Jubu Gearbox Cooler - Anyone fitted?

[CM96]

Hi All,

Wondering if anyone has fitted this gearbox cooler from Jubu? JUBU Performance - (jubu-performance.com)

Reading their write up it obviously sounds good, but would be good to know first hand from anyone with it fitted. Did notice before at Silverstone sometimes changes from 4th to 5th would seem to get a tad crunchy when hot. For this year have upgraded to Motul 300 anyway so that should help, have always changed gearbox oil each year additionally but if I can keep it cooler through fitting this I would. 

They have some lovely items on their website, the sequential box they do would be rather lovely... 😏

[El-RGB]

I have similar shifting issues, but from 2nd to 3rd when the gearbox is hot on track. It wouldn't engage after a few hot laps, and I suspect the samething regarding the gearbox temperature as well. I sent emails to Jubu, and again, promptly and very informative replies from Martin. Their system is an heat exchanger, so taking the coolant temperature to quickily heat up the gearbox and keeping the temprature at a stable range when running.

I've also done many researches on the stock 430 gearbox cooler, which is a similar system but comes with a sensor that kicks in by the ECU control. There are also very limited information on the Komo and Hangar111 cooler, where I found the Komo is an air cooling system that requires a sensor to kickin the circulation. However, the noise reported from the reviews found on this forum is loud.

I'm too very interested inJubu's cooler, which it seems running a very basic and foundamental principal that doesn't require an extra electric connection. I think that is very similar to many performance manfacturer's stock solutions, which is good. I hope we can find more information and share here.

Frank

PS: A cooler comes standard on all the Exige gearbox, I'm not sure that we can modify from it and save a few bucks.

This is the standard sandwich cooler, I think it has some cooling performances.

 

This is the 430 Heat Exchanger, which is beefer and looks similar to the JUBU size. The stock cooler however requires a sensor connecting to the ECU, and the price is similar to an aftermarket gearbox cooler.

 

[DH2]

6 hours ago, El-RGB said:

However, the noise reported from the reviews found on this forum is loud.

Our kit uses the same pump as the factory gearbox cooler - you'd do well to hear the pump whilst the engine is running (too much gearbox chatter )

Dave

[jmcvaughn]

Genuine question here as I don't know the answer, but putting more ideas on the table. Sure it isn't worn shift forks (though I'm not sure if that would mean that you experience crunchiness 100% of the time instead) and/or synchros? MWR and Komo-Tec both do upgraded shift forks, Jubu probably do as well:

https://www.monkeywrenchracing.com/product/mwr-hd-shift-fork-pad-set-4-evora-exige-v6-one-fork/
https://www.komo-tec.com/en/lotus-exige/mk3-toyota-v6350380/gearbox/1007/upgrade-shift-forks-v6-ea60?c=529

If there are similarities between the standard gearbox cooler on the 390-430 cars and the Jubu system, then it might not be the answer to your problems (awaiting an expert's input here). Even if the system has more cooling capacity, it may not actually be necessary.

Edited February 6 by jmcvaughn

[DH2]

Just realised the OP has a 420.  This will already have the factory gearbox cooler (as shown in 46.09 above).

So I'd be checking that it is working before doing anything else.

Dave

[CM96]

Cheers for the replies guys - some interesting points to look into. I am interested to see how it is with the Motul-300 fluid having previously ran on the stock Lotus fluid - that may well result in an improvement.

Never awful by any means, just didn't like to be rushed when hot - this may well be a characteristic/limitation of the box anyway. I would add it was only at Silverstone I noticed this, never at Spa or any other track and it was a hot day which may have emphasized it.  

[Paul_D]

I certainly noticed an improvement in performance on track when I changed my fluid to Motul Gear 300 75w90.

I originally had the same 'crunchy' behaviour when it got hot, and I can't really remembering it happening anymore.

[El-RGB]

 

On 06/02/2024 at 16:50, DH2 said:

Our kit uses the same pump as the factory gearbox cooler - you'd do well to hear the pump whilst the engine is running (too much gearbox chatter )

Dave

Thanks for the clarification Dave! Respectful products as always.

On 06/02/2024 at 23:36, CM96 said:

Cheers for the replies guys - some interesting points to look into. I am interested to see how it is with the Motul-300 fluid having previously ran on the stock Lotus fluid - that may well result in an improvement.

Never awful by any means, just didn't like to be rushed when hot - this may well be a characteristic/limitation of the box anyway. I would add it was only at Silverstone I noticed this, never at Spa or any other track and it was a hot day which may have emphasized it.  

@CM96 Always keep a good routine refreshing the oil definitely helps. I have recieved replies from JUBU which they suggest use oil gear competition 75W140 from Motul. I've pulled the trigger and placed an order trying out the JUBU cooler.

Some experienced race drivers suggested air cooler like Komo's product works better; however, I see Jubu's heat exchanger is very similar to the oem spec. After further explanation from Jubu, they preffered their kit works better in combination with cooling upgrade kit. Basically, it's a cooler thermostat, which I believe the theory making sense. The gearoil temperature won't go under water temperature. Due to the basic principal, the gearbox heat exhanger kit helps gearbox warm up faster on a cold start, and the combination with a lower temp thermostat would bring cooler and higher flow to the entire cooling system. Also, their pump works constantly in ignition, contrasting to the oem spec, the oem pump kicks in when the gearbox temperature reaches 90 degrees and then shuts when the temp drops. The principal behind making a pretty good solution to both road&track use, which it suits my situation of needs. I will give different products a try and see how it goes.

Frank

[Maxi_z]

For track use you should also consider that the Lotus is using the same reservoir for clutch and brake fluid so some improvement could be made by using some good quality brake fluid

as castrol srf or endless or motul RBF 660 or similar ( make sure it s some suitable spec ) and also purge the clutch line with it.

 

Make sure the gear shifter is properly adjusted by the dealer or a Lotus specialist.

 

I never used some higher viscosity 75w140 fluid so not sure if it s ok but Motul gear 300 or some Redline gearbox oil can improve gear shifting ( I think MT90 is the right one for the V6 )

The gearbox oil should be GL4 and not GL5.