Induction Posted August 29, 2002 Share Posted August 29, 2002 Found this on a site. Is this guy a visionary or just a mentalist? The URl for the full article with pictures is at the end. HPF Boost Mod Installation (for 93-98 Supra Twin Turbo) By Chris Bergemann Performing this modification may cause pre-mature turbo failure, pre-mature engine failure, pre-mature transmission failure, etc. This modification will increase boost levels beyond what are normally recommended for the Supra Twin turbo. HorsepowerFreaks is not liable to any damages that occur in your vehicle as a result of this modification. If you choose to do the following, you are doing so at your own risk. After this boost mod, you will control boost with your gas pedal only. A boost controller will no longer be necessary. Boost spikes will go up to 1.9 bar (1.7-1.8 bar on most), but will settle down around 1.3-1.4 bar to red-line on most BPU Supras. This mod is not recommended for automatic Supras, as some of the ones we've done have seen boost levels as high as 2.2 bar. Please read the entire instructions before you attempt to do this. I have been racing my Supra since 1996, and back in those days was unfortunately running with the 14 second cars! I installed a GReddy exhaust, down pipe, and GReddy Profec A boost controller, and was still only managing 13.7-14.3 second passes. At that time, there weren't many people who knew much about these cars, so I spent quite a bit of time experimenting with different things to improve my performance. Step 1 The biggest thing I learned the following year was found by reading books about how turbochargers work. Every book recommended a decreased spark plug gap as boost pressure increases. So I began gapping my plugs down until the car started to idle rough, then I backed them off a little. I ended up at a .026" gap (with the stock Nippon Denso plugs). With this modification alone, I went back to the track and ran a 12.8 (1 full second faster). Since that time, I would require every customer (who we installed the boost mod on) to purchase a set of stock plugs if they didn't already have them in their car, and I would gap them down to .026". This can be done with a 10mm allen wrench to remove the spark plug cover, unbolt the spark plug boots and remove them, and remove the plugs. This part is very easy. On installation, be careful NOT to overtighten the spark plugs. Then reset the battery for 30 seconds to clear you timing/fuel map. If the idle is rough after this, slightly increase the gap to .027" or .028". You might as well not do the remainer of the boost mod unless you are willing to do this, because the boost mod itself will greatly increase boost pressures, and you will get a miss at the higher rpms if you don't. Step 2 Doing this next step will provide a major increase in power on the #1 turbo, and will provide a significant increase in power in the upper rpm range as well (Especially on race fuel). Once I did this step, I ran a 12.2 with the same configuration as above. For this step, you will need the following parts... First, make sure your car is cool, or wear gloves, as the turbo is very hot. On the turbo towards the front, pull the two hoses off the turbo, and remove them entirely (in the picture below, that is right below where it says "Three plugs go under here"). This will leave 4 open ends (2 on the turbo, 1 on the turbo outlet housing, and 1 on the VSV in front. Plug all of those holes very securely with long black 1/4" rubber plugs. It is essential that those plugs are secure. The first turbo is what controls boost pressure, and plugging the openings will provide extra force against the wastegate to keep it closed slightly longer than it would otherwise. It will also prevent vacuum leaks, and not bleed air as the bleeder-T mod does. Next, take about 5 feet of 1/4" hose, connect it to a step down vacuum connector and connect the other end of the connector to 5 inches of 1/8" or smaller vacuum hose. It should be a real pain to push the hoses on to the connector, they should be really tight. The small hose should be very small, otherwise it will blow off the pressure can. Now pull off the hose where in the picture above it says, "Connect this to pressure can". Now connect the large end of the hose you just built to the IC pipe outlet shown in the picture, and plug the other end of the hose you just took off with a vaccum plug. Now, jack up the car, and crawl under the drivers side. The pressure can is very hard to see, but it's right below the back of the intake manifold. It is a can about 4 inches in diameter, with 2 small hoses coming out of the back of it. Pull the top one off the can, and off the vacuum piping to the right. The little hose you pull off should be around 5 inches long. Run the smaller end of the hose you attached to the IC piping to the top of the pressure can. Plug the vacuum piping to the right (the other end where you just pulled off the hose) with a little vacuum plug. Both should fit very securely. If they aren't, they WILL pop off. Note... A slightly different version of this mod must be done for cars that were previously equiped with a boost controller that ran into the Exhaust bypass valve on the back of the 2nd turbo. If this is done to your car, you will need to get to that line and plug it. Now you're all done and you can enjoy the power increase. One note... many people with the HPF boost mod have totalled their Supras due to the power coming on TOO hard on the first turbo. Please be careful. Do not ease into the power on any mild curves or especially in the rain. I don't want any more of my fellow Supra owners in the same boat. Enjoy. http://www.horsepowerfreaks.com/techarticles/boostmod/hpfboostmod.html Quote Link to comment Share on other sites More sharing options...
GavinL Posted August 29, 2002 Share Posted August 29, 2002 Just a load of US crap! Quote Link to comment Share on other sites More sharing options...
Mark Ayling Posted August 29, 2002 Share Posted August 29, 2002 I only read the first two paragraphs and stopped!! Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 29, 2002 Share Posted August 29, 2002 This would be tuning advice from 1996, then? There is a far easier and safer way of turning up the boost on #1 turbo using a bleed valve. And it doesn't dump to atmosphere either. Cost is about £10, and if I remember I'll get piccies tonight -Ian Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted August 29, 2002 Share Posted August 29, 2002 Don't know if this is all BS. A lot of the guys on the US list begged for the details of this mod, but Chris was reluctant to give any details because of the possible comeback (and i guess loss of potential revenue). Then he decided that he would release details with a lot of disclaimers. His tuning shop and work does seem to be fairly well respected over the pond. So if anybody does perform the mod, let us know how you get on. Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 29, 2002 Share Posted August 29, 2002 Well, from what I can gather without the pictures to work from, they are basically removing the wastegate and exhaust gas control valves from the loop, meaning neither turbo has any form of boost control other than the right foot. I've driven like that for a good few thousand miles while sorting out my injector upgrade and it's very unsatisfying, by the way. The long ol' hose to the pressure can seems to be routing the output of the can back to the intake manifold, so it doesn't vent to atmo or pop hoses off with built-up pressure. Why not simply bypass the VSVs I don't know. Two inline hose connectors for about 60p would have the same effect. Of course, this is all based on my understanding of the mod from the provided description, he disclaimered. -Ian Quote Link to comment Share on other sites More sharing options...
Syed Shah Posted August 29, 2002 Share Posted August 29, 2002 They do this in the US, it just means letting your turbos boost to destruction, and of course running lean at the same time, a VERY bad idea. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 29, 2002 Share Posted August 29, 2002 Everyone should do this, I need the work, I'll lay on a stock of engines and buy 2 more ramps, do it NOW Seriously, bad news, a typical example of why the US owners are always popping engines and why I won't even READ the US lists now. No wonder 90% of their serious race cars and engines are built over here... ;-) Quote Link to comment Share on other sites More sharing options...
Matt C Posted August 31, 2002 Share Posted August 31, 2002 Originally posted by Chris Wilson Everyone should do this, I need the work, I'll lay on a stock of engines and buy 2 more ramps, do it NOW LOL!! You've godda love Chris's sense of humour!!! Nice one! Quote Link to comment Share on other sites More sharing options...
Steve W Posted August 31, 2002 Share Posted August 31, 2002 mmmmmmmm... If WE all produced and sold a 'kit' for this mod' - anonymously ! - perchance it would have a side-effect of pushing the price of OUR Soops to a new, all-time high [due to rareity value !] Perhaps under the tradename "Whizz-Bangs" ? ? Fat - 'selfish' - S. ( We could put ENDORSED by Chris Wilson ! ! ) Quote Link to comment Share on other sites More sharing options...
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