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How to mod a turbo.. step 1...

:D now we is getting to the fun bit..

for those that aint seen inside a turbo.. (and want to lol).. heres a shot of the TD-04 (Renault Vel Satis) turbo in bits. (ciggy packet shown for size). estimated flow capacity is abt 290 cfm.. marked on the drawing are the areas to be machined to fit either a selected Garatt compressor wheel, or an -18t mitusbishi wheel, this will increase the flow to apx 500 cfm.. the exhaust turbine stage is fine for over 600 !.

these mods should be good to about 290-310 BHP at 65% compressor eficiency..

total cost ?.. hopefully about 70 quid.. a Captain Slarty Hybrid turbo - the easy way . :devilish:!!!

All good fun..


Simon.. soon I hope.. just getting the nitty gritty done...

I keep saying a few months...... but, I really do mean.... in a few months lol..

Twill be finished soon m8..

Joe... ps - Part of the fun is on the design........ sad, I know.. but hey !:devilish:

Joe again..........nice.......

But it seems like your extending the working time just so you can fiddle for longer!!! LOL
  Renault Laguna Coupe

Come on Ben, this man is an artist - didnt you watch Michaelangelo on the TV the other night? Joe is a Quik-Fit fitter compared to him!!


It will be finsihed when its finished ... Its really starting to come together now though.

Status as of today..

Block and Head

- at engineering shop.. turbo oil feed has been drilled into block. 172 Head having detonation marks tig welded and resurfaced, also redrill 2 holes for inlet manifold bolts. Acid clean both. Block awaiting pistons. being bored to 83mm (Cant be done before pistons arrive as they are custom made forged). Piston oil spray jets are being replaced as a matter of course, block face will be cleaned at 4 thou.


Exhaust manifold port mathched to 172 head (done)

Inlet manifold has had 4 extra injector bosses welded to tracts for boost fueling. TB end has been removed and ready to weld in 172 TB mount. Port matching to head will follow. Extra hole drilled for 2nd 3bar map sensor.


Now being made from scratch from forged blanks (Omega) CR= 8:1 (ish..)

Diameter altered to 83mm from 82.7 for greater choice of piston rings.


Following the above calcs, a new compressor wheel has been sourced. My local engineering firm will mod the core housing and comp housing to suit.. then it will be polished and ported. Turbine inlet to be ported.

Oil system

The most often overlooked area of turbo charging.. a custom oil separater has been sourced. All engine vents taken to the sep unit.. outlet fed to induction side of turbo compressor. Oil feed to turbo sorted, oil drain to sump needs a 5/8ths ali tube welded to sump wall .. need to measure under car to clear driveshaft.. Oil cooler (Thermostatic) modded to suit block (172) Oil rad obtained and pipework will be made once unit is fitted.

Fuel System

Hopefully the fuel pump wil supply enough to feed the second injector bank. (Aint looked at this in detail yet) otherwise an additional pump will be fitted.

Crank and rods

Crank is F4R turbo unit (new) rods are std. awaiting clutch then rotating assembly will be balanced.. rods matched and pistons matched. Bearing will be sourced once all machining is done.


Bit tricky lol... but looking at either a paddle clutch or a porche 911 modded st2 cover (270 foot pounds)


Probably go for a charge cooler but depends on whats available that will do the job effectively. Need to work out temp differentials and pressure drop.


to follow.. watch this space lol..


capt, can you get pics of the matched head.inlet/exhaust headers? just wanna look.

also, are you goin to tweek the std TB as its got such a fat spindle!! and such a fat plate!

but saying that, do you have to worry about strength of them under boost?

Hi Ben m8.

I am away for a week (next week) but will sort some pics when I get back.

re the tb, naw, dont rate it as a worthwhile mod really. (there is no issue under boost btw).

The plate is fat for a reason - strength obviously, but also in the design of the reno tb, there is a curved, eliptical boundry around the first 1/6th or so of butterfly travel restructing the airflow for lowdown throttle response. Thinning of the plate would cause a loss of this feature.

Joe ;)

Unless hes asleep spose lol...

Whats the old one ??.

"do you talk to your wife during love making ?"

Only if there is a phone handy

ps, smokings bad, yep.. is beer safe ???


  Shiny red R32

Joe, did you get the my pics of the Raider with my original 172 wheels that my mechanic has just put on it? They suit the Raider better than the 172, probably because of the chunky angualr spokes matching the angular GTT.


  Shiny red R32


I sent you both the rally pics and the Raider with the 172 wheels on, earlier this afternoon! Dont know what is wrong with your e-mail!

I dont know how to post pics on here so if I can send them to someone, maybe they can display them!

nice! and for some reason, the 172 wheels now look dated!!!

but if i had a turbo.....itll be straight bavk to 13" ultalights!!!! split rim too, and wide......


  Shiny red R32

Well Joe

We have Funeral Directors in my family and most of their hearses and limos are very dark metallic grey/graphite or black. They dont have any blue vehicles at all! Have you ever seen a blue hearse Joe?

Maybe I can get my 172 wheels put on one of them:sick:


  Shiny red R32


It wasnt my idea to try them on the Raider, it was the mechanic guy who would like me to let him have the car!


  Shiny red R32


The DVLA have several GTT registrations for £399 which isnt bad. Probably wont bother though.