically once completed.

I also cut an access port to allow me to reach and connect the wire harness to my instrumentation. Not everyone is going to like this approach, just another approach.

I'm struggling with making the anchor seal to the bottom of the IP for defrosting. I don't want constant air going there, so I'm looking for ideas on how anyone built a shutoff door and created a seal to the IP and anchor.

 

[Mesa]

From the 'been there' file ~ I would be concerned those feet might not clear the top of the footbox or possibly some of the gear that gets mounted on top of it. Also, have you checked the ease of installation with the winshield in place? The dash is more difficult to put in with the windshield on the car.

Nice work on those interior door handle mounts.

 

[Dan Carter]

Mesa

I was concerned with the feet fitting, but had it in and out at least 6 times or so yesterday with a mock windshield. The wiper stem actually presents the biggest challenge cause I’m too lazy to drop it down. Because the roll bar is off side to side by 1/2 inch some IP glass adjustment was necessary. I’m going to another approach on pushing air for defrosting, so I eliminated the bottom of the anchor completely.

Struggling with best approach to make windshield fit better in lower corners. Looking to see how much body contouring will be required and maintain the overall clean lines.

Thanks for the positive comment on door handle......they were a challenge but solution was rather simple. :embarassed:

 

[Ron McCall]

From the 'been there' file ~ I would be concerned those feet might not clear the top of the footbox or possibly some of the gear that gets mounted on top of it..

Just curious ..I have seen quite a few people mount all sorts of stuff under the dash on top of the chassis. There has to be a better place to mount these things such as relays , ECUs ,fuses and wire connectors that will be MUCH more accessible after the car is completed??
Once the windshield is installed ,it seems like it would be a nightmare to work on these things even after you remove the dash ( PITA on it's own) .I know it's nice to hide such things but they also need to be accessible if something fails.
Just wondering.

Ron

 

[Ken Roberts]

Here are the part numbers for new Miata locks and outside door handles Dan.

 

[Mesa]

Just curious ..I have seen quite a few people mount all sorts of stuff under the dash on top of the chassis. There has to be a better place to mount these things such as relays , ECUs ,fuses and wire connectors that will be MUCH more accessible after the car is completed??

Ron

Its no cake walk to get the dash out even when carefully engineered to be so by a builder. In my case the main instrument panel readout computer(s) are under the dash, with all the AC hoses and ducting (built before any factory solution was available). Access openings behind the instrument panel and the center panel readout help to make connections.

 

[Dan Carter]

Thanks Ken.


Ron, I agree with Mesa. I have placed nothing under the IP. I cut the access panel so I can get to the instrument plugs. Once IP is in, I hope to never take the IP out again (fingers crossed). While not the easiest to reach, a lot of my relays are under the chassis foot well attached to "ceiling". Its a challenge to get my rather large carcass under there but at worst I just remove the seat. Standardization, what standardization...lol