I had the RS2 on a rolling road late last year partly because I felt it wasn't as quick as it should be. The result is here if I have worked out correctly how to upload a photo. Question is please can anyone suggest why the torque arrives so late with only 150lbft at 3000 rpm, about half what was quoted as standard. It's running standard gear except for remap done at QST about 8 years ago before I got the car. The remap only took it from 315 to 330 bhp so no idea why they bothered!
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sounds like a bad map by qst. should be a lot more than that. Does it drive fine apart from that?
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RS2'd 93 UrS4 5 spd sedan
94 UrS4 V8 6 spd manual avantComment
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QST remap.................
Make sure it wasn't the full 330 package. QST "allegedly"
used to remove RS2 turbos saying they couldn't do 330 bhp when they could do up to 380 bhp and replace them with a different turbo then remap the car.
so they would have a better turbo from your RS2 and owners giving them money.
Check your turbo and make sure it's got K24-7200 on the blue tag and get a better map on your car asap.
A stock RS2 map with a free flowing exhaust can get 340-350 bhp, i remember S2avant and Sal_S2 hitting these figures with a full 3" tip to tale exhaust on the dyno. Back in the day things were the wild west for tuning I5
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Now you've got me thinking! Seeing a friend with a long camera this afternoon to find that blue tag. Looking at the history the print of the rolling road in 2006 shows the same late torque issue, both on the before and after prints. Also shows the remap did nothing under about 4500 rpm or above about 6000 rpm.
8/2/02 58000 miles. Refurbish turbo. £700
27/1/03 Standard RS2 eproms. £100
16/1/04 90560 miles. Hyperboost dump valve. £85
16/3/06 116600 miles. MTM Upgrade. £600
Mileage now 143000.
So on the face of it, no indication of a new turbo. I've got pretty much every piece of paper from new and there's no other indications of work done on tuning. What on earth is the standard RS2 eprom thing?Comment
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I'd also check the cam timing is ok, QST used to service a gentleman called Angus on the fourm with an RS2. They got the timing wrong and couldn't get it too boost so wound down the wastegate and put in a manual boost device.........
It was found at the forum garage meet the cam timing was incorrect, with the RS2 the cam marks need to NOT lign up and be half a tooth back.Comment
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Cam timing is definitely correct, spent ages trying to establish that because it wasn't at one time and when I had a new cambelt fitted we double double checked it.Comment
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Few observations for what they are worth!
Turbo died prematurely.
Eprom replacement probably to undo a previous chip set.
Whether there is a connection between the two is unclear. Certaintly if it was a Superchip conversion that might explain it! They basically disabled the stock boost control system and used a stiffer wastgate spring and a bleed valve I think.
It's possible that the turbo is as Jamo has said not correct especially if it suffered turbine/shaft damage and a hybrid was used. Perhaps the original Superchip bost control is still on it.
The vehicle appears to make more or less the power it should eventually. Whether that might be because of a different turbine/wheel housing say the 56mm rather than the correct 54mm is spectulative. It would in theory take longer to build the boost with a bigger turbine. Or perhaps the wastegate itself is stuck open a bit.
I suggest you take as many pics as you can of the engine bay including the turbo (the blue tag is on the rear of the compressor plate), the top of the wastegate and random pics of the small bore pipe from the turbo itself. If you are feeling brave carefully remove the top of the wastegate and post a pic of the spring so we can see if it is stock or not.Comment
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Tag and spring photos below:
This is the tag that Jamo and twoqu are talking about:
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This is what twoqu wants you to find out (by carefully removing the top cap on the wastegate):
Compare the spring to those in the photo. A stock spring is tall and soft like the one on the right. An aftermarket spring is going to be thicker, stiffer and shorter like the one on the left (IME).RS2'd 93 UrS4 5 spd sedan
94 UrS4 V8 6 spd manual avantComment
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What was the outcome of this?
Have you physically checked this or have you taken the word of whoever did the job. I have assumed as an RS2 owner you don't get your hands dirty! If they have aligned the cambelt using the pulley marks its probably incorrect especialy if the one tooth out comments were related to the setting of the previous belt.
It does seem odd that its has the same characteristic on different chip sets which implies that its on the vehicle.Comment
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Do you have access to fault code readers and boost measurement?
Really a boost gauge is essential for any turbocharged car. They are fun to watch and have some diagnostic function!
We even have model specific faces to choose from so they don't stick out even if you are a purist!Comment
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That's fair point twoqu. As an RS2 owner I do still get my hands dirty a little and enjoy that but my skills are definitely basic mechanical stuff eg Triumph Heralds. As an ex Audi Head of Business I also have access to a set of very skilled technicians, and I understand their limitations when it comes to cars of this age. As mine was almost the only RS2 they saw when their was a problem they had no prior experience to go on, even though some had worked on RS2 when new. Therefore it is wise to combine their skill and knowledge with that of other knowledgeable sources such as this forum to arrive at a diagnosis and fix. The technicians are excellent (and I still use them now) but part of being excellent is looking for help when unsure.
The cambelt fitting is a bit ambiguous even in the manuals and had been fitted one tooth out and having found that out and gained photos showing the correct fitment it was changed. It made give or take no difference to the performance! As the issue is on the car and has been there through two different cambelts, at least two of which I know were correctly fitted, it must be something else.
Couldn't see the blue tag today with a camera on a stick, so will get the undertray removed when a ramp is free later in the week. I hope that is not it as RS2 turbos don't seem cheap! I presume that carefully undoing the 6 bolts on the wastegate has no other pitfalls apart from the spring making a bid for eternal freedom so I'll try that this evening, photograph the result and post.
Thanks for everyone's help so far.Comment
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Here are some supposed dyno plots of a stock RS2 to muse over:
Obviously unless you are doing the work yourself there is the trust issue! The RS2 cambelt timing issue does not seem to be factory documented like you say which must have caused a bit of head scratching in the dealerships even when relatively new. So to labour the point is the cambelt pulley mark aligned to the left or the right of the factory seting?
Yes the wastegate cap is under the tension of the spring so needs to have some weight applied to it whilst the nuts are undone.
The turbo issue is not necessarily going to be resolved as a hybrid might use the RS2 compreesor side with another turbine housing/shaft so externally it will still look stock. The only way to establish whether it is still all RS2 would be to measure the turbine exit where the down pipe bolts on. The RS2 has a dimension of @54mm (54.2?) against the larger 56mm of a similar KKK26. The RS2 turbo seems to be relatively unique and the components therefore are rarer and expensive. If the turbo suffered turbine or turbine wheel damage the cost of repair might have been prohibitive and alternative components used. Again its only a conspiracy theory on my behalf!
Another thing to consider would be to put the car back to stock with the original eproms (chips) and if it exhibits the same characteristics we are back to eliminating possible causes.
By the way, depending on whether you want the car enhanced, there are now better chips available from a Forum member backed with a large amount of experience and technical knowledge.Comment
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I'll get the cambelt checked and hopefully no hat-eating is required! I can do the Wastegate check and photo and we can go from there. I don't want a massively modified car, it is a daily use car that I enjoy summer, winter, rain and snow. Equally I'm not wedded to standard. If we need to change the chipset I'd certainly look at the costs and benefits of non standard.
I have a chart of the boost from the last rolling road, I'll post that too.Comment
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