Drag Racing Tech - Cowl Cutting

Just got my motor back from Virgina Speed. Thanks Shawn. :D:D:D
Now got to fit this monster, with it's Super Vic and Fast 4150, in the engine bay.
I cut the top cowl about a 1/2" from the windshield almost all the way across.
I cut the bottom cowl to match the top.
I'm going to stich weld a piece of metal between the two. I think that's what most people do. Then fill in the gaps.
But, I've seen some pics, that looks like some people cut the bottom cowl futher back toward the firewall.
Which is the perferred method?

Also, what gauge metal do I need, and what to fill in the gaps? (Something I can sand or grind down smooth.)

I've done alot of research, but still alittle confused.

Thanks in advance, George

I cut mine just like you have described. I bought a sheet of 0.024" steel and it worked well. It is easy to bend and can be cut with snips. I haven't filled and smoothed it yet but I plan to use evercoat finishing putty.

her is some idea's
http://i242.photobucket.com/albums/ff113/fuel383/100_4640.jpg
http://i242.photobucket.com/albums/ff113/fuel383/100_4647.jpg
http://i242.photobucket.com/albums/ff113/fuel383/100_4650.jpg
http://i242.photobucket.com/albums/ff113/fuel383/100_4659.jpg

here is some more
http://i242.photobucket.com/albums/ff113/fuel383/mail.jpg
http://i242.photobucket.com/albums/ff113/fuel383/2011-01-02_16-55-39_692.jpg
http://i242.photobucket.com/albums/ff113/fuel383/tnghjghj.jpg
http://i242.photobucket.com/albums/ff113/fuel383/tnhfgh.jpg
http://i242.photobucket.com/albums/ff113/fuel383/securedownloadttt.jpg

Very nice work right there!

http://img.photobucket.com/albums/v225/9secZ28/imagejpeg_2_8.jpg

her is some idea's
http://i242.photobucket.com/albums/ff113/fuel383/100_4640.jpg
http://i242.photobucket.com/albums/ff113/fuel383/100_4647.jpg
http://i242.photobucket.com/albums/ff113/fuel383/100_4650.jpg
http://i242.photobucket.com/albums/ff113/fuel383/100_4659.jpg

That's the one I'm copying from.
After stich welding, what do I fill in the gaps with?
That's exactly what I'm shooting for.
Thanks for all the responses.

I cut mine just like you have described. I bought a sheet of 0.024" steel and it worked well. It is easy to bend and can be cut with snips. I haven't filled and smoothed it yet but I plan to use evercoat finishing putty.

Thank you, Sir.

I think I found some filler.
Evercoat Body Filler Z-Grip. Then go back over that with their Finishing Putty.
Sounds like the old Bondo filler we used back in the 70's.

heres mine, same as above but maybe a slight different, combine the 2 and make the best? I used a metal filler i bought from napa, IMO its better then bondo since its more of a metal. Just food for thought...

http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00130.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00133.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00149.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00159.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00157.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00145.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00150.jpg

wow man did you cut off the area along where the top of the fender bolts on? How much weight did that save?

U talking about the inner fender area?.. Yea everyone does, lol. I'd say 3-4lbs a side. And no the fender doesn't bolt to it, it bolts to the top flange, this is all extra metal that "doesn't matter" on a drag car

Could you have the stock windshield cut shorter?


Do you have to use some filler? On some spot on my car I welded it fully and ground it down. Solid metal edge with no filler. You have to move around welding it, and spend some time welding. But cuts any filler steps out, and letting that hardend.

Could you have the stock windshield cut shorter?


Do you have to use some filler? On some spot on my car I welded it fully and ground it down. Solid metal edge with no filler. You have to move around welding it, and spend some time welding. But cuts any filler steps out, and letting that hardend.

The process is to grind and it pretty much a hit and miss deal on safety glass. Pretty much a skill that might take more than one windsheild to master.

One thing to consider on these cuts is knowing exactly where you need to remove material. I saw a shop car cut up once just to find that they really did not gain much from a room perspective. Had they mocked things up instead of just cut they would have known that. It had to suck to go cutting again once all the work was thought to be done.

heres mine, same as above but maybe a slight different, combine the 2 and make the best? I used a metal filler i bought from napa, IMO its better then bondo since its more of a metal. Just food for thought...

http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00130.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00133.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00149.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00159.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00157.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00145.jpg
http://i45.photobucket.com/albums/f67/ibwsjerry/DSC00150.jpg

That looks nice, too.
Do you remember the brand of metal filler. Also can you hand sand it or do you have to grind it.

no i dont remember the specific name, just a metal filler from NAPA. It dries up hard but still able to sand it smooth, takes a little more time then bondo but works better IMO.

this is the final product after everything is painted etc. Clears the 6061 elbow with no problems at all (if thats what ur gonna run)....

http://i45.photobucket.com/albums/f67/ibwsjerry/6fb0f9fb.jpg

all metal is what i used.but ill be using rage on the engine bay this time.

Do you mig or tig weld the metal filler plate between the upper and lower cowl.
A guy at work said that he could tig it. I though that you would use a mig welder on that. I'm no welder, just asking.

Mine was deff mig'ed, tig I can see bein a PITA and not needed

Here's mine, same idea

Subscribing since I still need to do this to my car.

Here's mine, same idea

I cut mine like this, as several people have. But after I in sat the motor in, the IAC sensor on the 4150 TB, hits the lower cowl. The IAC sensor comes out the back on the 4150 TB. So I'm going to cut the lower cowl 2" futher in toward the firewall. I probally could turn the TB 180 degrees and use a longer throttle cable. But I don't like that idea.

Since I went carbed, I needed the room under the cowl as well. I cut the upper part to the windshield, then the lower pack to the firewall seam.

http://i280.photobucket.com/albums/kk166/LSWon02Z28/IMG00035-20090113-1245.jpg
http://i280.photobucket.com/albums/kk166/LSWon02Z28/IMG00036-20090113-1246.jpg
http://i280.photobucket.com/albums/kk166/LSWon02Z28/IMG00031-20090110-1450.jpg

Then I had Rhodes Custom Auto box, smooth, and paint it....
http://i280.photobucket.com/albums/kk166/LSWon02Z28/DSC01207.jpg
http://i280.photobucket.com/albums/kk166/LSWon02Z28/DSC01208.jpg
http://i280.photobucket.com/albums/kk166/LSWon02Z28/DSC01210.jpg

Since I went carbed, I needed the room under the cowl as well. I cut the upper part to the windshield, then the lower pack to the firewall seam.

http://i280.photobucket.com/albums/kk166/LSWon02Z28/IMG00035-20090113-1245.jpg
http://i280.photobucket.com/albums/kk166/LSWon02Z28/IMG00036-20090113-1246.jpg
http://i280.photobucket.com/albums/kk166/LSWon02Z28/IMG00031-20090110-1450.jpg

Then I had Rhodes Custom Auto box, smooth, and paint it....
http://i280.photobucket.com/albums/kk166/LSWon02Z28/DSC01207.jpg
http://i280.photobucket.com/albums/kk166/LSWon02Z28/DSC01208.jpg
http://i280.photobucket.com/albums/kk166/LSWon02Z28/DSC01210.jpg

Yeah, yours looks very nice and smooth.
I might end up doing just that.
I was just wondering if the top cowl was strong enought to support the factory windshield.

Here is what I did.....
http://i817.photobucket.com/albums/zz98/sbc98comaro/100_1514.jpg

I would think that the upper cowl has enough strength to suppot the windshield, as it has really no weight once it is glued in. You may want to support the upper while the glue dries.

is there any problem with leaving the cut area open?

heres mine..

http://i38.photobucket.com/albums/e147/cls-chicago/2011-05-31174913.jpg

currently looks like this..

http://i38.photobucket.com/albums/e147/cls-chicago/19347364.jpg

Nope, no probs. I ran mine open on my last set up, basically just wanted to tidy it up this time around. I cut the plastic covers out around the carb too, u just use a couple less of the lugs!!

i had to make room for an edelbrock proflo xt. im gonna leave the black plastin, irrc it just barely pushes it upwards.

not really show quality, but its a dedicated race car, but I just cut mine 1/2" from the windshield and straight across, then riveted l shaped panels to the upper cowl and the back. not the best looking, but serves its purpose. If i had to do it again, i woudldnt have cut so far on the pass side (had to box it in) With the motor in none of it is really noticable anyways.
http://inlinethumb23.webshots.com/49366/2786926110087494360S600x600Q85.jpg
http://inlinethumb23.webshots.com/44822/2797397930087494360S600x600Q85.jpg
http://inlinethumb36.webshots.com/48099/2331298460087494360S600x600Q85.jpg

not really show quality, but its a dedicated race car, but I just cut mine 1/2" from the windshield and straight across, then riveted l shaped panels to the upper cowl and the back. not the best looking, but serves its purpose. If i had to do it again, i woudldnt have cut so far on the pass side (had to box it in) With the motor in none of it is really noticable anyways.
http://inlinethumb23.webshots.com/49366/2786926110087494360S600x600Q85.jpg
http://inlinethumb23.webshots.com/44822/2797397930087494360S600x600Q85.jpg
http://inlinethumb36.webshots.com/48099/2331298460087494360S600x600Q85.jpg

Nothing wrong with that.
Looks nice.