GT4 Nosejob - "Euro/US" bumper mod.

Since getting my '79 308GT4, I have been envious of the more streamlined "Euro" bumpers...so decided to take the plunge and modify the profile -- both nose and tail.

Conceptually, this is an easy modification (a few notes to the contrary follow the summary). Concept: Remove the bumpers from the mounts/shock absorbers. Drill a hole to drain out the hydraulic fluid. Compress the bumper mounts. (I used piece of 1 x 3, and a scissor-jack against the side concrete wall of my garage. Not pretty, but effective). Re-drill a new hole while mounts compressed. Tap and insert metric set screw to hold in place. I drilled and tapped in both the original position, and in the compressed position, should I ever want to regain the original US Spec look.

Overall, I am very pleased with the result, although it tool a bit more work than I anticipated. I was able to remove about 3" from the front bumper (full compression) leaving about 1" extended remaining. It fits nicely with the curve of the bumper skin, and looks really nice in my opinion.

The rear, for reasons I will go into below, was reduced by just over 1-1.5"", with about 2.5 inches remaining extended. Just about in line with the indentation in the bumper. Not as dramatic a reduction, but a tremendous improvement from the 'diving platform' look that was there previously.

Learning experiences:
1) Drill into the shock units VERY SLOWLY. They are under pressure, and filled with hydraulic fluid. If you don't let the pressure off really slowly, they will blast you with a fog-like spray, and make a nice mess. The nice thing is that you only make that mistake once.
2) Drill the side of the shock unit, versus the bottom. Not a major concern, but the underside drill out gets more of the fluid out initially, but does continue to weep a bit if the car is parked at the right angle. The side drill out probably leaves more fluid behind, but doesnt weep. Either way, a problem that a paper towel will solve over a week or so.
3) Dry fit the bumpers to make sure that you have not compressed too far -- this is important for being able to put the front grill back on. Its mostly a matter of tight spaces in the front, but I was able to compress the full amount, and get the grill back on without major issue.
4) Deal with the rear bumper heat shield on later models. Earlier GT4's, without the thermonuclear reactor cats/muffler set up, don't have a form fitting rear hear shield attached to the bumper. Given how the shield was in place, it not only restricted your access to the rear bumper mounting bolts initially, but severely restricted the amount that you could move the bumper in before you hit up against the shield. It was a real game of take it on, take it off to figure out the maximum compression allowable....
The big issue besides the reduced compression room was that with the heat shield in place, you could not reach the bolts from under the bumper as in the front bumper, or I assume on earlier GT4's. Secondly, apart from access itself, compressing the bumper about an inch and a half left little or no room to reach in from the side, thread the nut on the bottom mounting bolt, let alone try to get some sort of a wrench in there. I really contemplated cutting the heatshield into sections, or cutting a hole to fit a wrench from underneath...but resisted. What a PITA. Multiple hours spent maneuvering, etc.
(Truthfully, I resorted to cranking down on the top nuts, and handtighten/locktite the bottoms for the rear bumper. Future "mod" to come when I figure out a better way. For now, its tight enough, and everything is good to go).

Take a look at the progress photo's, and I think you'll agree that despite the frustration on the rear, the 'surgery' was a success. Much more streamlined look, and I think well worth it.

Not too bad for my first F-Car mod. Now onto the 308 Air-box restrictor mod.
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nice work! excellent thread!

 

Your car looks great. I have to decide whether I am going to take the plunge and try it on my car. I am not 100% but in the photos it appears your right and left side markers are put on the wrong sides? Maybe when they repainted the car? The one on the drivers side looks like it is angled up?

Andrew

 

John,

GREAT writeup! The results are gorgeous. I like the front bumper look alot. Thanks for sharing this. Could be another tech article for Birdman's site...

JIM

 

Wow, Jim. No one has ever even mentioned "my name" and "tech article" in the same paragraph, let alone the same sentence.

I guess this is one of the benefits of F-Car ownership. You are motivated to tinker a bit, even if you are not a techie. I am having great fun with the projects, so far.

John

 

Great writeup! I recently did this "mod" on my GT4, but I saved a few steps. I just laid on the garage floor, looking up, and drilled a hole into each shock. I then "persuaded" the bumper backwards with a rubber mallet.

5 minutes, tops.

 

Ditto! Great job, great pictures and a great write-up too!

I really enjoyed seeing the SeriesII front grill too. And on a blue car no less! And it's painted black!

What more could I ask for?

In fact it looks so nice, I'm reconsidering my thoughts on doing mine in carbon fibre!

 

Perfusion - Please post a few photo's of yours. I am interested in how much you were able to get the rear bumper to compress, and whether or not you had to deal with the heat shield limitation on the back bumper.

Also, FYI everyone. I continue to be amazed at the seemingly frequent inconsistencies between model years, US Spec. If I look at the following thread on FCHAT for GT4 photos...you will clearly see later model Series II GT4's with the very extended bumpers. Probably just a bit more extension than Series I's.

http://www.ferrarichat.com/forum/showthread.php?t=118740&highlight=GT4+Series+photos

I started to say that as I looked at Dave Stacy's 75 in Photo#1. Then I looked through the other photos in the thread, and it seems like some 75's have bumper extensions that look very close to my '79. Dave, did yours have the bumpers moved in? or are my eyes off in comparison to Dom's, Alex L's or probably most visible in Peter's black 1975.

Seemingly odd. But not out of the ordinary.

Someone tell me if I am out to lunch here. Do Series I US bumpers typically extend out like Series II/III?

 

Look at my cat (post #1) and then the car in post #3.

#3 has the original bumpers that didn't meet DOT crash requirements. Factory correct and legal due to a waiver.
#1 has the bumpers addressed in the factory Tech Bulletin. Aslo factory correct and legal.

Handmade cars, no 2 are the same. Pretty fun huh?

 

Ah, yes. So it is confirmed. Series I US bumpers are as damned ugly as Series II US bumpers.
<smile>

 

Sorry John, I forgot to mention in my original post that I only did the front bumper. I wasn't as bothered by the rear sticking out as much as I was by the front, and I thought it best to keep the shock absorptive properties of the rear bumper at max capacity.

Just for grins, here's a pic Brian Harper took of our two cars (his is the white one - Series 1) once upon a time. Whoda' thunk it could come in handy in a bumper discussion thread?!

Note how you can actually *see* the pavement between the nose of my car and the back of the front bumper - now that's gap!
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I just looked at that thread again.

My car seems to be the only one with the original-style rear "picnic table" bumper. I think it's the worst. And I've only seen one other car (IIRC in Michigain) that has the same bumper on the rear. Does anyone else have one of these?

It's a is (was?) a two-owner (seller claimed "unmolested") car for $28,600.

The seller was the original owner. He sold the car to a friend, and was "helping" the new owner sell the car.

Here's a pic of the rear bumper.
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See the update to the rear bumper mod above. I went back in tonight and re-did it the right way. All bolts tightened as they should be, and bumper back in place and locked down with the set screws.

 

I took the plunge and modified my front bumper this morning. Here are the before and after shots. Note: I drilled a hole in the front of the bumper shock vice the rear. No oil came out, only compressed gas. The rear bumper had already been modified by the previous owner.

-GT
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That's a nice look!!! Any shots from the front? I'll bet that really makes a huge difference.

JIM

 

This looks like something like I must do also!

 

Silly question maybe, but why not simply purchase a pair of euro bumpers and bolt these on??

Or are these no longer available??

Hans

 

Apart from availability issues this is not a simple bolt on job. The fenders in the US version have a cut-out which you'd need to weld in or it would look really silly. From what I understand this is a big job and though you can't beat the Euro look it's too much hassle in my books.

 

Sure - here ya go!

-GT
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VERY nice! That really cleans up the front end.
Thanks for sharing.

JIM

 

Saw the 308 bumper brackets for sale this weekend, and DinoGT4Guys question about the potential for GT4's. The tubes could be the same, but the bumper mod is really easy to do with drill and set screws. You can leave in two positions for "original" and "modified".

 

I've been thinking about making some aluiminum brackets and removing the shocks alltogether. Though I wonder if I'll really save much weight in doing so?

Cheers!

 

http://www.ferrarichat.com/forum/showthread.php?t=151119&highlight=gt4+nosejob

 

Our struts are 1KG lighter per strut. So thats 4.4 pounds. Not a lot compared to the bumper but I guess every little bit counts. The first GT4 owner to PM me will get a special deal to try them out to verify they fit a GT4.

 

I let the air out and by buying a used set kept my OEM ones and now I can pull them out and in with some effort to clean, etc. David I think you and others with the original bumpers get a pass to instal euro bumpers if you cannot find the later series II ones!
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