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Rennsteig SICMA 1.5 / 2.8 Project
Final Update
This project is unfortunately permanently cancelled. Every pre-order deposit and payment will be refunded in full or converted to store credit if you prefer. That is your choice, and we are contacting each of you directly. No customer has been asked, or ever will be asked, to absorb any part of the cost of tooling that does not perform as intended. Please check your email for direct communication on this and a link to a full disclosure.
What follows is the full history of the past four years. It is long, and it is deliberately detailed, because you trusted us with your money and your time and you are owed the complete picture rather than a summary.
We want to begin by thanking all of you for your patience, trust, and flexibility while we worked through one of the most complicated development efforts we have ever taken on, including the design, development, and release of our SS1.0 Solid Contact, which we have supplied into the professional motorsport, aerospace, medical, and defense industries since 2021.
Race Spec® is not a company that withholds information, quietly misses deadlines, or pushes product out the door that does not meet our requirements simply to chase revenue. We have built our reputation on the opposite: eight first-to-market solutions grounded in innovation, in listening to your input and feedback, and in identifying gaps in the industry and filling them properly.
This update covers nearly four years of history, so please stay with us.
• August 2020 —We engaged Rennsteig Tools to develop an exclusive die set for the AMP Superseal 1.0 terminal range, specifically supporting M22759/32 and Spec 55 wire, based on our own requirements for this solution.
• May 2021 —Die set formally released.
• 355 pieces sold worldwide to date.
An excerpt from the email we sent to Rennsteig after completing FAI testing:
“I’ve completed my overview and final testing and can now definitively say Rennsteig exceeded all of my expectations on designing and producing this prototype as all values exceed MFG specifications and requirements.”
• June 2021 —We engaged Rennsteig to develop a second exclusive die set for the Molex CMC terminal, specifically supporting M22759/32 and Spec 55 wire and accepting both the 0.635 mm and 1.5 mm terminals in a single die set, in response to numerous requests from clients using MaxxECU products.
• June 2022 —Die set formally released.
• 177 pieces sold worldwide.
• February 2024 —We engaged Rennsteig to develop a third exclusive die set for the Sumitomo HX090II terminals, supporting M22759/32 and Spec 55 wire and covering both male and female terminals in one die set, based on a combination of our own needs and multiple client requests.
• December 2024 —Die set formally released.
• 31 pieces sold worldwide.
We offer that figure in the interest of transparency, because we have nothing to hide. Sometimes the effort involved does not result in product flying off the shelf.
We share the above to give you clear insight into how long a project of this kind normally takes, what drives our assessment of whether one is viable, and what the results typically look like. The sales figures provide context for what a development effort of this scale usually returns. Sometimes it does not pan out, and that has never stopped us in the past.
In each of those three projects, Rennsteig delivered excellent results and earned our trust and confidence. First articles were perfect, and no rework or redesign was necessary. The only items that needed refinement were laser etching, product labels, and similar small details. The primary goal was achieved every single time, without deviation from our requirements. That track record is important context for everything that follows, and it is the reason we extended the benefit of the doubt for as long as we did.
In 2025, we learnedour Business Development Manager at Rennsteig was unexpectedly no longer with the company. While that person had no direct engineering or manufacturing role in our exclusive products, they bridged what we would come to understand was a significant gap between the smaller US office and the global headquarters in Germany.
After their departure, we learned further information relating to the exclusivity of the products above, specifically the products were no longer exclusive to us, despite our having funded their development with the manufacturer. This had not been formally communicated to us for any of the three products above. In hindsight, the signal was there. As usual, we put our heads down and kept working.
• Clients first asked us to produce a solution for this terminal family, primarily those working heavily with ECUMaster products. We discussed the possibility with Rennsteig, but the quantities we could commit to at the time, based on gauging interest, did not align with their minimum requirements.
• After two years of accumulating requests, we reevaluated the opportunity and believed the increased interest could carry it across the line. Development began with Rennsteig. Manufacturing in Germany and Italy largely closes for most of August and sometimes into September, so we did not expect immediate movement. From that point through the close of 2024, much of the initial groundwork was completed: tooling dimensional requirements, supplemental data sheets for this very complicated terminal range (more on that below), and working through manufacturability challenges.
• We also closed on our new building during this month and began planning a move prior to the end of 2024.
• 43 pre-order deposits were taken by Race Spec at $50 per customer (not per set) to solidify interest.
• Terminal and wire samples were sent to Germany for development.
• Rennsteig’s project coordinator was out of office for personal matters, and the project hit its first delay.
• Communication and updates were limited, and it became clear the project was not moving at the pace we had been led to expect. This placed us in a difficult position, as we had relayed timelines to pre-order customers based both on our historical experience with this manufacturer and on an end-of-2025 release date provided to us directly by Rennsteig, which we understood as a commitment that both the 1.5 mm and 2.8 mm die sets would be complete and in our hands.
• Prototype and preliminary test details were received digitally and signed off on. Those test details reported satisfactory results. After roughly nine months of very little traction, we relied on twelve years of distribution history and three prior products brought to market with zero deviation and made a decision to keep the project moving: First Article Inspection was waived, on the strength of Rennsteig’s handling of the earlier projects and the reports we were given. We were promised delivery by the first week of December 2025.
With hindsight, waiving the FAI is the one decision in this project we would make differently, and it is ours to own. What it did not do was cause the underlying problem. The dimensional tooling requirements were supplied, in writing, well before that point.
• Early in the month, we began preparing to take payment for sets so that customers who had left deposits would receive what they were expecting, within the completion timeline the manufacturer had given us.
• Late in the month, we received notice of a delay with few supporting details, indicating that only the 1.5 mm die sets were likely to be ready. No information was provided on the 2.8 mm die sets.
• On11/18/25, we received the first prototype units for the 1.5 mm and 2.8 mm terminals and encountered significant issues that rendered them effectively unusable, alongside word that as many as 100 of the 1.5 mm die sets were already in production.
• Rennsteig’s position was that we had signed off on the design, though it was faulted as it deviated from the tooling details we provided months prior.
Some of this may be difficult to follow, and we want to be as clear as we can be. Working with an international manufacturer carries inherent challenges: time zone differences, language barriers, differing units of measurement, and most significantly in this case, communication. The test report we approved carried the note that the insulation crimp was “not executed optimally.” That phrasing did not convey the actual condition of the crimp, which was not usable in any form.
Specifically, the terminals selected and supplied for development require an overlapping insulation crimp, as outlined in the terminal manufacturer’s own tooling guidelines, which we provided. That requirement was not carried into the design. The result is a die set that will either destroy the terminal’s insulation support wings or damage the conductor’s insulation on every crimp. We spent hours going through datasheets and brought in a wide range of terminals to test with while we waited for a solution from Rennsteig. More than fifteen terminal variations were tested at that stage, and none of them passed.
With our previous BDM no longer at the company, we contacted the new points of contact immediately. The reply we received indicated our detailed email had been skimmed rather than read and asked us to send a photograph of a crimp with loaded wire.
• We held a phone call with Germany in which we were promised an internal reevaluation and a proposed recovery plan within two to three weeks.
• Nothing came from that call. We were left holding a prior commitment that could no longer be fulfilled, which we then had to relay to our customers, having already taken payment.
• Communication remained limited. The only proposal put to us was that we sign an NCNR (non-cancellable, non-returnable) agreement covering the defective dies, which would in turn entitle us to an additional 15% discount off the originally quoted price for those die sets.
• After months of requesting updates and receiving few responses within any reasonable timeframe, we held a call directly with Germany to discuss the damage to our business and the inconvenience to our customers. The discussion centered on payment for half of the die sets, which all parties understood to be unusable and which have remained in Rennsteig’s possession throughout this entire timeline. We did not receive any acknowledgment regarding the tooling supplements we had provided, any discussion of how the project reached this point, or any indication that the new commitments would be kept.
• On April 21, we emailed further information to Germany, asking their engineering department to fulfill their commitment to finding a resolution, which comes down to re-machining one of the three separate parts that make up what appears from the outside to be a singlepiece die set. We offered to press the alignment dowels out of 80 die sets ourselves and fit the corrected pieces at our own expense. That offer was declined.
• Two weeks of back-and-forth followed, with communication becoming increasingly difficult to sustain: out-of-office replies, away-on-business replies, and no substantive progress.
• We received an email stating that because we had not paid for the out-of-spec die sets in question that remain in Rennsteig's possession, for which we had not received an invoice, our NET 30 account might be moved to pre-pay terms going forward.
• Still no resolution and limited communication.
• On 7/31/26, we received a request to send in additional terminals, many of them the same ones already provided, along with wire samples. We were told the project manager and VP needed to meet to evaluate what could and could not be machined, and that we would be updated.
• Throughout all of this, it is worth noting that we continued to do a significant volume and value of business with Rennsteig annually, sending purchase orders, selling product, and paying invoices.
• On 8/4, after an unrelated purchase order for customer product was already prepared to ship, we were notified it would be held because our net terms had been suspended.
◦ This had not been communicated to us in advance, and we did not carry a balance at the time.
◦ We do not require terms, but they are useful when a project has been unresolved for more than a year. We emailed about this immediately and received an out-of-office auto-reply.
◦ We were subsequently told the change had been communicated months earlier. The communication referenced read:
“Our accounting team is considering moving Racespec to prepayment terms. I have been able to prevent this so far and would like to avoid it going forward as well.”
◦ We did not read that as notice that our terms would be suspended.
◦ For further context: Rennsteig has maintained that the out-of-spec product they manufactured, which has been sitting in California since December 2025, should be paid in full. We have discussed this at length, explaining that we will not ask our customers to pay for tooling that does not perform. That position has not been substantively addressed since early 2026.
• We made the decision not to send in a second round of samples for evaluation until a direct conversation took place.
• 8/10/26 — we sent another email requesting a response by 8/13. No response was received.
• 8/18/26 — we sentan additional email expressing our disappointment. As of this writing (9/24/26), it hasstill not been addressed.
There is one component of this that is worth explaining plainly, because it is not obvious from the outside and it is a genuine part of why this project was so hard. We do not intend any of this to come across as condescending.
The original manufacturer of the SICMA connector series was acquired by Delphi in 2012, and Delphi rebranded as Aptiv in 2017. That history produced multiple iterations and part numbers for the same physical terminals. In this case, over 38 different part numbers exist for the 1.5 terminal alone, and another 32 for the 2.8 terminals, leaving 70 total terminal part numbers that had to be sifted through using antiquated and conflicting drawings, specification sheets, and, most importantly manufacturer information, in order to determine what the product needed to support. It was not simply a matter of what worked best; we also had to factor in the commercial availability of these parts as many specific part numbers are not readily available in distribution.
Many of these part numbers supersede one another but are very poorly documented. As with most large companies, the path by which that happened was indirect to begin with, and it was made more complicated by multiple ownership changes along the way. Ownership of this connector series has in fact changed hands three times, and each change compounded the contradictions: incorrect data populated in part number matrices, sealed terminal part numbers listed as unsealed and vice versa, and additional conflicting information on datasheets were all found.
We understand that from the customer side this can reasonably look like “I need a crimper for this pin,” but we can assure you it is considerably more involved. Most people experienced with this connector know it uses a mat seal, meaning the terminal itself is unsealed and only seals against the jacket of the wire after the terminal has been seated in the connector housing. In fact there are both SWS (single wire seal) terminals and unsealed terminals in this family, and their requirements contradict one another significantly.
An example of one of the differences in the terminal’s insulation support wings.
A second example, showing differences in terminal styles depending on which version of the terminal and which manufacturer’s data you are looking at.
Our initial approach focused on accommodating the most versatile spread of wire sizes per terminal size within a single die set, which is a challenge on its own. Both a 1.5 mm and a 2.8 mm terminal are required for the devices this connector series is used with, and both require compatibility across a large range of wire sizes. When multiple terminal sizes are combined into one die set, as with our Molex CMC set, the available footprint becomes a significant restriction. In order to meet our own standard for the product, we split this into two separate die sets so that both the 1.5 and 2.8 terminals could accept the maximum spread of wire sizes.
The larger challenge was working against the original design intent of these terminals to have them accept much smaller wire, in both conductor size and outside diameter. Add to that three different manufacturers, reissued part numbers that are incorrect, mispacked material still circulating through distribution, and a phone call in which the current manufacturer told us verbatim that they do not have that information on file because they did not originallydesign the product.
The only thing that needed to happen for this project to be completed as promised was for the dimensional tooling prints we provided to be followed. In the image below, look at the insulation support crimp geometry and note how identifiable the cause is:
Left: the required overlap crimp geometry. Right: the single-seal crimp dimensions the die set was produced to.
In the image on the left, you will notice a high and a low point on the top nest. That geometry is what creates the overlap crimp required on the insulation. The die set was instead produced to the dimensions shown on the right, which are for a single-seal crimp. While many users of thisterminal familywill tell you that SICMA are not sealed, there is an entire line of sealed connectors within this product family. The slide-lock connectors used on ECUMaster devices use a mat seal, so the improper support crimp profile was incorrect from the start. We still have no explanation for why that decision was made, or why the discrepancy was not clarified before parts were produced.
The specific issue with the completed 1.5 die sets is that the insulation support wings on the terminals tested are longer, and there is not enough space in the radius of the tool nest for them to compress and wrap around the smaller diameters of M22759/32 or Spec 55 wire without physically colliding with each other, deforming the terminal and, in most cases, badly damaging the wire jacket.
We have done everything possible to find a solution internally. We tested 21 alternate terminals that could possibly work, including those not called out as compatible. We tried modifying terminals slightly to achieve the required result, as we used to do before our Superseal 1.0 die set came out. We have not been able to arrive at a single solution repeatable enough that we would feel comfortable offering it to you with the Race Spec® name behind it.
In the interest of full transparency, we were prepared to offer an interim solution using hand-modified terminals, supplied at no charge to every pre-order customer, while a replacement top piece of the die was machined. We were fine with that and ready to move forward with it. Ten months later, we are not in a position to keep you waiting any longer.
This project is permanently cancelled. Every customer with an outstanding deposit, payment, or backorder will be contacted directly and offered a full refund or store credit, whichever you prefer. If you would rather not wait to hear from us, reach out and we will take care of it immediately.
The damage to our relationship with Rennsteig is not recoverable, and we will no longer be selling Rennsteig products once our current inventory is depleted. We currently have many pieces on hand, so if you need something from that line, we encourage you to place your order while it is available.
We are not done yet. We are already evaluating new tooling partners for this terminal range. In the meantime, our sole focus is getting our patient customers their money back and making sure you have a full, unfiltered account of what derailed this.
Priorities and directives shift over time, and that is part of business. What is not part of business is being unable to obtain a substantive response to written correspondence for weeks/months at a time on a matter of this significance, or being asked to pay in full for tooling that does not perform while it sits in a warehouse.
Nearly every step of this four-year effort presented obstacles that would have caused most companies to walk away. Race Spec® takes an immense amount of pride in resolving issues, working through challenges, and making sure our clients feel like they have a voice, and that is what drives us every single day. We remain committed to doing everything To A Higher Standard®, and part of that standard is telling you exactly what happened, including the one decision we would make differently ourselves.
What matters most to us is not how this has affected our business. It is that we were placed in the position of relaying timelines to a customer base that supported and trusted us, and then watching those timelines fail to materialize. We are sorry for that. We have laid out the record above in full and we are content to let it speak for itself.
Thank you for your patience, and for continuing to trust us with your project needs.
With gratitude,
Joel & Chris
Race Spec LLC
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