205 Gti Big Valve conversions
Discussion
Afternoon all.
I had a guy who was going to do a big valve conversion for my 205 Gti 8v head but he called me last night to tell me he cannot source the valves to do the work which has put a major spanner in the works
.
Can anyone recommend somewere that can do this work? Preferably along either the M3/A3/A31/A32/M25 or even the A34 if i had to?
Cheers
I had a guy who was going to do a big valve conversion for my 205 Gti 8v head but he called me last night to tell me he cannot source the valves to do the work which has put a major spanner in the works
.Can anyone recommend somewere that can do this work? Preferably along either the M3/A3/A31/A32/M25 or even the A34 if i had to?
Cheers
Xsport racing are nearby and well rated, QEP are in Kent and well known and respected.
Although there has been much debate on the 205gtidrivers forum over the benefit of modded heads, as the 1.9 8v head is pretty good as standard.
More benefit of going down the 16v route, for the amount you'll pay. If you're determined to stay 8v, the XU10 head (which has bigger inlet valves) can be made to fit, QEP have converted some.
Although there has been much debate on the 205gtidrivers forum over the benefit of modded heads, as the 1.9 8v head is pretty good as standard.
More benefit of going down the 16v route, for the amount you'll pay. If you're determined to stay 8v, the XU10 head (which has bigger inlet valves) can be made to fit, QEP have converted some.
I'd certainly recommend QEP too, though I'm not certain they do big valves. You could try Puma Racing who are based near Gerrard's Cross. The website is www.pumaracing.co.uk.
A decent flowed head will see significant gains over standard, but will only see its true potential with compression ratio, cam and induction modifications too. The problem with all vaguely decent modern heads is that it tends to be very easy to reduce their flow potential from standard through injudicious modifications. You need to find someone good, otherwise there's no point.
A decent flowed head will see significant gains over standard, but will only see its true potential with compression ratio, cam and induction modifications too. The problem with all vaguely decent modern heads is that it tends to be very easy to reduce their flow potential from standard through injudicious modifications. You need to find someone good, otherwise there's no point.
I wouldn't use an Mi16 again, or at least not a proper one with a dry-sump. I used to hate driving around watching the oil pressure gauge flap out.
As I've got older my hankering for power has diminished and these days I'm quite happy with a standard 1.6 GTi, but if I did ever want more power I'd go down the tuned 8V route. Probably.
As I've got older my hankering for power has diminished and these days I'm quite happy with a standard 1.6 GTi, but if I did ever want more power I'd go down the tuned 8V route. Probably.
TEKNOPUG said:
Mi16/Gti-6 transplant makes a lot more sense than throwing money at an 8v, unless you are in a strict race series.
I'm determined to get as much out of the 8V as possible without blowing it to pieces. I'm sorry to say it and i'm going to get abused for it but i am getting really bored of listening to people tell me how the sqeezed a V6 in there or put 40 throttle bodies on a 16V bored out to 2100cc...Sorry guys, it's all about getting power from the standard engine, not transplanting...
Whatever floats your boat, it's your cash after all.
180+bhp is about the most that you can realistically hope to get from an 8v NA, whilst retaining some suggestion of reliability and not spending a stupid amount (it'll still be disproportionally expensive compared to other options). Go for a Longmans head in the first instance. Big valves if you can afford them. I really wouldn't invest money with anyone else. They are the only ones that have repeatedly proven to produce good, reliable power increases time and again (plenty of other people offer the service - you pays your money, you takes your chances). Mi16 balanced and lightened crank is a very good idea. 2.5" 4-2-1 exhaust will help a little. Still not going to get more than 15% from that. So assuming that you have a genuine 128bhp in the first place (unlikely) then you are still looking at less that 150bhp for a lot more cost than dropping in 16v lump that comes with more power as standard.
Change the cam for something a lot more aggressive for some top end power and raise the rpm. Won't do much for driveability but you've got to rob Peter to pay Paul. For more power you'll need to dump the induction and fit either 40/45 twin carb or throttle bodies. Again there will be the added expense of inlet manifolds and looking after the ignition side (stand alone ECU, remap etc). None of this is cheap of course. Then factor all the other miscellaneous items require to keep it altogether and running properly and you've got yourself a sizeable bill.
Don't get me wrong, 180bhp 8v's pull like a train and are great fun to drive but the cost involved, together with the continued maintenance just makes no sense when you look at other options. I honestly can't see any reason to spend money on an 8v other than to keep it in good fettle - it's such a false economy.
As an aside, have you considered forced induction?
180+bhp is about the most that you can realistically hope to get from an 8v NA, whilst retaining some suggestion of reliability and not spending a stupid amount (it'll still be disproportionally expensive compared to other options). Go for a Longmans head in the first instance. Big valves if you can afford them. I really wouldn't invest money with anyone else. They are the only ones that have repeatedly proven to produce good, reliable power increases time and again (plenty of other people offer the service - you pays your money, you takes your chances). Mi16 balanced and lightened crank is a very good idea. 2.5" 4-2-1 exhaust will help a little. Still not going to get more than 15% from that. So assuming that you have a genuine 128bhp in the first place (unlikely) then you are still looking at less that 150bhp for a lot more cost than dropping in 16v lump that comes with more power as standard.
Change the cam for something a lot more aggressive for some top end power and raise the rpm. Won't do much for driveability but you've got to rob Peter to pay Paul. For more power you'll need to dump the induction and fit either 40/45 twin carb or throttle bodies. Again there will be the added expense of inlet manifolds and looking after the ignition side (stand alone ECU, remap etc). None of this is cheap of course. Then factor all the other miscellaneous items require to keep it altogether and running properly and you've got yourself a sizeable bill.
Don't get me wrong, 180bhp 8v's pull like a train and are great fun to drive but the cost involved, together with the continued maintenance just makes no sense when you look at other options. I honestly can't see any reason to spend money on an 8v other than to keep it in good fettle - it's such a false economy.
As an aside, have you considered forced induction?
Soton Pug said:
TEKNOPUG said:
Mi16/Gti-6 transplant makes a lot more sense than throwing money at an 8v, unless you are in a strict race series.
I'm determined to get as much out of the 8V as possible without blowing it to pieces. I'm sorry to say it and i'm going to get abused for it but i am getting really bored of listening to people tell me how the sqeezed a V6 in there or put 40 throttle bodies on a 16V bored out to 2100cc...Sorry guys, it's all about getting power from the standard engine, not transplanting...
http://www.track-monkey.co.uk/2058v_spec.htm
Sean's had a few engines and spent a considerable amount getting something he likes.
Simes205 said:
You may want to think again about spending silly amounts on an 8v.
http://www.track-monkey.co.uk/2058v_spec.htm
Sean's had a few engines and spent a considerable amount getting something he likes.
That's not the engine's fault though is it? I think Sean would have had exactly the same problems if he'd gone after a 16V.http://www.track-monkey.co.uk/2058v_spec.htm
Sean's had a few engines and spent a considerable amount getting something he likes.
I know what you're saying; a standard 16V saves you a lot of bother for the same performance as a modified 8V, but the 16V's have their own problems too. The Mi16 is a non-starter because of the oil surge issues, and the GTi-6 doesn't seem to stand up to track use very well either.
TEKNOPUG said:
As an aside, have you considered forced induction?
I would agree with this, I have a xu10 2.0 turbo which won't suffer from surge like the mi's do. It might not be the revviest engine in the world but a well set up one running a bar is pretty quick machine for not much money.I looked into getting a tuned 8v when I was going to hillclimb but the costs to have it done properly for a decent power gain are very very high.
You can get 200+bhp 8v's but I think you would be into SERIOUS ££'s, whereas my 205 turbo has approx 200bhp and lots of torque! and has cost me just under £1.5k for everything.
I would guess for a tuned 8v with that power you could multiply that figure by about 6!
Soton Pug said:
Seems I've opened Pandora's box...
I think the only reason for that is because you are asking advice for something which isn't really a very financially sensible option to increase the performance of your car.So people are just trying to help you not "waste" your money. But its up to you as its your cash.
bales said:
Soton Pug said:
Seems I've opened Pandora's box...
I think the only reason for that is because you are asking advice for something which isn't really a very financially sensible option to increase the performance of your car.So people are just trying to help you not "waste" your money. But its up to you as its your cash.
Turbo-charge the 8v!
GT25, TT-Style exhaust manifold and run it on Emerald or similar.
Keep the standard compression so that's it's good off boost and will also make a lot more power for less boost. Keep the standard cam profile too so it revs and pushes hard above 4k. 200+ very easily but with good throttle-repsonse and off-boost performance.
How much are you looking/prepared to spend on the 8v engine?
GT25, TT-Style exhaust manifold and run it on Emerald or similar.
Keep the standard compression so that's it's good off boost and will also make a lot more power for less boost. Keep the standard cam profile too so it revs and pushes hard above 4k. 200+ very easily but with good throttle-repsonse and off-boost performance.
How much are you looking/prepared to spend on the 8v engine?
Speak to (Big?) Vern over at 205Gtidrivers as he did a similar conversion with very impressive results.
Also Henry Yorke converted his Cti used a combination of XU9 and XU10 parts.
Run a search for posts by "MattCony" and "MadProfessor"
For best results you'll need to go stand alone management, especially if you want to maintain standard compression.
www.dp-engineering.nl/ offer complete kits but at a price
http://www.205parts.com/ sell copies of the original Turbo Technics manifolds
After the manifold you would need: turbo, downpipe, oil return to sump, larger injectors, intercooler, pipework, stand alone management.
Most of the parts you can get second-hand from other vehicles.
Ask on 205gtidrivers as it's been covered many times. Also, look at the article on the homepage about the Emerald set-up on the original Turbo Technics
Fitting the XU10 is probably easier but it's a big old lazy lump. The XU9 suits the little 205 better, particularly with the higher CR and more aggressive cam (awaits flaming from Bales.....)
Also Henry Yorke converted his Cti used a combination of XU9 and XU10 parts.
Run a search for posts by "MattCony" and "MadProfessor"
For best results you'll need to go stand alone management, especially if you want to maintain standard compression.
www.dp-engineering.nl/ offer complete kits but at a price
http://www.205parts.com/ sell copies of the original Turbo Technics manifolds
After the manifold you would need: turbo, downpipe, oil return to sump, larger injectors, intercooler, pipework, stand alone management.
Most of the parts you can get second-hand from other vehicles.
Ask on 205gtidrivers as it's been covered many times. Also, look at the article on the homepage about the Emerald set-up on the original Turbo Technics
Fitting the XU10 is probably easier but it's a big old lazy lump. The XU9 suits the little 205 better, particularly with the higher CR and more aggressive cam (awaits flaming from Bales.....)
No worries 
Really, the first thing you need to decide is how you are going to manage the fuel and spark. As said, standalone makes it much easier and with better results. However, you are looking at £600+ outlay for that alone (unless you're brave and try megasquirt).
You can run on the standard ignition using a boost retard capsule in the dizzy and a 5th injector. It does work and will be cheaper but it's basically clock-work in a world of digital and you will need to lower the CR.
Also - you want old school RST/R5T turbo delivery with a big shove in your back at 4k or smooth, seamless delivery, akin to a V6?
Really, the first thing you need to decide is how you are going to manage the fuel and spark. As said, standalone makes it much easier and with better results. However, you are looking at £600+ outlay for that alone (unless you're brave and try megasquirt).
You can run on the standard ignition using a boost retard capsule in the dizzy and a 5th injector. It does work and will be cheaper but it's basically clock-work in a world of digital and you will need to lower the CR.
Also - you want old school RST/R5T turbo delivery with a big shove in your back at 4k or smooth, seamless delivery, akin to a V6?
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