Somthing for the weekend.

[pascal-GT]

all my friends to have had the same problem with the omp….

[Andrew Cooke]

I can't recall the gearbox number/code now, but see if you can sniff out a gearbox from an R11t - For some reason (Friday afternoon parts bin raid probably) Trusty had said gearbox in situ & it made for a cracking trackday 'box.

Was definitely a closer ratio/different FD than what was in my old Raider's gearbox, which probably helped made Trusty feel quicker than what it should've been, given the (v limited) engine tweaks.

ratios are the same as GTT, just a 4.09 rather than 3.73 final drive.

[Alastair]

Pascal - thanks for that, ive ordered a Helix/AP replacement and will be getting a new valeo cover. If you hadn't spoken up that this has happened to you and friends then i would have spent a lot more on another, bigger clutch so many thanks!

Mart - great info thanks!

Andrew, thanks for the sanity check! I still haven't sat down and done some tables...! I cant find the ratios for the later jc5s though either (172/182). Basically i want the car to max out at 120 mph at 6.8k and have a longer 1st, then a close set up to 120 mph, and that i can drop my diff into. Time is not on my side though as every time i start to look in any detail i get distrcted by a heavily pregnant wife

Am i best just getting a 172 JC5 box (i am sure you told me ages ago that is the way forward for my needs ) - but being blonde i can never be sure!

I would like to do some tables and compare the different boxes out there though, it would (perversely) satisfy my curiosity!

[Andrew Cooke]

172/182 have the same ratios as williams, the only odd one is PH1 172 (078?) and that has a 3.89 final drive.

There isn't really anything with a tall 1st, 172 is about as good as it gets. There is still a big drop 1-2. I tried a low diff (4.83?) to avoid using 1st, I didn't like it, too much changing gear.

[markey b]

I can't recall the gearbox number/code now, but see if you can sniff out a gearbox from an R11t - For some reason (Friday afternoon parts bin raid probably) Trusty had said gearbox in situ & it made for a cracking trackday 'box.

Was definitely a closer ratio/different FD than what was in my old Raider's gearbox, which probably helped made Trusty feel quicker than what it should've been, given the (v limited) engine tweaks.

i've got an r11 box in mine, lasted 5 years too! may swap it over for a std GTT box but have had bad experience with them and broke 4 in a year and a half

[Alastair]

172/182 have the same ratios as williams, the only odd one is PH1 172 (078?) and that has a 3.89 final drive.

There isn't really anything with a tall 1st, 172 is about as good as it gets. There is still a big drop 1-2. I tried a low diff (4.83?) to avoid using 1st, I didn't like it, too much changing gear.

Have you still got the low final drive Andy?

[Alastair]

Took the 5 out for a drive for the first time in ages today - loved it. Also fitted the lamp pod on for a pic or two...

Must get the front bumper sorted one day - alway hoovering up tyres!

[Alastair]

You can also see the wider track at the front with this pic, but it is a lot more noticeable from the rear....

[Tony Walker]

definetly wider, looks fantastic mate.

[Alastair]

Evening all... thought id post up a short update...

I fitted a new turbo today as i am hillclimbing at the weekend, a GT2554RS, with a .64 back end and .8 compressor... I took it for a spin over Dartmoor and WOW
Relentless is not the word, once it gets on boost it is just amazing, hitting the limiter in every gear and i had a blast with the wet tarmac and the hydraulic handbrake

Only snag is it is a bit laggy for rallying, but would be amazing for the strip or proper track.... so im going to have to part with it.

ive got a new Tomcat to go on, .49 back end and a .7 cold side. Hopefully that will spool up a bit faster ???

[Mart]

.49 hot-side might help the spool-up mate. As would advancing the cam timing, and/or mappable ignition.

[Alastair]

.49 hot-side might help the spool-up mate. As would advancing the cam timing, and/or mappable ignition.

Thanks Mart, i know they do a .49 rear housing for them but they are a funny exit bolt pattern and about 150 quid.

Cam has been advanced for a bit more torque on tight chicanes, i don't ned all out power really. TBH the EFi was fuelling well but the bigger back end could do with a tad more ignition advance to get it spooling up as you suggest

The wheels look very modern compared to a Tomcat wheel design, very posh indeed! I am tempted to try and find a second hand .49 rear housing that will fit though, i have a .49 from my old GT28RS in the garage but the bolts are seized and i haven't got time to faff with it if it isnt going to fit...

[Mart]

I'm behind the times - I didn't know you had efi!

In that case, try lean-spooling the blower to see if that helps matters.

I'd certainly try all that before junking the blower. Tomcat turbos are old hat now, and (re)fitting one is taking a big step back, imho.

Adam L should be able to help source a .49, or Owen Dev's, Turbo Dynamics, Turbo Technics, etc.

[Alastair]

I'm behind the times - I didn't know you had efi!

In that case, try lean-spooling the blower to see if that helps matters.

I'd certainly try all that before junking the blower. Tomcat turbos are old hat now, and (re)fitting one is taking a big step back, imho.

Adam L should be able to help source a .49, or Owen Dev's, Turbo Dynamics, Turbo Technics, etc.

LOL, ive been EFi for a year or so Mart The AFR were mid 13's as it spools and then 12.5-12.9 on mega boost. I didnt take it past 19 PSI but that was enough, just phenomenal, an animal. Fighting the torque steer with the quaife and PAS was fun. It is mapped to 22 so plenty more to go, but i didn't want to push it too hard.

I hear you WRT getting the .49 on and trying it, that was what it is mapped to originally. I am racing at the weekend so need to get the tomcat on ASAP, IIRC they boost by 3.5-4k ?

My last turbo was GT25RS with a machined .35 rear and a .42 compressor (not sure on the trim i need to measure it) - that was a torque monster and i loved it, but it did run out of legs at high rpm and olny lasted a few months....

[Mart]

Like I said mate, I'm behind the times

Aii, my other suggestion was to see if a machined out standard T2 back-end would do the trick.

Are you allowed to run NOS?

[Alastair]

Like I said mate, I'm behind the times

Aii, my other suggestion was to see if a machined out standard T2 back-end would do the trick.

Are you allowed to run NOS?

Not allowed any gas mate, apparently it isnt safe

Not sure why my last turbo went bang (millers oil and all spot on mechanically) so it is going back to Owen Developments for investigation.

the .35 back end had a big crack in it That might have been half the problem.

[Mart]

Good (or too much) oil pressure? That crack probably didn't help spool matters

I'm sure you could 'hide' the funny gas, akin to the grp B S4...allegedly

[Alastair]

Good (or too much) oil pressure? That crack probably didn't help spool matters

I'm sure you could 'hide' the funny gas, akin to the grp B S4...allegedly

Mmmm well oil pressure is 45-50 psi on the guage and i didnt put a 'restrictor' in (small bore JIC adaptor). I thought they were a myth? Perhaps that killed it?

[newbstar*]

LOL, ive been EFi for a year or so Mart The AFR were mid 13's as it spools and then 12.5-12.9 on mega boost. I didnt take it past 19 PSI but that was enough, just phenomenal, an animal. Fighting the torque steer with the quaife and PAS was fun. It is mapped to 22 so plenty more to go, but i didn't want to push it too hard.

I hear you WRT getting the .49 on and trying it, that was what it is mapped to originally. I am racing at the weekend so need to get the tomcat on ASAP, IIRC they boost by 3.5-4k ?

My last turbo was GT25RS with a machined .35 rear and a .42 compressor (not sure on the trim i need to measure it) - that was a torque monster and i loved it, but it did run out of legs at high rpm and olny lasted a few months....

Glad my old efi setup was good in the end worth every penny

[Mart]

Possibly. I know BB cores are a bit funny when it comes to high oil pressure - Whether ~3bar is defined as high pressure is another matter though, but defo worth asking Owens (or the such like) for their opinion.

[Andrew Cooke]

Have you still got the low final drive Andy?

attention failure on my part, yes I still have it.

[Big Steve - Raider]

Oh and Boris called round to help out and i couldn't resist a pic of two 5's together...

This has to be the best balls up of pictures on the RTOC for a long time

Either that or Al & Boris have been flashing the cash

[Alastair]

Unfortunately for me it isn't my or bens Porsches! Lol !

Most of the pics in this thread got jumbled up when we lost the site... Shame as there were some really useful ones and I don't have copies any more!