Now for something completely different

[Ryushin]

So I've been thinking over building something completely different than what has been done before. I've been mulling over the idea of a compound setup, but after reading everything I can find on twin turbo going into a supercharger, I don't think it's the way to go. Just too much boost for too little gain.

I've been liking the idea of just twin turbo's, except for having no low end torque. That got me thinking about going with a sequential quad turbo setup. I've been reading some, and it looks like this has not been done before on a SN95 platform. In fact it seems it's a very rare setup.

I'm just in the planning stages right now, looking at HP Performance or Hellion as the twin kit and then adding from there. It also might be that it's just to build a true custom setup from the beginning. I think I'll contact Rick at Amazon Racing has he said he's been doing a lot of Turbo stuff now.

I just wonder if there is enough room to make everything fit?

Goal is to make 800+ rwhp on pump gas with over 450 ft/lbs of torque starting at 1500 rpm.

 

[TRBO VNM]

I have thought about that type of setup, but that was about it. lol I haven't done any of the research. good luck, sounds like an interesting build.

 

[Digital]

You can make that power with a compound setup.
Since i've been dealing with this for almost a year i've learned a lot along the way.
The illusion that you wont make peak power is true and false at the same time.
One could say that you wont make peak power with a 57mm turbo, this is true, unless your peak power expectations are within that power range.
I.E. if you want 500rwhp a 57 would work fine, if you want 1000 it wont.
Same goes for a compound setup. Will you make as much power as if you had just a turbo? no. Is it able to make the power you're looking for? yes.

Once you limit your power to a certain number there are many ways to get there. Many setups can make 800rwhp and you'll never be hindered by the power of the kit, just your engines internals.

I think instead of a quad turbo system which would indeed be cool but costly and very custom you should go with a diesel type twin turbo configuration. A smaller turbo feeding a larger one.
That setup hasnt been done very often and it would surely be easier then a quad.

I wait in antisipation of your final decision.
Hopefuly you're serious about a new setup and have the funds to do it.

 

[candyroush]

I think instead of a quad turbo system which would indeed be cool but costly and very custom you should go with a diesel type twin turbo configuration. A smaller turbo feeding a larger one.
That setup hasnt been done very often and it would surely be easier then a quad.

That is what he is planning I believe, but dual sequential.

 

[Ryushin]

Candyroush has it right. Dual sequential. I have the funds and that is not the problem. I was planning on skipping the Whipple and going right to turbo's. But looking at the huge drop in low end torque was always bothering me. I like the idea of dual sequential and not a single sequential. I was planning on doing this project over winter.

Was also looking at moving up to a Ford GT block with GT500 heads and intake. I just don't know if it will fit under the stock hood when I'm done or not. Lots of planning to do at this point. Maybe a Teksid is all that I need. Though having the oil squirters, extra displacement, might just make it a true 900-1000 hp car on pump gas.

Just going to have to figure out if the room exists to have four turbo's and all the piping involved.

It would be nice to have something fairly unique in the cobra community.

 

[4sdvenom]

You will have room for the turbos, 2 in the bumper and 2 in the engine bay!
The piping will be the headscratcher!:dw:

 

[Ryushin]

You will have room for the turbos, 2 in the bumper and 2 in the engine bay!
The piping will be the headscratcher!:dw:

Yea, I think that is going to be the kicker. I think I'll let Rick at Amazon mull it over for a month or so and then see what he comes up with.

 

[EvilTwins]

I don't really think this is a very good idea.

First off, have you ever even been in a twin turbo Cobra? People sit here on these forums and talk about numbers and about how you're going to lose all this "low end torque" by going turbo from supercharged, but if you haven't even experienced what a twin-turbo cobra is like then in my opinion you can't make a good decision.

Twin 57's have very little lag and they are the perfect sized turbos to make 800rwhp. I think you'll find that going with any other setup with that goal to be counter-productive, it just won't be as efficient. Sequential setups are not a common choice in performance builds and there's a reason for that. Even the cars that did have these sequential setups from the factory (such as an RX-7), you'll quickly notice that the first thing people do when they upgrade is ditch the sequential setup and go with a single.

If you've never been in or driven a twin-turbo Terminator which I'm thinking you haven't, please try to do so. Trust me my brother has a 500rwhp eaton Cobra and while I'm sure his car has more power at 1500RPM, it does not mean anything. My car is a hell of a lot more fun to drive and a hell of a lot faster. Turbo Cobra's MOVE OUT!

It seems that most people that consider these Compound setups or Sequential setups are always people that don't even know what a twin-turbo Cobra is like. I don't know how many posts I've read from people that drive eaton Cobra's saying that a Compound setup is the only way to go??? Honestly what do these people even know about these setups? I don't really remember reading any posts from people that are currently twin-turbo saying what a good idea a compound setup is. I've experienced both supercharged and turbo Cobra's and I will never ever consider going compound, turbos don't need any help.

I can understand you wanting to be different, but just remember that different doesn't always mean better.

 

[TTBEAST]

I agree with EvilTwins i was really wanting to go compound and the more cars that i have rode in the more i appreciate my twin57 set up. It spools real fast and makes great power. I would find someone in the area with a twin set up and go for a ride. If it spools anything like mine you will like it. I admire you trying something different and would love to see it, but it may be just a waste of money. Or maybee not . There is a guy on turboforums.com doing a 4.6 with a quad turbo set up, i dont think he is done but its not sequential.

 

[EvilTwins]

IMO the only real way to make a sequential setup work well would be to of course have the proper exhaust control (through valves). Obviously at lower RPM's you would need to divert most/all exhaust to the smaller turbo on each bank and then when you hit a certain RPM point you would want it to divert all the exhaust to the larger turbo. This is going to be very hard to setup because it's not like there are a lot of "kits" out there to make this easy. You're going to need to program some sort of computer to perform the necessary valve actuations and then of course you would need the the actual valves. Even if you were able to accumulate the necessary parts to do this it would definitely require a lot of time to set it up and get it working properly.

How do you plan to arrange the turbos? Here's a picture of the Supra sequential setup:

I found a website ( SupraTT - sequential turbo operation ) with some pretty useful information and diagrams that explain how the sequential setup works on the TT Supra. I'm guessing you already know this though (I certainly hope so anyway). Here are the diagrams that show how each turbo is controlled:

1st Movement: Allegro --- Low-rev operation (up to 3500rpm)

2nd Movement: Molto vivace --- Mid-rev operation (3500-3800rpm)
(Also known as 'prespooling' stage)

3rd Movement: Adagio --- Mid-rev operation (3800-4000rpm)
(second turbo coming on boost)

Fourth Movement: Fugal finale --- High-rev operation (4000+ rpm)
(second turbo full on boost)

Anyways setting a system like this up is really going to be a nightmare. It's very easy to see why all the Supra and RX-7 guys ditch it because it is a huge hassle. But if you want to do it I say go for it. Just be prepared to spend a lot of money, have a lot of headaches and end up with something that in the end wasn't worth all the trouble.....

It would be cool to see pictures of a 4 turbo sequential arrangement though, it'd look like that 3d pipes screensaver!

 

[Turbo98]

The "cool" factor would be there for sure. But performance and the added weight of either the compoound or 4 turbos with all the heavy piping wouldn't be worth it to me. A couple guys have ditched the compound after having it--for whatever reason(s).

 

[Ryushin]

Eviltwins: Thank you for the information. I had not seen those last four pictures. Being in Colorado I don't get to see very many nice setups and I haven't had the chance to ride in a twin turbo cobra. I have seen dyno graphs using twin 57's and everything below 3000 rpm was not there. Hardly any torque was below 3000. Maybe your dyno graphs look different. Mind posting them for me to see.

The compound setup just seemed like a waste using twins into a supercharger. I didn't like how much boost it takes to make the power it was taking. Just seemed better to go with twin screw instead of compound setup if running pump gas was the goal.

This is why I'm really looking at the idea of sequential turbo's. I know a lot of the supra guys dump them. But from what I've read, it's because of cost and not because it's a better setup. If you want more power, you have to modify both turbo's so they work correctly.

I will have to find some kind of boost controller though that can operate the valves necessary to make this work.

 

[candyroush]

I do think you need to go for a ride in a tt termi. even my little 2v that put down only 560ish rwhp is a blast to drive. once you drive in one, you will understand. yes there is less torque down low, but honestly if you are cruising at 2000rpm and wot 3000rpm come pretty quick.

Plus there are ways to help spool the turbos faster. Depending on your peak power needs you may be able to 50mm turbos. using a bit smaller exhaust housing will increase spool(it will take away from top end though). Also a higher compression ratio like 9.5-10.0 will help spool and give more power out of boost (stock termi is 8.5).

I think you should check out theturboforums.com , they have a whole section for mod motors. There is alot of great info there.

 

[Ryushin]

candyroush: Okay, more reading is good of course. I was also thinking of maybe using turbo's smaller than 57's. If I want to not run more than 15-17 lbs of boost, then buying the correctly sized turbo's would be best.

 

[candyroush]

smashedheadcat on here runs twin 50mms. i think he makes around 700rwhp at 17ish lbs. im sure that set up spool very quick and thats still a ton of power. There is still room to grow there too. im not sure about the rest of his setup but maybe he'll chime in.

 

[Digital]

candyroush: Okay, more reading is good of course. I was also thinking of maybe using turbo's smaller than 57's. If i want to not run more than 15-17 lbs of boost, then buying the correctly sized turbo's would be best.

x10000

 

[Ryushin]

So in that idea, what are peoples thoughts about who makes the best twin kit? I like the Hellion idea for it's nice lines and little to no welds. But it's a lot of piping and I think that will delay spool up time. The HP Performance kit looks nice and it looks like it puts the turbo's down low like the Hellion kit. But HP Performance's service could be a lot better. I don't know if I like the HPP kit as it relocates the battery and puts the turbo's up top. If I'm going to have the weight of twin turbo's, it seems it would be best to keep it as low in the chassis as possible.

Thoughts?

 

[EvilTwins]

IMO the HP kit (especially the second generation) is hands down the best kit out there. I also think the HPP kit is very nice but it really clutters up the engine bay (which I personally don't like) and it also requires the relocation of many components. I absolutely love the way the HP kit looks (they make an awesome intercooler that mounts the BOV's in a very cool location - see sig ) and there's no doubt the HP kit makes big power. It also tunes very well and requires no modification unlike the Hellion twin setup, many people have found the location of the Hellion blowoff valve in their twin kit to be too close to the MAF which causes turbulence and tuning issues.

The Hellion kit uses uncoated Stainless piping while the HP and the HPP kits use steel piping with Jet-Hot Coating. Stainless is obviously very good but I don't think it looks that good compared to the coated piping of the HP/HPP kit. The Hellion twin kit does however route the wastegates dumps back into the downpipes while the HP kit dumps them to atmosphere. Venting them to atmosphere is definitely better for performance but some people don't like the sound of it, so those people can either muffle them or modify the kit to route them back into the downpipes.

I recently made a thread to get pictures of the new HP kit and that can be found here: http://www.svtperformance.com/forums/turbo-cobras-247/619410-hp-2nd-generation-hotside-piping.html

IMO the only downside of the HP kit is the questionable service/support they provide. They sell their kits on ebay too and they actually have good feedback on there so I dunno. I definitely love my HP kit!

EDIT:

One more quick note as well with regards to scavenge pumps. The HP and Hellion kits both require a scavenge pump. The Hellion kit comes with one the HP does not. The HPP kit doesn't need a pump at all.

 

[Ryushin]

I'd rather have the Jet-Hot coating as well. Does the coating prevent rust? I also prefer the look of a clean engine bay and rather not use the HPP kit.

Do you also have dyno graphs of your twin 57's going? I'd like to see that.

 

[SupraBL71GTS]

Boost Logic sell an aftermarket compound turbo kit for the Supra. Looks very promising , capable of 800+rwhp and builds 20 psi at 2800 rpms with a 3.0 ltr engine

Boost Logic SupraTT Compound Turbo Kit :: Turbo Kit :: 93-98 MKIV Supra TT :: Toyota :: Boost Logic