wojtrek

dude, I don't what how you came up with this conclusion. I wrote exactly the opposite. a power test for a 400-450bhp supra, in inertia mode, on very heavy rollers, in 5th gear (direct gear for a 6sp supra) takes around 15seconds (1200rpm to redline) this is a few seconds less than what it would take to do this on the road but in 4th gear in that same car. how is this more strain on the rollers? if JP does 0-125mph in 10seconds through gears, than his 5th gear pull on a dyno would be probably in 10s region, maybe 9 or even 8. there is no way he does 25mph to 125mph in 4th gear only, on the road, in less than that. so again, less strain on the rollers. and to make things clear again, if that power test is done with an extra load (with a brake on a dyno) it might be still shorter than a 4th gear pull on the road or longer if the power applied to the dyno brake is larger. a rolling road simulates road, right? the point of putting extra load on the rollers is to simulate road conditions - if you have succeeded to create the same load conditions (strain) as a 4th gear pull would on the road you're more than OK. putting more load is pointless unless you're tuning the car of course and want to see what exactly is going on with the car, or test extreme situations etc.

well, I had both stock cats out - I had an aftermarket downpipe with a 'high flow cat' - it wasn't that high flow as advertised... i think 1.4bar will be maxing these, and anything more will be just boiling the air. now I need to tune this and have no idea what with, what piggyback, if any, will handle tuning a MAF supra? I also have a greddy SMIC and 272 HKS cams waiting to go on the car, that should also make some power.

OK, I agree I assumed it was just a normal trip to a dyno - but I think this is the case, otherwise he'd say he's got a dyno session before him or sth. and I imagine the guy doing the tuning should know how to prepare a car for that. Anyway, I will not agree that a inertia pull on a dyno puts more strain on a car than a 4th gear pull on the road. And no, I don't have a problem with my supra - put a 400bhp supra in 4th, slow down to 1000-1200rpms (which is probably 40km/h or 25mph) and floor it, hold it to rev limit which equals around 195km/h or 120-125mph and time it if a 400bhp does this in less than 15s then I do have a problem with my car I currently have around 420bhp, it takes 5seconds to hit 62mph and it takes 10seconds to get from 100 to 200km/h (62-125mph) which is BMW M5 (the 507bhp one) territory = fast. so a 0-125mph is 15seconds flat out. And that is through gears (1st to 4th), which is faster that doing this in 4th gear only - obviously. add to that the fact that at 1500rpm there's not much going on and your time of a full rpm scale pull in 4th is in the 15-20s range If a dyno pull is done with a load, then of course it can put more strain on the car than a 4th gear road pull. But still - if you're afraid to do go to a dyno - you shouldn't be driving your supra like it is designed to drive

Hi guys, since I have a EDM supra, which is same as UKDM supra, just LHD, I have a MAF meter. I need to tune fuel. I know that tuning a MAP only Jspec 2JZ is easy, but tuning a MAF car is a whole different story. I have heard (correct me if I'm wrong), that tuning a MAF supra with any type of piggy back, is basically altering the MAF signal going to the ECU thus not only altering the fuel but also ignition maps - risk being that when you trick the ECU that way, there might be a situation that the ECU will alter the timing in a dangerous way. To add fuel you up the signal on the MAF, so maybe in this case all that can happen is the ignition being retarded (as MAF signal is way higher than expected by the stock ECU). Trying to lean out might be more dangerous, because this can advance the timing - I hope I got this right? So, what is the max I can get out of the MAF? is there a max signal level? Is 500bhp (or at least a safe 460-470) doable with a MAF and a piggyback? If it is, which piggyback should I use? I have td04 based hybrids, so still a twin turbo setup. Any advice much appreciated!

I own a dyno - nothing ever exploded on it I have a huge blower (1meter diameter), cooling not an issue. I understand that heat dissipation might be a problem on tyres or the radiator - but that's only an issue while tuning, doing pulls one after another and maybe even with some huge load. But going to a dyno JUST to check power, doing one or two pulls in inertia mode - not a problem.

A little update I got rid of the cat (turned out it wasn't metal), now the car (same setup minus cat) boosts 0.1-0.2 higher. putting the MBC too takes it even higher. so to goes like this with the cat on, all I was able too boost was 0.8bar first turbo, and 0.95 peak after transition, dropping to 0.85 at redline. this setup dynoed 350bhp. cat off, without the MBC on first turbo (only AVCR maxed out) I hit peak 1.0 dropping to around 0.95ish - that dynoed 400bhp! with bearly 1bar of boost. strange thing is that removing the cat caused the pressure on the first turbo to drop from 0.8 to 0.65 - weird! back to stock levels or something. I put the MBC back on (the Stu Hagen mod), raised the boost a bit - now I got 0.9bar first turbo and 1.1peak after transition dropping to 1.05ish at redline - dynoed it = 420bhp / 517Nm=380ft/lb. these two dyno pulls (400 and 420) together: http://img27.imageshack.us/img27/1251/mochybrydybezkatvsdodan.th.gif Uploaded with ImageShack.us for those who don't understand Nm, it's 450Nm = 330 ft/lb on the first turbo at 0.9bar. it's 275 at 0.6. also, once the MBC is fitted (red/brown) you can notice that the turbo spools quicker. it's especially noticeable at part throttle, almost instant boost... on a cool evening, in 4th gear (or higher) I hit 1.2bar and it's solid to redline, the car is even faster (maybe 440?) but evidently lacking in fuel, in 5th (motorway pulls 130mph+) basically undriveable = jerking etc. so I need to start thinking about some fuel control.

these sound like tips on how to maintain your car. not preparing for a dyno - if you have a supra that you're afraid to put on a dyno, and that's a 15second full load pull, how can you not be afraid to drive it anywhere? a 4/5th gear pull on the road is a lot harder on the car than a pull on a dyno, so don't worry

OK, here's how my first turbo reacted to raising boost (from 0.6 to 0.9bar). I got the TD04 hybrids. the blue graphs are power/torque for 0.6bar for 1st turbo and 1.0 - 0.95 bar after transition, and the red graphs 0.9 and 1.1-1.0 respectively. http://img27.imageshack.us/img27/1251/mochybrydybezkatvsdodan.th.gif Uploaded with ImageShack.us for those who don't understand Nm, it's 450Nm = 330 ft/lb on the first turbo at 0.9bar. it's 275 at 0.6. also, once the MBC is fitted (red/brown) you can notice that the turbo spools quicker. it's especially noticeable at part throttle, almost instant boost...

if you have it connected as on the picture, then you are connected to the first turbo. this is how I had it to control boost above 4000rpm. so if Arron and heckler are right, and you can control boost with one BC on both turbos, then this is surely not how you do it. I have never seen any instructions on how to control boost on both turbos in sequential mode with one BC. I mean, I want 1.2bar above 4000rpm, so I set the BC for 1.2bar, but this means I also have 1.2 running on the first turbo alone before 3500rpm, and this is killing it very quickly, they say - so, how do we do it?

from what I know, you need two boost controllers in a supra - if you install just one, before the actuator on the first turbo you will control boost after transition. you need a second BC for the first turbo and you plug that to the pressure feed on the second turbo actuator. here's where it's all explained: http://www.max-boost.co.uk/max-boost/supra/boosting_the_beast.htm

well, my stock twins made 0.7bar on the first turbo and 0.8 after transition. I also read, that others had 0.7 or 0.6, my friend has 0.65 or 0.7, so I thought 0.7 is normal. OK, if you have 0.8, it's probably not unusual. Unusual though is the big drop of pressure during transition, it goes down to 0.4bar. Talking about MBC / EBC - the point is, even with the hoses pulled off of the actuator I still have solid 0.85 boost to redline when I should have a lot more. no matter if I have the MBC on, AVC-R or just pull hoses, I always get the same boost pattern - after transition, a peak/spike of 0.95bar, and then, say, 4500 to 7000rpm a steady 0.85 bar. and I mean stedy, not 0.8-0.9, but only maybe floating between 0.84-86 like it was controlled by something... I have a high flow steel cat on my car (http://www.suprastore.com/higflowsupca.html this), maybe something happened to it thus restricting the flow needed to spool the turbos higher? Wez, like I wrote before - I own a dyno, I have a rolling road in my workshop - all testing is done on it. So I have graphs of every test - all I can see from it, is that along with the big drop of pressure during transition I also have a big drop in torque...

i didn't visually check the pressure tank, but it holds pressure, because after drivinf, when I pop a hose I can hear pressure escaping the system, so it does hold pressure. I set the MBC with a special tool, it's like a hand pump/gun with a vacuum and pressure gauge, used for testing vacuum systems on cars.

OK, the boost leaks like suspected were irrelevant, too small to have any affect, so it's the same, same boost pattern. APEXi AVC-R maxed out, 0.95 peak for a moment, then steady 0.85 to redline. ditched the AVC-R and I put my MBC instead, MBC set at 1.1-1.2 and still only getting the same 0.95 peak and steady 0.85 to redline. i'm totally puzzled

hope they didn't make td04 hybrids for supra i did a boost leak test, 2 hoses were leaking a bit, but nothing major I guess. i'll see if it changed anything, back on the dyno...

I don't think these are too big - the GT28 hybrids Speedforsale is selling are even bigger, and they work OK with the stock system. also, when all is reverted to stock, no MBC or EBC etc. I get 0.8bar of boost before I reach 3000rpm (2500rpm-2700 IIRC) so even more than a bone stock car. So it can't be that I'm not getting enough boost o prespool the second turbo. I don't know anyone who runs this setup, but I remember reading about a similiar setup on the web. I can't imagine somebody selling a turbo kit that won't work am at the workshop now, will check for boost leak now

I will check the BOV, maybe it does open too soon... And yes, my AVC-R is connected correctly - if the diagram I posted above is correct... it's connected between the turbo and the nipple on the actuator, the one pointing up (looking at the car). but anyway, I still don't know, why I have higher boost on the first turbo than I should have, why is there such a pressure drop at transition, and why the pressure rises to only 0.7-0.75 bar after transition...

OK, update... first of all, a bit thanks for all trying to help - much appreciated! I have spent many hours, again... Chris, dyno, dyno numbers etc. - a lot to write about, maybe I'll post my observations somewhere, sometime. I need to solve my problem first - it's killing me... thanks for the tip on the hose diameter, I'm using smaller hoses anyway, but not that small. But unfortunately I don't think it's the cause if my problems. OK, here goes... I have put everything back to stock - took off the MBC and APEXi AVC-R, to see how the car behaves. So, I have 0.8bar on the first turbo (which is a bit high, should be 0.7) and at transition, boost drops to 0.35bar - too low - and slowly rises up to about 0.7 - 0.75 max, which is 0.1bar short of what it should be... I don't get it. I have tried many things - I have tested all actuators, pressurized them and checked if they open at correct pressure levels - they do. I have checked the VSVs for correct resistance - all OK. There are a few weird things though: - when I put the AVC-R only, as the instruction says (the diagram I posted a few posts back) when I raise the boost (and I can only get it from 0.75bar to 0.85) the pressure also rises on the first turbo - if I'm correct, this shouldn't be happening? So, what I have is higher boost on the first turbo without doing anything to raise it. any ideas why this is happening? - with my AVC-R maxed out, what I get is about 0.95bar right after transition, just for a fraction of a second, after which it drops to 0.85bar and holds that to redline, - I have thought that maybe the second turbo is bad, and not working as it should hence the low pressure, but if the turbo was bad, it would probably not hold rock solid 0.85 to redline, would it? A dying turbo would, I presume, drop pressure as the revs got higher? - to check the max boost I can get from these turbos I have tried the bleeder T mod, didn't help. so I pulled the hoses off and I have pressurised the wastegate actuator so it stayed open - this, on a normal car, means crazy boost 1.5bar +, am I right? Well, I think I tried that once a year or two ago, to see what happens, and I got crazy high boost. but today when I tried that I had the same story with my boost - like with the AVC-R only - the car was of course in parallel mode, so the boost slowly went up, to hit 0.95bar for a fraction of a second, and held rock solid 0.85 to redline. is this possible? same boost pattern in parallel mode, with the wastegate fully open and all hoses pulled, as in sequential with all piping put on and just the AVC-R? it seems I have tried everything - I have no clue as to what is happening with my car... any ideas? Oh, btw, since I'm doing all testing on my rolling road, I have measured it while I was testing. so, stock car, with weird boost (0.8 first turbo, then 0.75 after transition) - 342bhp crank and 415Nm (305ft.lb). after I put the AVC-R on and maxed it out (the 0.9bar first turbo and 0.85 after transition) I had 420Nm (309ft/lb) at 2800rpm! then 480Nm at the 0.95bar 353ft/lb peak around 4200rpm and 352bhp...

mine's black aswell I kept gradually adding duty cycle until reached max (90%), going back to say 60 drops the boost to 0.6bar... I'm puzzled /vbb/images/smilies/bbcode_sad.gif

OK, I have solved one problem. total noob I guess /vbb/images/smilies/bbcode_oops.gif Since I have an Apexi BOV (leftovers from ma single setup), I left the stock blow off valve not connected, I just thought since I have the Apexi BOV I don't need that - wrong - the pressure found it's way trough there. So now, I have 0.9bar set on the MBC for the first turbo, and that's what I have. When in 5th or 6th, when floored it hits 0.9 bar as soon as 2700rpm give or take 100rpm. But now, at transition, boost drops to about 0.35 and goes up to 0.8 and holds that until redline, with my AVC-R set at max duty cycle. So what I need to do now is find out why I can't really control boost past transtion. Or, why is it only 0.8 maxed out. I have my avc-r connected like that: http://www.mkiv.com/techarticles/avc-r/install/diagram.jpg What could be the reason for low boost after transition? I have checked the EGCV, used a pump, it works.

cheers Ian, that's what I'm doing here, I guess we will not find out if someone doesn't test them well. so, going back to my problem - I tried again, spent some time on my RR testing the MBC and EBC trying to get more boost, but failed again. I guess I'm left with the option of testing boost leak, although even when I did the 'hose pull' mod, on both turbos, I get same 0.55 bar on first turbo, and the second didn't come online. I'll try to manually open the EGCV... it's strange that the MBC mod is not working, it seems I have it connected ahs supposed to, the MBC is sitting there doing nothing. I can set the MBC to 1bar, with a hand pump, put it on the car and still get 0.55bar, like it wasn't even there

I've been reading a lot about hybrids here, but it seems there's a lot of variations. Some call a hybdrid basically a rebuilt turbo with stronger internals, but same efficiency. And on the other end of scale you have the GT28 hybrids. From what I gather, my hybrids are just a tad smaller that those GT28s, so when you say "disaster" etc which hybrids do you have in mind? Remember, that what I have is a TD04 hybrids made from UK turbos, not the Jspecs. you lot are demotivating me with those negative comments on hybrids

UPDATE: the turbos are in the car, and the car is working. Everything's back to stock, apart of course of the bigger turbos. To answer some PMs, I don't know where these came from, ask Swampy422 where he bought them. All I know is what he wrote in the sale post, that they're from the States. Now, back to the car. I have a problem. After reverting back to stock I have a problem with boost. The first turbo barely reaches 0.5bar, usually hits 0.45 (my stock first turbo hit 0.7), and after transition it drops to 0.35, when it should be at 0.8. And I want to point out, that I had a faulty IACV VSV and with it the boost dropped to as low as 0.2bar after transition, which meant that the second turbo wasn't coming online. I have changed the valve and have a solid 0.35bar to redline, so the second turbo is doing something. I have checked the IACV valve and VSV it's all OK and working. After a few rechecks on all the piping I can't see any fault there. So what I did is put my APEXi AVC-R to control boost after transition and MBC to control the first turbo (the stu hagen mod), I set the MBC at 0.9bar and all I get is 0.5 bar, and after some driving eventually maxed out my AVC-R and all I'm getting is 0.75bar after transition. but it doesn't go stright to 0.75 but gradually and slowly. Any ideas what can be wrong? Besides the boost controllers, which I have put on a not so properly working system, so what can be the cause for my low boost? And to point out - I have spent half night reading threads about low or no boost. As I said, my IACV is OK, was dead but I changed it to a working one. Do these turbos require something else? a different setup or sth? Are the actuators different and that's why the system can't get the pressures or sth? I have spent 2 days looking for the cause and still nothing... Any ideas much appreciated.

I used my stock ECU at first. When I put my setup together I started the car to see how it runs, and it turned out, that the car ran great (AFR-wise) on a stack MAF up to around 1.0bar of boost (I made 420hp and 560Nm 410ft/lb at the crank on MAF _ONLY_). The problem was when I wanted higher boost, because the ECU boost map probably didn't match the boost from the GT30 and started to lean out at higher rpms (AFAIR 5500+), so I read around and found out that many people in the USA use the HKS VPC, so I went and bought it (it replaces the MAF). It came with the A chip, since the A chip is for stock twins I sort of had the same problems at higher boost. So I thought OK, let's go with either B or C chip which is for single turbos and 680ccs, installed 650cc injectors - AFRs were better, but the problem was, that when I tuned it to be OK at say 1.2bar, and on that setting checked how the AFRs were at part-throttle and say 0.6bar it was too rich (or lean, don't remember), so the problem was I couldn't have consistent AFRs at all boost levels. So I bought the GCC for HKS (to tune it more), didn't really help. My next step was to ditch the HKS VPC and go with MAP-ECU or similar and if that didn't help buy AEM EMS as last resort... But these hybrids popped up and so I bought them. So to list the full spec.. it's been changing a lot, but basically you get the idea. The problem is that it turns out that what you read on the internet usually doesn't translate to real world or should I say, your car And one other thing, you say you had positive pressure at 2100rpm. Well, positive pressure meaning 0.1bar? I had 0.05bar at 1200rpm, that's also positive pressure but so what. I had 220lb/ft at 3000rpm with 0.5bar - so it was still poor. Only above 3700rpm I had more torque than what the first small turbo made (390Nm / 290/ft/lb at stock boost levels). So in everyday driving you loose around 1500-1800rpm of powerband compared to a small single. People learn all their lives I guess I want to see for myself what can be done with these - from the moment I saw those GT28 hybrids I wanted them - if they turn out to be shit - well, so be it, but I least I had a go these td04 hybrids cost me exactly the money I got for my used GT30 and the Tial wastegate, so I am not risking much. We can discuss the cons and pros of a stock system vs a proper single setup. But I guess that it's more a matter of what you prefer and what I prefer - a different approach

A few weeks ago I had my friends supra on my dyno, we measured AFRs too. He has the same spec as you do, only that he has the full 4 row greddy FMIC, but othwr than that, same. We maxed out the turbos by pulling the hose that controlles them (regarded as unsafe ) but he is putting a td07s on it and knew his turbos are far from new cionditions, so he drove it like that every day and wasn't scared of blowing them. anyway, he only had 1.2bar at 4k and going down to 1.1 at 6k. What we saw on the AFR gauge shocked us - the car was running in mid 13s above 6000RPM, sometimes we have seen 13.6 at the redline! Stock ECU, just with a greddy FCD. apart from that more less same AFRs as you wrote. just at full pressure quite lean. I wouldn;t worry in your case. When you tune a car, you shoot for safe 11s, but many stock cars drive in high 12s and are fine.

well, there are few reasons... 1. the most power I have seen from a GT30R here, in Poland, is 478HP at the crank, and that's on a car with 272 HKS cams in/exh. even my favorite in this subject, the Amuse supra, didn't have 500HP, and they had some kind of hybrid fo the GT30R, not the off-the-shelf garrett. 2. from what I understand, Stu Hagen, on their Speed for Sale test supra, had somewhere near 600 at the wheels with race fuel and many supporting mods. even if the numbers are blown out of proportion, I think 500 should be doable on the stock sequential system. You must understand here, that what I'm trying to get here, is the perfect street supra, for everyday use. I love how the stock car works - I like the torque at low RPMs. Like I said, with the GT30 my car made 0.5 bar at 3000rpm, I had a crappy manifold - true, but the best manifold would maybe make the turbo spool 200rpm lower. One guy here has a GT30R with 0.86 A/R and he has 0.5bar at around 2700-2800 (netting 220ft/lb or 300Nm), which isn't bad for a single, but far from what the first turbo does on a stock supra. I had 220 ft/lb of torque (300Nm) at 2000rpm! from 2400rpm I had full boost of the first turbo (0.7bar), and 0.7 bar from 2500 to 3800rpm equals to 290ft/lb (390Nm) of torque. There's no way a single turbo on a supra will make that kind of torque. And I think, that with these hybrids, when I can safely raise the boost I will be looking at maybe 450-500Nm (330-370ft/lb) below 3000rpm, maybe as low as 2700rpm. I know, that if you are building a car for drag racing, or just for plain power noone cares about torque at low RPMs, but really, I drive this car every day. I want a fast car on the street, with power everywhere in the RPM scale. Now, on a 'not-so-fresh' set of stock turbos, only with an exhaust and intake I made 410-420hp, and 560Nm (410ft/lb). I don't want 600hp, Supras always had problems with traction, I want a car with a reliable 500HP at the crank. And here we have another key issue here - reliability... 3. Reliability - no modification will come close to the reliability of a stock car - with these hybrids I basically have a turbo system how Toyota intended it to be. Since I went single I had problems and didn't really like how the car drove, for instance, at part-throttle. I may be fussy, but that's how it was. In vacuum and WOT was great, but say I wanted to overtake, press the pedal half-way and sometimes I experienced boost spikes, lower boost than expected, jirking etc. It was all down to how boost was controlled I think - I had a Tial wastegate, new, I have Apexi AVC-R, I tried runnig with stock MAF, I have HKS VPC, tried different ROMs, different injectors etc. Maybe, finally I would get it right - but I know it would never be as good as a stock Supra, that is a fact. I don't want to have to worry about EGTs, AFRs, etc. I make 15-20k miles every year in this car. Before I bought these hybrids I thought that a GT30 size turbo would be perfect for what I wanted - I wanted around 500hp, and torque as low as possible. It turned out I had reasonable torque from 3500rpm, which was far from perfect, and also, that 500 is probably not possible (from experience on other supras). I think of my supra as a GT car, and I think/hope these hybrids are a perfect solution.