Turbochargers

[88ESPRIT]

Hello, Does anybody have any experience or knowledge on these? Are they worth changing stock turbo for? Is the power gain that noticeable?

Thanks for your advice in advance.

[t70]

the bosch k-jetronic system you have will not handle much more than the stock boost. If you upgrade to the Delco injection system, you can hit about 250hp-260hp (so I've been told) before the transmission detonates... I've been struggling with this idea for a while myself.. I was going to upgrade my pistons and rods and flywheel... but the tranny just won't handle the torque. you could add a boost controller and monitor your afr with a wideband to see what boost pressure starts to cause a lean situation... that's about all i can suggest without spending a small fortune to get more power to the wheels.

Oh yeah... I forgot to mention that the turbo lag you're experiencing is mostly because of the fuel injection system... and not the turbo itself...

[mwmackenzie]

I do not agree with the transmission statement above, My 88 turbo has well over 300bhp and the transmission is fine, the engine isn't at the moment though Currently under rebuild!

Cheers

Mark

Oh aboutthe turbo I have a T35 hybrid and a head made to greater than sport 300 spec running 650cc injectors and a stand alone DTA S60 ECU with wideband lambda... Lots of money to go down this route and most likely not worth the expense in my opinion. A standard car in pristine condition will be easier to sell on and a lot less money to get it that way..

All my mods are on the lef garage pages and also on LEW in the stephens owners section

Edited August 12, 2008 by mwmackenzie

[andydclements]

Mark.

The Renault box can handle the power (or more accurately it can handle the torque).

The Citroen box which was used in the Federal cars later than it was in the UK ones, cannot. That's probably the reason for disparity.

I've heard people in the know (factory) state that the turbo cars before the chargecooler put the Citroen box very close to its limit, a lot closer than the 40-50 safety margin indicated on this thread.

Andy

[t70]

Mark.. it's not a renault box.. It's a Citroen in 1988 in north america... I know.. I have one.

Edited August 12, 2008 by Mark T-C

[mwmackenzie]

Geez I feel for you...... What a pain! Good luck lads

Mark

[t70]

hehe... it's one of the few things that annoy me about lotus... why did the rest of the world get the renault box and either carb or delco injection... and the North American market get Bosch K-Jetronic and the Citroen Box?

[andydclements]

You've got a late 80s Stevens with Citroen and Bosch, I've got an early 80s Guigaro with Renault and Delco injection chargecooled setup.

It makes me think the idea of mating to written-off vehicles is a good one (recipe = take one badly body damaged llate car, one mechanically shot early car and one ex-development engine, through together and see what comes out).

Andy

[t70]

Now that's wild! Too cool that you have a G-car with a Renault box and a chargecooler??! WOW! That's super-cool! It would be fun to have a g-car with s4 mechanicals... that would awesome!

[Guy W Johnson]

I have a buddy who got a 450 hp v6 turbo in his 85 esprit, and it has been that way since 1985. After 20 years the Citroen revers gear gave out.

Guy

[t70]

What??!! REally??? Guy... I need more information on what he did to assist in the power handling capability... did he add more ribs to the box or anything like that?

[Guy W Johnson]

What??!! REally??? Guy... I need more information on what he did to assist in the power handling capability... did he add more ribs to the box or anything like that?

Nope, The only reason that the reverse gear gave out was no oil.

He takes the car out only at night looking for hopped up hondas.

Guy

[t70]

So... He did an engine swap the same year he baught the car brand new??? And it's been running like that for 23 years?

[Guy W Johnson]

yes

[DanR]

What engine is he running. Any chance of getting some photos and details on here?

[Guy W Johnson]

THe engine is a Buick Gnx V6 turbo.

Guy

Edited August 14, 2008 by Guy W Johnson

[t70]

Awesome!!!!! Thanks sooo much.. now I can modify my engine! WOOHOO!!!!!

[mchlrodrigues]

Serge/Mark-TC.

I have an '87 G-car which has the same mechanicals as the 88. Getting more power is easy. Green dot cam wheels, a European distributor from an '86-88 (has vacuum advance and retard, 18 deg BTDC total advance), and a T3/60 turbo upgrade.

If you have the head mildly ported, you'll be able to run an additional 2 psi of boost (w/o a chargecooler) before detonation sets in; i.e. 12psi. Add a chargecooler with an electric pump (I recommend a Johnson CM30), and an additional injection controller (AIC) and you'll be able to run 15psi. I recommend having the AIC set up on a rolling road dyno using a wide band O2 meter. As you only need to add fuel 10 to 15psi, tuning will be easy.

With all of the above including the the porting, and you'll probably make close to 330 hp at 15psi. The clutch won't hold it, but an AP tuning clutch will, and they're a direct bolt on to your flywheel.

This being all said, the first ring and pinion in my Citroen box lasted 8000 miles. I was driving the car easily while developing the motor and was probably making 275hp at this stage. The second R&P didn't last 4000 miles with the motor fully developed. Hit some ripply pavement under hard acceleration which can cause some wheelspin/shock loads and bang! Teeth sheer off the ring gear.

The R&P in the Citroen box are small and the case weak. It flexes, allowing excessive ring and pinion backlash, the hard facing will fail and the gears soon thereafter. If you're very gentle with the throttle, only using the extra power for high speed cruising or overtaking, perhaps you can get away with it. But if you want to accelerate hard in the lower gears while negotiating tight twisty roads, you're on thin ice.

Most people don't hot rod their cars to baby them . . . be forewarned. After two ring and pinions I converted to a Renault box.

[nodemgr]

THe engine is a Buick Gnx V6 turbo.

Guy

Awesome, do you have any more pictures? Did he do the swap himself?

[plumdeplakmuis]

With thick head gasket (lowering compression ratio) any power output should be possible till the max the gearbox can take. i think.

And as to avoid lag, maybe a Porsche 997 GT2 VTG turbocharger would be a nice option?

Or with max 850/900c EGT, a Diesel VTG can be a cheaper option.