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Andy
02-15-2000, 03:04 PM
Im' beginning to get quite attached to my 750. It might have a little to do with the $$$ and hours I have sunk into getting it to the point where I'm not constantly bombarded by visual messages and chime after chime as I start it...<p>...In addition, I love the smoothness and refinement of the car. Yes. It certainly is a great vehicle.<p>As good as it is, I can't believe that 300hp is all you can squeeze out of that beautiful, big 12 cylinder, 5 liter motor. Back in the "Olde Country" we can get close to that that out of a turbo charged, 4 cylinder 2.2 liter motor!!<p>I guess it's not a question of whether we can get more from our 750's, its a question of how...<p>... Can anyone offer any guidance as to what the performance upgrade options are, who supplies them and what are the REAL (dyno?)results of installing them.<p>Thanks.<p>Andy.<p><br>

Nathan F
02-15-2000, 03:20 PM
I think the turbo kit is $20K, which is a little<br>out of my price range.<br>

sam
02-15-2000, 04:50 PM
I believe both turner motorsports and dinan claim 40hp and 40ft/lb torque with their $400 multi-chip<br>for the 750il. I'm very interested in feedback about anyone trying it. I'd strongly suggest any 750il owners lurk over at the baby brother 850 forum because they talk about the motor (same) much more than over here. hehe.<br>Also theres a tranny kit that raises the shift points and switches from economy to sport automagically for you when you stomp it. hmm. thats like another $100 bux. You need the weigh the use of 92 octane gas in this beast, because it drinks more gas than my 5.0 mustang, it seems, and 89 works great in the stock computer configuration. I wonder if 87 would work too since the engine is only 8.8:1 compression. hmm.<br>any ideas?<p><p><i>: Im' beginning to get quite attached to my 750. It might have a little to do with the $$$ and hours I have sunk into getting it to the point where I'm not constantly bombarded by visual messages and chime after chime as I start it...<p>: ...In addition, I love the smoothness and refinement of the car. Yes. It certainly is a great vehicle.<p>: As good as it is, I can't believe that 300hp is all you can squeeze out of that beautiful, big 12 cylinder, 5 liter motor. Back in the "Olde Country" we can get close to that that out of a turbo charged, 4 cylinder 2.2 liter motor!!<p>: I guess it's not a question of whether we can get more from our 750's, its a question of how...<p>: ... Can anyone offer any guidance as to what the performance upgrade options are, who supplies them and what are the REAL (dyno?)results of installing them.<p>: Thanks.<p>: Andy.<p><br></i>

Nathan F
02-15-2000, 09:02 PM
It seems to operate fine.<p>

Greg K
02-16-2000, 08:21 PM
The standard 300hp V12 is relatively "underbuilt" compared to its sibling, the 850CSi with its 372hp. The 750 5.0 is running 8.8:1 compression, 2 valves per cylinder, and fairly restrictive intakes and exhaust systems. Why? It was built to provide gobs of smooth low end torque for cruising, not high-end M-like performance. With straight forward bolt on mods the 5.0 version can be brought up to about 375hp:<p>(1) Engine Management Chip--Conforti, AutoAuthority, Dinan. Conforti just did a series of 850 v12. They loved it. About 40 hp and 36 lbs torque increase on the dyno. 92 octane required.<br>(2) Cat Back Free Flow Exhaust--the v12 doesn't breath very well at high rpm (4k and above). Adding the free flow brings it to life, particularly with the a chip. Not an issue of increasing maximum power, just accessing it at higher rpm.<br>(3) Honed Intake Manifold--Extrude honing the intake removes narrow plenum runner areas. Steve Dinan is big on this mod. Havn't seen dyno figures. If used with Chip and exhaust, may net you 5-10 additional hp.<br>(4) Head Porting and Cams--Its amazing that the heads are single cam, 2 valve per cylinder given the technology floating around in M cars of the same period! As such, they just don't breath that well. With the other mods, porting the intake and bowl areas to create a free flow head, adding larger intake valves, and possibly adding a sport cam set will bring you up to the 375 hp mark. Contact Osh at RaceMarque if you need more information. I think he still has a nice used set of sport cams for about $1,500.<br>(5) Differential Gearing--if you'd like better off the line and low-end acceleration change the 750 stock differential from 3.15 to 3.45. Faster 0-60 times by about .3 to .5 seconds. Top speed loss is above 150mph. Cost of a used 3.45 open diff is about $350-400, limited slip about $500-550. Highly recommend this one for the heavy bodied cars.<br>(6) Transmission Chip/High Stall Converter--Not my area of expertise. Have a 6 spd manual. Apparently Dinan's transmission chip reprograms the shift points and makes better use of the torque curve.<p>After these, your into stroker/forced induction territory, and big money($15k plus). In addition to Dinan, check Korman and RaceMarque. Both are very familiar with the engines and upgrading them. <br>

Peter
02-17-2000, 10:06 AM
<i>: Im' beginning to get quite attached to my 750. It might have a little to do with the $$$ and hours I have sunk into getting it to the point where I'm not constantly bombarded by visual messages and chime after chime as I start it...<p>: ...In addition, I love the smoothness and refinement of the car. Yes. It certainly is a great vehicle.<p>: As good as it is, I can't believe that 300hp is all you can squeeze out of that beautiful, big 12 cylinder, 5 liter motor. Back in the "Olde Country" we can get close to that that out of a turbo charged, 4 cylinder 2.2 liter motor!!<p>: I guess it's not a question of whether we can get more from our 750's, its a question of how...<p>: ... Can anyone offer any guidance as to what the performance upgrade options are, who supplies them and what are the REAL (dyno?)results of installing them.<p>: Thanks.<p>: Andy.<p><br></i>I put in a 3.64 rearend, replacing the 3.15. What an improvement! Got it from a yard, cost $700 plus, but I could have done better in retrospect.<p>Can't wait to do the Chip, that's next!<p>A honed intake from Dinan costs $2,000. Great improvement, but you can pull yours and have it extrude honed for about $800, and I believe you have the same thing (maybe Greg K or someone else could verify). I do know that you must provide your core to get an intake, so I'm assuming they simply hone yours and sell it to the next guy.<p>Sport cams would be great. Look into having your cams reground to sport specs by a cam specialist before you drop huge coin on new ones. Regrinding is reliable and can cost a few hundred bucks, whereas new sport cams are at least $1500, usually $2500, which I think is highway robbery. I don't know for sure if you can have yours reground, though, and your only option may be to buy new ones. If I find out before you do, let the rest of us know. I have seen this done on Mercedes cams for $150/cam, so it has to be impossible.<p>Good luck and be sure to report back with your experiences!

John
02-18-2000, 11:13 AM
<i>I'd strongly suggest any 750il owners lurk over at the baby brother 850 forum because they talk about the motor (same) much more than over here. hehe.<br></i><p>Sam's right about this one. The traffic on the E31 board is full of stuff; from tweaking to all out pavement burning. If I didn't know better, I would think I was in a Chevy or Mopar wrench shop over there except that the technology has changed.<p>It amazes me how these guys can be jerking rear ends, changing cams, porting intakes and swapping chips when I have a hard time keeping the "F/Side Light" alarm from going off!!<p>They must just disconnect the EML and OBC!! Think I'll stick with putting a lift kit into the Disco!!<p>John<br>88 735iL (226K)<br>79 320i (250k)<br>95 Disco<br>


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