Suspension swap, Swap 911/930 front suspension to my 914 Options

[Eric_Shea]

QUOTE

The sport version is only available for 914´s and 911´s 75-89 w/Boge strut. P/N is the same as above with an "S" at the end.

Wait... you found two off the shelf Koni 914 inserts that fit a 911 strut. That's all they make isn't it? Standard and Sport?

So... you buy a 911 front end and put 914 inserts in it. It doesn't ride any harsher than any other 914.

[rickyhgarcia]

QUOTE

(18mm is the highest you can go with 15" wheels BTW... both cars are sitting in the garage with the wheels on them)

You are correct on this...my typo. From RennsportSystems.com:

The spindle height limit is determined by the choice of wheel diameters. 15" wheels allow no more than 18mm change in spindle height due to ball joint interference with the inside rim. Using larger wheels will allow higher spindle heights.

Checked my e-mail´s...my spindlers were raised by 17mm.

[rickyhgarcia]

QUOTE

Again, something's missing here. I 'think' you have modified 911 'Boge' struts. The 911 spindle being the key. You would need the much thicker 911 spindle to put the 5-lug goodies on this strut. Otherwise... too much effort to simply make the equivalent of a 911 'Boge' strut.

Eric,

This is the text from Rich´s email when we were talking about doing these mods:

"We will use the "A" spindles I have with a 914 Boge tube. In this combination you can use the 914 Koni Sport insert for proper valveing range and still raise the spindles. I have good luck setting the spindle height at 17mm for 15" wheels and 19mm for 16s and above."


However, the 911SC front suspension I had was with the Bilstein struts. Perhaps this is why it could not be used if I intended to use the 914 Koni inserts.

[Eric_Shea]

QUOTE

I have a 914 Boge strut with 3.5" ears, with a 15mm raised spindler.

It's a spindle.

QUOTE

Installed on my struts are all the pieces from my previous 911SC front suspension. These include 911SC vented rotors that I bought from performancerotors.com. These are not drilled rotors...and no adapters were used.

Sorry... you can't install 'all the pieces from your previous 911SC front suspension' on a 914 strut. The spindles are not the same size... UNLESS, they have some custom bearings to adapt. So let me get this straight:

Cut spindle off SC struts - $
Raise and Weld Spindle on 914 strut - $?

-or-

Custom bearings - $?
Cut and Raise spindle - $?
Mounting ear modification - $?

-vs.-

Custom valved inserts?

It doesn't add up, especially when you'll basically have a 911 Boge strut with 3.5" ears when you're finished. (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

QUOTE

I bought Koni´s P/N 8641-1077S which is the correct P/N for 914/914-6.

Those will drop right in the most common 911 'Boge' strut. Says so right in your description (914-6).

QUOTE

If you say that the 914-6 strut is identical to the 911 (any year?) strut, and, according to Koni´s P/N, 914-6 and 914 use the same insert, then the 914 insert should fit the 911 (any year?) strut. Right??

I didn't say 'any year'. There are roughly 4 different 911 struts. Correct?:

Boge - Most Common (takes 914 inserts)
Koni - On many 911S models (special valved insert)
Bilstein - On many 911S models (special valved insert) and
Hydronumatic (sic) - Option on 911E models (you don't want...)

In saying your 914 insert would fit 'any' strut, that would be misleading. Just like saying that 911 struts make a 914 ride harsh. A 911 'insert' in a 911 strut may make for a harsh ride.

The 914-6 strut is a 911 'Boge' strut from the same era. A 914 insert should fit any 'Boge' threaded strut... yes.

So... I say:

Buy a 911 front suspension, if that's what you want. Drop some 914 inserts in it and go, go, go... If you're going the serious 3.5" (Koni/Bilstein) route then it's still cheaper and easier to get custom valved inserts than it is to have all the chopping and welding done. Chris Foley charges $225.00 for the spindle operation alone. Then you've got to modify the ears...

Fill me in. How did you get a 911 hub on a 914 spindle?

[rickyhgarcia]

QUOTE

Cut spindle off SC struts - $ Raise and Weld Spindle on 914 strut - $?

This is what was done....

[Eric_Shea]

QUOTE

"We will use the "A" spindles I have with a 914 Boge tube. In this combination you can use the 914 Koni Sport insert for proper valveing range and still raise the spindles. I have good luck setting the spindle height at 17mm for 15" wheels and 19mm for 16s and above."

Now it's beginning to make sense. He welds the entire 911 spindle on a 914 strut.

Ricky, this is still a 'LOT' of work when:

1.) Most narrow body cars will 'never' need anything more than an M-Caliper hence a 3" 911 'Boge' front end.

2.) The cost of the mods should well exceed the cost of specially valved inserts for your original front end.

I think what you have is a neat setup. I also think you're misleading people when you say a 911 front end makes a 914 ride harsh. It's simply not true. For me, custom valved Koni's are a much more viable and much less expensive alternative.

Thanks for clarifying.

[army dude]

(IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif) My head hurts with all this. When I start this mod I will have this printed out to read over and over and over...... Or I will just send it to somebody to do it for me. Anybody want to adopt my projrct??

[rickyhgarcia]

QUOTE

I think what you have is a neat setup. I also think you're misleading people when you say a 911 front end makes a 914 ride harsh. It's simply not true. For me, custom valved Koni's are a much more viable and much less expensive alternative

Eric,

Thanks about the neat setup comment.

I am sorry if I was misunderstood. All along I was trying to send the message that the off-the-shelf 911 INSERTS are not ideal for 914´s. This is very true.

Isn´t it also misleading to say that a 911 front end swap is just a bolt-on upgrade? This statement sounds to me that you swap the front end, and that´s it. Most buyers will buy these expensive complete front suspension setups expecting a plug and play improvements in the handling qualities of the car, when actually dampers from another car with very different characteristic has been introduced. When I originally did the swap I felt let down because I did not feel an improvement in handling and actually got an uncomfortable ride.

I think most people that would install a 911 front end will either keep whatever inserts came with the suspension, or buy the direct replacement for model and year 911 the suspension came from, again thinking that this is an improvement in suspension and ride characteristics. I did. It is great information to know that the 914 insert directly fits inside the 911 Boge strut, honestly, this I did not know.

After all this interchange, however, I would recommend anyone contemplating this upgrade to avoid 911 suspension setups with Koni or Bilstein struts. I myself made the mistake of buying a 911SC setup with Bilstein struts just because I did not know.

When thinking about these upgrades, I also investigated the valving of the Bilstein inserts in my 911SC front end because at the time I had sports Bilstein rear shocks, however, there was a long wait for this process, I had to provide the parameters for the revalving (which I did not know...again before 914world.com days), and set the car on jackstands while it was done. I chose the easiest route, and the one that would get me where I wanted.

Rich did all that work for about $750 plus my SC strut cores. A complete 911 front end, I been reading in this forum, goes for about $1200, so pricewise is about the same. Of course, when I started all this I already owned a complete 911 front end...i.e. brakes, calipers, 5-bolt conversion pieces, etc.; I guess these parts will have to be considered in the pricing of the final product. The cost of these components in used condition, however, is affordable...I just sold a pair of recently rebuilt SC calipers in the classifieds for $150. But if the intend is to lower the car also by displacing the spindle (I got it right this time), then this is not so outrageous.

When I replaced the Bilstein 911SC inserts with the Koni 914 inserts, there was a lot of improvement in ride quality and the handling of the car.

[rickyhgarcia]

QUOTE

1.) Most narrow body cars will 'never' need anything more than an M-Caliper hence a 3" 911 'Boge' front end.

Eric,

About three weeks ago I sent you an e-mail because I was considering upgrading my rear brakes to 911 calipers, and ask you about the e-brake setup that you sell.

My current brake configuration is 911S alloy front calipers, OE 914 rear calipers with spacers, steel braided lines, 19mm master cylinder, and vented/crossdrilled/slotted 911 rotors on all four wheels.

At that time you told me my braking was about right and that I should not change it. Your quoted comment says that my front brake setup is probably overkill since I have a narrow car.

Are my front brakes too much for what I have in the rear? How to balance it?

[Eric_Shea]

Thanks Ricky for the explanation.

Again, as evident with our new Friend 'Army Dude', I think you're causing a lot of unnecessary confusion.

Folks, 911 front suspension components will simply bolt on a 914. It is 'highly' advisable to get 914 inserts for your 911 front end. To take it further:

For narrow body 914's, I like what the factory used:

69-73 911T front suspension - These were generally set up for through body sway bars. They have 3" mounting ears for 911 M-Calipers Which are all you will need with the tire packages that can fit under the narrow bodied car. These will accept 'any' 914 strut out there (Boge, Koni, Bilstein, KYB, etc.)

For wide body 914's, I like what the factory used:

67-73 911S (Koni or Bilstein) front suspension - As above but are set up for 3.5" caliper mounts (A or S-Calipers). These calipers are good for much larger tire contact patches and are better suited for HP up to 240-250. With these you will have to special order custom valved inserts.

QUOTE

All along I was trying to send the message that the off-the-shelf 911 INSERTS are not ideal for 914´s. This is very true.

Hmmmm... that's not what you said here:

QUOTE

911 front struts are not the best option for a 914 because you can only install inserts that are designed for 911 chassis dynamics

Regarding the INSERT statement, (IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif) for the most part. Keep in mind, you experienced "Bilsteins" valved for a VERY heavy late model 911SC. I believe a set of Koni's for an early 911 turned full soft (where I keep all my Koni's) would be 'fairly' indistinguishable. Bilsteins are great shocks but they are a set-em and forget-em 'Sport' shock. For that reason alone, I like Koni's.

QUOTE

Isn’t it also misleading to say that a 911 front end swap is just a bolt-on upgrade? This statement sounds to me that you swap the front end, and that’s it.

The front suspensions are virtually identical in their form and function. I don't think most buyers buy these expecting plug and play improvements. I think they want 5-lug hubs and possibly bigger brakes. I agree, there's probably a large contingent that just swap them out and call it a day, but, I think there's an equally large contingent that know what's going on with inserts... you simply don't run 911SC Bilstein inserts on a 914 (as you now know).

QUOTE

After all this interchange, however, I would recommend anyone contemplating this upgrade to avoid 911 suspension setups with Koni or Bilstein struts. I myself made the mistake of buying a 911SC setup with Bilstein struts just because I did not know.

This is where we'll have to agree to disagree. What you bought was an SC front end. I don't think the purchase was a mistake. I think leaving the 'ultra-wrong' 911SC Bilstein inserts in there was a mistake (as you yourself attest to). For 1/2 the money spent on 914 strut and spindle mods you could have had the proper inserts to slide into your struts.

This is also where I think it becomes misleading. For people who want or need 3.5" brake spacing, these Koni or Bilstein front ends are a 'very' viable solution. These struts (struts only) can be purchased for $250-$300 a 'pair' all day long. Complete 911 front ends go for anywhere from $200-$600... not $1,200, hell, you can buy a sawzall roller SC on the birdie board for $3k, why would anyone pay $1,200 for the front suspension. Someone recently asked about a front end from Oklahoma Foreign at the wonderful $1,200 price and the replies came back unanimous "RUN AWAY".

QUOTE

I chose the easiest route, and the one that would get me where I wanted.

Again, I don't want to belabor or nit-pick but I think the easiest route would be to buy some revalved inserts for 1/2 the cost. You chose a route that got you what you wanted. Here's some real world cost examples that should be fairly easy to beat:

Yours with the cost of struts thrown in:
Labor $750
SC strut cores $250
Total $1,000

-vs.-

911T Struts $250
Your 914 inserts $free
Total $250

-or-

911T front end $400
Your 914 inserts $free
Total $400

-or-

911T Struts $250
Koni 914 inserts $275
Total $525

-or-

911T front end $400
Koni 914 inserts $275
Total $675

-or-

SC Struts $250
Proper Inserts $350
Total $600

-or-

SC Struts $250
Proper Inserts $350
Chris Foley Raises the Spindle $225
Total $825

QUOTE

When I replaced the Bilstein 911SC inserts with the Koni 914 inserts, there was a lot of improvement in ride quality and the handling of the car.

Ya think (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif) (IMG:http://www.914world.com/bbs2/html/emoticons/lol3.gif) I really think this is the issue here Ricky. People need to understand that you had a bad experience using Bilstein 911SC inserts on your 914. I would add… of course you did.

Again, Ricky, not bashing you... to 'me', your previous posts are extremely misleading. They read like "If you bolt a 911 front end on your teener you'll have a harsh ride". I agree wholeheartedly that the inserts should match the car not the strut, so, if this thread will help more people understand that then it's a good thing. I already had someone PM me last night worried about buying a 914 now that has a 911 front end on it... this is the wrong message to send.

I also think that 80% of the people out there can find some 911T struts and bolt them on their car for less than 1/2 what you paid (maybe even 1/4) and have all the benefits they might be looking for (5-lug, vented rotors, m-calipers, cheaper rotors, larger spindles, beefier bearings).

On to your brake question:

Your A-Calipers up front are overkill but the “system” you have with the T-fitting and the vented rear calipers should be “OK”. You are seriously on the edge of what I would call too little rear brake but that’s much better than too much rear brake.

Options:

* Keep your eye out for a set of –6 calipers.
* Watch for Marty’s “Spot-Caliper” to hit the market and then move to 911 rear M-Calipers.
* Perform the 911 hand-brake conversion (whew… find cables, find early hand-brake assemblies, grind, etc.)

I would keep what you have and have a friend video tape some parking lot stops. See if your rears are even in the game. You’ll want them to lock up after the fronts for sure.

(that's the end of my new, New Testament... I promise) (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[rickyhgarcia]

QUOTE

* Watch for Marty’s “Spot-Caliper” to hit the market and then move to 911 rear M-Calipers.

What´s this??

[GTPatrick]

Eric & Ricky, . . . . .

What do you guys mean by a 911 insert & a 914 insert ? What's an insert ???? Do you mean shocks or what ??? (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif)

Being a relative newbie to 914s , sometimes the terminology befuddles me. (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif)

[rickyhgarcia]

QUOTE (GTPatrick @ Apr 1 2006, 10:39 AM)

Eric & Ricky, . . . . . What do you guys mean by a 911 insert & a 914 insert ? What's an insert ???? Do you mean shocks or what ??? (IMG:http://www.914world.com/bbs2/html/emoticons/blink.gif) Being a relative newbie to 914s , sometimes the terminology befuddles me. (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif)

The insert is the front suspension damper...the front end shock absorber.

[rickyhgarcia]

QUOTE

Again, Ricky, not bashing you... to 'me', your previous posts are extremely misleading. They read like "If you bolt a 911 front end on your teener you'll have a harsh ride".

This was never my intention. A strut is just a casing...what causes the harsh ride is the insert inside.

I was looking at 911 weight data from 1963 thru 1989 from a British magazine (GT Purely Porsche). In 1963 the 911 weighted 1080Kg and it kept going up to 1210Kg for the 1989 Carrera. The 80´s 930 was 1300Kg. The same publication lists the 914 weight at 970Kg. Even the 1963 car is already 230lbs heavier than a 914.

The 911 has a rear weight bias with a near 40/60 weight distribution, while the 914 is close to 50/50.

These are the reasons I was refering to when talking about 911 inserts being wrong for the 914.

When I started modifying my car, I wanted: late 911 front brakes (911 has to be better..right?) although they must have the correct 914-era appearance (i.e. no big red Porsche calipers), 5-bolt conversion since I like those 911 Fuch alloys (again 911 must be better), and better suspension components for A/X. Additionally I wanted a lowered car. I got 2 out of 3 when I obtained the 911SC front end suspension. But this "911 must be better" attitude without researching made me buy what later on resulted in the wrong suspension components.

I hope these pages will help others to choose the correct setup when upgrading their suspensions.

[JFJ914]

QUOTE (Eric_Shea @ Apr 1 2006, 01:17 PM)

QUOTE After all this interchange, however, I would recommend anyone contemplating this upgrade to avoid 911 suspension setups with Koni or Bilstein struts. I myself made the mistake of buying a 911SC setup with Bilstein struts just because I did not know. This is where we'll have to agree to disagree. What you bought was an SC front end. I don't think the purchase was a mistake. I think leaving the 'ultra-wrong' 911SC Bilstein inserts in there was a mistake (as you yourself attest to). For 1/2 the money spent on 914 strut and spindle mods you could have had the proper inserts to slide into your struts.

Eric,

Original Bilstein, Koni and Boge struts do not have inserts in them. Pull the cap and all the oil and guts fall out. IIRC, all the Bilstein and Koni inserts sold as replacement parts will only fit the Boge strut. I believe you have to have the Bilstein and Koni struts rebuilt as their own inserts will not fit.

[Eric_Shea]

QUOTE

Original Bilstein, Koni and Boge struts do not have inserts in them.

(IMG:http://www.914world.com/bbs2/html/emoticons/smoke.gif)

I've seen this before and it may have been on a few select Bilstein inserts. If you think about it, there really isn't much need for the casing around the insert. However, in the face of replacing or repairing one, the inserts have the advantage. In some cases you may experience 50ml (50 right?) of anti-freeze in the strut tube. This is what the mfg. recommends. You also may be talking about a Hydropneumatic strut. The Boge strut takes all three inserts and then some. They definately come with inserts or can be retrofitted if they came in naked form as you describe.

QUOTE

I believe you have to have the Bilstein and Koni struts rebuilt as their own inserts will not fit.

This is not accurate. I have Koni struts on both my 911 and my 914-6/GT clone. They both have new Koni inserts.

Koni Struts = Koni Inserts Only (you can get inserts)
Bilstein Struts = Bilstein Inserts Only (you can get inserts)
Boge Struts = Boge, Koni and Bilstein Inserts

Again, this is why I like the early 911 Boge strut for all of the narrow 914's out there. It comes with a brake that is a worthy successor to the already excellent 914 front brake (they look nearly identical, the M is just slightly larger). The M-Caliper won't seriously overpower the rear 914 brake if a T-Fitting is used. The other manufacturers make excellent 914 replacement strut inserts that drop right in this little beast. You'll get vented rotors and an ever so slightly larger t-bar (18.8mm) which may help a bit at the auto-x course.

QUOTE

But this "911 must be better" attitude without researching made me buy what later on resulted in the wrong suspension components.

Well... there are a lot of nice things about the 911 components (beefier spindles, bearings, vented rotors that are fairly inexpensive and you don't have to get wheel bearings etc. when you replace the rotor, brakes can be more substancial) but I agree, I agree, I agree. A 914 suspension is excellent and literally identical to a 911 unit. A 914 dimed in with a nice set of inserts, good bushings and a sway bar should really afford no difference in ride quality and performance over the proper 911 counterpart.

If people want to go for the 5-lug look, (which I still think is the way these little beasts should have come from DE (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif) ), then a nice early 911 front end is definately the way to go. JUST GET 914 INSERTS (IMG:http://www.914world.com/bbs2/html/emoticons/laugh.gif)

QUOTE

What´s this??

Marty (MSDS) is rumored to have been working on a spot caliper. I'm 'guessing' the mount would replace the bearing cover. Now you can add a 911 rear caliper and not have to worry about the parking brake. These spot calipers are small calipers that are cable actuated and act as the handbrake. They're rumored to utilize the factory handbrake cables. When these become available, they will take a large trouble spot out of a standard brake upgrade. Yours for instance... 911 rear M-Calipers and this spot caliper. Done.

As mentioned in other threads, this is for cars with flares affording larger contact patches and higher HP engines. We don't want to get caught up in the 911 is better thing. 914 brakes are excellent for all narrow bodied cars with the exception of those who are working seriosly demanding road course circuits. This is the only time we've heard of fade.

James started an excellent thread on this (brakes) a couple of days ago.

[soupbone]

So the question for me is who can do custom valved bilstien fronts for a 914 with 911 front end with A calipers? What sized aftermarket sway bar would be a good match? Polybronze or roller bearing? Opinions or gospel on a primarily street setup with some DE.

[neo914-6]

QUOTE

Marty (MSDS) is rumored to have been working on a spot caliper.

Check the MSDS link in my sig. they will be on my car at Nov SEMA. They only fit on the vented early 911 (9146) rear rotor right now...

BTW, my V8 914 has 911 Boge struts, Automotion conversion kit for Koni adjustable inserts, Brad replaced my "S" w/ "A" calipers, 8" wheels...

[jasons]

QUOTE (soupbone @ Apr 1 2006, 11:43 PM)

So the question for me is who can do custom valved bilstien fronts for a 914 with 911 front end with A calipers? What sized aftermarket sway bar would be a good match? Polybronze or roller bearing? Opinions or gospel on a primarily street setup with some DE.

(IMG:http://www.914world.com/bbs2/html/emoticons/icon_bump.gif)

Enquiring minds want to know......

[Eric_Shea]

Try Jack French at Bilstein he can be reached at 1-800-537-1085

If you purchase new struts you can generally tell the supplier that you want them revalved by Bilstiein and that you have the specs that Jack French at Bilstein needs.

Price will be the cost of the struts, plus the shipping to Bilstein. The revalve fee is usually $65 per strut and then you will have return shipping charges from Bilstein to you.

If anyone already has the struts you can send them to Bilstein yourself and your revalve fee is a little less at $55 per strut. Send them to:

Krupp Bilstein of America
14102 Stowe Dr.
Poway, Ca 92064
Attn: Jack French

They will only work on your struts if you pay the revalve fee in advance or use a credit card.

Regarding your street/autocross car. I would recommend a stock 15mm or at the most a 19mm sway bar.

Regarding bushings... your choice. They're both excellent.