artinist Posted December 22, 2003 Report Share Posted December 22, 2003 since i put a lot of miles on the car, I drove a good distance in 4th at around 80mph to see how it will be to have 3.90s, its definetly not an issue for me. Heefner, even with a 5500rpm limit 4th gear will have plenty of rpms left in it for the 1/4, and for the racers, their engine will have more room to rev so the faster speeds still will not be an issue. launching in 2nd gear??? its not THAT much of a difference between the 3.90 and 3.54. this will also be impossible for the fidanze owners. anyone who plans on doing that, should also have a bottle of A1 ready for the BBQ party. Link to comment Share on other sites More sharing options...
haztoys Posted January 1, 2004 Report Share Posted January 1, 2004 Theres a sticker on the back of the rear end housing that will say what gears are in it . At least out west there still there on most Mitsu rear end ,truck or Quest . In the rust belt states I do not know? If the stickers white its a open diff if it yellow its a LSD. 3:90 WILL say 3:909 i "think" 3:45 says 3:545. 4:202 is 4:20. So just drop the last number I'll try to explane this I do not write that good so here go's To find out what gears are in a rear end (any rear end) ----------------------------------------------------------------------------------------------------------- If its a "open" diff Get "one" wheel off the ground ! LEAVE ONE WHEEL ON THE GROUND!!!! or have some one hold one wheel!! Mark the drive shaft yoke with chok Turn the wheel "TWO" turns . If the driveshaft "turns" allmost 4 turns thats 3:90 If the driveshaft "turns" 3 1/2 turns thats 3:54 If the driveshaft "turns" 4 and a little more thats 4:20 If the driveshaft "turns" 4 1/2 plus a little more thats 4:62 ________________________________________________________________ If you have a LSD like a Quest GET "BOTH" WHEELS OFF THE GROUND AND TURN THE WHEEL "ONLY" ONCE AND DO NOT HOLD THE OTHER WHEEL!!!! And look at the number of turn on the shaft just like a open diff . The count on the driveshaft is the same as above. __________________________________________________________________ Doe's anyone under stand what I've wrote?? Car MUST not be in gear at the trans!!!!!! I hope this is OK to post here? David Hazardous Toys inc Link to comment Share on other sites More sharing options...
marksweet Posted January 2, 2004 Report Share Posted January 2, 2004 Interesting post! The 3.90 rear would cruise less rpm's than the 3.54 in 4th gear as the OD with the 3.90 yields a 3.31. Mike I believe you will have NO trouble running mid 12's except for the street tires, though with practice launching you could do it. Slicks/11's! Back when I was younger I was a Buick driver, GS models. Skylarks with big blocks. Most had 2.92's or 3.08 rears and a Chevelle rear wit 3.55's made an impressive difference. These cars really need more of a drop from 4th to 5th or an automatic that will hold up. Gears have been the way to go fast all long. Having them streetable was the problem. New vettes have a .50 drop in 6th gear. That would drop our 4.22's to a 2.11!!! That's how those vettes can make nearly 30mpg cruising. Shelby has had his share of big block mopars. The Hemi of those days really needed the 4.11's to really move the 4000lb. cars they were in. I rode in a 3.54 equipped R/T Hemi and it was not as impressive as I expected. Looking foreward to your thoughts UL when you get the 3.9's. Personally due to my 6'2" frame and a multi surguried back I will try to find an automatic that will last. 4.22's would bce just fine with an auto/OD with their big drop in OD, usually just 68% of the rear gears. 4.22's bececome 2.86's!! in OD. The possible drawback at the track would be dropping into OD before the finish!! Certainly gearing has been overlooked with our cars and UL may get us going in that direction. Mike are you going to 3.90's also? Link to comment Share on other sites More sharing options...
ZPI28 Posted January 14, 2004 Report Share Posted January 14, 2004 Id consider the 3.90s or even the 4.20s with my auto. Wonder how much longer my Auto tranny would last with lower gears and more boost? = Link to comment Share on other sites More sharing options...
marksweet Posted January 14, 2004 Report Share Posted January 14, 2004 I think the 4.22 rear and an auto would be great. Kevincar1 is working on a stronger auto for his quest and he will post results. The stock auto is just not strong enough even for a stock quest. I bought my quest from the 2nd owner, both females. The auto had to be rebuilt at 61K I bought it at 71k and burned it up in 5k. Admittedly I ran it hard. I will foreward Kevins email to anyone who wants to see his plans and contact him if you like. A strong auto with 4.22s would be very quick not lose boost between shifts and still cruise at less rpms than a 5speed with 3.54s. Mark Link to comment Share on other sites More sharing options...
Shelby Posted January 25, 2004 Report Share Posted January 25, 2004 for the auto tranny cars theres two things i'd recomend, first the  oil cooler has a  tmp  control valve on it , this can stick and  not alow the fluid to  flow thru the  cooler,,not  good , i'd sugest a  swap or  switch over to an after market  tranny cooler  with a larger  capasity , this  has alway been a requirement for  auto's when  toweing, so  the same applys to  drag raceing , and may explain  many of the  auto tranny failure over the yr's ,esp  some of the multi  failures another thing i can say from personal experiance that installing 3:90's in an auto makes the OD gear ratio the same as the 5 spd cars in 5th gear at road speed, doing so in a 5 spd tranny car will increase the 5th gear rpm by 500 rpms at any given speed so the 5spd would see more of a gain then the auto cars ,but the drop in top mph will be no problem for the guys with biger then oem cams , cause of the extra top end rpms gain'd from the use of the cam this will cause the 1-2 shift with any cam to be a little earlier , but if you have 500 to 900 more rpms on the top end , you may end up shifting at the same point in the frist part of the launch meaning if you are past the 60ft mark with the 3:54 gears you should also be with the 3:90 gears with the extra rpms avaiable , the lower tourqe load put on the engien will alow a little more rpms unless you get into vave float Link to comment Share on other sites More sharing options...
marksweet Posted January 25, 2004 Report Share Posted January 25, 2004 Shelby a quest with an automatic could go to the 4.22's and once in OD it would still turn LESS rpm's at a given cruising speed than the 5-speed with the stock 3.54's. Too bad the stick in OD(5th) runs at 85% of the rear gears while the automatic is only at 68% of the rear gears. The stick in 5th has in effect dropped to a 3.00 ratio (with a 3.54 rear) while the automatic car with 4.22's drops to 2.87. A strong enough auto tranny would be a blast with 4.22's and some boost! Remember how some of those Road Runners and GTX's with autos and a shift kit would leap forward a car length when they shifted from 1st to 2nd? It would be wild with 18psi from even a Big 16G plus the 4.22's. There is a SQ member working on a auto that he feels will hold up. He told me that 87-92 Montero's with V6's had a Toyota A44D tranny. And with a 4 cylinder bellhousing could bolt to our G54B and still have a lock-up converter. The part about a proper tailshaft is the next to be solved as these tranny's were not rear wheel drive tranny's? We'll see what he comes up with! Link to comment Share on other sites More sharing options...
Shelby Posted January 25, 2004 Report Share Posted January 25, 2004 >Remember how some of those Road Runners and GTX's with autos and a shift kit would leap forward a car length when they shifted from 1st to 2nd? It would be wild with 18psi from even a Big 16G << yep sure do i had an 11sec road runner with the 383 engine Link to comment Share on other sites More sharing options...
marksweet Posted January 25, 2004 Report Share Posted January 25, 2004 i RAN A '66 bUICK sKYLARK gs WITH THE "NAILHEAD" 401". i DID HAVE A BUDDY WITH A '69gtx-440 THAT RAN MID 12'S WITH AN OCCASIONAL STREET RUN/hang on!! MAN DID THAT REV QUICK!! Link to comment Share on other sites More sharing options...
Starcon88 Posted February 2, 2004 Report Share Posted February 2, 2004 Question, can we do a speedometer correction? Since its going to be off. Kurt Link to comment Share on other sites More sharing options...
marksweet Posted February 2, 2004 Report Share Posted February 2, 2004 The speedometer would read faster than the car was actually going so a different speedo driven gear would be needed. Fuel injection specialities should have the appropriate gear availale or part # since they offer the ring and pinion upgrade. Mark Link to comment Share on other sites More sharing options...
spoolinturbo Posted February 3, 2004 Report Share Posted February 3, 2004 sounds like a lot of work to me... ??? interesting though... jeff Link to comment Share on other sites More sharing options...
marksweet Posted February 3, 2004 Report Share Posted February 3, 2004 Jeff I aqgree. Unless your car is spending most of it's time on the track I do not believe the expense is worth the results. 3.54's aren't slouch gears and the money spent to go to 3.90's would reap greater benefits if applied elsewhere on the car. Just my opinion. Mark Link to comment Share on other sites More sharing options...
Shelby Posted February 9, 2004 Report Share Posted February 9, 2004 guys if you have never personaly try'd swaping gear ratio's while drag raceing please say so so we can tell if your speaking from personal experiance or hear -say that said if you have no more rpms to work with other then the stock valve train , lower gears may not help you , but if you have the upper rpm range to be able to get to 6.5 and 7 k then your going to need them Link to comment Share on other sites More sharing options...
KT Posted February 11, 2004 Report Share Posted February 11, 2004 Hey Chip, Someone earlier mentioned you would need to shift at 6K, but we run out of power at 5K. I find it hard to believe that a MPI won't make power past 5K. Any input? KT Link to comment Share on other sites More sharing options...
Starcon88 Posted April 5, 2004 Report Share Posted April 5, 2004 Yeah thats a bunch of bull. Its all about your head and how it can make power. If you got a cam that makes power between 3k and 7k then you can shift at 6k or higher but if your stock then you start to run out of power at 5k but with MINER mods like helping the engine breathe then you can make power up to 6k, things like 3in exhaust, more boost, 1g mass, and things like that. So when you say MPI guys there's kinda a lot, some have head work and some don't, I personally think that our cars with the right head work and intake and exhaust on a stock turbo with 15PSI would move like HELL then throw on a 3.90 gear and DAMN talk about MOVING. Kurt P.S. I would like to talk to some guys that have actually done the swap and whats there 2 cents on the subject, worth it or not? Link to comment Share on other sites More sharing options...
UltimateLurker Posted May 19, 2004 Report Share Posted May 19, 2004 I'm seeing this reply a little late...lol, but I can tell you that my car (with 3" exhaust, 1G MAS+K&N, and EVC set to 15 psi) didn't make power after 5,000 rpm, and I've got the dyno sheet to prove it. Making power after 5,000 is all about the cam & head, not the bolt-ons. Link to comment Share on other sites More sharing options...
artinist Posted May 19, 2004 Report Share Posted May 19, 2004 I put on a lot of freeway miles over the weekend with the 3.90s its defintely not the biggest sacrific in comfort i have had to make. its actaully quieter in the car too becuase the rpm is a little off than where it used to resonate a bit. very nice overall. Link to comment Share on other sites More sharing options...
marksweet Posted May 19, 2004 Report Share Posted May 19, 2004 UL is that your car in your post? I thought you had a red one. Very nice car either way but better if it's yours. Quests can make power to 6000 rpmwith work. Mine did it easily even with my 16G. Ran a 19C for a short time and then a 20G. I liked the 19C the best. UL you have the best dyno run that I've seen with a 12A. Congrats! Even the guys with MPI and other big mods start to drop off at 5800 or so. First gear 6k easily. and close to that, probably 5800, then 55oo for the rest was the best for me. Unfortunatly most cannot afford to make the internals strong, which should be done first. Even TEP says that. Build and run what you can afford STARTING WITH A STRONG BASE ANd TOP NOTCH TUNING. Then chose the turbo you will run even though that does nor necessarily need to be the next purchase. 1G mas, 3" exhaust, fuel pump, clean all filters. Basic tune up of course. Don't get fixed on a HP goal or top speed. Those wll take care of themselves. Those 3.90's will be complimented with all of your other motor work. gears are usually the best bang for the buck except with one of ours!! Mark Link to comment Share on other sites More sharing options...
Shelby Posted May 28, 2004 Report Share Posted May 28, 2004 3.54's to 3.90's is aprox 500 rpm drop this will show up in a 5spd much more then an auto tranny car , in the auto it'l make the car much more driveable at normal road cruise speeds ,because your more into the peek tourqe rpm range , just droping out of OD at 60 mph is like hiting passing gear and a stock quest with only exh mods will pull better at top end because of the lower'd tourqe stress on the engine , it takes less hp to actualy move the car due to the gearing , even if your peak power range is droping off 3.90s is not a steep gear at all , maybe not the best for $2.50 a gal gas prices but thats not the gears fault , an 1.5 diff in tire heigth will make up for all but a couple mph 3-4 4.56 , 4.88's now that geting into steep gears , i've even ran 5.33's but you better have an 8k rpm + engine for them Link to comment Share on other sites More sharing options...
haztoys Posted May 28, 2004 Report Share Posted May 28, 2004 Mr Artinst Could I get the" what" for on what you think of the 3:90 gear change now that you have had a little time to "play"? Hows your MPG? How do you think it would work at the drags? Was it a good move or ????????? Thanks Captain Gear Box Hazardous Toys inc Link to comment Share on other sites More sharing options...
artinist Posted June 1, 2004 Report Share Posted June 1, 2004 I have not noticed a change in the fuel mileage and after a while, its hard to tell the car has different gears without having a stock one to compare it to. I havent taken the car to the track yet but I definetly recommend it. Link to comment Share on other sites More sharing options...
88StarionESI-R Posted June 4, 2004 Report Share Posted June 4, 2004 3.90s  is not a steep gear at all , maybe  not the best  for  $2.50 a gal gas  prices  but  thats  not the gears fault , an  1.5  diff in tire heigth  will make up for all but a couple mph 3-4 So making the circumference of the tire bigger will almost make up the difference you see on the speedo. But what about the loss in torque? I imagine a 10" tire (with infinite tracktion) will accelerate A LOT faster than a 20" tire. By changing the gearing in the LSD, we gave it more torque, but by increasing the tire size, we lose torque. If we make the tire big enough so that the speedo is totally accurate, would we lose all the torque we've gained from the 3.90 gearing? Or the gain of the gearing outweighs the tire size eventhough the final rpm vs. speed is the same. Link to comment Share on other sites More sharing options...
artinist Posted June 4, 2004 Report Share Posted June 4, 2004 if you made the tires tall enough to make the speedo correct then it would be as if the gears never changed. it would take some really tall tires to make up the difference. maybe 30" Link to comment Share on other sites More sharing options...
88StarionESI-R Posted June 4, 2004 Report Share Posted June 4, 2004 if you made the tires tall enough to make the speedo correct then it would be as if the gears never changed. it would take some really tall tires to make up the difference. maybe 30" That is what I figured. If the final speed is the same, the difference in the gearing must have been nullified. So tire trick doesn't really help, you're losing torque for the sake of the speedo. Changing the gears for the speedo should be the way to go. Link to comment Share on other sites More sharing options...
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