CJ Posted November 27, 2004 Share Posted November 27, 2004 I am confused - mind you, I am easily confused! I have read several threads recently of cars still over boosting up to 1.4 bar even when they have a restrictor ring in. So does that mean the restrictor rings don't work? I also had a problem when I was running my twin set up on TTC. Even when the boost controller was turned off, the car then hit 1.4 - 1.5 bar even though I too had a restrictor ring fitted. So what gives? Link to comment Share on other sites More sharing options...
Soonto_HAS_soop Posted November 27, 2004 Share Posted November 27, 2004 Did it stay at 1.4/1.5 or did it just spike to that? B.. Link to comment Share on other sites More sharing options...
CJ Posted November 27, 2004 Author Share Posted November 27, 2004 I used to hit that when doing my drag strip practice runs on my private area near to where I live. It would also do it when I was motoring along and then used kick down with my auto. Link to comment Share on other sites More sharing options...
MONKEYmark Posted November 27, 2004 Share Posted November 27, 2004 mine used to hit 1.4 1.5 before with restrictor ring in place. took it out now and its hitting 1.3 bar the restrictor ring just restricts airflow in exhaust. you have to experiment with the size of the hole if you still overboosting. smaller hole supposed to bring boost down. it supposed to boost more in TTC mode. i have mine in SEQ and feels ok. i do like TTC mode as it feels stronger. are you having problems? whats boost controll like on your single and what exhaust and DP/MP you using? Link to comment Share on other sites More sharing options...
CJ Posted November 27, 2004 Author Share Posted November 27, 2004 No, I am not having problems - I now have a single turbo fitted remember My question was aimed at finding out how people can say they are "restrictor" rings when they dont seem to restrict Link to comment Share on other sites More sharing options...
MONKEYmark Posted November 27, 2004 Share Posted November 27, 2004 Originally posted by CJ No, I am not having problems - I now have a single turbo fitted remember My question was aimed at finding out how people can say they are "restrictor" rings when they dont seem to restrict thats why i put this on bottom are you having problems? whats boost controll like on your single and what exhaust and DP/MP you using? i know u have a single. Link to comment Share on other sites More sharing options...
Jake Posted November 27, 2004 Share Posted November 27, 2004 Originally posted by MONKEYmark mine used to hit 1.4 1.5 before with restrictor ring in place. took it out now and its hitting 1.3 bar It's making LESS boost with the restrictor ring taken out? How can that be? Link to comment Share on other sites More sharing options...
CJ Posted November 27, 2004 Author Share Posted November 27, 2004 Originally posted by MONKEYmark thats why i put this on bottom i know u have a single. Sorry mark, I didnt read it properly. Link to comment Share on other sites More sharing options...
Jake Posted November 27, 2004 Share Posted November 27, 2004 Originally posted by CJ how people can say they are "restrictor" rings when they dont seem to restrict They do restrict, if it isn't restricting enough it must mean that the hole in the restrictor plate is larger than it needs to be. Link to comment Share on other sites More sharing options...
Sharpie Posted November 27, 2004 Share Posted November 27, 2004 External air temps will contribute to the spike too. I guess this is why some tuners leave one cat in and then use a BC to up the boost = more control ? Link to comment Share on other sites More sharing options...
CJ Posted November 27, 2004 Author Share Posted November 27, 2004 Originally posted by Jake They do restrict, if it isn't restricting enough it must mean that the hole in the restrictor plate is larger than it needs to be. I thought that when you buy them they were drilled ready to restrict to a given level? Peter - I can understand peaks due to temperature, but surely it would not peak from a supposed restrict figure of 1.1 bar to 1.5? And, if i remember correctly, that was during the summer months. Link to comment Share on other sites More sharing options...
MONKEYmark Posted November 27, 2004 Share Posted November 27, 2004 Originally posted by Jake It's making LESS boost with the restrictor ring taken out? How can that be? before when it was in ttc it was hitting 1.4 1.5 with ring out in seq mode used to hit 1.3 1.4 bar about a month ago with ring in i was in seq mode and hitting 1.1 bar (could not boost anymore than 1.1 bar) at the present time with no ring in and running seq mode i have hit a high of 1.3 bar, happy to run it at 1.3 at track with some good race fuel. so they do work. i have been in and out of seq and ttc mode and had ring in a couple of times. will have to re try ttc mode to see if it hits more than 1.3 bar. Link to comment Share on other sites More sharing options...
Sharpie Posted November 27, 2004 Share Posted November 27, 2004 Bloody hell, in summer Link to comment Share on other sites More sharing options...
MONKEYmark Posted November 27, 2004 Share Posted November 27, 2004 some people say you cant tell difference from 1.1 bar to 1.3 bar when car was running 1.1bar it dont feel that fast, seems more lively in 1.3 bar. if you worried about your turbos blowing i would keep the boost down to 1bar. Link to comment Share on other sites More sharing options...
Jake Posted November 27, 2004 Share Posted November 27, 2004 Originally posted by CJ I thought that when you buy them they were drilled ready to restrict to a given level? The amount of boost any particular car will get with the same sized restrictor varies. CW supplied me a RR which he said I'd probably have to file out a bit if I wanted 1.25 Bar, but actually my car makes more than 1.3 bar with the RR in place. It's not an exact science. Link to comment Share on other sites More sharing options...
CJ Posted November 27, 2004 Author Share Posted November 27, 2004 Originally posted by Jake ...but actually my car makes more than 1.3 bar with the RR in place. It's not an exact science. So what do you think it would make if the RR wasn't in place? My point being, are they really worth it? Link to comment Share on other sites More sharing options...
Jake Posted November 27, 2004 Share Posted November 27, 2004 Originally posted by CJ are they really worth it? If they're the right size, yeah. Seems like a lot of folks have RRs that have a larger hole than they really need to keep the boost down. Link to comment Share on other sites More sharing options...
Grazer Posted November 27, 2004 Share Posted November 27, 2004 When I fitted my Nur Spec I was hitting 1.5 () so fitted a CW restricor ring which held boost at around 1.15bar. Then I decatted and the boost was very variable - hitting 1.4bar at times. However, I was mis-firing like mad, and now that I've fitted a Walbro and some decent plugs, the mis-firing has gone and the boost is sitting at a nice steady 1.1bar Link to comment Share on other sites More sharing options...
Chris Wilson Posted November 29, 2004 Share Posted November 29, 2004 Right, here's the definitive answer from the guy that first brought the "restrictor ring" to the MKIV community, me You should ONLY need or use a restrictor ring if you are running a stock J-Spec sequential turbo pairing, or hybrids, with a freer than stock flowing exhaust system and no cats. Removing both cats and fitting a free flowing system will give enough exhaust system gas flow to overcome the stock wastegate gas flow / pressure curve capability. Toyota designed the stock wastegate very small (for reasons I am not able to go into here as it it is complex and I haven't time..). Anyway, if you derestrict the exhaust on most J-Specs the wastegate can no longer control boost. I "invented" a calibrated restrictor ring to match my de cat pipes (I was the very first person in the UK to offer these, I developed them years ago on my own MKIV J-Spec TT). My own de cat pipes are a specific size, as are the rings, and I developed a flow chart that enabled me to sell rings with a good certainty they would kep boost at or below 1.2 bar, given the customer telling me roughly what boost they were seeing without one fitted. However, if people use them with other, say 3 inch, de-cat pipes I can supply a different ring that should keep these monsters in check too, although a 3 inch de cat pipe is way OTT for the stock turbos, even "hybrids" on J-Specs and UK cars. UK cars have different size turbos and don't suffer the boost creep when the exhaust is de restricted, in fact most still need a further artificial means of raising boost higher still, to reach circa 1.2 bar boost. Cars with single turbos should need NO FORM OF RESTRICTION WHATSOEVER in the exhaust if they have an adequately sized wastegate port in the manifold and the wastegates flow itself is sufficient, (wastegate is big enough, wastegate dump pipe is big enough and correctly routed back into the main system), assuming they have a wastegate spring in them that will allow their opening at a pressure at least as low as the required lowest boost. If you find you need to artificially restrict the exhaust gas flow post turbo something is very wrong. You should have no need for a restrictor ring, or any other restriction, in fact a megaphone exhaust on the turbo would probably be the ultimate, if impractical post turbo system. I am going to say something very controversial now, but it's well intended. I am horrified at the number of forum members who honestly believe you can nail a single turbo on a MKIV, and get it running properly for anything even approaching the costs that seem to be being bandied about. The yanks offer cut price kits, but if the engine does a few 1/4 mile runs without grenading they seem happy. These kits with the control systems they seem happy to use with them, and the mapping time costed in, do not, to me, offer the potential to make good daily drivers, or create an engine that will survive any long term high mileage hard usage. Track days would seem even more risky. People are always very happy to hope that £X (fill in a low figure) will buy stunning power and good reliability, when the reality is the whole package needs upgrading and the budget probably multiplying ten fold. The MKIV is a complex car, already making good power, doubling its output and hoping to retain drivability and reliabilty will not come cheap. in fact, you'd have to be a total petrol head, because the costs will always FAR outweigh the end value of the car, and the pains getting there will be immense. I predicted some time ago that, sadly, an era of blown engines and ill feeling was coming, and it seems I was right. There's nothing so frustrating as spending a not inconsiderable amount of dosh on modifications only for the end result to disappoint or even annoy. It's NOT THE FAULT OF THE MAPPERS, or the kit vendors either, I feel it's ignorance of the realistic costs of achieving what you really need, and the willingness to virtually re engineer the car. That's why I have always advised people to consider stopping at a full de cat, decent SMIC, WI, boost cut controller and decent exhaust system. Beyond that the next step is the big one, and you will be looking at spending the sort of money that might be better spent at a house auction Link to comment Share on other sites More sharing options...
Ian C Posted November 29, 2004 Share Posted November 29, 2004 My final costs can be broken down like so: MVP order: ---- HKS Super Sequential Blow Off Valve, Universal HKS Super Sequential Blow-Off Valve Flange - Aluminum HKS Blow-Off Valve Fin Inserts Field's Harness HKS Twin Power Ignition Amplifier HKS Fuel Rail for 1993-98 Supra Twin Turbo Shipping from MVP motorsports £850 ---- Boostlogic Turbo kit £3041 after VAT, duty, and delivery 6* 720cc RC Engineering top feed low imp injectors £415, 2nd hand Greddy E-Manage £295, 2nd hand, used once Spare fuel pump cage £35, 2nd hand Turbo heat blanket free as compo for delays on delivery RPS Street Max clutch £485 + £120 to fit Fuel kit £750 Extra fuel components £112 Wideband O2 sensor, module, and gauge £190, 2nd hand never used Gauges and sensors £120 Exhaust manifold gasket, coolant, and oil filter £78 Pipework/welding £90 Misc. VWP stuff £50 Oil change £48 Total: £6679 Things that make this figure less than it should have been 1) I did all the labour myself, and there was a lot of it 2) I did the mapping myself, and I've done a lot of that too 3) I scored a few second hand bits/freebies 4) I already had a pump, FMIC, hard pipes, brakes, suspension, wheels, boost controller, boost gauge etc etc installed Things that make this figure more than it should have been 1) I went for a fully blown replacement fuel kit, whereas drop-in 650's and a fuel pump would have been cheaper. This breakdown should give people and idea of what's involved above and beyond the "turbo kit" and the costs associated with it. Add on all the labour and mapping if you aren't prepared to do the work yourself and you'll soon get a five figure sum, especially if you need the support stuff (FMIC, brakes, etc) I already had in place. -Ian Link to comment Share on other sites More sharing options...
Guest Terry S Posted November 29, 2004 Share Posted November 29, 2004 Originally posted by Chris Wilson I am going to say something very controversial now, but it's well intended. I am horrified at the number of forum members who honestly believe you can nail a single turbo on a MKIV, and get it running properly for anything even approaching the costs that seem to be being bandied about. The yanks offer cut price kits, but if the engine does a few 1/4 mile runs without grenading they seem happy. These kits with the control systems they seem happy to use with them, and the mapping time costed in, do not, to me, offer the potential to make good daily drivers, or create an engine that will survive any long term high mileage hard usage. Track days would seem even more risky. People are always very happy to hope that £X (fill in a low figure) will buy stunning power and good reliability, when the reality is the whole package needs upgrading and the budget probably multiplying ten fold. The MKIV is a complex car, already making good power, doubling its output and hoping to retain drivability and reliabilty will not come cheap. in fact, you'd have to be a total petrol head, because the costs will always FAR outweigh the end value of the car, and the pains getting there will be immense. Whilst I agree with most of this, it is far to general with regards to the single kits. A kit with a reasonably sized turbo can be made to work relatively cheaply, but once the owner decides on silly power ( you would not believe the requests I get) then it becomes a completely different ball game. Link to comment Share on other sites More sharing options...
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