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Some of you may have read the good news? Rasant Products was recently acquired and the company was relocated the Pacific Northwest (Seattle-Area.)
Production of the beautiful, quality and very functional 6-individual throttle-body kits, velocity stack trumpets (and optional custom GT3 intake plenums), has resumed. Rasant Products ITB kits are offered for ALL Flat-6, air-cooled Porsche models (including 964 and 993 models) and with butterfly sizing for anything from 2.0 litres to 4.0 Litres in displacement and beyond.
When the company was acquired, Andrew sold his red house / demo car separately, so we have selected this very cool 1974 wide-body with a 3.0 litre from a 911 SC (that was installed sometime after 1980), to be our test-mule going forward. The intent here is to eventually install all available 911-related Rasant-developed products on this car (including those upcoming, high-quality custom taillights, but more on that later!) First, we want to hear these six individual throttle bodies screaming to red-line.
We took the car to a local DynoJet chassis dyno this week for some baseline pulls to have a pre-Rasant ITB installation reference point.
Without changing anything else, we will head back to the same dyno after installation of the Rasant 6 ITBs with the custom GT3 intake plenum, so that all interested parties can see exactly what they might expect, from similar modifications. We're not going to change cams, or exhaust, or wheels and tires, or even the flywheel, or clutch-kit. We want pure data for installation of JUST the 6 ITBs, so that we can see how well they perform!
As with several other notable Porsche customization specialists and tuners, Rasant Products has distanced itself from MoTeC for several practical, technical and business reasons. We will be installing the feature-rich, fast-processing, Emtron KV8 stand-alone ECU (along with one of our custom, in-house, concentric-wound / twisted pairs motorsports-grade wiring harnesses!)
Here is the car. Any guesses as to how she did!?
Last edited by Rasant Products; 11-26-2023 at 09:22 PM.
Reason: Added the term "911" to the title.
Thats good to hear. Because the after sale service and delivery commitment was crap when we ordered it. The hard product itself was ok and is performing well, the harness had to be totally reworked (despite spending hours with them to ensure it was right) and the plumbing had to be totally reworked. Where Rasant needed a lot more work was in the software design and tuning of the Motec controls of the base maps they provided. My shop (BBI) spent substantial effort reworking all the maps, cold / hot start, etc. The car drives fantastic. Literally starts, idles, runs, like a modern car. No dead spots. NO stalls. No weird stuff.
Hopefully you guys get those issues sorted. I feel, personally, the product was about 60-70% there and who knows, maybe Andrew got bored or got slammed trying to run a business. Good idea, generally good product, nice guy, not fully executed to the level that I expect. And being brutally honest, if I were to do it again I'd just know that I'd be building it near 100% from scratch and go with a system like Kinsler.
But, we saw good results out of my 2.8L build after all the effort.
You can see more in my Tang/71 thread linked in signature
Good to see you continuing the development of this system and the GT3 plenum kits are fantastic! It would be good to understand the ECU strategy on AEM->MOTEC->Emtron as this is an important part of getting systems to work well as you need the right tools/software/tuner ecosystem as @Spyerx mentions. I have the original velocity stack/AEM system from Rasant on one of my cars.
Let us know the dyno #s and I look forward to seeing how the white project car progresses!
Pleased to see you purchased the original Rasant systems and are committed to future development.
Thanks for the input so far folks! I feel like one of the major bridges to gap is going to be "expectations"... The product (when shipped and not installed here), will require a lot of setup, synchronization, balancing the banks, balancing between the ITB units, fine tuning of the fuel and ignition maps etc. If the expectation is that a buyer receives it, "slaps" it on the engine and it's going to be good, then that will be a BAD expectation and a recipe for disaster!
Same with the tune, the product will ship with a base start-up map that can be expected to be "close"... Any expectations above that, will be yet another recipe for disappointment! Each engine is different. Your car would HAVE to go to a local dyno for fine-tuning for things such as local fuel quality, base altitude settings and then also for the nuances which exist from one engine to another (as well as the differences in hardware, mileage, age, ring wear / cylinder seal, leak-down / compression, cams, head-seal etc.)
Here is the dyno graph - she made a blistering 166 horses at the wheels! That CIS was running pretty lean throughout the full-throttle run. With the modern EFI tunability of the Emtron, we can fix all of that without fighting old, dated mechanical fuel injection technology.
Last edited by Rasant Products; 10-28-2023 at 12:39 AM.
Here are some pictures of the mock-up process. Still debating what should go on the first full Rasant installation (under the new ownership, here in Seattle - the 6 ITBs with 6 open trumpets, or the six individual throttle-bodies still, but with these attractive custom-cast GT3 intake plenums...?)
Last edited by Rasant Products; 10-30-2023 at 06:51 AM.
We also have this 964-based build in the works (going into a '77 chassis), but we want to first get the house / demo '74 with the 3.0 single-plug installed, tuned, driving and sorted, before installing a set of the ITBs on the customer M64 twin-plug 3.6 litre engine (seen here in one of the pictures...)
Thanks for the input so far folks! I feel like one of the major bridges to gap is going to be "expectations"... The product (when shipped and not installed here), will require a lot of setup, synchronization, balancing the banks, balancing between the ITB units, fine tuning of the fuel and ignition maps etc. If the expectation is that a buyer receives it, "slaps" it on the engine and it's going to be good, then that will be a BAD expectation and a recipe for disaster!
Same with the tune, the product will ship with a base start-up map that can be expected to be "close"... Any expectations above that, will be yet another recipe for disappointment! Each engine is different. Your car would HAVE to go to a local dyno for fine-tuning for things such as local fuel quality, base altitude settings and then also for the nuances which exist from one engine to another (as well as the differences in hardware, mileage, age, ring wear / cylinder seal, leak-down / compression, cams, head-seal etc.)
I'm not quite sure you understood my point. I work with one of the best shops in the country. They build these entire systems from scratch. They were fully aware of what they were getting, and what we weren't getting, and so was I. The expectations, for price paid, were very far off. We'd have been better to piece it together.
We spent hours at the shop on the harness with andrew mapping it out for the application we were doing. It showed up wrong, badly wrong, and it had to be totally ripped apart and remade (my shop did it, I didn't trust Rasant to do it again, given they delivered over 6mo after they promised). The coatings on most of the parts were terrible, I had them stripped and redone. The plumbing and routing was badly thought out, we redid it all (i'm talking fueling, ICV, vents, etc). The sensors didn't all work and we had to order new ones after Andrew become unresponsive for example The Crank reference sensor could not handle over 8k RPM, we had to buy a Motec part. The base map wouldn't even start the car nor was it usable, we built an entire map for Motec M130 from scratch. Additionally, added features we paid for were not in the base firmware files, so I paid my shop to fix it. The throttle return and control looked like a 3yr old designed it, we custom machined a proper setup. I could go on... All through this Andrew just shrugged his shoulders, I nearly thew the entire thing out. If you want some candid feedback, feel free to reach out to BBI, I'm sure Jeremy, Jared, and Betim will be happy to share the experiences and frustration they had.
Again, there were no expectations this was a bolt on kit, zero, but the product as supplied did not even meet the definition of what was promised in the components supplied.
I hope you fix these issues. I know you probably don't love a noisy prior customer here, but i've been here a long time, and built several cars I'm not new to this, and, this was probably about my worst (ok the crankshaft issues I had were pretty bad too...) service experience I've had caused me to not recommend their product to anyone who asked or sees my car.
I'm not quite sure you understood my point. I work with one of the best shops in the country. They build these entire systems from scratch. They were fully aware of what they were getting, and what we weren't getting, and so was I. The expectations, for price paid, were very far off. We'd have been better to piece it together.
We spent hours at the shop on the harness with andrew mapping it out for the application we were doing. It showed up wrong, badly wrong, and it had to be totally ripped apart and remade (my shop did it, I didn't trust Rasant to do it again, given they delivered over 6mo after they promised). The coatings on most of the parts were terrible, I had them stripped and redone. The plumbing and routing was badly thought out, we redid it all (i'm talking fueling, ICV, vents, etc). The sensors didn't all work and we had to order new ones after Andrew become unresponsive for example The Crank reference sensor could not handle over 8k RPM, we had to buy a Motec part. The base map wouldn't even start the car nor was it usable, we built an entire map for Motec M130 from scratch. Additionally, added features we paid for were not in the base firmware files, so I paid my shop to fix it. The throttle return and control looked like a 3yr old designed it, we custom machined a proper setup. I could go on... All through this Andrew just shrugged his shoulders, I nearly thew the entire thing out. If you want some candid feedback, feel free to reach out to BBI, I'm sure Jeremy, Jared, and Betim will be happy to share the experiences and frustration they had.
Again, there were no expectations this was a bolt on kit, zero, but the product as supplied did not even meet the definition of what was promised in the components supplied.
I hope you fix these issues. I know you probably don't love a noisy prior customer here, but i've been here a long time, and built several cars I'm not new to this, and, this was probably about my worst (ok the crankshaft issues I had were pretty bad too...) service experience I've had caused me to not recommend their product to anyone who asked or sees my car.
Good luck.
Sam here, I manage Rasant in its new iteration and came onboard having setup, tuned, and supported several Rasant builds as a customer prior to coming onboard for this role. I've got 13 years of professional experience in this industry niche (high end/boutique performance part sales/manufacturing/support), and have been tuning German resto-mod street cars for 17 years.
First off, I'm sorry to hear about the experience you had in terms of the product and the support you received for those issues. It sounds like there were issues on every level and they were not handled well. I won't editorialize what might have happened there, but I can say that in the process of taking over the project and in making it our own, we have established much higher standards for ourselves than what your experience bore out, and have spent the last several months working behind the scenes to establish and ensure we can deliver product and service that meets those standards.
To me, the Rasant ITB kit occupies a unique niche of both form (in terms of the physical design/aesthetic of the hardware of the throttle bodies, linkages, plenums/trumpets, and accessories needed to run) and function--the entire intake system and the engine management that goes with it offer a huge step up in performance over any of the stock equipment and several of the other ITB kits, while incorporating features to make this more user-friendly, driveable, and reliable for use in what are often street-based applications. It offers a leg up in both appearance and function over some of the lower end, or less complete kits on the market, and in order to cement that stake it has we have to make sure we deliver at a level appropriate to that. To us, doing this has included some particular focuses as we've moved through this transition:
Wiring harnesses are being manufactured to a much higher standard of quality by dedicated, experienced techs. All harnesses are tested on a dedicated rig upon completion, ensuring that the harnesses we ship out are wired correctly and functioning for the specified application.
We purchased the company with a robust amount of well-quality controlled inventory, and as we restart or newly establish previous supply chains we are being extremely diligent about making sure the quality of the parts being made is up to our own standards and then testing these parts ourselves prior to public consumption to ensure there are no hidden issues we're unaware of.
We have made some changes to the throttle linkages and sensor array to greatly improve the ease of initial setup/syncing of the throttle bodies and the subsequent tuning done on that mechanical setup. In the past, the process required to properly establish this baseline was complicated and not well documented, and the Motec engine management model did no favors in helping this setup or accommodating any error introduced as the car was run or maintained down the road. The first few cars I did took a couple go-arounds of this setup process and multiple trips to the dyno to remap everything before I figured out the full procedure on my own to get a car that was running and behaving how I wanted it to. Simplifying and improving the ease of this setup process and properly documenting it were huge priorities of mine, as they're THE key to getting an end result that drives and performs well.
Switching to the Emtron ECU brought with it a change to a much more robust engine management model than pure Alpha-N (where throttle position, or to be precise relative throttle position, is the main load signal). This strategy essentially makes it much easier to handle things like slight differences in absolute throttle position from bank to bank, as well as idle control and some driveability tricks to smooth out throttle response than what was possible before and sort of lowering the bar of mechanical precision and setup required to properly tune the car and make it run according to that calibration.
Developing proper base calibrations for the Emtron is well under way. These base calibrations include things like properly setup inputs/outputs, injector characterization (often overlooked when custom tuning, but plays a HUGE role in being able to properly tune the car using any ECU), basic setup/configuration for things like idle control and plenum changeover, and then good safe/starter maps for VE and ignition timing. We will develop and release 'fully' calibrated base maps for the common/OE engine configurations as well (so factory 3.0/3.2/3.6, and probably a common build like a 3.4/3.8), though there are so many variables at play with the engines on these cars it will always be recommended to have the car at least looked over and fine tuned once it's together. Emtron has a tuning strategy that may allow us to do even better than this that I'm really curious to play with, we'll see how well that works in practice.
We have been working extensively with manufacturers and suppliers to evaluate and offer some new options as far as finishes and coatings. We want to offer finishes that fit the 'theme' of these builds, and look great out of the box and that will hold up to heat/damage/chemicals for years and years, and ensuring that the application of these coatings does not affect the function of the throttle bodies and linkages.
In short--we believe strongly that quality and performance are paramount to this brand and these kits, and are being extremely diligent about making sure that what we're offering meets those standards. We're in this for the long run, and our processes and these changes are aimed at making sure that this is a product that works and that we can support for years and years.
Spyerx, this is John - and from my perspective as well - I am sorry that Rasant (under the previous ownership), did not hit your standards. You sound like a detailed guy - and that's the type of customer that we aim to satisfy. I read through the entire 46-page thread on your build (funny to see you refer to yourself as very OCD - I'm there myself... ) An amazing build and a great thread.
Perhaps this thread for the relaunch of Rasant under new ownership is not the best place to beat up on the business, but we'll take it and commit to try and do better under our ownership of the brand. Sam, myself and the rest of the team are here to chat to folks like you and to turn that ship.
Rasant has many satisfied, reference-able customers as well, but unfortunately, one typically only hears from the installations that experienced issues. That's just life in a niche business.
We're adding great new products under the Rasant banner (liquid-cooled tuning packages, as well as relaunching a Rotrex supercharger kit for the 928 models - in addition to relaunching the base ITB products), so we certainly have our work cut out for us.
Last edited by Rasant Products; 11-03-2023 at 01:29 PM.
@Rasant Products
John, glad to see you guys are trying to move this product forward. As an owner of a Rasant system, would like to see it continue and improve.
I don't want to get into critiquing the execution of the past -- it was both great and not so great under Andrew. Suffice to say I did not have nearly as many issues as @Spyerx . My map fired right up out of the gate, and Andrew got on the phone with me immediately to help debug the first cranking / sync setup. The car drives well in any temp, hot or cold, starts with just the key, not pedal needed. Of course, I spent a huge amount of time setting up all the edge cases -- cold start, warm start, idle, hot days, cold days, fuel and ignition maps. But that's to be expected and frankly part of the fun for me. The car is really, really responsive and smooth. Runs like a top.
I would say my main limits are the Motec M84 I went with at the time. Things like lack of wireless or even ethernet, inability to custom tune for things like mapping the IAC using IAT, map and alpha-N hybrid fueling, etc., are the fault of the ECU. I should have added wiring for knock sensors and a second MAP sensor for the intake, but that's hindsight.
Hardware issues I would recommend fixing:
I had issues with the intake not fitting in the engine bay due to the filter being too high / bad angle, and had to fabricate an angled connector and use an offset filter. Not a huge deal, but could have been better.
The left side fuel and air rails are too close to the chassis to fit the fuel / vacuum lines on the rear of the left side (1-3) bank. Had to route to the rear of the engine bay, though would look tidier in the front.
The throttle return springs are too weak for a longhood that utilizes throttle rods from the pedal to the engine bay -- I had to add an auxiliary return spring to make it reliably return the throttles to fully closed (0 TPS). This caused a number of headaches until I realized the throttles were sometimes returning to 1-3% and not 0. I had to experiment with different springs to get the correct amount of pedal feel and not make it jumpy. This is soluble.
What is excellent about the Rasant hardware in my opinion:
The Cam/Crank sensor is an elegant implementation. The other solutions involving drilling the cams isn't one I want to use. Can't speak to the high RPM limits that @spyerx had. I have had no issues.
The ITBs themselves are very well designed. The ability to have a GT3 or 964/993 intake with the ITBs is well done -- few if any make a low enough profile ITB to enable full sized 964 intake on a longhood. Personally, the throttle linkages have been flawless on mine. I do not ever have issues with maintaining throttle sync, they are easy to adjust, and keep their settings.
I have a few questions I will ask you directly. Some pics for reference and everyone likes pics anyway.
@TheTorch thank you SO much for the invaluable feedback! We take it to heart (ALL of it - the positive and the negative) and will work to implement those changes and improvements.
PM answered - sorry for the delay (we've been buried in getting the first installation on the new house / demo car perfect.) We're also working on the 928 Rotrex supercharger kits (and the 07K swap / Rotrex-boosted 944 swaps simultaneously.) It never stops - on and on.
For everyone else - please check out our initial release of the new website - now featuring "Air-Cooled" / "Liquid-Cooled" / "Transaxle" model sections and products! It's a work in progress, but it's up.
It's been a while and time for a comprehensive update. I'll try to break it up into shorter bites - interspersed with some project pictures on this particular 911 demo / house project (subsequent to this post.) In a broader sense, here is what has been accomplished in the past 3 months, since our last update;
1) A very high profile 964 project came up with a short timeline fuse and we decided to set that custom build ahead of the house car. Gorgeous restored M491 "Turbo Look" wide-body (2WD) car with a rebuilt 3.8 litre M64 engine. We installed the full 48mm Rasant 6-ITB setup, with the custom GT3 intake plenums, a custom wiring harness along with an Emtron KV8 engine management system. That car fired up today. Headed to the dyno later this week after we complete the base tune and put some more miles on it. Keep an eye out for this car in the Rasant products booth during the late-May, Luft Air / Water event in Costa Mesa.
Last edited by Rasant Products; 04-04-2024 at 12:36 AM.
2) We fired up and started tuning the Rasant 928 S4 demo / house Rotrex supercharger project. The Rasant kit bumped power from 270 ATW horsepower to 385 horses ATW (and that on only 5psi boost - before even adding an inter-cooler to it.) Have a gander over in the 928 forum for updates on that exciting project. Installation of a second kit on another '87 S4 has commenced and that car will run on an Emtron stand-alone engine management system as well, with an inter-cooler and something more in the order of 12-15psi boost. Please stay tuned - as they say.
3) The first of two 944 projects with a 2.5-Litre 20-valve 5-cylinder VW / Audi "07K" swap engine and a Rotrex supercharger is making great progress! We've installed on of the engines in a customer's 951 chassis and employed a rapid prototyping process there (3-D printing the various iterations of the Rotrex bracket to get the adapter / bracket file to a ready for machining stage, more quickly.) While the two 07K engines are off to machine shop services to be rebuilt with forged internals, there is yet a third 07K core sitting in the engine bay of this customer's 944 turbo for mock-up.
4) The house 3.0-Litre '74 911 (the original subject of this thread), has a 42mm set of the full Rasant Products ITBs installed and the engine is back in the car! As soon as the customer-964 is out of here, we can refocus on that car and get it fired up and tuned - ready for summer. Hopefully that car heads to the dyno next week. We can't WAIT to see what happesn to the power (remember that the little 3.0-Litre only made 166 horses ATW.)