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Discussion Starter #1
I was wondering if anyone knew of a way to sequentially operate my GT2835's, just like the stock turbo configuration? It really sucks that I have no boost until 4500 RPMs, and then WHAM! it hits like a mack truck on 92 octane, 2 gallons of toluene and 29PSI. I would love for one of the turbos to begin at 2500 RPMS.
Anyone?

BTW the reason I finally get around to asking is because I had the pleasure of racing a 2001 TT Porsche. Off the line he immediately had 2 cars on me after that we were near even to 70.(city traffic). I felt that he had near FULL boost at 2500 rpms. I hate tearing up my clutch just to get low speed boost, or boost at the start of certain gears/speed.

Advice apreciated.....

Just so you know......

A recent study indicates that toluene, a solvent found in many commonly abused inhalants,activates the brain's dopamine system. The dopamine system has been shown to play a role in the rewarding effects of many drugs of abuse. --Is this why I am soooo happy when driving?

Thanks guys....


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:p
 

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It would be pretty cool if you could do that... Not sure if you can or not, but I believe thats the price you pay for BIG ASS turbos and Monster horsepower... ive also noticed a lot of people buy huge Turbos because they want that 3 digit number that starts with 8 or 9 then realize that all that extra power doesnt amount to shit in everyday racing situations... only on highways... I hope you are happy with them though, if you wanted a highway racer then you definately got the right setup.. if you wanted something for stop light racing.. Totally the wrong set up... Top end setups dont seem all that useful in real life driving situations as far as I can tell.. I think they are mainly for high speed track racing...

If it is possible to set that up sequentially and not lose any power or anything, that would probably be the best of both worlds... im curious to see what people have to say about this.. Wonder if anyone has tried anything like that?... hmm... Good luck.. How do you like that setup.. is it what you expected or are you dissapointed with the lack of low end power? I sure hope not those puppies are expensive :D
 
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Discussion Starter #3
I'm no expert and I dont know how much this would cost, nor do I know if this will work, but it is an idea. Why not change the size of one of the housings on one of the turbos? That would make one of them spool quicker. I just dont know if the car will still operate properly after that, that is the only problem, hopefully one of the pro's can step in and help me out here.

later

Hamid
 

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"Philzilla"
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gottagetaTT said:
Why not change the size of one of the housings on one of the turbos? That would make one of them spool quicker.
I'd recommend against that mod - you risk one of the turbos overpowering the other and starting to spin it in reverse. This would lead to turbo failure in no time.

HKS twins could be made to spool sequentially, but it would require lots of custom work. and you'd have to completely redo your headers. Right now, you've got 3 cylinders feeding each turbo with a crossover tube to balance the flow. You'd have to change that to have all 6 feeding the 1st turbo AND keep 3 feeding the 2nd turbo with gates/valves on these tubes to keep the flow shut for sequential mode. Those additional 3 tubes to the 1st turbo would have to have a gate/valve on them which would close when you went over to full twin operation, while opening the gate(s) to the 2nd turbo. You'd also need some sort of system to prespool the 2nd turbo. There'd have to be actuators and vsvs controlling all of these gates just like in the oem setup. All in all, an expensive and complex project.
 

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snyper27 said:
I was wondering if anyone knew of a way to sequentially operate my GT2835's, just like the stock turbo configuration? It really sucks that I have no boost until 4500 RPMs, and then WHAM! it hits like a mack truck on 92 octane, 2 gallons of toluene and 29PSI. I would love for one of the turbos to begin at 2500 RPMS.
I got a ride in a Supra w/ HKS GT2835s - you're right - that car drives like an NA until 4500 rpm. Then it felt like we were rear ended and the thing started pulling like crazy! shift (rear ended again) pulls again... MAD top end power.

I wonder if the HKS 2530s might make more boost at low RPM...
Those seem to be designed for the 300zx - true twin.

-Darryl
 
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Discussion Starter #7
Get a small shot of NOS.

Like pwpanas said, it would require a total hack to your headers. Would have been better to save yourself the huge cost of the kit in the first place and have custom ones made. The changes involved will be incredibly expensive, I'd guess about $5000 or more.

I'd think the better route for something like this is to make the stock header able to fit bigger turbos. Or at least use it as a basis for designing a similar shaped, but larger header. Why reengineer something Toyota spent millions getting right?
 
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Discussion Starter #8
Didn't pay retail, thank god...

Thanks for all your quick replies guys....I purchased the car already modified, 2835's, twin walbros, HKS fuel rail, FMIC, RPS 6 puck, aluminum flywheel(whick I hate)S-AFC, etc, etc,

My reason for purchasing this car with the HKS 2835's was that I wanted be able to have room for expansion(forged pistons 900 HP, etc. But you guys are right in reality, first off most of us prefer to run pump gas daily, not put in $40-$50 worth of gas per tank all the time to even be able to utilize even 645HP, much less 900HP, AND I would ANY day sacrifice 200 300 top end HP to have awesome spooling characteristics.

I paid $37K for the car('95, 48K MI), already modified so I don't feel as if I got raped by HKS. I have owned it for approx 4 mos. I found myself consistently on the highway because that's where the real fun is at with these turbos(as stated) but also where real trouble could be(high tickets and idiots) I would prefer not to get into NOS because it's such a ripoff, and a pain in the ass, plus that's what turbos are supposed to replace, IMHO. I am attaching a pic of my ride. If anyone is perhaps interested in purchasing my 2835 twin for a great negot price, for the dragstrip etc let me know. Thanks again guys, I don't think I will drop another $5K into sequential, although I think it would be the ultimate setup.
 
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Discussion Starter #9 (Edited)
GT2835's are ball bearing, right?? I've read that ball bearing turbos need to be rebuilt every 10,000miles or so. Is this true?

Thanks:)
 

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good info! now I know NOT to get HKS 2835s ;-) all I want is something that will net me 550-600RWHP but has FAST spooling. the research continues...
 

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twinturboman,
I was thinking about going with a TO4R with a small ex. housing. The housings are not too hard to change from what I have heard, and are fairly inexpensive. Just an idea....now all I need is the cash ;)
 
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Discussion Starter #12
I have a theory on how to sequential those turbos, email me privately. It's a project in my head for big sequentials, but I don't have the funds to execute.
 

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No Mercy
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I'd say you've got two real options.

Option 1: Sell your HKS twins, buy an SP60 kit.
Option 2: Buy a nitrous oxide kit. This is what I'd do.

To get sequential GT2835's, you'd have to essentially re-engineer the Toyota sequential turbo setup, which basically means you'd have to design an exhaust gas bypass valve for the HKS manifold. This would probably include redesigning the manifold, plus you'd need to figure out how to slowly redirect gas pressure to #2 turbo without slam-starting it ... plus you'd have to devise some kind of mechanical boost control...

I recently saw a closeup of the Toyota #2 turbo... it's got some strange characteristics, like a faux wastegate (boost is only controlled by the #1 wastegate, hence the free VSV mod) and other stuff in there... it's really complicated. Not to mention all the damn vacuum lines you'd have to run and keep track of. I say you're better off with some nitrous.
 
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Discussion Starter #14
ive also noticed a lot of people buy huge Turbos because they want that 3 digit number that starts with 8 or 9 then realize that all that extra power doesnt amount to shit in everyday racing situations
Not true. I hear this logic mainly from people who don't have big turbos. You very rarely see people going larger to smaller. Why? Because you learn to drive around it. I still get the same 60' times I did as BPU, same tires, all turbo. You learn to drive it, and it's not too big of an issue. You just have to adjust your rpms as appropriate.

BTW, an aftermarket sequential system has been attempted a few times before. Suffice it to say, it is VERY complicated, more than whatever you think it is. We're talking custom designed headers, solenoids and valves to interact with standalone engine management; the stock computer won't cut it. It's just not worth it. It may come out sometime, but if you thought the GT2835 kit by itself was expensive, whoa boy.

I wonder if the HKS 2530s might make more boost at low RPM...
Those seem to be designed for the 300zx - true twin.
I had that setup on my car before my 2835s. It drove and made power like a large TS04. Once again, the maxim holds: big turbo = more lag = more power and vice-versa.

GT2835's are ball bearing, right?? I've read that ball bearing turbos need to be rebuilt every 10,000miles or so. Is this true?
No.

good info! now I know NOT to get HKS 2835s ;-) all I want is something that will net me 550-600RWHP but has FAST spooling. the research continues...
Yes, the GT2835s are about 200 rwhp and 500 rpms north of what you are looking for.

If you are looking for ways to maximize "low end", here are a couple:

lightweight flywheel (which it sounds like you have)
underdrive pulley (somewhat scary)
carbon-fiber driveshaft
lightweight/smaller diameter wheels

These reduce your rotating mass and allow quicker revving, getting you to your boost rpm quicker. An Apexi ITC will enable you to optimize timing down low for better response - I have heard this helps a lot. Getting fuel trim right helps. I personally want a 3.3L stroker. Of course, if you want to make low end like a V8 LS1, there's always NOS. A 90 shot gives you 300 ft/lbs of torque at 2000 rpms. (Yes, I wanted to kill the dyno guy) I mean, if a TT AWD Porsche only got you by 2 lengths off the line and to 70, the power your turbos make should enable you to roar past him a second or two later.
 

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Great post... I loved watching you kill those Busas :D If you are looking for a top end setup like I said earlier thats definately the one, but as you can see from the 11.1 1/4 mile time its definately not ideal for drag racing, since you can pull low 10's with quite a bit less horsepower using a MUCH smaller single on an Automatic... But if i was going to get one for top end power dont get me wrong I would definately look at those... I have an Auto however, so that would really suck for me anyway...

When I go single Im gonna do those mods you said to help the low end.. thanks for the info.. I already thought of the Underdrive puley and Flywheel.. didnt think about anything else beyond that though.. however Ill probably have an SP63 so it will be considerably quicker anyway...

The one thing I keep seeing everyone say is "get nitrous" Its definately a solution.. but a lot of us guys like to have the power ALL the time.. not just when we have the Bottle armed.. If you are one of those guys who gets a kick out of getting on it very often, even for a short amount of time over the daily drive (me) I cant keep my foot off the accelerator when Im on an open stretch of road.. Nitrous isnt going to be the perfect solution.. you will eat a bottle in a day if you are like me... thats not cheap by any means, plus you need to use it constantly.. But of course, if it was only used during a race, then thats completely different.. but if you are lined up at a light, you may not have enough time to open up that bottle and get everything the way you want before it turns green (dont wanna get caught purging at a redlight either :D ) But all in all everyone provided some good info, I love reading these threads..

Keep it coming! :)
 

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Here are a few things to think about

first of all do you have CAMS for your Turbos? A proper cam will help in reducing your lag. Also something others have been doing for a long time is to get a 272 exhaust cam and 268 intake cam.

You can also port and polish the turbine housings. Also I am not sure if the 2835s turbine wheels are clipped but you can also replace the turbine wheels. You will loose a bit of flow but your lag will decrease.

But when the day is done I would just get a NOS spoolup kit and call it a day :)
 

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I would think that the best and most effective way to make 2835's spool faster would be to change the exhaust housings. They are garrett turbos, so the housings shouldn't be too hard to come by. Doesn't one of those Supra shops modify them to spool sooner?
 

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i have someting to say......... ive ben to nopi twice and i took my supra there with others, but i have to say there is one hks twins in the states that have a sequential setup, and its own by a black guy, forgot his name, but he has somehks 2830,s or 2035 or something like that, its the first gen of those twin setup tey made, but they actually run in sequential mode, they got to the stock location of the stock twins, and ifyou look at the engine bay you will see nothing but wha you saw when it has stock twins, bt look closely, nd on the bottom they are piloshed, and youcan see the hks letters stamped, and i havenever seen this setup until i went to nopi the first time in 2000, and the car is a 98 quicksilver, and when bought it the bumper had a a little sticker that said "dont blink" and he took it off this year, also he has some blits rims, they looklike the mesh type, but if anyone in gorgia has seen him they know who im taking about, becuase he has a brother that has a 3000gt and they are always together, but he said they only made that kit becuase t was too complictaed to mass produce and also other setups would cost less and produce the same power, but right now hes running n stock fuels system, but i guess he wants to preserve them and have them as long as he can, but this is what i saw and im pretty impress fromthose. peace:)
 

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Re: Here are a few things to think about

There are no cams out that will decrease lag... except maybe the JDM spec cams, btu why would anyone do such nonsense?

Carlos Ramirez said:
first of all do you have CAMS for your Turbos? A proper cam will help in reducing your lag. Also something others have been doing for a long time is to get a 272 exhaust cam and 268 intake cam.

You can also port and polish the turbine housings. Also I am not sure if the 2835s turbine wheels are clipped but you can also replace the turbine wheels. You will loose a bit of flow but your lag will decrease.

But when the day is done I would just get a NOS spoolup kit and call it a day :)
 

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boostinsixtt said:
i have someting to say......... ive ben to nopi twice and i took my supra there with others, but i have to say there is one hks twins in the states that have a sequential setup, and its own by a black guy, forgot his name, but he has somehks 2830,s or 2035 or something like that, its the first gen of those twin setup tey made, but they actually run in sequential mode, they got to the stock location of the stock twins, and ifyou look at the engine bay you will see nothing but wha you saw when it has stock twins, bt look closely, nd on the bottom they are piloshed, and youcan see the hks letters stamped, and i havenever seen this setup until i went to nopi the first time in 2000, and the car is a 98 quicksilver, and when bought it the bumper had a a little sticker that said "dont blink" and he took it off this year, also he has some blits rims, they looklike the mesh type, but if anyone in gorgia has seen him they know who im taking about, becuase he has a brother that has a 3000gt and they are always together, but he said they only made that kit becuase t was too complictaed to mass produce and also other setups would cost less and produce the same power, but right now hes running n stock fuels system, but i guess he wants to preserve them and have them as long as he can, but this is what i saw and im pretty impress fromthose. peace:)
Kevin and I met that guy this year. I believe it's a Blitz kit actually. I have pictures of his car on my site in the Events section under Nopi.
 
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