Toyota 86 Forced Induction issues... Turbo Charging vs Supercharging My GT86

[pizzaeater]

I have just clicked up 14,000kms on my White GT86 and I am starting to get bored with the power the car has. Sure the car is loads of fun in the twisties, I have Shockworks Coilovers and RE001 tyres, but having owned a BA XR6 Turbo, I'm finding when I hit the accelerator that little underwhelming.

Long story short I want more power, which leaves me to be undecided and leads me to the question Should I go for a down the Supercharger route or the Turbo Route.

Some background information that i've collected over the past few weeks...

Fuel

Fuel seams to be a no brainer in that I will be running E85. High comp turbo will love it.

Engine Management Options

EcuTek Engine Management

This seams to be the most common form of engine management used on the Toyota 86 for Forced induction regardless wether it is a SC or Turbo. The software is fairly expensive and effectively is a license to enable the stock ECU to be reflashed. There is a bunch of cool features like launch control, flat shifting etc and a few guys are running this setup on E85 without issues.

The communication cable is quite exy too, but most installers will refund the $300 odd once the cable is returned to them.

MRT appear to be the Australian distributor for ECU TEK.

Haltech Engine Management

The hatech sports 1000 is also a viable option that has been successfully setup to run the FA20c by a few tuners, but given the re-wiring autoelectrician costs and that I am leaning away from using this option. If a plug in model was available it'd be a different story.

Traditionally when it comes to the ECU I have decided on a tuner and gone with their recommendations, but in this case I think given one is a reflash and the other is a complete rewire it makes a significant difference to the costs associated with it.

Forced Induction Choice

Super Charger

Sprintex Superchargers seams to be the SC of choice and a bolt on kit world wide. On my 4a setup, I found it allot easier to get power out of a turbo charger than the supercharger, but that was only because I was running around 18psi vs the 10psi on the supercharger. Naturally it is quicker given the amount of boost being fed to the engine.

For my GT86, I doubt this would be a significant factor as i would be only running between 8-10psi anyway on the stock engine. The amount of torque the SC12 on my gze gave me was amazing, and not having lag was great also. Though given the high compression ratio of the FA20c I doubt turbo lag would come into it either.

Changing the boost is a new pulley which adds price, but not one that is unreasonable. Nothing really compares to that supercharger whine.

Bullet superchargers in QLD australia are the distributor for the sprintex supercharger.

Turbo Charger

The turbo choices are endless and there are many different manifold options available for the Turbo route. The ability to turn up the boost and get more power (within reason) is great. Turbos are cheap and can be sourced new or second hand easily and come in all shapes and sizes. A TD04 off a wrx or similar sized turbo seams to be a decent choice.

With my 4agze when I converted it to turbo, literally doubled my power output on 18psi from when the supercharger was on. This kinda plays a part in what in my decision making, though it is hard to know if i will goto the effort of rebuilding the engine with lower comp pistons / stronger rods etc.

But being turbo charged it is definately allot easier to up the boost as such than what it is with the supercharger. But is it worth the extra $$$

Workshops to install the Turbo Charger or Supercharger

I've rang a few of the shops around and here is my initial feelings regarding them.

Castle Hill Performance

The first guy i spoke to wasn't sure if he could offer me a turbo installation on my 86. After asking if they had done it before he finally put me through to a guy by the name of Dale.

Drive in / Out Cost: $10,500
Kit: Haltech Platinum 1000 ecu, wiring, turbo, scavenger oil pump,
Warranty: None - It was like I asked if i could sleep with his mother when i mentioned if he would warrant his work. I was told to be prepared to rebuild the engine at some stage as it was a naturually aspirated motor i was installing forced induction onto.
Expected Power Output: I was told around the 200kw mark at the wheels
Experience: They have done 1 car

Gut Feeling : No way would I get them to turbo my car, the one they did blew up within a few weeks of being done. I asked if they had any issues with it and there was a pause and an answer of not on low boost no.

Bullet Superchargers

Drive in / Out Cost: $6,000
Kit: EcuTeck reflash / tune, Sprintex Supercharger
Warranty: None, but they assured me that they have driven their own test car for the past 12 months daily, thrashed it on the dyno and never had an issue with it.
Experience: Have done more than 20 of these kits within Australia.
Expected Output: Around 45% up from standard output.

Gut Feeling: Good price and seam to know what they are doing. Was confident the product is good when the sales rep said he is considering buying the test car as his daily driver.

MRT

Drive in / Out Cost: Turbo - $8,500
Drive in / Out Cost : Super Charger - $7,500
Supercharger Kit: Ecutek reflash / tune, Sprintex Supercharger,
Turbo Charger Kit: Ecutek reflash / tune, front mount cooler, Turbo Charger
Warranty: Said they would warrant the engine if Toyota wouldn't cover it
Experience: >30 - Claim to have assisted with all Ecutek tunes within Australia
Power Increase: At a minium 30kw at the wheel increase

Gut Feeling: Whilst they are the most expensive, they are the only company out of the 3 that i spoke to that are prepared to provide a warranty on a forced induction setup for the Toyota 86. This to me says they know what they are doing, have done it a few times and are confident they won't lunch an engine. I discussed at length the difference between the turbo and supercharger which really left me with more questions rather than answers as to which way to go. Though the answer was pretty evident around 10psi it really won't make a huge difference as to which one I decide.

Though covering the factory warranty does make the extra $1,500 to go with MRT a very sensible decision for the supercharger route or the $2,500 for the turbo charger route.

My Decision

So there you have it I'm torn between supercharging which will definately meet my requirements right now and I'd expect to give me around a 40% increase in power or turbo charging which will yield similar results but make it much easier in the future to extract more power out of it.

Do I make it easier for me to increase the power output long term or do I pick something that will meet my requirements for now.

I am leaning towards the turbo route, having owned the GZE and loving it much more after turbo'ing.

MRT will most likely do the work purely for the warranty reasons unless someone else can recommend a workshop who would also cover it.

[dove grey 64]

Sounds like you'll end up wanting a turbo so just go for that. Mrt have been around for quite some time and I've only heard positives so I'd go with them aswell.good to see you've got your suspension sorted

[Matt]

Looks like you've done some research on this. Changing the boost on a turbo engine is still a headache in that you should retune it. It would be interesting to know what turbo mrt are using and what their kit looks like installed on the car. Supercharger pullies are reasonably priced and easy to change too.

It would be good to know how much boost the sprintx chargers are capable of running.

I am surprised to read that mrt will honour factory warranty on a turbo engine. They must be pretty confident the engine can handle what they are doing. They are massively into evo's and Suby performance work. They also have a good reputation for the quality of work they do, but you pay top dollar for it.

To be fair to castle hill they were running approx 20psi when the engine blew. Which is comparable to running around 40psi on a low comp engine.

[filfilfil]

Im not sure you should consider the extra wow of the ae86 turbo over the gze supercharger difference as a factor since that engine was already designed for boost being low comp and specially stronger. Is it worth asking around to see what a proper boost ready engine package (ie low comp pistons,cams etc) costs as that seems to be where the real WOW figures are being splashed around on the interweb (some of the youtube vids are very impressive!)? Yeah I know its easy for me to spend your money!!! ;-) just saying...worth a question to the tuners?

[Matt]

Watch this video, might help you make up your mind.

[Vance]

dont know why you want more power so early. just drive the balls off the thing.


that said i will be buying a hks s/c kit in the future. but i will also be rebuilding the engine myself for lower comp and more boost.


i would suggest spending the extra money on getting a centrifugal supercharger if youre going to s/c such as a rotrex as they are as efficient as a turbo and can get as much power as a turbo without the lag.

if you are going turbo get a variable geometry turbo made by holset. spool up faster than any other turbo and do not require a wastegate as boost is regulated internally.


personally i prefer superchargers as they rev up quicker and rev down quicker than a turbo, and have better throttle response.

[Konakid]

Don't lower compression, compression is a good thing! Just run E85 to compensate. I would go turbo. 10psi.

[SamsTA22]

The guy in that video is talking about the advantages and disadvantages of a centrifugal supercharger, whilst showing what a roots supercharger looks like...

Luckily, it looks like sprintex only make twin-screw superchargers. A T-S supercharger would be far better to drive than a turbo (Open to opinion, I guess), and suit the engine bay better than the ridiculous plumbing a turbo would require in the cramped engine bay.

[Matt]

Nice build thread

[johl]

that build thread was a great read