Sequential gearbox for high torque application

[teamHOLDENracing]

Dear all

Any direct experience of the following sequential boxes? It is for fitment to a Chevy LS2 powered GT car (front engined, rear drive). I am looking for a fit and forget solution - i.e. stick it in at the start of the season and other than lubricant changes (and possibly ratio changes) and maybe a half season check over, I don't want to touch the thing again until winter.

It needs to cope with 500-550 lb-ft of torque and I will run it with a cooler, mated to a BTR cone diff also with a big cooler. Race durations initially up to an hour, but subsequently anything up to 24 hours.

Options I am considering are

Glebe GT6
Holinger
Hewland IGT-C
Drenth

The Holinger and Hewland are proven as far as I can ascertaion - so I'm looking for eaxmples of the Glebe and Drenth boxes in big torque/power applications

I'm also interested in experience of spares availability /servicing on all.

I'm even more interested in good condition secondhand examples, though I suspect I may have to buy new.

Many thanks

Andy

[anonymous-user]

That's not big torque/power.

As to the coolers, you need to size the coolers to provide the required temperature range, big doesnt tell you anything and it's important you dont overcool the box otherwise the tolerences will be out.

If you want a fit and forget solution then by defination it's likely to be a heavier unit than you could probably get away with should you be prepared for more maintanance time, which could be the diference between a few places in a race or even a car that is balanced and one that is dificult to drive.

Dog boxes do need regular inspections, you dont want to wait until it's jumping out of gear because of a worn dog before you know there is a problem developing, the wear rate also varies vastly from driver to driver so it's going to need some inspections just to stay on top of the situation and advise the drivers.

[Scuffers]

johnfelstead said:

Dog boxes do need regular inspections, you dont want to wait until it's jumping out of gear because of a worn dog before you know there is a problem developing, the wear rate also varies vastly from driver to driver so it's going to need some inspections just to stay on top of the situation and advise the drivers.

DING to that!

Some drivers can make the dog rings last all year, others seem to find 60 minutes a challenge..

[lanan]

teamHOLDENracing said:

I am looking for a fit and forget solution - i.e. stick it in at the start of the season and other than lubricant changes (and possibly ratio changes) and maybe a half season check over, I don't want to touch the thing again until winter.

I don't think it has been invented yet.

[teamHOLDENracing]

Guys I don't really need the lectures on maintenance thanks.

The Holinger and Hewland will, I know, be absolutely fine in this application, but I have no experience of the Drenth or Glebe. I don't know anyone who runs the Glebe (but am told that somewhere in Belgium someone is running one in a Viper) and whilst I know plenty of people who run Drenths in BMWs, none of them run V8s with the sort of torque we have.

So any tales of direct experience gratefully recd. Thanks

[anonymous-user]

Why dont you pick up the phone to Nick Cresswell at Glebe and ask him who is using his box in that aplication and what experiences they have had to date with it then? Ask for references from his customers etc.

[NightDriver]

What exactly are you looking for? - weight? 5/6spd? km between rebuilds? ease of maintenance? cost of spares?

As has been said, fit and forget will be dependant on how its driven so its pretty difficult for anyone to comment without knowing your drivers style.

Out of all of them Hewland are the easiest to get parts for (if your in the uk). This is what I'd go for if it was one of my cars.

I'd say get on the phone to all of them, discuss your application and make your mind up.

[teamHOLDENracing]

johnfelstead said:

Why dont you pick up the phone to Nick Cresswell at Glebe and ask him who is using his box in that aplication and what experiences they have had to date with it then? Ask for references from his customers etc.

I did excatly that, which is how I know someone somewhere is running a GT6 in a Viper. Nick couldn't be more specific that that in the case of the Viper which is closest in application to mine. He has been very helpful. There are one or two BMW V8 engined applications that I have some details on and will follow up i the New Year

I am looking for reliability first and foremost as I won't be able to carry a spare box to circuits. Races will be 2 x 45 or 2 x 60 minutes per weekend and the ability to change ratios to suit the circuit appeals. 5 v 6 speed doesn't matter too much as the engine has enough torque we don't need to keep it in a sweet spot in the rev range. Weight is not critical as we may end up needing to ballast or resrict the engine anyway.

Given the torque there is not a huge choice. As expected none are cheap, although the Glebe is the most affordable.

Holinger: no drop gears and I hear that parts can take more time to come through from Oz since they won the Porsche contract. No worries about reliability. Expensive particularly when the European distributor has taken his slice

Glebe GT6: drop gears and significantly cheaper than Holinger and Hewland, but far fewer in use and therefeore arguably (and perhaps unfairly) a less proven option

Drenth - an unknown to me but plenty of the guys in Dutch Supercar using them

Hewland: drop gears and proven reliability, 15 miles from us but the most expensive option.

[thunderbelmont]

Andy - serious question here - with that much torque on tap, and the weight of your car (under 1400Kg), do you REALLY need 6 cogs?

The LS2 has a very broad torque band, and being brutal here, you could get away with four on the floor! Though five would give you that extra one to shuffle the deck and run them even closer.

What's the rev range of your LS2?

My heap would pull like a train from 2000 to just over 8200, though it produces another 100lb/ft torque, but isn't benefiting from fool injection. With a proper mapped system, I'd expect to see even more bottom end/mid-range oomph.

I would side with those who talk about the Hewland in terms of support & simplicity.

I too talked to Nick at Glebe about his H-pattern 6speed, but when I saw the torque results of my engine, I decided to go for an agricultural GM Muncie M22. It'll do abt 85 in 1st gear, and with the 3.25:1 diff and 245/680R18's, it'll top 200!! The M22 was purchased brand new from the 'States for $1800.

My only change was going to be a change from the Ford 9" rear end (a Strange Industries 9" actually) to a Winters Quick Change. That would allow me to change the final drive ratio in minutes, which is a ruddy site easier than changing cogs in the 'box.

Those are my thoughts - which are usually wrong.

Rob.

[anonymous-user]

With that kind of weight and torque i would want at least a 5 speed, 6 speed would be better IMHO.

Edited by johnfelstead on Sunday 30th December 00:34

[Ramthorne]

They are a few people using the Drenth in 4x4 racers, one of them behind a tuned LS2.

I have not heard of any issues other than clutch problems, which I believe is more down to instalation.

[s.m.h.]

Have you looked at X-Trac boxes? Looked after a sportscar with one in, the company owner was part of Hewland previously (I believe).

Question - Are you using a flat shift or paddle arrangement?
What is you budget for ratios?
Are there any teams selling s/h boxes with spares?

You need to look into tools as well, as I can remember seeing the price of setup tools and it costing half the price of a box!
Also who is driving the car, just yourself or a few of you?
Everyones driving is different, I would take the cassette out of the LMP car and tell you which of 3 drivers had been in the car that day.

IIRC just a hewland dog ring is around £150, a pair of gears start £200ish.
Layshafts and mainshafts can sometimes have no or restricted choices of 1st and 2nd gears which may mean a change of diferential as well.

[lanan]

I ran a C5R and C6R GT1 cars with Xtrac and Hewland LGA boxes. Both were superb, haven't any experience with the others mentioned. If I were in your position, I would go Hewland, they have the box to suit your application, they have a proven track record and they are 30 mins from you. You may even find one of the factory guys interested in helping part time, keeping everything up to spec.
Graham

[teamHOLDENracing]

Thanks guys - I am leaning towards Hewland who are just 9.4 miles down the road.

Rob - I'd expect the car to come in at a shade over 1,000kg. And with the torque band there is probably not as much to be gained from the sequential as there would be with the existing AJP, but there you go. There is far less chance of a missed gear with the sequential and flat shift will make a difference.

[Graham]

teamHOLDENracing said:

There is far less chance of a missed gear with the sequential and flat shift will make a difference.

I think there's the real advantage in the sequential... no missed gears or over rev's hitting the wrong gear... The Team I do some work with go through a lot less motors since they fitted everything with sequentials !!!

G

[s.m.h.]

Graham said:

teamHOLDENracing said:

There is far less chance of a missed gear with the sequential and flat shift will make a difference.

I think there's the real advantage in the sequential... no missed gears or over rev's hitting the wrong gear... The Team I do some work with go through a lot less motors since they fitted everything with sequentials !!!

G

You can still get false neutrals between gears if youre unfortunate, even with sequentials. You only neeed to dog to dog and the gear wont go in. Sure its less of an issue but the ignition cut needs to be spot on.
Even with the correct gear cut, new ratios and an ex F1 driver, F3 champion and a muppet in the car, in 24hrs went through £12k worth of gearbox internals. Its down to skill and mechanical sympathy!
Down shifts are the real trick as unless you have a full air/electrical shift system there is always human error.

[taffyracer]

I wouldn't discount the Drenth, from what I have seen of their boxes on BM's i'd say they could be a very good option indeed and they are extremely helpful

[thunderbelmont]

teamHOLDENracing said:

Thanks guys - I am leaning towards Hewland who are just 9.4 miles down the road.

Rob - I'd expect the car to come in at a shade over 1,000kg. And with the torque band there is probably not as much to be gained from the sequential as there would be with the existing AJP, but there you go. There is far less chance of a missed gear with the sequential and flat shift will make a difference.

I guess you're right in the issue of flat shifts saving lap time.

And the comment about seeing who's been driving by the wear on the dogs is very valid! Get it spot on and they're sweet. Otherwise they'll be playing tunes!!
"God Save The Queen" on a dog box isn't cheap!!

That reminds me, I have to drag the Jerico out of my ASCAR and give it a birthday.

Rob.

[Graham]

The dogs are fine on mine after 2 seasons, its just the bits of the lay shaft that are lying in the bottom of the box im concerned about