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Twin engine GTP project progress thread



TwinV6GTP said:
It's on order lol..

no seriously we are just scratching the surface.
imagine if we build both engines to race specs... 850whp each with boatloads of torque.

Now we are making around 1200HP or 950whp and weigh 4400lbs. I think next year we will lighten up by 150 lbs at least and go all out on both engines.
so 1700whp AWD and 4200lbs or so ! That's next year's goal. For this year, I'm not sure, I'm pretty motivated to do more I'm just out of time... too busy at the shop.
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TwinV6GTP said:
When you have a car this heavy, you need boat accessories lol
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yeah, real quick ya'll see the writing on the wall. your biggest improvement is gonna be weight.

dont go nuts with the motors like we did. while you should at least do some of the simple windage mods, all you should do is a cam/chain/springs and a full regasket job on each. put that full tilt money into a chassis fund to kill the weight and make sure you can walk away if something happens.

most of what ive found is that twin drivetrain cars are quite prone to wrecking if a powerplant goes down during a run, especially if its the front.

im gonna suggest it since im looking at it but a simple engine kill that kills the opposite engine if one reads 0rpm.
it may or may not help, but my thoughts align with others that if both powerplants go out youd have a much more recoverable car.

besides keep in mind at ~3500lbs being able to hit mid 9's/140+ with just two full boogie sc setups...at 400whp each

a stock 80e would conceivably live 100k with that load.
at your weight with much more power we're probably looking at breaking hard parts and engineering replacements or massive power limiting. at which point its far more cost effective to go lighter to go faster.

ill be here to lend a hand or advice any way you run with the moose knuckle gtp...lord knows how many times we've reworked and changed crap on our heap, might as well save you some of the hassle.

i do look forward to the first hard part failure of an 80e but im gonna guess its gonna take an 80e with valve work to get the pressures high enough for any shafts to see shock loading. ill hazard a guess it'll be at the IS TCC ORing groove, but the calculated cross sectional area of the 80e Oring point is nearly the same area as a GMR Oringless shaft.

good news is that if it does prove to be the weak link...making a better one is far simpler to the much more complex 65e IS. even better is that with the ORinged converter/ringless IS mod it would have a cross sectional area nearly 3 times that of the GMR shaft.
 
So do you manually shift the car while you drag it? If so do both trannys shift at the same time or not? I think it would be kind of cool to go ahead and fab up a nice horse shoe shifter like the old muscle cars have if everything is in sync, that way you have something to grab onto while you're out there running it plus then you can be lazy while you drive it!
 
87IROCZOWNER69 said:
So do you manually shift the car while you drag it? If so do both trannys shift at the same time or not? I think it would be kind of cool to go ahead and fab up a nice horse shoe shifter like the old muscle cars have if everything is in sync, that way you have something to grab onto while you're out there running it plus then you can be lazy while you drive it!
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I like that idea
 
I shift them seperately I use to shift them both manually. But now I set up an automatic shifter for the rear set up but the front is still manual.
I start in 2nd gear on both engines. You can see inside the car with the go pro on this video.

 
TwinV6GTP said:
It's on order lol..

no seriously we are just scratching the surface.
imagine if we build both engines to race specs... 850whp each with boatloads of torque.

Now we are making around 1200HP or 950whp and weigh 4400lbs. I think next year we will lighten up by 150 lbs at least and go all out on both engines.
so 1700whp AWD and 4200lbs or so ! That's next year's goal. For this year, I'm not sure, I'm pretty motivated to do more I'm just out of time... too busy at the shop.
Click to expand...

I said things like that $3000 ago, and I still havent went faster.
 


darkhorizon said:
I said things like that $3000 ago, and I still havent went faster.
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Sometimes simple recipes are the best.. But I can definately feel a lack of top end.
High rpm Torque converter will allow much bigger turbo to be used especially in the rear engine. Just that is worth some ET and MPH.
Simple drivetrain mods to move my powerband up 1000 rpm would really help too.

Right now my 4t80E has such a short ratio with 26" high ET street I shift to 4th gear before the 1/8 mile !
 
If you haven't already you should monetize all your youtube videos. With the amount of views your getting I think you'd make at least some money. Start a car fund with it or something.
 
SomeDudeAtHome said:
If you haven't already you should monetize all your youtube videos. With the amount of views your getting I think you'd make at least some money. Start a car fund with it or something.
Click to expand...

My highest viewed video in my channel is my customer's RZR with the Z1 turbo engine using our tune and antilag system (sled engine) making 300HP.
It's extremely fast...

176 000 views... that one could make a little money most likely.

 


4t80e is very strong. Only 4th can't handle the power.
You also have to be careful off the line not to brake boost too much and create too much torque off the line.
Once under way the 4t80e has proven very tough 1-2-3 gear.
You just have to get a 3.11 ratio one for higher MPH in 3rd gear. That combines with a tall tire will give all the gears one might need.

I have over 40 runs on the my latest 4t80e trans most of which with a 1.4 60 foot with zero failure except 4th won't go in anymore. It failed quickly after trying it.
We have to keep it out of 4th. I launch with up to 20 psi of boost.

As a front transmission in my twin engine car it would be 100% bulletproof I have no doubt. My stock 4t65e-HD latest easily over 250 runs before it stopped shifting into 3rd gear.
 
You've probably been asked this before but, have you ever tried putting the front tranny in reverse and the back tranny in D? Should do a wicked burnout/ donuts.
 
smoke14 said:
You've probably been asked this before but, have you ever tried putting the front tranny in reverse and the back tranny in D? Should do a wicked burnout/ donuts.
Click to expand...
Yup we did it...
But I wondered why it didn't work as planned. The Reverse always pushed us back.

I forgot I had a 4K rev limit on the front engine in reverse lol...
With two engines you can't hear the front engine that much.
 


At about 35 mph in reverse on a gm transaxle, the forward band can apply just from drag and blow the transmission. Gm had a bulletin warning against running the fwd cars in reverse on a hoist for this reason. A reverse burnout is a very bad idea.
 
The trans has no 3rd gear. It did over 300 runs total. I took a chance and it didnt break but i was at 4000rpm in reverse whatever that speed is


Sent from my iPhone
 
Just another thing the Twin engine can do with it's independant rear engine controls.
Lots of fun. Things get interesting when during the spin you get in the throttle on the front engine.
Going to need more practice for this !

 
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