OBD1 Turbocharging Limitations

[Devildub_06 0]

Right picking some smart VR6T brains here....I'm conducting some research ahead of stripping a golf for a project. It's a '94 OBD1 car which i'm aiming to hit 350 horses using a combination of sensible advice on here (and obviously some money's worth of kit lol). I do not wish to go standalone, nor faff about with converting to OBD2 (though may consider it as it is to be totally stripped out), but if someone could point out the limitations of the OBD1, and what is the ceiling of the power that can be sensibly acheived??

Many thanks all

[Bobtrude 0]

Ive heard that the "magic" line is around 300 Whp. You dont have to do diff, or any other mod. just the chains and cluch. And thats around 9 psi. After that you would have to do a number of mods to get it reliable.

If i where you, I would go for some sort of turbokit with a T3 turbo and mapping on rolling road.

I have ca 300 Whp and its very fast:).

[Devildub_06 0]

Many thanks Bobtrude, does this mean then that the OBD1 ECU can itself be remapped (apologies for my lack of expertise in this particular area, but we all have to learn something lol). If not fitting an ATB or LSD would it not be suseptible to quite a lot of torque steer?

[Bobtrude 0]

No stress:). The ECU can be mapped yes. Its on the forum somewhere how much u can have with the original ECU. Dont need standalone even thoug it has it advantages.

If you get an lsd, the grip will get better, but the gearbox will get more beating . . . . . . I get some torque steer, but when its boosting youre going to keep both hands on the weel anyway and then its no problem;).

I think you get a quite amount of torque steer with lsd also, but dont know. . . . . .

[FishWick 21]

I think Markie on here has 400whp from his OBD1 VRT.

If you use a 4" MAF and 440cc injectors, then it should work for you too. Your trouble will be getting a map written as more and more tuners are moving away from OBD1 to concentrate more on OBD2 and standalones.

Stealth racing could do you a map.

The limitations of OBD1 are mainly from a monitoring point of view on the dyno. For instance it does not report to the operator, air mass, knock regulation or lambda work load, so mapping it with a gas analyser and a wideband probe up the exhaust is probably the best way.

OBD2 tells you all that and much more, so is far easier to map and it's just a better ECU full stop. So before completely discounting it off hand now, think about your long term goals and plan around that. OBD2 for what it costs, will give you a lot more scope.

[Devildub_06 0]

If I wanted an idiot's guide to OBD2 conversion?

[Ciaran 4]

If I wanted an idiot's guide to OBD2 conversion?

comments like that won't get u much help

[Devildub_06 0]

Well what can I say, some things I know, and some things I don't! I was hoping that somebody could point me in the general area of a shopping list for OBD 2 conversion? I'm aware of some differences namely ECU, loom, throttle body, immobiliser with transponder box. but from there on in I get stuck. Would anybody be able to point me in the direction of a thread where I could gather the rest of the missing pieces? So I do apologise Ciaran, wasn't trying to put a bee in anyone's bonnet!

[FishWick 21]

LOL, your comment read as being dismissive but I think you meant "Where can I get an OBD2 idiot's guide?", didn't you? :-)

One doesn't exist, but you'll need:-

ECU

Throttle

Intake manifold

Key & coil reader

Transponder unit

Entire engine loom

It's quite a bit of work because to do it neatly and properly, the brake servo has to come out and some of the bulkhead grommets are different sizes and shapes, and some bits of the loom are shorter and longer etc. It'll probably take you a weekend to do neatly I reckon, poss longer depending on how fussy you are!

[UnitedMotorsport 55]

Is your aim 350hp at the wheels or at the crank?

Both is more than possible, OBD1 or 2

[Devildub_06 0]

Ahh, I see Kev, having re-read it now I can see where Ciaran was coming from lol, it was loosely a question about a shopping list and I am the idiot!! As for fussyness, I would say perfectionist bordering on OCD, it aint coming out of the garage until i'm happy with it!

C2 Motorsports, i'm aiming initially for 350 flywheel horsepower, but will not exceed 350 wheel horsepower. It's a great help to know I can do this OBD1, saves ripping looms out. I shall tap you up nearer the time as it sounds like you have the right answers to my question lol! Many thanks for your answers and pointers, all very much appreciated.