Results of mods on SC400

[traps1971]

jibbby id like to know how you fig. that a car that makes about 250tq stock is going to jump up to 600 with a 150 shot of nos?

 

[jibbby]

It's mostly all torque in my car...I guess the way my drivetrain is setup..T.C., gearing, wheels, etc made it so.......My first dyno was 300whp and 490 torque with 100 shot... Then I fully opened up my nitrous feed with the built tranny and then you can see where the numbers would jump and make sense... Went from a 100 shot to a 150 shot...

Even the dyno guy said you have major torque going on compared to the whp output... This was Lextreme's dyno connection...

Also, even if the dyno machine was off, there is no way anything under 500 torque would waste two SC4 trannies... One was built up too... It's the torque output that killed both my trannies and not the 300-350whp...

It is what it is.... I wish it were more balanced to be honest as I may have one of my busted trannies still working now in my SC400 which now is collecting dust as I write...

I am reducing my nitrous shot again as another stock tranny is about to go in... I may go manual tranny soon...No one likes to restrict power on their rides...

Also my SC400 puts out more then the stock 250 stock bhp without nos as I've done many external mods as outlined in this thread....

 

[traps1971]

first i said 250 wheel tq. give or take 10 or 20. a stock 92 onyl makes 260 at the crank.so 250 rear wheel is a safe number.i know nitrous makes more tq than hp on any kind of dyno.i have 2 sprayed camaros right now.one lt1 and a ls1.both cars have spent a lot of time on the dyno.my lt1 has over a 100 pulls on it.so to think 100 hit your going to pick up 250 rear wheel tq,and 50 more and and you get a 100 more.NO WAY!!! i bet your dyno sheet has a tq spike. ie.... when they sprayed you car the tq converter flashed spiking your number,a false reading. print a copy of your dyno sheet na and on the gun....lets see.if you dont think iam right chevy high performance test a tnt kit on a ls1.on a engine dyno,it made 400 hp and 402tq on a 150 hit it made 564 and 633 tq so your going to tell me your car makes as much tq as a ls1 on a 150 hit on a engine dyno no less at the rear wheels.agian NO WAY!!!!!!

 

[jibbby]

Yes way....

I hear what you are saying but you are wrong... First off torque at the wheels is derived and measured with the differential and transmission gearing, drivetrain setup as well as the engine power output on an automatic transmission setup... Smaller tire and rim size diameter makes a difference, lightness of moving parts makes a difference, etc... Torque converter stall rate makes a difference, etc.. The 1uz-fe motors are bit torquey to begin with by nature... Torque can be improved with those changes from the stock setup...

To further this conversation there was no T.C. flash when the dyno was done. Why? because it was performed several times, four times to be exact...2 with nitrous and 2 without... I too was skeptic and suprised as well as the tuner and dyno operator... As you know Nitrous loads does create major torque as you stated.. I cannot say for sure if I hit the 600 torque mark at the wheels but I can gaurantee I am somewhere in between 550-600 tq..on a stacked nitrous run...

Lastly, why do my tranny's keep giving up the ghost on just 300-350whp? Not likely as they are proven to hold 400whp-450tq over time on many other SC4's..... I have broke a spindle and sent a rear wheel flying under that torque, I have busted a driveshaft on this SC4 under that same torque load. I don't see that happening on other SC4's pumping out 400whp and 400 torque...

Also my nitrous output may be slightly higher then I suggested as well I can not say for sure as it is wide open and heated.....I have my bottles heated and under big pressure with the flow being wide open with no restrictions to the throttle body...It may be more then the 100-150 shot...

With all that said I don't know how else to prove the torque numbers so I give up...However, I will say when I light it up from a dead start I have more power at the wheels then I know what to do with...It's very impressive thru the first 3 gears as it hauls and grips......

On a side note - I just got the replacement tranny and it's going in tomarrow with the cooler..Maybe I can dyno again as it has been a while anyway...

 

[traps1971]

i wonder how you can say a motor thats rated a 260# of tq stock is a tq monster.how much tq did your car make na? ive seen your other post on how you put some better tires on the can and it hooks hard in first gear.if you really had that much tq you would blow the tires off through two gears.and you hook a car with 500-600# OF tq on a street tire not even a drag radial.like i said your going to tell me 4 liter motor makes more than a ls1 on a engine dyno.i dont know your back round with fast cars or with the use of nos but ive seen you say that running up wards of 1500psi bottle pressure makes more power.wrong!!! nos kits are made to run at between 900-1000 psi. any more or less will change how hard it hits.your lucky you did not lean your motor out and somke it.i had 20 years experince building and racing cars.i help on the crew for nmca racer nick scavo.one of the pioneers in 10in tire racing.my to camaros both run nos right now one running high 9's and the other mid tens.

 

[traps1971]

ive notice that all your posts here you talk about the mods done and how much faster they made your car[feels faster] i dont see any track testing no et slips?so you base all your performance numbers on seat of the pants.this tells me you dont have much experince racing cars.you also have a grand total of 4 dyno pulls.you said that some one found you a trans shop.so you really dont know how good thet are.ive blowin up 4 trans in three months before in my buick t-type.**** happens,stuff will break and the guy who built them builds for all the nmca and nmra cars.post your dyno sheets na and then tell me how this motor can double its tq out put on a 100 hit.

 

[jibbby]

Dude, It sounds like you are calling me a lier... I began this thread to help others, my mods are real and my torque is real... I have no reason to exaggerate or make false claims.. My car is not the fastest, nor the nicest but it is very clean and pretty fast for a heavy automatic 1992 SC400...

I will post my last dyno test sheet just for you if I can find it... I am not a racing pro and do not claim to be.. I do not build race motors and race on the tracks... However, I do know the ins and outs of the SC400's/Soarers and the early model 1uz-fe motors....I would venture to say I know more about them then you pal... I can speak intellegently and honestly about my car and it's capabilities period!!!

Lastly, if it is set in your head that my SC4 is not what I am claiming it to be, that's fine believe what you want... You have made your point and I have made mine...

Let me ask you this Traps - Do you have a 1uz-fe motor that is running nitrous? I know you have the almighty LS1 motor as stated above in what ever race car it is in. I don't dought you have some racing experience and knowledge but you are coming up short on this thread...

Are you familiar with Torque Converters and their set stall rates and how it can effect torque at the wheels? Did you read about all the changes on this thread that I made or are you just speculating from a stock SC400's and a 100-150 nitrous load in general?

I just tried looking for my dyno sheet and cannot find it, my last computer hard drive froze and I lost the scanned dyno sheet...However, I did post the results of a half dead bottle dyno under "jibbys dyno results". You are welcome to search and find and see the differences and comparisons between my torque and whp numbers.. That should prove my points to be valid and your assumptions to be incorrect......

Just so you know my nitrous bottles holds pressure on average from around 1200-1500psi...10lb and 15lb bottles... The 10 pounders really heat up and unload...I have two bottle heaters active.....That is the norm for me when heated and ready to unload..... Your 900-1000 guestimate falls short... There is a blow off valve on each nitrous bottle so you can heat them up to 1500psi which I do safetly... Just a little info. to ad to your vaste racing knowledge....

Do you have any hands on experience with a wide open dry nitrous system with a bottle that is heated to 1500psi on a 1uz-fe motor at the dyno rack combined with the dragon torque converter stall rate and all my other little goodies? I didn't think so...

I do love the LS1 and LS7 motors though I will give you that much..... They are my favorite motors on the planet to go along with the uz's....

Just incase you have never seen a nitrous bottle hear is mine...

 

[jibbby]

so you base all your performance numbers on seat of the pants

No traps - I do not base my performance numbers on butt dyno's...Headers, exhaust, and all other mods, ect.. I quote gains based on what the manufactures suggest and other dyno reports with those mods... I have studied each of these mods for years on this forum and others and know fairly close on what to expect... I do not throw darts at a board sport or post up garbage... I try and post as accurate as possible so I do not have the issues come back and bite me in the arse...Kinda like the situation I am currently having with you....:smoker:

 

[jibbby]

I found my dyno sheet of old -

N/A no nos I dyno'd at 207whp and 220 torque

When activating on a dead Nos bottle showing 500psi I was able to dyno at 248whp and 294 torque this was when my nos shot was also regulated for 100 and not wide open...

On average with the Nitrous I am gaining 75 pounds of torque to every 40whp.... That is nearly double the gains which makes my statements correct...

So if I gain around 150whp off the juice I should make nearly 300 additional torque to my already 220 N/A torque... Man I wish I could find my most recent dyno sheet... Here is my very old dyno sheet pre a few mods showing the differences with the nitrous gains...

 

[traps1971]

bro iam not trying to pick on you.i posted on this thread because your making some crazy claims.600# of at the wheels=20% driveline loss 720# at the crank out of a car with full exhaust,bfi and a converter.by the way a higher stall speed will dyno less than a stock one.just because it multiplys tq does not mean you will dyno more tq.i know your trying to help people out there thats a good thing.but your telling people its ok to spray there cars with 1500psi in the bottle.some poor young kid is going to follow your advice and melt there motor down.i never said you could not get 1500psi in a bottle.if the gauge when to 2500 would you run that much.iam worried yoyu might.i dont know if i should tell you what that safety valve is set to pop at.and guess? 3000psi. dont belive me call nos or and other company.at the same time tell them your planing to spray your car with 1500psi a dry kit no less and see what they say.also dry kits make less power than a wet kit. final point granted ive only owned my sc for three months now,but the fact is a motor is a motor there all just a air pump air goes in air goes out.ive own 7 nitrous cars over the years.three dry kit cars the other wet.the later make more power are safer and easier to tune.you do have a nice car it looks kick ass mine is also a sand stone 95.

 

[jibbby]

Well said as you are entitled to your opinions, no harm no foul.....

Just so you know, I am not advising any poor kids to follow in my footsteps with a true 150 nitrous shot...It is clear I am wasting my transmissions and other stock parts putting out that kind of power... I push my SC400 to the limits as you can see and tend to break stuff regularly... I push the stock injectors to the limits as you suggested for sure as I have never been afraid to blow the motor as they are cheap to replace..... For the life of me I can't blow this 1uz-fe motor with my current nitrous system as it still continues to pur......A testiment and praise to the stoutness of the early model 1uz-fe motors...

Again, I don't advise anyone to do what I do, I just posted the result of mods and nothing more.....However, I will say to those poor kids that it is safe to run a 100 nitrous shot on stock SC400 with the addition of tranny cooler and an electric high output walbro fuel pump and a piggy-back ECU SAFC-II to richen the fuel mix and fine tune..... With that I think the poor kids will be ok... Anything more you will break stuff over the long haul as proven with my ride...

On a happy note - I now have the car running again as of today thanks to David the founder of Lextreme as he was able to supply me with a replacement tranny... I did find out that the rear bearing on one of my rear wheels is wasted and making noise...Just another thing that has failed and broke on my Sc400 probably do to the power output...

 

[jibbby]

Also just so you know I have owned 50 or more SC400's in my life time, some with low miles and some with high miles as I owned a car dealership for many years and bought and sold and drove these cars daily... I have a very good idea on what can go wrong with these cars in stock form over time.. So it is very uncharacteristic to be breaking the stuff I am breaking comparing my SC400 to any other stock SC400... It's clear to me the torque power output is the culprit in just about every break I have experienced...

 

[traps1971]

i would agree that your car would be making over 400# of tq on a 150 shot and if thats the limit then for sure it should break.iam just saying your 550-600 number is on the high side.just my two cents.about the bottle pressure thing,iam also letting you know because i dont want to see anyone burn there motor down.just call ant nitrious company and ask for your self.and i know your not a track guy,but go to the track and walk around the pit and ask other racers what bottle psi they run.my guess will be 900-1000 maybe 1050-1100 on the upper limits.last thing just google the name nick scavo.maybe you might belive some of what ive said here.nick has been my best friend for 15 years.

 

[jibbby]

400 torque??. What ever you say.....Traps my lad, if your so confident I won't reach 500 torque or more on a dyno test with my SC400 then place a friendly wager with me via paypal and put your money where your mouth is and see what happens.:smoker: I'll be happy to slap it on the dyno rack once my rear wheel bearing is replaced and my tranny cooler is intact...That is how confident I am...... Like I said you are entitled to your opinions...

I've been riding my nos bottles at that high pressure for more then three years regularly and have never eperienced any problems with the motor...It comes on hard, no pinging, and no knocking within the motor, even at higher rpms without timing retardation as well.....The norm is 900-1000psi with most nitrous users and probably even less, but I don't do anything normal..... I've experienced no problems with my motor what so ever with the higher nos bottle pressure release and I don't see a problem with it in the future...... This is why they make bottle heaters right? To heat them up....

Safety standards are always exaggerated with companies to protect from lawsuits. Just my take.. The nos bottles definetely won't blowup in the trunk but some engines might if your not tuned and dialed in right...... If your running the motor lean then I can see a problem...

 

[SuperRunner]

jibby, why are you still using lexus trannys? Use a TT tranny.

Also you should probably put in a trans temp guage. There is a thread about this on SF, and I think you should never allow your temps to get above like 270 degrees or something or you will fry it. That is why people ruin trans, it is almost related to heat, or the instant traction on a 2nd gear burnout that breaks the sprag.

 

[jibbby]

The TT auto trannies are not much stronger but the V160 6 speeds looks like a possibe swap choice.. Alot of money and work involved for that V160 swap...

SuperRunner - I just wanted to keep the car running and on the road, this lexus tranny is temperary.... I am looking at the V160 and the R154 trannies as possible manual swap options, but I am really interested in the Newer Chevy Corvette C6 trannies as a potential automatic swap option to accomadate a future LS1 engine swap... Working out that plan now....

The problem is I don't have the work area where I am currently living to perform the tranny swap nor a second car while the SC4 is down...Working on getting an SUV now and moving to a residence with a big garage and work area hopefully soon....Need some time, so I will putt around with the stock tranny and cooler, tone it down some for now and try not to blow this one in the mean time.....

 

[jibbby]

Superrunner - It was different with the two failed trannies on this SC4 of mine..The first stock tranny snapped and gave up the ghost in second gear under a hard nitrous run.. I new it was dead immediately.. I think the power and torque definetely broke that one..

The Second built tranny slowly gave up the ghost. That failure was not from power but from excessive heat I am sure.... I had roasted the car for a couple of straight hours and that was when the tranny overheated and started to slip out of gear slowely..... It still grabbed a bit when it was cold, but when it warmed up neural city and a no go when in gear... No cooler on the built tranny...That was my fault on this last one...Just plain stupid....

 

[SuperRunner]

so the one you broke, were you in second gear and suddently got traction? That seems to be the cause of breakage.

As for the new Tremec trannies. I almost picked one up out of a GT500 mustang for like $1200. GRRR. I didn't know what a deal that was at the time. T5600 is I think the new tranny. VERY strong, and VERY VERY smooth shifting.

You should give the R154 a try. Dunno if I would bother with the V160 as you also have to change out the rear end too. Not very cost effective, and for drag racing, you really don't get the best gear combo, what you get is what you get, where as tremecs have a range of gear sets.

 

[jibbby]

I grabbed and gripped in the higher rpms in second gear if I remember correctly, about when the rears settled down and then I heard a snap cluck and out of gear it went... Wasted... Something like that...

The GT500 mustang tranny would work well I am sure...The only problem with going American on the trannies is mating up the tranny codes to the ECU of the Lexus...That little part scares me... The mounting process, belhousing, driveshaft mating and everything else I could handle well with the welder and some innovative thinking..... Just the electronics and instrument integration is the tricky part..As you know the Lexus ECU throws codes to shift the stock lexus tranny, now how do you mate that up with an American transmission? May have to go stand alone ECU and wire up as needed maybe....Those SMT6 and 7 standalones can get pricey and complicated as well with installation...

I really am trying to keep this car of mine an automatic as there is tons of traffic here in LA, California USA... Most of my racing comes on the straights anyway...Even with the lowered suspension and fat tires I don't think a heavy Sc400 will ever handle like a Porsche so what's the point of a manual tranny?

The Powerglides are track worthy but not street friendly
The Th400 can work but again there is limits with that....

So I am looking at the C6 trannies possibly as they are built to hold power and shift nicely...We will see... I may go manual when it is all said and done or I may just go ahead and sell the car and get a newer Vette or Supra TT.......

I figure with the money spent on trying to swap in a nice tranny, ect..Those costs combined with the worth of the car, maybe it might be a better financial move just to buy a Supra TT or C6 Vette and sell my SC4 as is......

The standard costs on a V160 swap is around 10 grand and a R154 is probably half that or so.. Any tranny out of a newer American sportscars will cost a pretty penny as well as all the swap expenses involved....

What would you do?

 

[cribbj]

I think you're on the right track with getting your car running again and selling it. Then get into something that'll handle the power that you want to make.

Of course, one of the nice things about your SC is that you're probably not attracting the insurance premiums that a 'vette or TT Supra would.

If you do go the Supra route, and you stay with an A/T, you'll find the Supra's A/T doesn't last much longer than the SC's. When you're pushing somewhere north of 450 BHP, the stock Toyota A340E's days are numbered. That's definitely one area of the Supra which is not overbuilt.

So you're back to square one, where the A/T is still the weak link in the system.

You can get a "built" A340E from a reputable shop like Boost Logic which will probably hold as much power as you'd want to make on the street, or you could do a full TH400 conversion, which would turn the car into a real gas guzzler, but it'll hold the power.......

I'd forget about the bargain basement "built" A/T's. You've already seen how well they work. Go with a known and proven product.