Guest Posted January 1, 2002 Share Posted January 1, 2002 Im wondering if anyone has experience with the 240sx TB modification and can share info? Looking for installation and actual performance improvement info. I currently run 12.8 @108 w/15 psi.using a conquest TSI intercooler. I will be upgrading to a NPR intercooler and am considering the TB upgrade also. Thanks, Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 1, 2002 Share Posted January 1, 2002 must be a magical number... i was runnin 12.83 best @109 with my 73 z turbo... ive been reading this also, the 240sx throttle body, i would like to know also.. doing another project. a zx now... i did finally get my other z to run 10.52 @ 131 ... buick powered.... i am in northeast too...http://www.beaversprings.com/profile/dgrubb.html Quote Link to comment Share on other sites More sharing options...
Guest Posted January 1, 2002 Share Posted January 1, 2002 Thats Funny! You sold me the car..... Howdy bro. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted January 1, 2002 Share Posted January 1, 2002 Derek, Welcome!!! Now I won't have to talk about your car so much. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 3, 2002 Share Posted January 3, 2002 Sabu and all: I'm not sure if this will be helpful, but I have a 240sx t/b on my '79 zx N/A. I had to have a special spacer plate to be made, for if it were mounted upsided down I would have really had to do some rearranging w/ the air reg and cold start valve (which I honestly need), the bccd I could really care less about, "produces less hydrocarbons when coasting"..hmm.. I wonder if chopping the cat helps that out too.. hmm.. I'll have to think anyway, with the plate adapter I had all of the stock stuff in there. I haven't made it down to the tracks, mostly because I'd rather spend a few hours tearing apart the turbo motor I'm working on than racing my N/A with bad compression. Anyway, on the gtech (which I know, some of you refuse to believe reliable ) After tuning the AFM lean-rich screw a bit richer until it was correct air/fuel, I noticed a bit deeper sound up at 5000 rpms.. hey hey! Anyway, I went from about 15.9 to 15.48, not bad for a single gain (mind you I have 2.5 inch exhaust, better fpr, headers, bigger intake, turbo afm housing). I did these trials quite a few times to ensure that the gtech margin of error would be small, I kept running bests at about 15.5. Slow huh? Well, the hp readout was 158, so go figure, I have a slow Z right now. But hey.. that's what the turbo motor coming in is for! Anyway I liked the results I got from the 240sx t/b, I'm definitely gonna swap it over to my zxt motor when in a few months when i put it in. If you guys are still inquiring I'll be sure to get some results in difference between the stock TINY turbo t/b and the 240. Have fun tuning! -980mak Quote Link to comment Share on other sites More sharing options...
Guest Posted January 7, 2002 Share Posted January 7, 2002 I have heard about similar gains with the Weber Big throat on NA systems so, I would believe it. I need to try to find out more about switching to a cable system instead of the linkage. How would you find a spacer?? Sounds like it might be expensive or difficult to have something made up. Sabu. Quote Link to comment Share on other sites More sharing options...
J Taylor Posted January 8, 2002 Share Posted January 8, 2002 What year and model mercedes are we talking about exactly? I have a 240x TB at the moment but surely wouldn't mind something bigger. JT Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 8, 2002 Share Posted January 8, 2002 Hey, guys... Just an Idea, but why are you using a 60mm t/b (240SX) when you can use a 65mm t/b from a mercedes? The t/b from the V-8 uses mechanical linkage and the only mods needed are slight slotting of the mounting holes and slight boring of the intake to match the new larger size. I noticed BMW has a large t/b too, but I don't know the size. Just a thought. Quote Link to comment Share on other sites More sharing options...
Tony240ZT Posted January 9, 2002 Share Posted January 9, 2002 Saw the post about the Mercedes throttle body. I don't have my car running yet, but I have it installed on my L24ET setup. I've ported out my intake manifold, wasn't sure that it would stretch that far, but it made it. The TPS can be bolted on if you shorten the shaft a little bit, but it'll be reversed. To fix this you'll need to swap some wires around, and if you're using a turbo wiring harness you'll need to find a NA plug with all three wires/plug terminals so that you can swap easily. I had to bring in the mounting holes towards the center, and weld on a throttle linkage. If you have the time to fabricate these small things I'd say it's worth the trouble. Wish I had some horse power numbers for you, but I think my ECU that I picked up from the junk yard is bad. I have another one that I picked up because I knew someone would be interested in it. I think you can get them off of 450SL (Old Mercedes with a fuel injected V8). If you're interested in buying the one I have I'll bead blast it for ya, and ship it for $55, it includes the mercedes TPS and harness plug. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 10, 2002 Share Posted January 10, 2002 Well, I think most use the ka24 t/b because it bolts up to the intake without a spacer--upside down. The allenhead boltholes match up though. I kind of doubt a mercedes 65mm would bolt up, but if you're getting a spacer plate made (which is probably necessary, I can give an email addy of a guy who does it), then sure, why not. Or why not go with like a Jag 72mm. That would be about a 2.8" bore so those of you running 3 inch pipes ( ) might benifit from a jag. I figure a 65mm would be perfect. I thought it would be possible to just bore the ka24 to 65 on both ends (inlet end already is like 67mm, outlet is 60, or something like that, I sold mine so I can't do measurements).. I thought maybe just doing a straight rebore would be possible, and getting a 65mm plate made. use the same valve plate shaft, tps, etc. 240's are so easy to come across, in fact you should be able to find or pull one for $25 or under with tps. They get sold on ebay for like $100, I should know, I sold a few .. so don't go there. Go to a 240sx forum or club site and look in the ads for parting out ka24's. All in all, I know one thing for sure... HELL if I use the stock tiny turbo t/b -980mak Quote Link to comment Share on other sites More sharing options...
Tony240ZT Posted January 10, 2002 Share Posted January 10, 2002 As you can see in my pic that I posted earlier a plate is not necessary. Just need to bring the holes towards the center with a round file. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 11, 2002 Share Posted January 11, 2002 Tony - thankx for the photo's and info, I had it written down, but lost the paper Sabu - I liked the Merc. t/b because it was bigger and used mechincal linkage... so Why not?? I went to the yard (and am going tomm.) and found 3 V-8 merc. and NO 240SX's. It's been like that for a few months now. 240SX's are hard to find and the bone yard. My only concern is if the larger t/b will effect a S.D.S. cpu (which I plan to buy soon) or would it be better all areound to use a fully adjustable laptop style cpu...? who knows. Nic Quote Link to comment Share on other sites More sharing options...
Guest Posted January 11, 2002 Share Posted January 11, 2002 This is getting interesting. The mercedes seems kind of logical. I have just read in the past about how the 240 sx modification is realtively easy.I am only a "shade tree" mechanic armed with 200 pc. craftsman tool kit and a dremmel tool Tony- Pix looks great. What is involved with welding the throttle linkage on? It is hard to see in the pix. I could be interested in your other one. I would like to see what the overall consensus is. Nick-Good point about SDS. I am considering an electromotive system in the future..??? Quote Link to comment Share on other sites More sharing options...
Sean 83ZXT Posted January 11, 2002 Share Posted January 11, 2002 The TB shouldn't affect SDS or TEC II. The thing you need to be concerned about should be the TPS. There are 2 types, Potentiometer type and Switch type. As far as I know SDS requires the Pot. type and I think most programmable FI systems require a Pot. type TPS. To be sure I'd look at the manual for the FI system. Quote Link to comment Share on other sites More sharing options...
Tony240ZT Posted January 12, 2002 Share Posted January 12, 2002 You can easily bolt up a KA24 TPS (potentiameter type) if you shorten the TPS output shaft of the Mercedes TB by about a 1/4 inch. I think you will have the same problem as me in that the TPS will now turn the oposite way as expected, and I'm sure there is an easy way around this, and maybe it is programable into the stand alone engine management system. I picked off a cable type swivle linkage off of a Z31 throttle body, and just placed it on the side and tap welded it on where I wanted it to be. The Mercedes TB does come with a ball joint that could be used in some way to use the existing mechanical linkage, but I shaved my intake manifold linkage towers off, and I think it'll just be easier this way. There is a large PVC type hole that will need to be plugged. Here is a small web site I made about the TB a while back, James Thagard used to run one on his car before he went to the custom intake manifold: http://www.zhome.com/~aktar/zcar/engine/mtb.html Quote Link to comment Share on other sites More sharing options...
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