Are the ALSTONS alone enough for the average joe ?

One of my cars is a built 305 and the other is a bone stock 89
in my sig to the left.......

surely these alone would be enough ?

 

Yes, imo the alstons and macs add more rigidity by themselves compared to side sfcs apart from pinch welded spohns maybe. I have macs on one car. Home made side mount x braced ones on another and macs + home made sides on another. My buddies gta had umus and I added alstons recently. They improved upon the umis.

 

I agree. I have alstons on my 86 alone and they added a ton of rigidity to the car. You do lose a little ground clearance over other styles, but that's not an issue unless the car is stupid low.

 

Stupid low...lol.....I agree

 

Yes, they are enough.

 

Wait, are you guys saying that they add more rigidity than perimeter ones? If yes that's definitely counter intuitive...

 

No it's not, they tie directly into the fr and rr subframes. The side ones don't. Only the spohns are welded to the pinch and as such tie the whole into a large triangulated structure. The sidemounts tie into the front subframe from tge side. Itls like comparing a straight bar to a c. What us more torsionally stiff?

 

Stock high guys are you dragging these SFCs ?

I decided against a deeper tranny pan because I was concerned about dragging....obviously a bigger prob if tranny drags but would rather not drag the SFCs either ?

 

Mine don't drag anymore since I swapped to 19s ut they did when I was running 18s and also with the stock wheels. Car IS lowered.

 

My car is lowered, not stupid low, but a good looking height. I have never scrapped the alston connectors.

 

My car with them was pretty low, but I had the T56, I know I bottomed out the trans xmem, but dont think the sfc's hit anything, they didnt reduce ground clearance much, if at all.

 

Stock height here, no scraping to report.

 

I drag my alstons from time to time....car is fairly low.

 

Can you run stock exhaust with the Alstons? I'm thinking about getting a set but I don't plan on changing my exhaust for awhile.

 

I had a great local muffler guy in California- Rod's Muffler in San Juan Capistrano- put mine in. He got them high and tight AND redid the catback system so it fit correctly and everything fits like factory with no interference at all. Great guy if you are in the area...
BUT mine scrap on speedbumps etc. Mine is STUPID LOW(thanks for the vote of confidence in my intellect by the way!) though. The upside is that the SFCs are the lowest thing on the car, so IF I scrap I know that it is not the cross member or the exhaust...

 

You guys convinced me.............so I need two sets of Alstons
for two cars. Best place to buy price wise ?

 

I have MAC (essentially the same as Alstons) and SPOHN SFC's on my 86. The MACS changed the car completely, the SPOHN's added even more rigidity and stiffened things up (most likely due to the stitch welding along the rocker). I have Edelbrock headers with a 3" walker cat and flowmaster 3" catback exhaust and it fits good. The SFC's hang ever so slightly lower than the lowest point on the cat and i am lowered about half an inch and it has not scraped on anything (speed bumps, curbs, etc.) I am about 27 to 27.5" ground to fender height so it's not that low compared to many other 3rd gens on here but so far there is not scraping.. Actually, the air dam in front is the LOWEST point on my car lol so if I'm going over something I'm not sure of, if that air dam doesn't scrape it's fairly safe to say the rest will be pass over it fine.

 

I have Alstons and ProKit 1 on my 91 TA. My car is lowered about an inch and I find that speed humps love my connectors if I dont go slow enough over them. I was going to put a set of Spohns on mine but I dont think that is the correct way to go. They mention to weld them to the sill area of the car but I dont think they take into account that there is that sheet metal boxed area running along the sill. I just dont think that it is suited for welding along that box and I dont have any intention of welding to the floor. I think that is a source of rust in the later life of the car. My Alstons are very good, so I think I will stay with that. By the way, I did purchase the Spohns and decided not to install them. Hope that helps.

 

Yep good info but whats a Prokit ?

 

Sorry, Eibach Pro Kit lowering springs!!

 

Got my Alstons today...........so those that have installed their own ?

How much of the factory exhaust did you have to lower/remove ?

Thanks..............

 

I believe I just had to unbolt the cat from the hanger.

 

I keep reading this from you and gotta say you are so wrong on this. Respectfully- you are looking simply at the underneath of the car in a 2 dimentional form.

The rear chassis area inside and above the chassis attachment point of the LCA where the perimeter style SFC tie into happens to have alot of upper chasiss struture. The horizontal boxed structure of the rear seat metal chasis structure(then floorbaord shear walled), as well as the vetical rear seat panel tied into the fenderwells- then both spotwelded and glued together . This whole section is so strong it is rediculous. Tieing periemeter SFC's intot he LCA points does in fact VERY STRONGLY tie the rear chassis section into the front half of the car. the chassis on these cars show their weakness with a stress crack right at the upper rear of the side windows where the fornt half of the car and the back half flex in chassis twist. Your inner SFC's will not reduce twist not nearly as well as the outer style SFC's do especiall when properly installed with increment welds to shear wall the structure.

 

No, they are not.

If you could take a brand new 3rd gen off the factory line with 0 miles on the chassis structure, and then weld only alston SFC's onto it, the upper rear side sindow corners of the body will still crack in due time like they all are notorious for. ift will prolong this from happening due to slightly more rigidity, but it will still eventually happen and probably 12 years rather than 10 years of chasiss fatigue. The hard top cars are notorious for these cracks from lateral chassis twist. FACT! and DOCUMENTED!

 

Please don't intertwine whats not good enough for autocrossing with whats not good enough for the average joe street driven vehicle.
You know what I mean.............

Your facts and documented theories below are just that...theories and wouldn't hard top cars be more rigid than t-top cars.......have to question your theories when you single out hard top cars which we all know would be stronger than t-top cars.

Not here to make friends or kiss *** but we need solid info, not someone's theory.


Obviously perimeter connectors along with INNER bars would be the ultimate just like a blown big block would be nice as well.

But on your average bolt on street driven vehicle lets be honest and understand the average joe doesn't need both and TBH the extra weight and clutter underneath the vehicle is a deterrent to me.

 

I do not know if you can not comprehend what you read and answer upon? ...but no, I do not know what you mean.

1)I listed a very clear fact that hard top cars have a notorious weakness for developing roof cracks at the rear of the side window corners.

2) I never said this was for autox only- I listed a perfect example of a 0 mile brand new chassis will develop these cracks over time. the harder the car is driven, the quicker they will appear, but they will appear eventually on every hardtop car because of weakness in this area combined with chassis fatigue- it will happen to all of them if not supported better than OEM.

3) Jetmech, where did I ever say a hardtop car is inferior in strength to a T-top or Convertable? If you want a fact from me then ask for it and quote it correctly- Hardtop cars are the strongest of the 3 OEM chassis designs- that is my statement. To argue that is nonsensible given the known in the automotive industry.

4) A blown bigblock is not ultimate. "Ultimate" being stated without specifics means the best for everything combined. These cars are not and never were designed to handle the weight or size of a bigblock- so your statement here makes no sense either. Do you think when you post? Or do you just like to argue with people regardless of facts and helpful info?

5) I have made the comment that inner and outers would be best as long as ground clearance is not an issue(To go over every thing you worded whether I agree or not, this I agree)- I have also stated that the added weight of innse styles is not that much for harmful acceleration or braking or cornering weights, and the actuallity of it is the weight these add are added in the best place possible to a chassis. That position being low and centered between the axles of the wheelbase. I also feel that it was never needed on my car so I never did it nor would I do it if I still had that car- just my choice whether its right or wrong in anyone elses eyes- to me it was not necessary. The amount of beneficial would not overcome the amount of harm to me being low. I could drive plenty fast over bumps and dips with the car low becuuase of my low oveerall chasiss weight and very low unsprung weight. Most could not at my same height (pretty much all could not- the weights of my car were very unique to anything on these boards)

6) I agree with not sugar coating things. I list facts and experiences so people can best make a purchase decission. What I listed here are facts, not theories. I would adviose you to reread what I posted and then what you responded because your response does not hold water , nor pertinant info to help anyone. Mine doies and it is very descriptive as to why I posted helpful info and facts.

7) The fact that I take the time to type this stuff shows I car about people learning correct info. I have no quest to be right, I have a desire to be right so I am helpful, and I have a quest to be factual and admit and thank others when it is addressed that I posted wrong info or misleading info, or also just plain wrote something with something else on my mind- yes I am guilty of all three and have no shame in someone pointing out I make mistakes- I am human. What I do NOT tolerate is someone like you coming into here twisting my words trying to make me look bad just because you have a superiority complex. I stand by my post and my facts. Dean

 

In other words you say I'm full of **** since you are right?

I do not look at this as a 2 dimensional thing, I look at the SFCs as 2 dimensional because that's all they are and like a ladder frame, a 2 dimensional trus type beam, setup delivers marginal torsional stability because of the failing height or 3rd dimension in the structure. Welding them to the car adds the chassis as the 3rd member but it's still stock and as such the structure there performs just as stock. You are not beefing up the dimensional stability of the front subframe and rear subframs (fore of firewall aft of rear wall) as much as you would with a full cage tied into the suspension points.

Realizing this, the spogns only have the added benefit of adding the weld poionts on the rocker boxes to tie the structures together a good bit better BUT THEY DO NOT triangulate anything, nor do any of the others. In my 1st post in this thread I specifically distriminated between the pinch welded spohns and the others

 

I wish people would refrain from putting words in my mouth.

Waht I said was, "RESPECTFULLY, you are wrong with your quote that the outer style SFC's do not tie directly into the subframes. They do tie directly intot he very rigid rear boxed chassis section. I also said to thouse that assume they do not by looking under the car and see a 2" void betweent he LCA mount and the innser subframe rail is that the top side of that section is engineered as a boxed sheetmetal support area that is very rigid.

I never said you are full of ****

 

I did not say that they do not tie into the subframes, I said directly as in they tie in from the sides. That leaves them as a long force arm ready to twist and this makes them a whole lot less efficient. The front torsional forces and the rear torsional forces are both submitted to the unibody through the subframes since that's what the suspension and engine mounts to. If you want to keep those structures from twisting the quickest way is a direct shot set of bars between them, these bars withh lave to twist lengthwise to allow twisting. This is a much stiffer solution thanh a simple set oif beams running along the side that come straight forward off the rear arm mount and connect to the front subframe with a several inches long beam perpendicular to the lengthwise beam. This is the force arm that will try to twist the long lengthwise beam. No triangulation anywhere, all of these commercial SFCs oily have 1 bar running to the front sibframe.

Check out this post, that is exactly what's happening (poists by anesthes)

https://www.thirdgen.org/forums/susp...rs-design.html

 

I read this quote and will suggest that you are not getting the understanding of the chassis. I will make further drawings so you understand better. What you are saying is completely backwards about the twisting. The Alstons twist, the Spohns do not. For some reason you are not seeing that concept when at least to me it is quite obvious when I know the OEM structure of the unibody like the back of my hand. I will start by highlighting both the front subframe structure and the rear in separate colors. then we will go to the next post for more pictures after this. To further add, even though the Spohn style is longer in span, it has stitchh welds along it that the Alston design can not do. Also, the spohn style has mid attachment support with a lateral (triangular) connector arms that helps keep the span from twisting (hence the ladderbar concepton the beam). Why are you not getting this? The leverage of the shear panels acting upon each style puts much more twist strain on the inners as opposed to the outers- look down more for example pics. They make the Alstons alot larger diameter to try and compensate for this, but given the shorter length and larger diameter, they are not subjected to the same twist force. The inners are free floating and way too close together to hold the wider lateral structure from twisting upon them. The inners are taking at least 10x the force acting upon them.

Also as for the link- that BMR is a completely different design that both Alston and Spohn, and is foiolish of them not to span all the way up front and tie into the lateral subframe block that exists already in the OEM chassis under the firewall section. What I think you are not seeing is strong solid sections of the OEM subframe with the green dots.

 

Now lets look at the lateral shear walls in the front and the rear of the cockpit. The front is the firewall, the rear is the rear seat panel that shear walls the entires rear spring cup areas of the chassis. Note the fore of the firewall we have standard frame rails up in front of the unibody that front subrame turns into obviously (I know you know this, Im just going over basics) so the firewall and front unibody section of the front subframe are vetricaly boxed by the shear wall of the firewall strength. If the the firewall assembly moves in a longitudinal twist (ie-from engine torque, or from road imperfections forcing up on one side of the front suspension spring pocket, etc) it will be out of line with the rear subframe. To paint a better picture= look throught rear diff towards the engine. Think of the rear diff as the rear subframe, and the engine as the front subframe. in clock position they both point up at 12 o'clock when static. When the above forces are applied in twist, the rear diff goes to 1 o'clock and the engine goes to 11o'clock in chassis twist. That twist takes place throught the mid section of the car. The further out on each lateral shear wall the SFC's connect to, the less this twist will happen....period.

 

Sorry to bump this, but I just installed the Alstons, which went in without too much effort, but the hanger from my cat is hitting the passenger subframe connector, and is now vibrating the hell out of me inside the car.

How important is the cat hanger? Is it a big deal if I eliminate it all together?
Or should I attempt to grind/clearance the hanger?

 

you can see mine in black

 

A rocket scientist could find flaw and improvement needed in the entire car 100x over.

Alstons are nice, a nice contour tubular shape connecting the frame,
[And yea you could find 999 ways to improve them or any design.]
not just some straight runs of square tube anyone could build.

Before them, jack up left front and left front rises.

After them, jack up left front, entire left side rises up.

And its very stiff over stock. Like riding a gokart across a cornfield if there are cracks in the road, you feel everything……….