Jump to content
The mkiv Supra Owners Club

Full BPU vs Single Turbo!!


jjs_82

Recommended Posts

I've had a single turbo for nearly 10 years now and I wouldn't go back to the sequential system. I've driven them since and that artificial lag to 4000rpm no matter what the gear you're in drives me mental.

 

Have a look here for some raw performance stats of a T67DBB - it's a Garrett GT35R unit, and a GTX version would spool even better by all accounts. 50mph to 90mph in 3 seconds is a lot of fun.

http://www.mkivsupra.net/vbb/showthread.php?68090-Dual-ball-bearing-turbo

 

I have found that the power my car is pushing out with this setup is ideal. It'll get a bit squiffy in 3rd gear at 70mph, so I can't see why I'd ever want more power, and I feel like things would just start breaking anyway. It's bonkers daft on the road but still perfectly tractable if you don't go balls-out as well. The power is easily controlled by the right foot, the power comes in smoothly but rapidly, it's got reasonable poke below 4000rpm.

 

Fuel economy actually improves slightly off-boost when you go single as the exhaust system is far less restrictive. You can negate that with bigger cams and more overlap, but I've since found that overlap is just bad in a turbo car at all stages so you tune that out with adjustable cam gears.

 

As for reliability, well, it's got that annoying warm start problem but it always starts second go :) It might depend on how you drive it, but I've had little trouble with the single setup. It definitely depends on parts quality, what you choose to change and what you leave alone, how it's all fitted together and the tuning afterwards. It's no good banging on a fat HKS turbo kit and then using crap oil lines or a MAP ECU, or wiring it up with scotchloks. All the stuff I was paranoid about when I did the install has been absolutely fine because I paid attention to what could go wrong - hoses rubbing, leaks, vibration of wires, water ingress, all that jazz.

 

UK spec brakes are fine, an non-trick RPS clutch is fine (mine is from 2004 and going strong). Stock intake system is fine, drop in 650cc injectors are fine, 600bhp or less is fine. An e-manage will happily run the car if you can get someone who knows how they work. Decent tyres and suspension are a good idea. RLTC is a must have for me, others may think running any traction control isn't manly enough :shrug:

 

-Ian

Link to comment
Share on other sites

  • Replies 104
  • Created
  • Last Reply

Top Posters In This Topic

I've had a single turbo for nearly 10 years now and I wouldn't go back to the sequential system. I've driven them since and that artificial lag to 4000rpm no matter what the gear you're in drives me mental.

 

Have a look here for some raw performance stats of a T67DBB - it's a Garrett GT35R unit, and a GTX version would spool even better by all accounts. 50mph to 90mph in 3 seconds is a lot of fun.

http://www.mkivsupra.net/vbb/showthread.php?68090-Dual-ball-bearing-turbo

 

I have found that the power my car is pushing out with this setup is ideal. It'll get a bit squiffy in 3rd gear at 70mph, so I can't see why I'd ever want more power, and I feel like things would just start breaking anyway. It's bonkers daft on the road but still perfectly tractable if you don't go balls-out as well. The power is easily controlled by the right foot, the power comes in smoothly but rapidly, it's got reasonable poke below 4000rpm.

 

Fuel economy actually improves slightly off-boost when you go single as the exhaust system is far less restrictive. You can negate that with bigger cams and more overlap, but I've since found that overlap is just bad in a turbo car at all stages so you tune that out with adjustable cam gears.

 

As for reliability, well, it's got that annoying warm start problem but it always starts second go :) It might depend on how you drive it, but I've had little trouble with the single setup. It definitely depends on parts quality, what you choose to change and what you leave alone, how it's all fitted together and the tuning afterwards. It's no good banging on a fat HKS turbo kit and then using crap oil lines or a MAP ECU, or wiring it up with scotchloks. All the stuff I was paranoid about when I did the install has been absolutely fine because I paid attention to what could go wrong - hoses rubbing, leaks, vibration of wires, water ingress, all that jazz.

 

UK spec brakes are fine, an non-trick RPS clutch is fine (mine is from 2004 and going strong). Stock intake system is fine, drop in 650cc injectors are fine, 600bhp or less is fine. An e-manage will happily run the car if you can get someone who knows how they work. Decent tyres and suspension are a good idea. RLTC is a must have for me, others may think running any traction control isn't manly enough :shrug:

 

-Ian

 

Spot on reply there ian, hit the nail on the head tbh.

Link to comment
Share on other sites

Agreed. I've perhaps come across as I've got a downer on going single but actually I'm a big advocate for it. It gives the car a new lease of life. :love:

 

However (and there always is one...) if you want to stay relatively mild with the tune (~500bhp) then actually a BPU setup with a Syvecs ECU doing the electrickery MAY be preferable - although less powerful again (~430bhp) - simply from a usability perspective. I'll caveat that statement by saying that I've never actually driven a car with that set-up and also that I LOVE my big single and wouldn't change it back at all! I enjoy the visceral experience I mentioned before with the rasp of the twin-plate clutch on the run-off; the howl of the big turbo; and the mechanical knocking of the suspension with the accompanying tyre roar letting and me know I'm as unlikely to end up backwards in a hedge as you are likely to be in a road car... Also just popping the bonnet to check the oil level or whatever makes me grin like a kid at the thought of all that poweeeerrrrrrr! :eyebrows:

Link to comment
Share on other sites

thanks ian C. this is exactly the kind of thing i was talking about.

 

you can be sensible with the single upgrade. you don't have to go for twin plate clutches that make loads of noise, or power levels that end up fighting for traction all the time. I've already got a power fc ecu as i hate the idea of running a fcd it just screamers "wrong" to every bone in my body when you know how they work.

Link to comment
Share on other sites

haha yeah i guess there is that.

 

But alot of my customers want cars that they can get into and have fun with, then just put away end of the day over having to constantly repairing it, or worrying it drinks to much, or its way to much power and wheel spins all over the road. I do agree with them and all my own personal cars i've built to the same level where it could have been a factory option power increase without removing to much of the character of the car. And i think what Ian C has said is perfect.

 

Looking at his car its over 600bhp power levels, so even that is in the higher regions of what i was trying to say, and hes running perfectly fine.

 

Tim

Link to comment
Share on other sites

Mine was running a nice 455bhp BPU (one of the quicker BPU set ups seen) set up before I was running my single 680bhp set up.

 

The BPU set up felt great, loverly daily runner very smooth and felt quick. Nicer drive than the set up I have now. Its juts an animal now buy I love it and wouldn't turn the clock.

 

So Its up to you for what your after. If your after an animal that will smoke most cars you see on the road and want to void that smoother comfort drive so Single. If not got for a nice BPU set up..

Link to comment
Share on other sites

Mine was running a nice 455bhp BPU (one of the quicker BPU set ups seen) set up before I was running my single 680bhp set up.

 

The BPU set up felt great, loverly daily runner very smooth and felt quick. Nicer drive than the set up I have now. Its juts an animal now buy I love it and wouldn't turn the clock.

 

So Its up to you for what your after. If your after an animal that will smoke most cars you see on the road and want to void that smoother comfort drive so Single. If not got for a nice BPU set up..

 

What spec was the 455bhp BPU?

Link to comment
Share on other sites

I take it that's a typo seeing as the S362s / B362s are 62mm turbos? Clue's in the title. ;)

 

From the sounds of it you're going for a sort of similar set up to mine, albeit with a much lower target for power. BPU is a great set up for a road car and I loved mine when it was at that level of tune for responsiveness, reliability and relative refinement (alliteratively... :innocent: ). Going single isn't cheap and to be honest an argument could be made for it not being hugely appropriate for a road car due to an increase in road noise, potentially expensive problems and a decrease in MPG (not that any of us buy a Supra expecting it to be a frugal choice I like to think...) and future saleability. BUT... I personally don't regret going single at all. The shove in the back as the turbo hits full boost just DOES NOT get old! As long as you do things sensibly and upgrade the brakes and suspension to cope with your expected level of power either before or at the same time as your single conversion, everything is entirely manageable. There will be teething problems and little niggling bits that you'll need to rectify over the first few months so don't expect plain sailing.

 

It all depends what you want from your car.

Is a single converted Supra:

Refined? No.

Comfortable? Not really.

Expensive? Certainly.

But above all fun? Oh yes... :eyebrows:

 

the car is a 98 so it already has the bigger brakes but i have grooved disks all round with yellow stuff pads and it has the toms advox coilovers all round so she handles very good so braking and handling side of things should be ok.

Link to comment
Share on other sites

Guest Budz86

At the moment I am running a 6 speed TTC BPU with syvecs and 650 drop in's, and I have to say the first few weeks I was not 100% sold. I knew it was a good set up and had been built properly by SRD and mapped by Ryan, but wasn't sure it suited me as I loved how the 2nd turbo kicked in before. Now I've had a chance to drive it properly I love it! Very smooth, progressive and fast! Of course these are still neigh on 20 year old cars so any performance increase like this is going to stress existing parts, but it comes with the territory. It's all about the right parts, fitted in a sensible and logical order, and keeping a cool head when you get issues! Rush and cut corners and you'll spend more time and money fixing things than it would have cost to do it right in the first place!

Link to comment
Share on other sites

What spec was the 455bhp BPU?

 

Syvecs

TTC

264 9.3mm Whifbitz Road Cams

HKS Exhaust

Walbro Pump

Intercooler

Cone Filter

Double De Cat

Water Meth

Whifbitz Pullys

NGK Grade 8 Plugs

Fuel Pulsator Bypas

Whifbitz Uprated Coil Packs

650cc SARD Injectors

NTK L2H2 (LZA-09-E1) Wideband Lambda Sensor

 

This is will give you an Idea of the power gain differences

 

http://img248.imageshack.us/img248/6887/img013ib.jpg

 

http://img199.imageshack.us/img199/9955/680bhp.jpg

 

Hope thats helped

 

Paul

Edited by a98pmalcolm (see edit history)
Link to comment
Share on other sites

Syvecs

TTC

264 9.3mm Whifbitz Road Cams

HKS Exhaust

Walbro Pump

Intercooler

Cone Filter

Double De Cat

Water Meth

Whifbitz Pullys

NGK Grade 8 Plugs

Fuel Pulsator Bypas

Whifbitz Uprated Coil Packs

650cc SARD Injectors

NTK L2H2 (LZA-09-E1) Wideband Lambda Sensor

 

This is will give you an Idea of the power gain differences

 

http://img248.imageshack.us/img248/6887/img013ib.jpg

 

http://img199.imageshack.us/img199/9955/680bhp.jpg

 

Hope thats helped

 

Paul

 

amazing how the spool rate is similar to the single im mean its only a couple 100rpm different just you have 230bhp more

Link to comment
Share on other sites

haha yes i know but shows how TTC is very similar to a single if one wanted to test the water ;)

 

In my case it couldn't have been more dissimilar! I ran in TTC mode for a few years before doing the single install and the difference was night and day.

 

My stock turbos running in parallel were VERY laggy, under 3.5K rpm there was very little (the ECU was mapped to suit), in comparison the GT35R came in at just over 2K rpm and pulled hard and fast to the redline. When I initially fitted the GT35R for the first week or so I was constantly hitting the rev limiter as I wasn't use to how responsive the thing was and wasn't changing gear quick enough.

 

Give me a medium frame (62mm-67mm), double ball bearing turbo over the stock turbos everytime, there is no comparison.

Edited by Nic (see edit history)
Link to comment
Share on other sites

I went full BPU (GReddy FMIC, piggy back, euro-spec turbos running 1.4 bar) in 2007.

 

the difference between stock and BPU was impressive.

In 2008, I wanted to give single turbo conversion a try (little 60mm tubbie). The power jump was immense.

2 yers later, a bigger turbo came...and another one this year.

 

Single is different, and certainly not so daily usable than BPU ... but I would never go back.

Link to comment
Share on other sites

In my case it couldn't have been more dissimilar! I ran in TTC mode for a few years before doing the single install and the difference was night and day.

 

My stock turbos running in parallel were VERY laggy, under 3.5K rpm there was very little (the ECU was mapped to suit), in comparison the GT35R came in at just over 2K rpm and pulled hard and fast to the redline. When I initially fitted the GT35R for the first week or so I was constantly hitting the rev limiter as I wasn't use to how responsive the thing was and wasn't changing gear quick enough.

 

Give me a medium frame (62mm-67mm), double ball bearing turbo over the stock turbos everytime, there is no comparison.

 

this is the kind of setups I'm talking about, fast response low lag single setups. Make very good power, good response and if kept sensible can be just as refined and reliable as they came out the factory.

Link to comment
Share on other sites

this is the kind of setups I'm talking about, fast response low lag single setups. Make very good power, good response and if kept sensible can be just as refined and reliable as they came out the factory.

 

Full spec and dyno graph in my garage if interested Tim.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.