sequential turbos?
- Thread starter chrisj
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While you might get away from solenoids, you'd probably need some stepper motors to control some *venting*, and a FBW throttle to get it to be seamless in operation.
Might also want to start with a 4.1L just to have that extra bit of exhaust flow.
Porshe has done a number of interesting designs.
Might also want to start with a 4.1L just to have that extra bit of exhaust flow.
Porshe has done a number of interesting designs.
i am pretty much thinking the same thing, but this is not for a turbo buick, but a 2.2 dohc dodge. i come here all the time because the buick guys know their crap. there would be two wastegates, one for the let's say stock turbo that could be internal. and a second external wastegate placed right before the second turbo. but i could imagine that this would require extensive turbo swaps to get it right.
I'm thinking that if you're gonna do sequential turbos, the Supra/RX7 TT guys would be the ones to talk to.
If you've looked at a lot of the TR under hood pics you're really gonna be pushing for room honestly.
Quite honsetly, you'd be shooting yourself in the foot NOT to use electronic control for the wastegates. if it were me (I'm just getting started in micro programming) I'd end up with 2 MAP sensors one for the high pressure side, one for the low pressure side.
The first thing I'd do after being sure it worked decently would be to go find a dyno and tune the hell outa it.
On turbo selection I would start looking for turbo maps that had efficiency "islands" overlapping heavily, and this is how I'd design a sequential setup with one big and one small turbo.
To conclude this rant there's a lot to be said about spool linearity potential with sequentials, but they're probably one of the least researched turbo configurations too.
If you've looked at a lot of the TR under hood pics you're really gonna be pushing for room honestly.
Quite honsetly, you'd be shooting yourself in the foot NOT to use electronic control for the wastegates. if it were me (I'm just getting started in micro programming) I'd end up with 2 MAP sensors one for the high pressure side, one for the low pressure side.
The first thing I'd do after being sure it worked decently would be to go find a dyno and tune the hell outa it.
On turbo selection I would start looking for turbo maps that had efficiency "islands" overlapping heavily, and this is how I'd design a sequential setup with one big and one small turbo.
To conclude this rant there's a lot to be said about spool linearity potential with sequentials, but they're probably one of the least researched turbo configurations too.
GNVYUS 1
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All the fastest Supras have ONE turbo. They pay out the wazzu for the header and monster T88 but in the end, its well worth it.
GN's spool pretty fast already, and if you want top end get a bigger turbo, or put your exsisting turbo in a bigger housing.
GN's spool pretty fast already, and if you want top end get a bigger turbo, or put your exsisting turbo in a bigger housing.
Chrisj; The thing that I have notice about the import crowd is their ability to take advantage of technology? The buick crowd has a tendency to be VERY narrow minded and very frugal.(unfortunately) This is why if anyone has ever notice their car's are getting faster and faster and FASTER......... 
but is there increases based upon the fact that their automotive companies spend millions in research and developement work sort of like honda and their f1 program. that all trickles down to what the average consumer receives. also these companies are spending big dollars on sponsored drag cars that further push the limits and that also trickles down. advances are easy to reach when manufactures are developing their own technology. the same advances for buicks could be reached if the frugal began dumping big dollars into their blocks as well. just about anything can work with enough money and time dumped into it.
trading t/a
I'm Angry!!!!!
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The reason so much money is invested in the supra is because of the drivetrain you start with. Internals are forged, mains and webbing are huge, head configuration is designed well for boost, non interference motor (if the timing belt breaks your not gonna implant the valves into the piston crown)tranny is damn good as well.
For the american market comparable equipment would be a BBC, strong block, forged internals, etc. But that 3.0L is less than half the size and can put out very good numbers. I think you can get a 454 BBC shortblock from GMPP for less than $4K and it'll handle 900hp worth of abuse.
It would be like Buick throwing in a built stageII out of the factory, we Americans are greedy and maximizing the profit is the only concern. The closest would be the 03-04 Cobras as a good platform to build on for not alot of money. Now if the new LS2 motors came with forged internals and an eaton GM loyalists would go nuts.
I've read that in Japan all manufacturers split the cost of R&D when it comes to designing new vehicles. Nissan i think has a similar engine in the skyline but I believe it's smaller than 3.0L.
For the american market comparable equipment would be a BBC, strong block, forged internals, etc. But that 3.0L is less than half the size and can put out very good numbers. I think you can get a 454 BBC shortblock from GMPP for less than $4K and it'll handle 900hp worth of abuse.
It would be like Buick throwing in a built stageII out of the factory, we Americans are greedy and maximizing the profit is the only concern. The closest would be the 03-04 Cobras as a good platform to build on for not alot of money. Now if the new LS2 motors came with forged internals and an eaton GM loyalists would go nuts.
I've read that in Japan all manufacturers split the cost of R&D when it comes to designing new vehicles. Nissan i think has a similar engine in the skyline but I believe it's smaller than 3.0L.
I'm not sure, but I'd think that the biggest concern would be exhaust flow through the smaller turbo's housing limiting the flow potential to the bigger turbo. Maybe a large external wastegate for the first turbo that would allow enough exhaust energy to pass (I think that's why the RX7 uses solenoids???). A lot of the fast Supras do use single turbos, but they are mostly straightline cars. If all you plan to do is 1/4 mile (or straightline) your car I would agree the sequential would be a waste, but if you have expanded views of your cars use it might be fun to try.
Adam
Adam
GNVYUS 1
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Better is in the eye of the beholder. If you want a fast spooling car, sequential is great. But at what cost considering you will have to custom fab it into a GN?
One turbo is more efficient as it receives all the cylinders gases.
Supras have had plenty of sequential vs. single turbo showdowns. There was one done in a Turbo Magazine around 2 years ago that showed this ( cliff notes )
Sequential spooled a bit faster but let off up top
Single spooled pretty well and developed more upper mids on power
They tried to match the outputs so that it was as fair as it could get, same car, same day on dyno with no tweaks.
One turbo is more efficient as it receives all the cylinders gases.
Supras have had plenty of sequential vs. single turbo showdowns. There was one done in a Turbo Magazine around 2 years ago that showed this ( cliff notes )
Sequential spooled a bit faster but let off up top
Single spooled pretty well and developed more upper mids on power
They tried to match the outputs so that it was as fair as it could get, same car, same day on dyno with no tweaks.
yes i am not potentially pondering this for a GN. How did they have the sequential vs single battle outlined? What was the size difference between the smaller and larger turbo for the sequential setup? Do you have anymore info regarding this? Looks like it's time to search in supra forums. Thanks guys.
There's an article I read recently in one of the car magazines (Road and Track maybe?) that talks about sequantial turbos. The main thing I got from it was the extra plumbing involved. There were basically dual intake and exhaust so that at low speeds all the exhaust is routed to the small turbo and then a flap opens up and exhaust also goes to the bigger turbo. At higher speeds the exhaust to the smaller turbo closes somes so it doesn't over take the little turbo. With the intake a similar thing goes on. I assume there was some sort of solenoid to tell when to open the flaps.
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