My builder said I have to tune for 750WHP until I can get a HP90 then we can turn it up. Youve talked to my guy so MoparMike is all over it. Thanks for the video Don.
Well, as experience has it, your builder is pretty informative and well versed in the Hemi world as well. That's the best advice you could have gotten. 💪💪💪
Good video, one thing that was not mentioned, The stock TCU tuned will still try to save the transmission, going aftermarket control will clamp the clutches harder, tuning the engine ECU to lower torque on gear changes also help's. again depending on the ECU
Great information. Don, thanks for bringing on Mopar Mike with his insight on the HP70 and HP90. Always great to hear actual and factual experiences. As i said before, great information.
Just trying make sure people have better real life facts , I’ve seen some claim that they are making 1k whp on a built hp70 but the second you ask where their shift points are , who’s done the tcm tuning etc you get hit with the clueless mindset.
Great video and outstanding information! Sharing your experience and knowledge will only help other Mopar fans go faster and that's a win for everyone.
I have a Toyota Supra with 8hp70, probably the most powerful car in the world with 8hp70, power 1800 horses, 1/4 mile 7.1sec, just change the basket and add 2 friction discs 8hp90 is more powerful but doesn't like high revs. Better than 8hp70 is 8hp75 because it has higher pressure on the clutches.
My trans tune from DSMLIGHTS is amazing! Super brutal quick shifts with no nose over at all! It’s breaking 3rd shift in 17 Mickeys at the track! No boost but running 11.2@122 in 2800 DA on 93
i have a stage 2 built 8hp75 all billet internals with an a90 supra torque converter (smallest 8hp converter) with billet stator setup for 5k stall built by pure drivetrain solutions. its in my e92 335i n54 car. 11:1 compression , n53 head from europe, 288/284 +11 cams runs on e85 and nitrous on a standalone and ill bet money my little bmw probably makes twice what your average high hp hellcat makes at the wheels and i shift at 8k rpm at 40 psi and launch at 5k rpm off trans brake. the 8hp70/75/76 and 8hp90 run the same clutches and steels pretty much, theres not much difference in a built 70/75/76 or a built 90. a stock 90 has upgraded clutches over an 8hp70's but when you build them, they hold the same power and the 8hp70 is way smaller. the new 8hp76 in the bmw m5 can handle 900nm for reference. the only difference in the last number of the 7x series 8hp are the generations. 8hp70 is first generation, 8hp75 second and got diff gear spread internally same everything else now 8hp76 same internal gear change, everything else the same. theres an identical car to mine with an 8hp90 that makes more power and is much slower because of the different gear spread. for what its worth, 8hp51 in the a90 supra is the best suited for drag racing gear wise on 28" tall tire. if you run a 3.31 final drive on 8hp75 its identical to the 8hp51 in the supra with its 3.15 final drive. the little 8hp51 with just clutches is holding 1000ft lbs and running DEEP into the 8s, the 8hp75 is the closest big transmission to that gear ratio and its probably the best suited for any swap.. 8hp75 is the holy grail of 8hp swaps. i spoke with zf engineers who helped me over the last 2 years develop the best program from their arsenal of 8 speeds. they told me if you keep it under 1000hp a built 8hp51 would do the trick, if i had more power to run the 8hp75 with 3.31 final drive as that would identically match the smaller transmission but hold twice the power. i cant say how long it would hold up in a 4k lb land yacht hellcat, but in my 2500 lb fully drag e92 it doesnt even get warm lol.
Thanks for the input brother! Yes, I know there are BMW and other manufacturers running more power through the same transmissions. I will look into the possibility of using one of the other 8HP transmissions but not sure how they would work with our TCM. I know a few running built HP70s and doing well but there are some horror stories out there too. 💪💪💪
@@ModernRedHemi i spent 12k on fully built to the max 8hp75z with billet stator high stall tc , another 2500 on the tcu, adpater plate and mechanical swap parts. my car is built for 1600ft lbs and im swapping a turbo coyote in when i blow it up so i built it for future application. you dont need to go crazy on a build either, you could just add an additional clutch to the packs and use the alto g3 friction clutches, you can get the transmission for literally $500 shipped from the uk. clutches and basic rebuild is like $1500 , so really for about 5k you could do this swap properly and hold 1000hp /850 ft lbs no problem. im already working on my second 8hp swapped car. im putting a pro charged gen 5 viper engine with heads and big cam mated to awd 8hp75x with pure built transfer case, stock trans with just clutch upgrades in my bmw e60, all it requires is motor mounts, front diff swap and driveline mods. it wont see more than 800whp but its going to be one hell of a half mile airstrip car i know that much lol.
You must have port injection too I'm guessing? You've got my dream build man- cammed N54 on a standalone with the 8HP75 swap. Also you basically answered my question of whether or not the 8HP90 is worth it over the 75.
Thanks as always Don, I have been wondering about this. One of my 300 friends had Helraizer ( spelled wrong on purpose ). Do a lot of work, including the HP90 swap. The trans seems to work ok, but they did so much other cheesy shit, and kept the car beyond long. The engine is supposed to be at the 1250 crank power. Our local Mopar shop won't build over 600 to the 70.
That's about right. I think it's more about the torque than HP but everyone understands HP numbers better. Right now, per the specs of the 70, I'm right on target (516 ft/lbs) and not having any problems. I am sure if I turn it up a little I'll be in the gray area. Thanks for sharing and letting folks know about your and/or your friend's experience. 💪💪💪
Got ya but haven't seen, on a consistent basis or tracking their cars every weekend, a built 70 or 90 for that matter hold up. Got another video on these trans coming soon. 😉
Thanks brother! Sometimes is sucks starting at the bottom and have to use parts from big brother to make it all work, but that's just the way this goes. 😂
When it comes to the transmission, you have to look at torque and how much you are making, not necessarily horse power. Mine started slipping around 650 lb/ft and around 750 whp. 😉
Well. The main issue here is that the in the 8HP70 version has a torque handling limit of 700 newton-meters (516 lbf⋅ft). A Stock 392 already maxes out at 475 Net Max Torque. Already getting kind of close. Exceed specs at your own risk.
@@ModernRedHemi It's will be an interesting engineering experiment. I would love to know if the specs were conservative and if the tranny holds up. Hopefully, it will
It certainly didn't hold the power that Mike is putting down (~900 RWHP) so if you are anywhere near that then probably will not help you. It may hold a little more power but I am not sure how much. I know that doesn't help much but that's my best shot. 😉
this is what another hemi shop said: Transmission fail from torque not HP. We have been able to keep them alive around 700-750tq for awhile. But it is on borrowed time. Built ones can take 850-900 generally. But beyond that we are fans of hp90 swaps.
@@chrish1215 I would definitely do the 90 swap. I know it's quite expensive but well worth the security of knowing your car won't leave you hanging because of the trans.
ZF says the 8HP70 is good up to 1000 newton meters or 738 ft / lbs. Undoubtedly using significant torque management to extend its capability. But the HP70 is short for Hp700 relating to its rating of 700 newton meters or 516 ft / lbs. Dodge is making our transmissions not ZF so hopefully they are NOT skimping on parts 🤞🤞. Likely your PCM / TCM tuner is going to let you know how far your hardware will let you go with HP and Torque.
Dodge isn’t making these transmissions, they are made by ZF and sold to dodge , max on a built hp70 is 700/800 foot pounds and built is typically upgraded clutches, if you over lap the tcm file of a 70 to a 90 you will see the 70 has a lot more allowable slip , this it’s self is a issue as no one is keeping stock shift points when you are a blower car , even on my built 70 you’d feel the nose over on every shift , now compared to my built hp90 there isn’t any nose over at any gear shift and the shift points are at 7k vs my 6600 on the hp70. Here in a week I’ll be back at the track making test hits and I’ll have more factual data to compare.
Yes, the specs on the 70 are 516 ft/lbs so folks beware when adding significant torque to your set up. I'm at 528 ft/lbs right now and not having any issues. When you get to the 700 ft/lbs range your are in the danger zone for sure! 💪💪💪
He has suffered for real! One of the top reasons I did the Hemi Shop video. Yes, he is very resourceful and conducts exhaustive research before diving into something he is not sure of or doesn't have a thorough knowledge of. Super smart on the entire Hemi platform. Someone to have in your corner for sure. He has saved me countless time and hurt my pocketbook when I didn't listen. 💪💪💪
@@widebody_moparmike how easy is it swapping a hp70 to a hp90 ? What parts would I need besides the trans and hellcat drive shaft in order to make it work on my boosted rt?
@@saulcruz9024 mechanically easy , parts wise you need the Hellcat cross member stock or aftermarket and then you need the bracket for the trans mount (the mount is the same ) and you’ll need a Hellcat driveshaft (so if your a charger you need a Hellcat charger ds and same for a challengers ) the. All that is needed is tcm tuning to match to the pcm and the one code p1dd2 to be turned off ) via hptuners
@@widebody_moparmike so would a pure stage 1 hp70 trans be even worth it cost wise vs just swapping in a hp90 based on your experience? Thanks for the reply by the way
Who do I talk to, to get that demon tune file? Just finished turbo install on my Durango and wanna mess with the 70s shift points and firmnesses and what not
The Demon file is for the HP90 not the 70. Transmissions and tunes are totally different. If you are HP Tuners you can mess with the shift points and tune the TCM through them and I think you can with Diablo too but you are limited. My shift points are set at 6500 by the way 😉 If you still want the Demon file, I have it or it's posted on most of the Hellcat forums. 😉
I have a stock scatpack and yesterday i pushed the gas and it accelerated like normal but out of no where the car didnt shift and it just stoped going even tho i was still pushing the gas so i let of and then it accelerated like normal what can it be?
Did you get any codes? That would be key. If not, could be a multitude of things. Fuel pump cold be going bad, clogged injector, bad fuel, pad accelerator pedal, etc. If it's under warranty and does it more consistently take it to the dealership. 😉
Hypothetically speaking if you were able what would recommend for a transmission if you really wanna get at it? If you had the means to run in the four digit horsepower numbers?
Th400 or 4L80 , doing the swap not really bad , with hptuners you can just tell the pcm it’s a 6speed car and bypass the clutch pedal module. About 10-15k doing this swap (depends on which th400 you go with and shifter)
Widebody_moparmike nailed it. I wouldn't trust either of the stock HP versions to handle that much power at the wheels and it's much cheaper going the TH400 or 4L80 route.💪💪💪
@@ModernRedHemi I had a TH 400 trans in my '77 Chev half ton with a 400 sbc. That trans was bullet proof, had shift kit and it worked well. I run a 545rfe in my ram, so far so good lol..... I daily drive it and race once a while. Thanks for your input and really appreciate it. I might be work on something😈😈😈😈😈
His had just over 20k miles on it and started having issues at the 800ish range. Mine has 110k and has a bunch of fail safes in the tune (no timing in the shifts and a lot of torque management) and I am at 733 rwhp and 595 torque. Keep in mind the 70 is only rated for a little over 500 lb-ft of torque.
Well, here ya go. 1. An HP90 to start. 2. Someone that can flash the TCM. 3. Someone that know how to tune the TCM for the HP90 swap. 4. Hellcat driveshaft (either stock or aftermarket). 5. HP90 mounting hardware. I think I hit everything. Flashing the TCM and tuning are the hardest part. 😉
I believe they are different as the transmission itself is bigger (you need a new drive shaft it you do the swap) but not 100% sure. That would be a question for a trans builder. 😉
clutches and steels the same, mechatronics different, 8hp90 limited by rpm , i wouldnt spin one to 8k under full load.. i spin my built 8hp75 to 8k at 40 psi with a 200 shot and leave at 5k off the trans brake in my e92. car makes just over 1000whp and i leave at like 600 of that. the a90 might have bigger baskets and beefier internals but if youre going 8hp, go with pure drivetrain and spend the $10k dollars, youll have a full billet internal transmission that can handle anything. my e92 has the stage 2 8hp75 with 5k stall converter billet stator etc etc and it fucking rips. no issues at 1000+ even with trans brake going ham. one thing i can tell you is the 8hp90 has a wider gear spread than the 8hp70, the 8hp70/75/76 all have different gear ratios internally, the only 2 8hp with matching gear spreads are the 8hp75 (when you run 3.31 final drive ) it matches the 8hp51 in the supra with its 3.15 final drive. the a90 supra is the best ratio for drag racing in any 8hp trans so a built 8hp75 with 3.31 on 28" tire would put your 1/4 mile times right where the the top of 4th gear , ideally .
@@ModernRedHemi My RT Charger is a Road and Track so I have the same diff you had. Did the LSD make much difference? I'm still confused about my car because it is supposed to be open but if I turn off traction control and do a burnout both wheels spin.
@@ryotaryuu LSD made a big difference as I was getting one wheel peels on the street and track. That's why I went for the LSD. Dodge uses ABS among a few other things, for traction control and sometimes you'll get the one wheel. With the LSD you don't get it at all.
The truth hurts sometimes, I think I’m begging to slip 3rd, doesn’t like the 2-3 shift and now isn’t liking the 3-4 shift. (3.0l whipple/forged 392) sucks because the 90 swap is harder in a 14 Jeep and I heard the wiring is a pain, I have no idea what to do now
It sure does, not only in the price tag but getting it put in, working, and then tuned. Oh yeah, doing the swap in the Jeep is a totally different ballgame. Good luck and hope you get it figured out brother! 💪💪💪
933whp on a stock 8hp70 and it holding well is impressive. I have seen them working hard coming from the 335i community. I was here to see how it would hold 500awhp lol
That's interesting as I am up to 733 RWHP and 595 torque and she seems to handle it pretty well. I think it boils down to the tuning and how they handle torque management. 😉 Probably putting someone on the spot but, who is your tuner?
Its the Torque that destroys the ZF870HP gear box, not the BHP. They are rated for a max of 700 Nm Torque, which is 516.3 ft-Ibs to all the Americans out there.. ZF gearboxes don't have a BHP rating, so the info this guy gives is rather meaningless without knowing what torque he destroyed the gearbox at! A 750bhp Diesel engine would shred a ZF870HP gear box in seconds due to the enormous Torque it would also be producing! But a 550-600bhp BMW can get away easily with the same ZF870HP gearbox used in my humble stock BMW 310BHP 640D! A remapped, tuned 3 ltr diesel inline 6 cylinder BMW 640d, producing 390BHP can produce well over 730-750 Nm of torque, that's far more Torque than a Lamborghini aventador with a huge 6.5-liter V-12 that develops 769 horsepower, but it maxes out at 720 Nm of torque, even with all that 769 bhp the aventador engine still only produces 531 pound-feet of torque. Forget BHP when it comes to ZF8 gearbox's its all about the torque! Diesels have a longer power stroke and have massive torque, but slow burning fuel and lower rpm as a consequence. Petrol engines produce less immediate power, ie torque, but they burn their fuel much quicker, so they can have shorter strokes and much higher revs, its that higher revs that gives them the higher BHP. Take that to the next level and you get a 1000 BHP formula 1 car, which produces only 200 Nm of torque! If you're going to talk about the zf8 gearbox, then you need to talk about the torque!
You are 100% correct and I don't disagree at all. Problem is, 95% of the folks listening in don't understand torque and only speak in HP and a vast majority of my subscribers are Mopar fans. I get that a 6.4 makes way more torque than a 5.7, but basically speaking, the HP ranges, for Challengers and Chargers with the HP70, isn't far off without speaking torque. Now a non-Moparian may get the wrong impression and I apologize but that's not my main audience. Appreciate the input with an excellent explanation! I should've explained it like you did. 😉
