I can't drive 90mph

[evilfij]

At least I could not before . . .

Now I am disco cold start chip enabled!

Have not hit the highway yet to see if the speed limiter is disabled, but I can confirm the vehicle runs normally on the disco PROM.

PRM3652 (correct number now!)

I have an updated D90 prom (3665A) if anyone wants to try it out in their D90 or keep their Disco driving wife/kid/self from speeding too much.

Ron

[chrisvonc]

Whats involved? I might be interested.

[Mike Hippert]

First off Ron I really like the Signature:thumbs , second how do you get the disco PROM, from the dealer? I know allot of D-90 guys would like to know how they can get their larger tired, incorrect speedo, to be able to go past the 75 to 80 mph range.

[evilfij]

Once the ECU is out (5-10minutes depending on AC panel) about 2 minutes for the swap $35 for the part and a T-15 torx bit screw driver.

Ron

Follow-up Post:

Mike,
Yes I got it from the dealer. PRM3652 (correct number now) Disco I cold start, the PN is in a bulletin.

If you regeared to 4.10 and did not go to some huge tires it will allow you to go at a decent speed.

It will not correct the speedo though. That can be done with the correct output gear on the speedo drive if you really want.

Ron

[chrisvonc]

I'll give it try Ron. Might have to wait a couple weeks. Got some stuff going on at the moment thats taking up my free time.

[Mike Hippert]

Cool only $35 and yu can go faster then 80! I new it wouldn't correct the speedo but Jimmy has 32" tires and his speedo is off by 10 mph and it sucks on the highway when he is trying to follow me and I want to do +80mph.

[evilfij]

Let me know if you need help. Make sure to ground yourself before doing the swap of the PROM (lick finger and touch something metal).

I am now considering going putting on a set of disco sized tires and lowering it. Make it real zippy (note should probably reconsider this after I get the BMW back from the shop 21 days and counting grrrrrrrr)

Ron

PS the only tricky bit is making sure you get the PROM in the right way. ONe side has a little half circle and one does not. Look at the old one (or the spot where the old one was removed from) and you can line them up. No biggy but it looks like it will go in backwards so make sure to get it right. :cool:

[mdmccallum]

So let me get this straight. The disco cold start chip keeps the engine as it is but disenables the govenor? Does it have any other advantages? Depending on how you look at it, the disenabled gov. could be a disadvantage. Is gas mileage changed or performance improved? As you can tell I am not very informed when it comes to chips.

[BarryO]

I'm not someone who is against driving fast -- had a Porsche that used to do 130; I know from personal experience. But 90 MPH in a D90? 'sounds like a disaster waiting to happen. The lousy aerodynamics coupled with the compliant suspension indicates things could get real ugly if you have to do anything evasive at that speed.

I really like application-specific machines. Which is why I like the D90 so much: it is so capable off-pavement. But driving it at 90+ on the freeway makes as much sense to me as going mud-bogging in the Porsche.

[DJ Menasco]

90MPH Ron!!! Geeez! Since I put in 4.10's I struggle to get to 65mph without going over 3500 rpm! Even before with 3.54's the best I could do was 75mph, downhill, with a tail wind!

DJ

[jaherring]

Let me know if you need help. Make sure to ground yourself before doing the swap of the PROM (lick finger and touch something metal).
Or you can go buy an anti-static wrist strap and clip it to the body ground for an even more foolproof antistatic system than the old 'wet finger' ;)

I would be interested to know how this affects the power curve and torque curve.

Did you choose the same year Disco to purchase the chip? If so, we can look at the following to understand differences:

1) are the fuel injector sizes different between the 3.9L in the D and the 3.9L in the Disco?
2) how is the intake system different? How much CFM will each flow in comparison?
3) transmission and axle ratios can affect how the engine's power curve should be optimally fit

etc etc.

I'm not someone who is against driving fast -- had a Porsche that used to do 130; I know from personal experience. But 90 MPH in a D90? 'sounds like a disaster waiting to happen. The lousy aerodynamics coupled with the compliant suspension indicates things could get real ugly if you have to do anything evasive at that speed.

I think it's more about personal responsibility rather than having an engine with diapers on. So long as the engine is not redlined the thing should not be artifically limitted except by it's driver's discretion, IMO. At 130mph you are definitely not driving at a safe speed in the Porsche in the US, but I'm sure you would not be happy with a chip limitting you to 110mph.

Soon enough our cars will be snitching to the police about our excesses and perhaps issuing us speeding tickets from a printer in our own dashboards if we are not already cut off at the knees by being limitted to the posted speed limit by a quick conversation between our onboard computer, the ECU and a speed limit sign with an RFID chip in it. (Orwellian 1984 doom and gloom, etc).

I for one would not mind a chip that I could tune the power curve for better economy and/or more power.

[Eric Siepmann]

I for one would not mind a chip that I could tune the power curve for better economy and/or more power.

Search the Board. Different results for different years of Trucks. Be thankful you don't have a GEMS system. What a nitemare.

EwS

[Defender50th]

Hi,

I have got specially programmed chips in my Defender 50th (basically a 1997 NAS station wagon) running the GEMS ECU.
It has lifted the speed restrictor and I have driven it to its max. It will go up to about 115mph and it did it with no problems. You could probably cruise at 100 on a good bit of road.

James

[Buckon37s]

Holy crap, you guys actually think it is the govenor keeping your trucks from going over 90 :lol :lol

[Eric Siepmann]

I gotta agree with David on this one. My stocker gets me over ninety. Got the ticket to prove it.

EwS

[Mike Hippert]

The speed limiter can be tricked, actually in most cars it can be, you need to be going down hill and floor it, when you hit the limiter keep it floored, as soon as you pass the limiting spot the engine will kick back in (I have done this but not in a 90). And 90mph isn't all that big of a deal, I've done it with rear DS out!:grin

[evilfij]

90 is the average speed on the turnpike. I kept hitting the rev limiter so I disabled it. The disco is the same as a D90 engine wise. 1994-95 DI cold start PROM.

[Roadsiderob]

I put a Disco I cold start chip in my 1994 D90 in 1997? or so and have run it for 130K+ miles. I have not noticed any difference in power or fuel economy, however, it is nice on long drives, especially since the speedometer is approximately 10% optimistic. The main reason that the D90s have the speed limiter built in is due to the speed rating on the tires...BFG wouldn't certify the tires for over 90mph and anyone considering doing the changeover should bear this in mind.
Rob Dassler

[Vadim]

Hello everybody.What is 'PROM" ? And how I can reprogramm my chip?And were chip located?
Thank you
'Vadim

[Defender50th]

The main reason that the D90s have the speed limiter built in is due to the speed rating on the tires...BFG wouldn't certify the tires for over 90mph and anyone considering doing the changeover should bear this in mind.
Rob Dassler

I agree there. Forgot to say about that. Make sure your tires have the corect speed rating or they might blow up and that could be disasterous !!!

I have the limiter lifed but also changed to fast road tires.

Best regards

James

[Vadim]

Hi.Question to Ron. Ron did you drove on highway with new chip yet? I just want change my chip too.Do I have to buy reguliar Disco 1 chip or I need to reprogramm it too? I have 1995 D90,you think I can do this modification to it? And at last ,I am wonder if I need to change just chip only,or its any adjastment involved ?Sorry for so many ????
Thank you in advance
Vadim

[evilfij]

I have not driven on the highway yet. I will confirm when I do. (BMW gave me a loaner so I am driving that little POS as it has a roof and AC)

You need a regular disco I 94-95 cold start prom. (part number is above)

Just swap the chip and all is well. No reprograming, no adjustment. Your ECU is under the passenger seat on a 95 D-90.

Ron

[Vadim]

Thank you Ron.I will try that.
Vadim
P.S.

[jaherring]

90 is the average speed on the turnpike. I kept hitting the rev limiter so I disabled it. The disco is the same as a D90 engine wise. 1994-95 DI cold start PROM.
The reason I asked about the engine is that I noticed somewhere that the same engine in the same year Disco and Defender had two different power ratings - the Disco engine was slightly higher. I forget where I saw that & what year it was regarding, though - but I'm pretty sure it was the 3.9L V8.

So, I didn't know if this is simply because of the chip, or if something else was subtly changed -- such as the fuel injector size or maybe the throttle body having a higher CFM rating...

[Vadim]

To Ron Brown.Did you drove you upgraded D90 with new chip on hwy? I am ready to install this chip in my 95 D90.
Thank you
Vadim