Twin engine GTP project progress thread

[TwinV6GTP]

Been a long time since I touched the GTP at the shop. It's been sitting waiting for DR Frankenstein to complete her !
We've been extra busy with customer's projects.
We worked on it about 2 days since the last update.

We made a landmark tonight. It's now a rolling chassis.
There is about another week of work for it to be track ready but we'll probably be driving it for early testing with 2 more days of work.

We have some reenforcement to do to the chassis to handle the torque of that engine.
For now it is very stiff already. No noticeable chassis flex when jacking it from the back which surprised me.
Also the rear strut towers showed no signs of movement when we put all the weight on the ground which also was a surprise.

Now we will double if not triple the strenght of the current set up. Put gussets add 1/8 plate along the rails to help them take the load of drag racing.

The last thing will be a roll cage.

I'm trying to decide if I'm going thumb throttle (snowmobile thumb throttle) to controle the Front engine or if we link them together with the gas pedal.
The advantage of having seperate control, with a lot of pratice I could be able to control how much power goes to front vs rear wheels.
For example when drag racing go full throttle in the rear but part throttle in front and gradually roll into the throttle for the front engine.
It will be tricky to drive but could be very rewarding.

I can only imagine the face of people when I pull up and do a FWD burnout, then do a RWD burnout and stage !

Do here are the pictures. Keep in mind that was an actual structural test.
This is the basic engine connection and will be significantly reenforced. I was very curious to see if there would any flex or any weakness with only the two towers for the front connections.
No flex was observed. That leads me to believe with the reenforcements (Gussets, more links, roll cage) this thing will be a tank.

Best part of this thing is the engine will very easily worked on. Also it will be easily replaced as the engine drops with just a few 10.9 grade metric bolts.

[cavell]

many fiberglas kit cars with midengine setups. i had a corvair with a 350 in the backseat. SO flipping easy install. we also had a corvair van with an olds 455 toronado auto trans setup. crazy dumb. taking a fwd motor/trans package and mounting it midships is pretty straight forward.

[QUICKSILVER462]

You can do an all wheel burnout by putting one engine in "D", and the other in "R".

[TwinV6GTP]

many fiberglas kit cars with midengine setups. i had a corvair with a 350 in the backseat. SO flipping easy install. we also had a corvair van with an olds 455 toronado auto trans setup. crazy dumb. taking a fwd motor/trans package and mounting it midships is pretty straight forward.

It's not that hard to do although to do a good job and get the suspension right with all that weight is going to be a challenge...
With all that traction the middle of the car might look to bend from the stress. And the car will squat pretty hard. Which is why we have a lot of preload on the springs.

[Nighthwk12]

I'd say have a thumb for the front. AS for the pedal, set up a linkage that you can engage and disengage easily to have the ability for the pedal to control the front and back

[SnowFlake]

What a killer project.
Instead of playing with different throttle inputs, you might want to think about power differential to create the front/rear bias.
Specifically a turbo on the rear engine LOL
Big slicks out back with 500+whp
Smaller slicks up front with ~300whp

That'd be a sick "Twin charged" combo!

[blownGP]

this is gona be sweet cant wait to see it go down the track

[TwinV6GTP]

What a killer project.
Instead of playing with different throttle inputs, you might want to think about power differential to create the front/rear bias.
Specifically a turbo on the rear engine LOL
Big slicks out back with 500+whp
Smaller slicks up front with ~300whp

That'd be a sick "Twin charged" combo!

That's the plan for the long run.
Run Turbocharged in the back with about 550WHP and Supercharged up front 350WHP.
The front wheels won't have much traction with the rear hooking up so well and having more power.

For now it will be twin S/C with the same combo to keep the cost low.

But you still need to control power off the line. 350WHP is enough to do a smoke show while the rear is hooking.
We will need to roll the thumb slowly in the FWD engine to hook up and get in it full at around 250 foot mark.

[SnowFlake]

Can you make traction bars or something? Also raise the rear way up so that when the back tires dig in, it almost pushes against the front.
If you wanna go turbo on the cheap, you could weld a flange to the stock crossover and a wastegate perch on the rear manifold. Get a cheap a/w on ebay (frozenboost) and go from there. UJ pipes on amazon/ebay are dirt cheap as well.

I'm sure you've got it under control, I'm just throwing ideas that pop into my head out there.

[TwinV6GTP]

Can you make traction bars or something? Also raise the rear way up so that when the back tires dig in, it almost pushes against the front.
If you wanna go turbo on the cheap, you could weld a flange to the stock crossover and a wastegate perch on the rear manifold. Get a cheap a/w on ebay (frozenboost) and go from there. UJ pipes on amazon/ebay are dirt cheap as well.

I'm sure you've got it under control, I'm just throwing ideas that pop into my head out there.

I don't mind that at all. Ideas are always good and can help.
I definately have a good plan for it and we are, I'm not sure if you know or not, a performance shop specialized in turbochargers.
I have the perfect precision turbo sitting on the shelf for it capable of 500whp.

I just don't want to spent too much time on upgrades. Lots to do on the chassis to get it ready and somewhat safe as well as heat management and the final throttle set up and all.

The traction bar is one of the last thing to go on it as it loses the surprise factor. I want to make it a sleeper. Once maxed out, it will need traction bar to put the power down in front.

[SnowFlake]

Good stuff man.
I love talking turbos, can you share the specs on that precision?

[TwinV6GTP]

Good stuff man.
I love talking turbos, can you share the specs on that precision?

Precision 5830 with V-band flange. Should be an instant spool turbo on that stock cam engine.

[TwinV6GTP]

We worked on it 2 hours today we took out the rack and pinion and cut the shaft going into the rack and pinion so we have a full assembly with outer, inner tie rod and shaft (to be welded). Our tie rod support will be where the rack and pinion used to sit and will be stronger, camber and toe will be ajustable.
The struts hole will be slotted and the knuckles slightly modified.

Pictures to come.

[SnowTh1ef]

Sub'd, This is an awesome killer project man! Keep it up excited to see some videos and pics!

[darkhorizon]

Most guys with twin engine cars run 2 pedals next to eachother. Possibly with enough room that you could 2 foot it if you wanted.

Expect well less than 450whp out of the 5830 turbo. A 6262 is almost a 500whp on race gas and big boost numbers.

I would expect some solid low 10s even out of a small trans build with just the rear engine.. the front engine may not be help you run much faster at a dragstrip unless you set that up with an even bigger turbo than the rear has....

[TwinV6GTP]

Most guys with twin engine cars run 2 pedals next to eachother. Possibly with enough room that you could 2 foot it if you wanted.

Expect well less than 450whp out of the 5830 turbo. A 6262 is almost a 500whp on race gas and big boost numbers.

I would expect some solid low 10s even out of a small trans build with just the rear engine.. the front engine may not be help you run much faster at a dragstrip unless you set that up with an even bigger turbo than the rear has....

I have made 580 crank HP on a 5830 at 54 psi of boost on a 2 cylinder 1.1 liter engine.
These turbo can make power past their rated chart when everything is perfect (tune, wastegate set up).

I'm sure I could squeeze 500whp with a good timing map, maxed out turbo and such.

But that turbo is on the shelf. A 6262 would be a much better turbo for Power but it would need a much higher stall and some boost off the line.
I want to keep things simple and share the load between the two engines.

If you think about it, each engine will have approximately 2400lbs to handle underway with equal traction. Once the rear hooks hard off the line most of the load goes to the rear engine. I want to the front to gradually come in to help the rear engine...

Yes, just the rear engine would work but it would be a drag only car. I really don't like rear/mid engine cars when the HP is very high. The front end becomes really light and it's not a good feeling.

[darkhorizon]

Sigh....

I'm sure I could squeeze 500whp with a good timing map, maxed out turbo and such.

Ive built more than one 6262 powered 3800 car... I think I know what I am talking about. The 58 is a god awful small turbo.. Its smaller than the HX35 I ran for years at MAYBE 400whp.

A 6262 would be a much better turbo for Power but it would need a much higher stall and some boost off the line.

Yeah? You really think you need more than the 15psi at the line that you can get on a stock converter?

I really don't like rear/mid engine cars when the HP is very high. The front end becomes really light and it's not a good feeling.

Lol wut?

[TwinV6GTP]

Sigh....
Ive built more than one 6262 powered 3800 car... I think I know what I am talking about. The 58 is a god awful small turbo.. Its smaller than the HX35 I ran for years at MAYBE 400w

Sigh...

Here we go. ..it can't be done they say. It won't make more than X amount of power. You can't make more than X amount of boost with that turbo.
Did you even know that the 5830 could produce 58 psi of boost and move 60 lbs/min at the same time ? Looking at the chart you wouldn't know.
Did you notice some Garett compressor maps changed after drag racers proved them wrong about their model predictions (airflow chart)

We race on classes where we are often restricted in the turbocharger size and sometimes MODEL. We aren't allowed to change wheels or housings.
We have to find ways to maximise power through other means. That's my specialty. I always under turbo and get excellent spool up caracteristics.

We get 340HP @ 30 psi (crank) through a turbo that is rated at only 260HP maxed out. This is what we have to do to have the record e.t and mph for the class.


I will say this, I have not built any GTP but I understand motors and turbos very well. How many Turbo GTPs are out there with that exact turbo?
Not many.

I will put that turbo just to prove a point and I'll dyno it.

P.S. I know the 6262 is a better suited turbo for a 3.8L V6 but there is no way it spools as hard as the 5830.
The 5830 will make my 500whp goal.

[/QUOTE]

[darkhorizon]

I can easily say my hx35 was better and that I was pushing it and that even in my fiero I didnt "need more spool".

[Frosty]

I could care less what turbo you use. I just want to see a twin engine ******* grand prix doing retarded burnouts and launches. You sir make me happy.