Iron Spec Coilovers

[sheizasosay]

Spec Iron Coilovers

Ok, so after nobody had any info on these coilovers and only speculation in regards to the rears looking a lot like AST 4100's I talked via phone and email to Brian Hanchey of HVT. Actually I talked to a guy named John first who runs the Roehrig shock dyno and does rebuilds and custom valving jobs. I have never heard of Hanchey or HVT before Dontlifttoshift mentioned JRi's that he saw at SEMA. That's how I found the Iron Spec coilovers.

When I saw the front shaft I immediately thought "Bilstein Frankenstein", but in a different strut body. And as CSamsh pointed out, the rears looked suspiciously like the AST 4100's which apparently have had some serious issues. So, after having talked to Mr. Hanchey for a while, it turns out they have been supporting endurance races such as Grand Am Continental Tire Sports Car Series. I asked Brian a handful of questions and one of them was "why are those rears not AST 4100's". Brian's reply was: "They are not AST 4100s. Some parts are made to our spec by AST, but I don't really want to go down that road or discuss what is and is not made from them. Needless to say, I have personally lived through the disaster of AST 4100s (especially with Mustangs) and we have made something that works well and is made to last. Otherwise, we won't sell it. I'm done with untested products. The products we sell come directly out of our involvement with professional road racing. Three years of racing has shown us how to build this kit for the street and track. These are all proven parts from the street and track and should be considered better than 4150s."

The spring rate range the Spec Iron's were designed for are: fronts 350-600in/lb and rear 175-450in/lbs. They can do custom valving and I think he said about $75 a damper.

One of things he mentioned more than once was how little stiction these dampers have. He said the Spec Iron's, depending on the car, are within the 0-40lbs range. He listed competitors at about the 125lb range. I asked what G they tested it at and he replied 1.5G and thats as far as their equipment would allow. He mentioned top-tier dampers to include Moton when he was talking about stiction. Since the fronts on the Iron Specs looked like Bilstiens, I asked if they had tested the Bilsteins on their machine. He said he had not. I would be willing to bet it would be low on the Bilsteins, but that is still a guess. I know of one AIX champion that was running Bilsteins specifically because they were better with side loading. That's probably a discussion within itself in regards to side loading and stiction and what impact it can have.

I realize this isn't an all-inclusive info in regards to the Spec Iron coilovers. The obvious information is here: http://www.hancheyvehicletech.com/product/HVT-F1001-SI.html.
The other stuff on "specifically" what has been done to make these different you might be able to get if you called him. I don't know. For $2400 you get a full set of rebound adjustable, monotubes and they come with your choice of springs and have been engineered or spec'd out by a company supporting road racing for several years that can do rebuilds and shock dyno's and custom valving in-house has an appeal. There are other products they offer like the ability to adjust your damper settings in-car and with the push of a button select "oversteer" or "understeer" and lot of other features that while I think neat....WAY outside what I'm willing to pay. But I will give it the "neat" award.

Some interesting info: In 7-post rig testing, our new design created more grip than 22mm shaft race dampers. Recently, our new 6200r was the fastest Mustang in IMSA Daytona testing and beat all infield sector times for the pole position BMW during the test! Proving, our design handles better than some 4-Way designs from our competitors.

Furthermore, our HVT 6100 kit is used for NASA's Spec Iron race series that uses the Mustang S197 chassis. Spec Iron Mustangs are consistently running American Iron times, winning poles and even races in some regions. This is in full Spec Iron trim running against prepped American Iron cars! Our 6100 kit works well for dual-use vehicles that drive to the track and run track day weekends as well.

 

[ArizonaGT]

Interesting.

 

[sheizasosay]

I want to try them out. Know anybody that needs some low mile Koni Yellows and springs?

 

[jayel579]

What is the cost limit per axle for Spec Iron on dampers? Is it still $2k?

 

[sheizasosay]

What is the cost limit per axle for Spec Iron on dampers? Is it still $2k?

You have to use mostly Ford Racing parts. They list the parts allowed to be used for Spec Iron.
7.14.9 lists the HVT shock package as being permitted http://www.nasaponycars.com/uploads/2014_Spec_Iron_v1_0.pdf

For American Iron it is :
7.12 Suspension
7.12.1 Control arm mounting points are unrestricted on all cars but may not violate any rules herein (i.e.
frame modification or IRS rules).
7.12.2 AI cars must utilize upper rear OEM shock/strut attachment points. Any shock attachment mount
may be utilized in order to fit to the OEM shock attachment point. Note section 7.3.2 for
exceptions to this rule.

And I didn't bother looking, but American Iron Extreme shouldn't have a price limit.

 

[DILYSI Dave]

I want to try them out. Know anybody that needs some low mile Koni Yellows and springs?

Maybe...

 

[SoundGuyDave]

SI is essentially shaking themselves out as a spec series (hence the name Spec Iron), and HVT has been tapped to provide the spec damper sets. AFAIK, everybody is supposed to be on those dampers, and no others. Spring rates are open, within a defined range. From what I've heard (and seen), these are supposed to be some pretty good dampers, actually.

 

[sheizasosay]

Delete

 

[modernbeat]

So I got a message asking me to give my thoughts on these. Initially I did not want to because we are competing vendors in some aspects, and we also supply parts to each other. But there are misconceptions about the appropriate application of the Spec Iron kit that when used on the street may give AST and HVT and undeserved black eye.

First, I understood that the NASA Spec Iron Championship race was canceled at Miller this year because non-delivery of HVT suspension components meant that there were only two legal cars that registered.

Hanchey is correct that the 4100 dampers for the S197 that he specified had some issues. We specified a different design that did not have an eye-to-eye or inverted damper in the rear and had no issues with them. There are issues with the adjuster in the 4100 that were corrected in the 4150.

We also built the prototype housings for some of his strut designs. And we built the rig to test side loading on struts because there are some minor issues with overcoming initial friction (sticktion) on inverted struts at very high level motorsports. We typically only recommend them when necessary, like on rally cars, or for heavy sedans with long stroke suspensions that end up with very little overlap between the strut and casing at full droop. Sticktion on non-inverted struts is fairly low. And high end inverteds like EXT-TC and Bilstein Motorsports tend to fare well.

I took a look at those Spec Iron shocks. The rears are the same short-stroke eye-to-eye design that we refused to accept and look suspiciously like a mix of a copy of the JRi Harley dampers up top and the same cap on the bottom used on the short stroke rear AST Xida shocks made for Miatas. Looks like he is making the front strut housing out of AST 4150 S197 casings adapted to the inverted design (stronger, but lose some stroke). Having already worked with dampers in this form factor on the S197 I would not recommend them for dual-duty use, but only track use. The lack of rear stroke is the real turnoff. But I know that Brian knows how to valve a damper decently and he learned something from his trial by fire in Grand Am. Just ask the Grand Am teams.

The HVT-AST S197 Grand-Am kit.

The current Spec Iron kit

The early 4100 S197 design we refused to accept

The AST 4150 for the S197 in the Vorshlag Configuration

The JRi Harley shock

AST Xida Miata damper

 

[SoundGuyDave]

Interesting, Jason! I know exactly what you mean about the stroke limitation on the 4100 rears (still have 'em on my car, ride-height up to compensate). Just in the spirit of full disclosure, though, for those that don't know:

2013 was Spec Iron's debut season. The rules were announced in early 2013 after the details were hammered out with Ford Racing to define the "spec" package.

The actual damper "definition" specifying HVT as the sole vendor of the sole model number legal dampers was published as a rules update in late March, immediately after reaching agreement between NASA and HVT. At that point, production had not started, nor had materials been ordered from suppliers for the damper construction.

Initial deliveries of finished product were projected for April (rears) and May (fronts), and a variance was granted to allow SI cars to compete on a regional level without the spec dampers until they became properly available. IIRC, the cutoff date for conversion was the first day of Nationals, in September.

The first kits finally shipped (issues given were parts supply, inconsistent plating from a vendor, and one design error that necessitated re-order of the strut casings) in late June, which is still fairly quick to ramp up production on a relatively complicated part essentially from scratch.

There were further issues with installation involving endlink length, and that further delayed widespread use.

Given that at the time of Nationals in 2013, there were probably only 10 serious SI builds completed (+/- dampers) that could meet Nationals tech in all respects, it's not a shock that only 20% signed up.

For a brand-new race series, I think you would have to call 2013 a typical development and growth year. It takes time to get the bugs out of the designs and cars, and to get them dialed in with all the new parts. If you were to put yourself in the position of a privateer racer (not shop- or manufacturer-supported), would you commit to the VERY expensive haul to/from Miller with an under-developed car in the hope that everybody else there would be less developed?

Not trying to lean either way on this issue, honestly, just getting the info out there so that there's some perspective.

Jason, out of curiosity, for a coil-over application on an S197 (NOT using the OE spring location) rear for race-only duty, what would you recommend, and what's a rough price? Not looking for a hard quote, and not looking for paperwork, just trying to get an idea of what it'll take to do the conversion in back.

 

[modernbeat]

Unless you were allowed to re-tub the back of the car and build new shock mounts far inboard of the OEM location, I would NOT recommend a coilover in the rear. It takes up far too much inboard room for wide tires and the "advantage" of being able to swap springs quickly that is touted on the Spec Iron page is a fallacy. It's easier and quicker to change rear springs when they are located in the stock location. But if you HAD to run a set because of rules, it would be about the same price as a non-coilover would cost. The savings on not having to purchase rear ride height adjusters would compensate for some of the other parts and the more expensive narrow 2.25" or 2.0" springs necessary to run a coilover.

FWIW, almost everyone's rear shock is threaded today. If someone really wanted to they could source a couple perches, space out the top mount and add springs to the rear shock. Even the MCS we offer for the S197 are threaded, but you won't find us offering the parts to make them a coilover. There's no real benefit.

Linear springs in the stock location do not require any tools to swap out.

This short shock that was run in Grand-Am has caused other spillover issues. We constantly hear from customers that want a very stiff rear spring relative to the front spring because they heard that was what this or that Grand Am team ran. Well, they have to run a stiff spring to keep the car from bottoming out the suspension due to short stroke. That spring rate causes other issues, but re-educating customers that ask about it, and the confusion it creates is a hassle.

 

[SoundGuyDave]

We had an interesting discussion a while back on rear spring rates relative to the motion ratio due to the inboard spring mounting locations... Essentially, in pure bump, you can add the rates of the two springs to get an ideal of effective rate (300lb springs yields an effective 600lb bump rate), however, in roll, you wind up with a percentage of a single spring; in the case of 300lb/in springs in the stock location,you get a "roll rate" of 114lb/in, but a "bump rate" of 600lb/in.

I can understand where you're coming from with respect to shock location to allow wider tires, but if you're running AI (for example) you're limited to a 275mm tire on a 9.5" wheel, so space isn't an issue. Do you see a benefit from running a more consistent wheel rate in both bump and roll with a smaller bar or no bar at all? I'm thinking in terms of damper control over squat versus roll. Shaft rates would look similar, so the same valving would be in play, but in roll, there's a great big whopping rear swaybar that has to be controlled as well...

I hear you with the "spillover" issue. This is one of the BIG problems with people playing "monkey see, monkey do" when they may not have the whole picture. Just because "so and so" run a specific part doesn't necessarily mean that it's the best possible choice. There well may be other factors playing into the equation. The short-stroke shocks are a perfect example. With mine, I have something like 1.5" of bump travel, but a MILE of droop travel. Not fun.

 

[STEVE_POE]

First, I understood that the NASA Spec Iron Championship race was canceled at Miller this year because non-delivery of HVT suspension components meant that there were only two legal cars that registered.

Just a fyi that is not the case at all. The reason it was canceled was because guys like myself found the amount of Time and money and the drive for a track like miller was not worth the costs.

I know of 6 that stayed home for that reason alone.

Spring rate is totally open this year and hvt is our spec shock everyone has to run it .

I have installed and ran a few sets of these. For the money they are fantastic in my opinion. They are no Moton Triples but If I was starting out and didn't have a clue about can pressure,Taking tire temps and pressures and carrying a box of other spring rate then they can't be beat for what you get for the money.

I don't know about using these on a street car per say Though . my car is a dedicated Track Car .

Also they require a specific sway bar end link for the front. so figure that into your costs on them as they are a few hundred dollars.

 

[sheizasosay]

The rules of AI also call for minimum ride heigth of 5". So these cars aren't slammed. Good to know about the end link.

We got HVT saying "Our 6100 kit works well for dual-use vehicles that drive to the track and run track day weekends as well."

Steve Poe saying "For the money they are fantastic in my opinion." and "I don't know about using these on a street car per say Though . my car is a dedicated Track Car ."

Vorshlag saying "But there are misconceptions about the appropriate application of the Spec Iron kit that when used on the street may give AST and HVT and undeserved black eye."

And taking into consideration of the fact that AI has a rule that won't allow lowering below 5". I will see if I can get clarification on the designed ride height range. Also, good point to note on the wheel width/tire of AI using 9.5" with a 275 tire.

 

[ArizonaGT]

Good discussion and perspective on these.

 

[dontlifttoshift]

I will pass along what (little) I know about the dampers I have.

JJ at JRi sold me the struts and rear shocks. JRi did not have strut bodies at that time but HVT was putting together the SI stuff so that is what I got with what I assume is a JRi cartridge inside and a JRi dyno sheet. I did not disassemble to verify but I have no reason to believe otherwise. Other than the strut body, the parts I have bear no resemblance to the HVT SI package.

The rears that I have are JRi with a JRi serial number and dyno sheet. Oddly enough, on my car with the hotchkis springs I was running at the time, I did not have enough droop travel. After one _sketchy_ track day, I used the adjustable spring perches and went to a standard coil over type spring in the rear to get the ride height where it needed to be and everything has been wonderful since. Also worth noting is the rear shocks mount conventionally, body down with a spherical on the lower mount and a stud on the upper mount. I used Maximum Motorsports bearing mounts for the upper stud, I think for SN95 applications, and machined my own spacers for the shaft.

 

[sheizasosay]

Response on ride height from HVT:

So they are made for that ride height (AI ) using 450/200 as the softest spring. Many guys run 500/250 or so. Remember this is a coilover configuration. Depending on spring rates you can easily go 0.5" lower. I would not go much higher though.