Kibort Official 928 Racer Rebuild project Thread
#182
Rennlist Member
Thread Starter
another nice thing about the fendermod, the way Im doing it, as it actually lifts the fender off the wheel too. my ride hight is 110mm, yet it doesnt look that way at all. gives a less slammed look, and more fender clearance.
all the wheel fender inner panels are installed now as well.
all the wheel fender inner panels are installed now as well.
#183
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Thread Starter
Finally attacked the side rear windows. replaced the Driver side, and now will have to cut a piece of lexan to fit the passenger side. Does anyone know if you heat lexan with a heat gun, can you get it to form easiliy??
Anyway, very little weight savings for the little rear windows. guess what they weigh?
6lbs with the rubber stripping, which is 2lbs of the problem. so, there is 12lbs for both windows being replaced with lexan.
Anyway, very little weight savings for the little rear windows. guess what they weigh?
6lbs with the rubber stripping, which is 2lbs of the problem. so, there is 12lbs for both windows being replaced with lexan.
#184
Rennlist Member
Hi Mark
I used to do R & D work in a plastics factory and I've worked with polycarbonate a lot.
Lexan is the brand name for polycarbonate, which is a thermoplastic ..... get it high enough in temperature and it'll become plastic. Lexan becomes plastic at a higher temperature than acrylic and so you need to be careful you don't overdo it and cause discoloration or bubbling, which is easy to do if you're not paying attention.
The procedure is much the same as acrylic but more difficult because you need to get it to, and hold it at, a higher temperature ... so do it in a warm/hot room to make that easier. To get a nice looking formed shape you need to heat the sheet up beyond the area you're bending, to avoid thinning the sheet too much where you bend it to a radius, and getting visual distortion. Getting the sheet up to the right temperature evenly over the area you're bending will give the best result. You can do it with a heat gun, but you'll get an even better result if you're doing a slow radius over a large area by using an old fashioned electric radiant heater (which I used to use a lot for doing large radius bends in pipe). The radiant electric heater will allow you to get an even spread of heat over a larger area than a heat gun, and hold it at that temperature. Factories vacuum form and bend sheet using infra red heat banks.
If you've got a scrap of sheet do a trial run to get a better idea of the temperature you need to get it to .... wear gloves! ... yikes! it needs to be hot. HTH
I used to do R & D work in a plastics factory and I've worked with polycarbonate a lot.
Lexan is the brand name for polycarbonate, which is a thermoplastic ..... get it high enough in temperature and it'll become plastic. Lexan becomes plastic at a higher temperature than acrylic and so you need to be careful you don't overdo it and cause discoloration or bubbling, which is easy to do if you're not paying attention.
The procedure is much the same as acrylic but more difficult because you need to get it to, and hold it at, a higher temperature ... so do it in a warm/hot room to make that easier. To get a nice looking formed shape you need to heat the sheet up beyond the area you're bending, to avoid thinning the sheet too much where you bend it to a radius, and getting visual distortion. Getting the sheet up to the right temperature evenly over the area you're bending will give the best result. You can do it with a heat gun, but you'll get an even better result if you're doing a slow radius over a large area by using an old fashioned electric radiant heater (which I used to use a lot for doing large radius bends in pipe). The radiant electric heater will allow you to get an even spread of heat over a larger area than a heat gun, and hold it at that temperature. Factories vacuum form and bend sheet using infra red heat banks.
If you've got a scrap of sheet do a trial run to get a better idea of the temperature you need to get it to .... wear gloves! ... yikes! it needs to be hot. HTH
#185
Rennlist Member
Having just finished glass replacement all around, I would suggest that you not use any heat to form the poly. Just cut it to fit and attach it. It will start to self form. It will depend, in part, with how it will be attached. I'm using 8 zeus fittings on each side and it's pretty good after 3 days.
I would also thind about using Percy's Speedglass, as it's coated on both sides for scratch resistance and has better clarity.
Also, check your pms as I will be sending you one later today.
I would also thind about using Percy's Speedglass, as it's coated on both sides for scratch resistance and has better clarity.
Also, check your pms as I will be sending you one later today.
#186
Rennlist Member
Thread Starter
I just installed the side window with no shape changes. the heat i was using wasnt hot enough or wasnt able to be spread out enough. either way, it looks fine, but Im worried about the force on the edges, even though i used the stock window frame to spread the load at the edge. (see the pics)
im thinking about using some heat now that its installed, or should I not worry about it, as over time the plastic will just change shape with sun heat?
anyway, the car is done except for the painting of the front and rear bumpers that Ill do someday soon. (as well as putting on a black rear hatch to keep the new theme, Black! )
first race (real race, not tuning day) will be next month, June 13th at laguna seca! New front rims with the bigger tires and no weight in the back as far as the bumpers and rear glass . (i.e. about 40lbs )
im thinking about using some heat now that its installed, or should I not worry about it, as over time the plastic will just change shape with sun heat?
anyway, the car is done except for the painting of the front and rear bumpers that Ill do someday soon. (as well as putting on a black rear hatch to keep the new theme, Black! )
first race (real race, not tuning day) will be next month, June 13th at laguna seca! New front rims with the bigger tires and no weight in the back as far as the bumpers and rear glass . (i.e. about 40lbs )
Having just finished glass replacement all around, I would suggest that you not use any heat to form the poly. Just cut it to fit and attach it. It will start to self form. It will depend, in part, with how it will be attached. I'm using 8 zeus fittings on each side and it's pretty good after 3 days.
I would also thind about using Percy's Speedglass, as it's coated on both sides for scratch resistance and has better clarity.
Also, check your pms as I will be sending you one later today.
I would also thind about using Percy's Speedglass, as it's coated on both sides for scratch resistance and has better clarity.
Also, check your pms as I will be sending you one later today.
#187
Not the sharpest tool in the shed
Rennlist Member
Rennlist Member
Great news Mark!... I like the black. Any names picked out for it yet? "Mamba's Boy" (as in the venomous black snake)
#188
Rennlist Member
Thread Starter
Here it is at the Thunderhill race in April, and now going into Laguna Seca this weekend, it has a few more tweaks on it . wings, splitter, hood vents, wider and vented fenders, wider tires (f/r) rear tail vents, less weight, plastic rear windows, and I just cut the nose with a new idea I had after seeing one of the euro race cars with similar cuts. I basically cut 4 more narrow sections, the same height as the stock 2-3 inlets at the base of the nose area. from a distance, it just looks like there are more inlet slots and the square area is greater than my single rectangle cut out last year, which certainly helped cooling on the hot days.
#190
Rennlist Member
Thread Starter
update
Just finished putting some interior paint to make the car look a little better on the inside. Had to spend a few hours grinding off all the old foam glue that held the insulation in place. Then, installed the stereo for tunes while driving to the store or to the race track. And, fabed up my old door panels, fitted with some new speakers. It almost looks like a rough street car. its amazing what a bunch of carpet sections will do for a race car interior.
everything is still removable for the track.
everything is still removable for the track.
#193
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Thread Starter