Variable nozzle turbos were first launched in the industry by Garrett in the mid 90’s and are now found on most diesel engines. It was the introduction of variable nozzle (also known as variable geometry) technology in turbos at the same time as common rail fuel injection systems, which led to the huge increase in popularity of small displacement diesel engines in passenger cars.
As the decades moved on, emission levels have continued to reduce as vehicles have been designed to meet the Euro 4, 5 then 6 regulations. As a result of these changes, engine technology and turbo technology increased in complexity, and the settings and control of the variable nozzles in the turbocharger have become more critical to the correct operation of the turbo. This is now presenting new challenges to turbo repairers as the correct setting of the turbo on later models now requires further specialist equipment in the form of an air flow rig.
VNT Air Flow Rigs - A Changing Market
There has been an ongoing debate for many years between the original turbocharger manufacturers and the turbocharger repair industry, over whether a turbo can be repaired.
Over the last decade, vehicle technology has continued to improve to reduce emission levels in order to meet the Euro 4, 5 then 6 regulations. As a result of these changes, engine and turbo technology has increased in complexity, and the settings and control of advancements, such as the Variable Nozzles, have become more critical to the correct operation of the turbo. This is now presenting new challenges to turbo repairers as the correct setting of the turbo on later models, now requires further specialist equipment in the form of an air flow rig.
What is a Variable Nozzle Turbo?
When a turbocharger is matched to an engine, the Engineers have to balance the low speed response with high speed efficiency. The variable nozzle (also referred to as a variable geometry), is designed to change the exhaust gas inlet area with the engine speed to closely match the desired boost requirements of the engine. For low speed response, the nozzle vanes move to the ‘closed vane’ position to reduce the nozzle area – this increases gas speed through the turbo giving improved response at low engine speeds – similar to squeezing the end of a hose pipe to make the jet of water more powerful. As the engine speed increases, the actuator moves the nozzle vanes to the fully open position to maximize the exhaust gas flow.
Vane Setting Accuracy
During the manufacture of a new complete variable nozzle turbo, vane positions are set using accurate air flow equipment, which ensures that the ‘minimum vane opening’ position is set to allow a specific mass of air flow through the vanes. If the vanes are too closed, this can cause choking of the engine and overspeeding of the turbine. If it is set too large, the turbo will have too much ‘lag’ and not respond as well as it should.
Traditional methods of setting the vanes when repairing a turbo can produce quite large inaccuracies in the air flow. The actuator arm measurement is often set against a cast finish on the bearing housing, the position of which is not accurately controlled during manufacture. However, as the older engines would accept quite a large tolerance of air flow, the repaired turbo still performed well compared to the broken turbo which it replaced, so the vehicle owner was still happy with the results. On older turbo repairs, the variable nozzle position had to be a long way out before the performance was unacceptably affected or for the ECU to flag a problem. From an OEM perspective, this is not acceptable and is the reason for their lack of support of repairing.
Today’s Turbos
In more recent years, as engines have improved to meet tighter Euro emission regulations, the control over the whole air / fuel system has improved dramatically. Many premium brand vehicles have moved to electronic actuation which gives positional feedback to the ECU. Some more advanced turbo controllers now sit within the CANbus talking directly to the injection system and air mass sensors, to respond more quickly to engine demands. For these turbos, the settings are both correct and accepted by the ECU – or not, which results in warning lights, limp home mode or refusal to start.
As more of the Euro 5 compliant vehicles enter the aftermarket, problems will continue to arise and for some turbo models, flowing the turbo will be a necessity and only possible by workshops who have the correct equipment. This will naturally mean that older turbos also become more widely repaired using air flow equipment, which will bring further improvements to the turbo repair market.
Availability of the Air Flow Rig
Just as the market demand led to there being several high speed VSR machines on the market, so too has the demand for air flow rigs. Over the last 10 years, the need to set the accurate air flow of a turbo has been well understood by reputable repairers, who recognised it was not acceptable to guess at the vane setting position. As a result, in the absence of machines on the market, many quality repairers developed their own air flow equipment to accurately set their turbos – giving them a competitive edge and a marked reduction in warranties, whilst also building on their reputation as a quality repairer. In more recent years there have been a number of different air flow rigs released to the mass market. This is good news for the repair industry and for customers looking for a quality repair option, as the bar for quality has been lifted further.
Melett UK will close for the Jubilee bank holiday at 17:00 on Wednesday 01 June and reopen at 08:00 on Monday 06 June. Any orders that are not picked or dispatched before we close will resume preparation when we reopen. If you would like any more information or guidance on the above, please contact our customer care team on +44 (0)1226 320939.
Memorial Day 2022
Melett North America will be closed for Memorial Day on Monday May 30th and will reopen at 8.00 am on Tuesday May 31st.
Melett Polska
Melett Polska will be closed for a public holiday on Thursday 16th June and will reopen on Friday 17th June. Any orders that are not picked or dispatched before we close will resume preparation when we reopen. If you would like any more information or guidance on the above, please contact our customer care team on +44 (0)1226 320939.
Godziny otwarcia w dni wolne od pracy w maju
Melett UK
Zamknięte od 30.04 do 02.05.2022 roku.
Melett Polska
Zamknięte od 30.04 do 03.05.2022 roku.
PLEASE NOTE -THE ABILITY TO SUBMIT YOUR ORDERS THROUGH THE MELETT WEBSITE HAS BEEN RESTORED
We are delighted to advise full website functionality has now been restored, meaning you can view stock and pricing, add parts to your basket and submit your order via the website. In addition, all turbo/part number searches are fully working.
Until further notice please place your orders by 2.30 pm and we will endeavour to dispatch the same day dispatch.
We will keep you updated as we navigate through the remaining internal connectivity issues, we have dedicated teams working round the clock to resolve any remaining issues as quickly as possible.
We, at Melett, would like to stress our gratitude for your continued patience and support throughout this difficult time.
Please note you can now view your pricing on the Melett website.
We appreciate this is not a complete solution at this stage, however, please be assured our internal website and IT teams remain focused on reinstating the stock availability function.
We cannot stress enough that we are doing everything we can to reconnect our internal system, and we will restore full website functionality as soon as possible.
If you experience any problems whilst ordering online, please do not hesitate to contact:
Z przyjemnością informujemy, że możliwość składania zamówień poprzez stronę internetową Melett została przywrócona.
Przywróciliśmy funkcje wyszukiwania na podstawie numeru turbosprężarki, dodawania części do koszyka i składania zamówień poprzez stronę internetową. Jednak pomimo to prosimy o dodawanie każdorazowo adresu dostawy do zamówienia.
Niestety, nie jesteśmy w stanie pokazać rzeczywistego stanu magazynowego (wszystkie nasze zapasy będą wyświetlane jako pomarańczowe) oraz cen.
Zdajemy sobie sprawę, że na tym etapie nie jest to pełne rozwiązanie, za co jeszcze raz Państwa przepraszamy. Nasz zespół IT niestrudzenie pracuje nad przywróceniem funkcjonalności zamówień online, jednak nadal nie jesteśmy w stanie połączyć strony internetowej z pozostałymi systemami tak, aby pokazywały stany magazynowe i ceny.
Prosimy o dalsze składanie zamówień do godziny 16:00 w celu wysyłki tego samego dnia, wewnętrzny zespół nadal przetwarza zamówienia ręcznie.
Zapewniam Państwa, że robimy wszystko, co w naszej mocy, aby nasz wewnętrzny system powrócił do działania tak szybko jak to możliwe.
Jeśli doświadczysz jakichkolwiek problemów podczas składania zamówienia online, prosimy o kontakt: Email: [email protected] Tel: 52 320 00 49
YOU CAN NOW VIEW STOCK AND PRICING ON THE MELETT WEBSITE
We are delighted to advise full website functionality has now been restored, meaning you can view stock and pricing, add parts to your basket and submit your order via the website. In addition, all turbo/part number searches are fully working.
Until further notice please continue to place your orders by 2.30 pm for same day dispatch.
We will keep you updated as we navigate through the remaining internal connectivity issues and hope to move back to the standard 4 pm cut off shortly.
We, at Melett, would like to stress our gratitude for your continued patience and support throughout this inconceivable time.
MELETT WEBSITE - PRICING NOW AVAILABLE
Please note you can now view your pricing on the Melett website.
We appreciate this is not a complete solution at this stage, however, please be assured our internal website and IT teams remain focused on reinstating the stock availability function.
Internally, we continue to process orders manually, as a result, please allow a 1–2-day processing and packing time.
We cannot stress enough that we are doing everything we can to reconnect our internal system, and we will restore full website functionality as soon as possible.
If you experience any problems whilst ordering online, please do not hesitate to contact: [email protected] / +44 (0)1226 320939
Thank you the Melett team
Melett Polska will be closed for a public holiday on Monday 15th August and will reopen on Tuesday 16th August.
Any orders that are not picked or dispatched before we close on Friday 12th August will resume preparation when we reopen. If you would like any more information or guidance on the above, please contact our customer care team on +44 (0)1226 320939
Thank you the Melett team
We are pleased to advise the ability to submit your orders through the Melett website has been restored
You can search by turbo number, add Melett parts to your basket and submit your order via the website - please add your delivery address to your order.
Unfortunately, we are unable to show stock (all stock will be showing as orange) and pricing due to our ongoing internal ordering system outage.
We appreciate this is not a complete solution at this stage and we again apologise for the frustrating situation. The Melett website team have been working tirelessly to restore online ordering functionality, and whilst we remain unable to connect the website to our accounting system to show stock and pricing, we hope this will make ordering easier for you.
We are doing everything we can to get our internal system back up and running and we will restore full website functionality as soon as possible.
If you experience any problems whilst ordering online, please do not hesitate to contact: [email protected]
Thank you the Melett team
Wielkanocne godziny otwarcia
W związku z przerwą Wielkanocną Melett Polska będzie zamknięte od 14 kwietnia (czwartek, od godziny 16:30) do 19 kwietnia (wtorek, do godziny 8:00)
Essential Maintenance
W związku z pracami konserwacyjnymi, strona internetowa Melett będzie chwilowo niedostępna w piątek 25 luty od 19:00 do 21:00. Przepraszamy za utrudnienia.
Planned maintenance – Thursday 24 March 2022
We will be undertaking planned maintenance on our internal systems this evening between 17:00 and 20:00 GMT, which will affect some website functionality.
We aim to keep disruption to a minimum and the website will remain online. However, we will need to temporarily disable online ordering during this time.
Thank you for your understanding.
Essential Maintenance
We are undertaking essential maintenance this weekend (February 19-20) and some of our website services may be unavailable at times. We apologise for any inconvenience this may cause.
Essential Maintenance
- W związku z pracami konserwacyjnymi, strona internetowa Melett będzie chwilowo niedostępna w piątek 28 stycznia od 18:00 do 20:00. Przepraszamy za utrudnienia.
Świąteczne godziny otwarcia
- Melett UK Będzie zamknięty od czwartku, 23 grudnia od godziny 17:00. Ponowne otwarcie nastąpi we wtorek, 4 stycznia o godzinie 8:00.
- Melett Polska Będzie zamknięty od czwartku, 23 grudnia od godziny 16:30. Ponowne otwarcie nastąpi w poniedziałek, 3 stycznia o godzinie 8:00.
- Melett Ameryka Północna Będzie zamknięty od czwartku, 23 grudnia od godziny 17:00. Ponowne otwarcie nastąpi w poniedziałek, 3 stycznia o godzinie 8:00.
Please note: Due to essential maintenance the Melett website will be temporarily unavailable on Friday 10 December from 5:00PM (CET) to 11:00PM (CET). Apologies for any inconvenience caused.
Please note; Unfortunately, we are experiencing processing delays for all orders which may result in delays in shipping. If possible, please confirm orders at your earliest opportunity to help minimise disruption to our normal high standards. Please accept our apologies and rest assured that we are working hard to resolve the issue.
Melett Poland will be closed for a Public Holiday on Thursday 11th November. Any orders that are not picked or despatched on Wednesday 10th November will resume preparation when we return on Friday 12th November.
Melett Poland will be closed for a Public Holiday on Thursday 6th November. Any orders that are not picked or despatched on Wednesday 5th November will resume preparation when we return on Friday 7th November.
Melett will be closed for a Public Holiday on Thursday 11th November. Any orders that are not picked or despatched on Wednesday 10th November will resume preparation when we return on Friday 12th November.
Melett will be closed from 5 pm on Wednesday 24th November until 8 am on Monday 29th November for the Thanksgiving holiday
Online ordering now available
In addition to viewing inventory levels and pricing, you can now place orders directly from our website. Download our user guide below to help you get started.
Melett UK will be closed for a Public Holiday on Monday 30th August.
Any orders which are not picked or despatched on 27th August will resume preparation when we return on Tuesday 31st August.
Notification
Melett North America will be closed for a Public Holiday on Monday 6th September.
Your browser is no longer supported
Internet Explorer is approaching end-of-life and no longer supports some of the complex functionality of the Melett website.
For the best and most secure experience, please switch to a modern browser, such as Google Chrome, Microsoft Edge, or Firefox.
×
×
Szczegóły konta
Chcesz naprawić turbo?
Whether you’re looking for a turbocharger repair or a complete reconditioned unit, Melett’s network of repair specialists provide quality service and national coverage. Find your nearest Melett approved service centre.
Jako nasz aktywny klient, mogą Państwo cieszyć się pełnym dostępem do naszej szczegółowej bazy informacji technicznych, a także do naszych katalogów, informacji o kalibracji i nowych produktach.
Prosimy o kontakt z Melett w celu uzyskania dalszych informacji.
×
Szczegóły konta
Chcesz naprawić turbo?
Whether you’re looking for a turbocharger repair or a complete reconditioned unit, Melett’s network of repair specialists provide quality service and national coverage. Find your nearest Melett approved service centre.