GTM Libra B18C
Discussion
Yeah there's not many cars out there with it fitted, maybe 10 or 15. Supposed to make a big difference and after all the work I've done it would be daft not to as the opportunity may not always be there. David Rose the new owner of Z cars has been very helpful and willing to support the GTM, he's got his hands full as it is so it's great he's located the jigs and is up for doing it as it probably won't be a huge seller compared to all the mini stuff they do.
Yazza54 said:
Around 750-800 Kg, Honda engine is heavier than my old VVC k series car that got written off. But it's such a better package.
My track car was c750kg with a B16 and far superior to the VVC K series so it will fly with a B18.......I'm very jealous TBH 
eta now read your posts properly...apologies for asking the Q's..........enjoy the smiles
Edited by alfie2244 on Sunday 5th February 20:52
Just thought I'd post a little update
Still plodding on, date of the 4th march for paint looming but it's getting there. Have done a number of crazing repairs.. basically this consists of grinding any cracks out of the gel coat and filling back in with short strand fibre filler, flat back then finish with very fine filler ready for primer.
Seem to start a panel then find another, then another etc etc. But it needs doing right, it adds strength to the stressed areas where crazing has occurred and means it can't come back through and ruin the paint.
Readers of a nervous disposition look away now
Basically got patches like that all over the car. Well, clams and a little on the doors, not the tub.
Think it'll probably be a month or so yet till I get anything from Z cars too but there's no major rush...
One idea I have been toying with is turboing it, there's an abosulute mass of info out there regarding turbo B series Hondas and I'm quite confident it can be done reasonably cheap and with a good safe tune be able to churn out a reliable 300ish hp.
I was always tempted to do something mad with it once the paint is done and it's handling right and TBH was favouring an NA build but it just seems like a bottomless pit of spending, for what, 250hp? Plus it's the torque that will really be impressive.
There's plenty of guys running low ish boost on fairly high compression, if I pop the 11:1 type R pistons and rods out I can easily fit B18C4 pistons on H beam rods without even removing the engine, that will net 9.8:1. The main difficulty will be fitting it all in such a tiny space...
I've thought about it a lot over the last few days and just found these turbo flange to V band adapters
I think that with 2 of these, I.e one on the manifold and one on the turbo, I can basically just pipe between them and mount the turbo wherever I want it... obviously the shorter the better. It would be a quick and easy way to replicate a sidewinder style exhaust where the turbo sits more over the box where there's more space. V clamps allow everything to be turned too which helps on something custom like this. Then wrap all the tubing and make some support brackets. Bit of a brain fart at the moment but I think it's do able, otherwise there's simply not enough space infront
Of the engine.
This is the normal kind of setup
Maybe a top mount would be better to keep some room below for the downpipe etc.
Possibly something like this bolted to the manifold either on a top or bottom mount manifold with the straight v band adapter on the turbo. This should put the turbine facing upwards which would even make it easier to plumb in but would mean I couldn't use an off the shelf down pipe. But there's going to have to be a compromise somewhere.
Anyone have any ideas?
Theres basically some room around the gearbox and plenty of room above the engine, just not much in front
Still plodding on, date of the 4th march for paint looming but it's getting there. Have done a number of crazing repairs.. basically this consists of grinding any cracks out of the gel coat and filling back in with short strand fibre filler, flat back then finish with very fine filler ready for primer.
Seem to start a panel then find another, then another etc etc. But it needs doing right, it adds strength to the stressed areas where crazing has occurred and means it can't come back through and ruin the paint.
Readers of a nervous disposition look away now
Basically got patches like that all over the car. Well, clams and a little on the doors, not the tub.
Think it'll probably be a month or so yet till I get anything from Z cars too but there's no major rush...
One idea I have been toying with is turboing it, there's an abosulute mass of info out there regarding turbo B series Hondas and I'm quite confident it can be done reasonably cheap and with a good safe tune be able to churn out a reliable 300ish hp.
I was always tempted to do something mad with it once the paint is done and it's handling right and TBH was favouring an NA build but it just seems like a bottomless pit of spending, for what, 250hp? Plus it's the torque that will really be impressive.
There's plenty of guys running low ish boost on fairly high compression, if I pop the 11:1 type R pistons and rods out I can easily fit B18C4 pistons on H beam rods without even removing the engine, that will net 9.8:1. The main difficulty will be fitting it all in such a tiny space...
I've thought about it a lot over the last few days and just found these turbo flange to V band adapters
I think that with 2 of these, I.e one on the manifold and one on the turbo, I can basically just pipe between them and mount the turbo wherever I want it... obviously the shorter the better. It would be a quick and easy way to replicate a sidewinder style exhaust where the turbo sits more over the box where there's more space. V clamps allow everything to be turned too which helps on something custom like this. Then wrap all the tubing and make some support brackets. Bit of a brain fart at the moment but I think it's do able, otherwise there's simply not enough space infront
Of the engine.
This is the normal kind of setup
Maybe a top mount would be better to keep some room below for the downpipe etc.
Possibly something like this bolted to the manifold either on a top or bottom mount manifold with the straight v band adapter on the turbo. This should put the turbine facing upwards which would even make it easier to plumb in but would mean I couldn't use an off the shelf down pipe. But there's going to have to be a compromise somewhere.
Anyone have any ideas?
Theres basically some room around the gearbox and plenty of room above the engine, just not much in front
Edited by Yazza54 on Thursday 16th February 07:41
I'll be honest... I think staying NA is the way to go for a car like this, especially with that gem of an engine!
I know we all love speed and power but that must really shift, as-is and turbo-ing would change the character a lot, I'd think!
There's something about a high-revving engine in a light, mid-engine car. It's that 'delicacy' of floating it through the twisties with maximum momentum.
I know we all love speed and power but that must really shift, as-is and turbo-ing would change the character a lot, I'd think!
There's something about a high-revving engine in a light, mid-engine car. It's that 'delicacy' of floating it through the twisties with maximum momentum.
Hmm I tend to agree, but the fact remains I want to do something with it. I was leaning towards possibly a rotrex but that's even worse for space, dearer and I don't like the complication of the extra belt.
I've looked into NA tuning and to make any meaningful gains it would probably mean sleeving the block out to 85mm so it's close to 2 litres, forged pistons, rods, and all new valvetrain, inlet manifold etc etc and after all that it might make say 250hp. Doesn't seem worth it. There's a lot of people running high ish comp/low boost turbos now which are supposedly nice and tractable. With a good tune they can make a safe 300hp and have more low down pull on 10:1 as opposed to let's say more boost on 9:1.
I've looked into NA tuning and to make any meaningful gains it would probably mean sleeving the block out to 85mm so it's close to 2 litres, forged pistons, rods, and all new valvetrain, inlet manifold etc etc and after all that it might make say 250hp. Doesn't seem worth it. There's a lot of people running high ish comp/low boost turbos now which are supposedly nice and tractable. With a good tune they can make a safe 300hp and have more low down pull on 10:1 as opposed to let's say more boost on 9:1.
That's very true. When you can (hopefully) carry more speed everywhere with the new rear suspension set up then you may feel differently.
I am guessing you have 200+bhp with a nice exhaust, filter and remap on the B18C, which does sound 'a lot' on a car that small and light.
I'd tend to agree that an LP turbo might give you a little 'more' without losing too much character but it would be a shame if any 'zing' was lost.
I am guessing you have 200+bhp with a nice exhaust, filter and remap on the B18C, which does sound 'a lot' on a car that small and light.
I'd tend to agree that an LP turbo might give you a little 'more' without losing too much character but it would be a shame if any 'zing' was lost.
I always struggled with the idea of big power in the Libra - following Bertram's (?) build with the VAG turbo and DSG box I always thought that it was a tad daft.
Not big gains, but how about irtbs? Just the noise and crisp throttle response would give the feeling of a huge improvement, regardless of actual dyno figures?
Surprised at the amount of crazing on the clams, mine had absolutely none of that - wonder if it's an age thing (my tub was one of the last GTM ones, the clamshells were from Potenza after they bought GTM)?
Not big gains, but how about irtbs? Just the noise and crisp throttle response would give the feeling of a huge improvement, regardless of actual dyno figures?
Surprised at the amount of crazing on the clams, mine had absolutely none of that - wonder if it's an age thing (my tub was one of the last GTM ones, the clamshells were from Potenza after they bought GTM)?
Sway said:
I always struggled with the idea of big power in the Libra - following Bertram's (?) build with the VAG turbo and DSG box I always thought that it was a tad daft.
Not big gains, but how about irtbs? Just the noise and crisp throttle response would give the feeling of a huge improvement, regardless of actual dyno figures?
Surprised at the amount of crazing on the clams, mine had absolutely none of that - wonder if it's an age thing (my tub was one of the last GTM ones, the clamshells were from Potenza after they bought GTM)?
I don't want to speak ill of the previous owner, but it's blatantly obvious to me that the car wasn't very well looked after. I've heard stories of the GRP being better on the original cars but a lot of the repairs I've had to do were more down to lets say user error from what I can tell... Not big gains, but how about irtbs? Just the noise and crisp throttle response would give the feeling of a huge improvement, regardless of actual dyno figures?
Surprised at the amount of crazing on the clams, mine had absolutely none of that - wonder if it's an age thing (my tub was one of the last GTM ones, the clamshells were from Potenza after they bought GTM)?
I agree regarding the idea of a big power Libra, however, neither you or me have ever owned a Z cars converted Libra.... I'm 100% certain that in standard form the car couldn't handle it, but with the Z cars kit it should be a different kettle of fish. After all there is someone running a K20 Rotrex'd Libra at the moment with 350hp and he says it's a great package.
Bertram's car was very well done but also quite complicated especially with the DSG, extra radiators for charge coolers etc etc. I would look to keep things as simple as possible.
dom9 said:
That's very true. When you can (hopefully) carry more speed everywhere with the new rear suspension set up then you may feel differently.
I am guessing you have 200+bhp with a nice exhaust, filter and remap on the B18C, which does sound 'a lot' on a car that small and light.
I'd tend to agree that an LP turbo might give you a little 'more' without losing too much character but it would be a shame if any 'zing' was lost.
It is a lot in terms of power to weight, but nowadays every baseball cap turning kid is blatting round in a 300hp golf, civic or insert other.. cars are just a lot more powerful nowadays, although a big player in this is because cars have also become much more bloated!!I am guessing you have 200+bhp with a nice exhaust, filter and remap on the B18C, which does sound 'a lot' on a car that small and light.
I'd tend to agree that an LP turbo might give you a little 'more' without losing too much character but it would be a shame if any 'zing' was lost.
We'll see... with regards to zing it'll still rev to 8500 whether it's got a snail attached to it or not
Valid points Yazza, really intrigued to the difference those arms will make...
Have to say, I put any handling deficiencies (not that I felt there were many) down to the ratio of track to wheelbase, if the opportunity arises I'd love to come and have a look over yours once the arms/paint are done - although I already regret selling mine!
I'm in Sussex, if you're ever down this way give me a shout...
Have to say, I put any handling deficiencies (not that I felt there were many) down to the ratio of track to wheelbase, if the opportunity arises I'd love to come and have a look over yours once the arms/paint are done - although I already regret selling mine!
I'm in Sussex, if you're ever down this way give me a shout...
if you were to go turbo you would be better selling the b18c6 and getting a b18c4 found in the mb6 civic, they are a lower comp as standard and take better to turbo conversions, the b18c6 you have now would sell for around £2kish and you should be able to pick up a c4 for around £500
Ant_ITR said:
if you were to go turbo you would be better selling the b18c6 and getting a b18c4 found in the mb6 civic, they are a lower comp as standard and take better to turbo conversions, the b18c6 you have now would sell for around £2kish and you should be able to pick up a c4 for around £500
I know but there's something nice about having a unit you know works. I can easily drop a set of C4 pistons in anyway. Plus it remains a type R with its better balanced crank and type R head/cams. I'm not looking to do a major transplant, if I do anything at all. TBH initially I was just thinking of cams and map, then I thought that wouldn't make much difference so started thinking about sleeving the block and now here we are talking about bloody turbos
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