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RennTech ECU Upgrade for the 2016-2021 SL 550: OBD tuner plug

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RennTech HHT hand-held tuner graphic with the grey OBD2 module - RennTech ECU Upgrade for the 2016-2021 SL 550

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Compact black power module - RennTech ECU Upgrade for the 2016-2021 SL 550

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Back of the RennTech HHT tuner with its USB port and status lights - RennTech ECU Upgrade for the 2016-2021 SL 550

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RennTech HHT tuner seen from the connector end - RennTech ECU Upgrade for the 2016-2021 SL 550

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RennTech ECU Upgrade 2016-2021 Mercedes-Benz SL 550 R231

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Regular price: $2,172.80
Regular price: ~~$2,240.00~~
Sale price: $2,172.80
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Subtotal: $2,172.80

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RennTech ECU Upgrade 2016-2021 Mercedes-Benz SL 550 R231

Subtotal: $2,172.80

Not sure it fits? Text us your VINSee all fitment

Vendor: RennTech

SKU: 54.231.SL550BI.FL

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Overview

RennTech built its name in Florida tuning high-performance engines, and this ECU Upgrade for the 2016-2021 SL 550 is the result of in-house dyno development on the 4.7L M278 twin-turbo V8. Timing, throttle, air-fuel and boost tables are revised as one calibration, so the car pulls harder everywhere while staying a comfortable daily driver. RennTech rates the SL 550 at up to 500 hp and 625 lb-ft with this upgrade, a gain of 26 hp and 59 lb-ft.

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Features

Revised ignition timing, throttle mapping, air-fuel ratios and boost control
Gains across the entire rev range, not just at peak
Developed on RennTech's own dyno and road tested
Keeps factory-like drivability and reliability for daily use
RennTech lists a CARB Executive Order for this calibration

What is included

RennTech calibration for your car
Delivery as listed by RennTech for this model (HHT tuner or ECU flash)

Specs

Part number	54.231.SL550BI.FL
Engine	4.7L M278 twin-turbo V8
RennTech rated output	500 hp / 625 lb-ft
Gain (RennTech)	+26 hp / +59 lb-ft

Fitment notes

For the SL 550 (R231), 2016-2021 as listed by RennTech. Please include your VIN with the order so RennTech can confirm the exact application. Check the fitment table before ordering, and contact us if your car differs.

Fitment

Make	Model	Chassis	Year	Engine
Mercedes-Benz	SL 550	R231	2016-2021	4.7L M278 twin-turbo V8

Fitment

Year	Make	Model
2016–2020	Mercedes-Benz	SL550

Not sure? Text us your VIN and we’ll confirm.

Shipping & returns

Shipping: Orders ship via UPS, FedEx or USPS, from our facility near Los Angeles or directly from the manufacturer. Rates for many items are weight-based and shown at checkout. If you need it by a certain date, text us before you order.

Returns: Unused items in brand-new condition and original packaging can be returned within 30 days of the invoice date, with a 25% restocking fee unless otherwise specified. In some cases we can offer a lower fee with the balance as store credit. Shipping charges aren't refundable in either direction unless approved by AutoTalent.

Not returnable: special-order or custom items, and anything that has been installed, modified or altered.

Cancellations: free if the item is out of stock or we miss the ETA you agreed to. Other cancellations carry a 5% processing fee to cover card fees we can't recover. Special-order items can't be cancelled.

Damaged in transit? Report it to the carrier and to us within 48 hours, keep all packaging, and don't send anything back without our written approval.

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