the-jewish-rx8

i have been going back and forth on what to buy (when i get enuf money) should i get a turbo or a supercharger? what are the prices of each? what are the prices of instillation? what are the hp gains?

guy321

Save up around 5k, then start looking. It's really too early right now to weigh options. If you have money now you have 2 options, both are turbo.

Fanman

No current Supercharger application out for the car yet. Pettit Racing & Blitz have working prototypes on cars right now, but no "For Sale" SC's yet. Both claim about 50 hp gains & about $5000 (not final) for the Pettit Hi-Boost version, & $7000 for Blitz.

For the turbo the Greddy kit has been out for a few months now. Several people on the board have it. List price is $4200, but street price seem aabout $2900. Proven 60-65 whp gain. SSR/Speed Force Racing is coming out with their kit shortly, claims of 100+ whp, but the kits retail is $5500 WITHOUT air/fuel management. They have been offering an "introductory" special price of $5000 for the kit. After all is said & done expect to drop about $6000+ on this kit.

the-jewish-rx8

what are the instillation prices but thanks that was some really great info

Fanman

$1000-$1500 depending on how clean you want the work, i.e. blow off valves, gauges, etc.

WestCoastFun

Although there is no supercharger available yet for the 8, I can speak to them in general. I supercharged my 01 Miata and loved it.
The biggest thing to consider is your driving style. In spite of all the arguments that tend to come from likes and dislikes I am a firm believer that throttle response is superior in a supercharged car vs a turbocharged car.
If you are looking for the highest horsepower boost go to a turbo. If you love the fast throttle response when coming out of corners etc then I am sure that you would be happier waiting for a supercharger.
In short a supercharger will feel more like dropping in a more powerful engine.

IZoomZoomI

I would recommend supercharger if you're looking for more stoplight to stoplight power. It's a little more practical for a street car, not to mention they're mostly carb legal. Turbo would probably give you more peak hp in this specific application, but good luck on getting it to be carb legal.

Rotoman

I like the superchargers to, but what I'am seeing from the current vendors about to release the SC is at about 7,000-7,300 rpm's the has peaked , that's great for a piston engine but the Rotary loves the 5,000-9,000 rpm range and I don't want to give up that extra 2,000rpm (approx.) It's like defeating the purpose of having a Rotary, Otherwise I would love the Supercharger.....

Fanman

In this case I wouldn't be too sure about the SC giving you more throttle response. My Greddy Turbo gives me nice tq starting as low as 2000-2500 rpm. In this case maybe because of the size of the turbo I get almost immediate response from the turbo, & if anything I think it tapers off a bit at the end. Seems more characteristics of an SC. But I'm not complaining I love the increased torque I have now (low/mid range).

Rotoman

Hey fanman, you say ( it seems to taper off at top end) is your boost the same throughout or does it drop off..

Fanman

My boost like most greddy kits (are supposed to do) tapers off at 5 psi at max revs (7 psi through the rev range, to 5 psi at peak), or my case 4 psi (need to take my car in to tune the system as I am only running 6 psi/4psi). This was supposedly done because they could not source a colder plug (which my car has). You can feel that the tq seems to plateau around 7000-7500 RPM. I'm bringing in my car to tune & throwing in a few other goodies so that I will be turning up my boost. I will try to get 9 across the board (ultimate goal). But the charateristics of the Greddy turbo kit are almost roots SC like in that boost is available at right above idle.

Rotoman

I like the fact that your saying, your not feeling any lag that's very good.. I don't like the fact you say, your boost is dropping... But I think with the Greddy E0-1 would help smooth out that boost problem. And by the way I here Greddy is about to release a new version of their E-Manage unit and it will have much more control, I here pricing will be about 600-700 range, That's more then the current 300-400 range, But should be much, much better..

Fanman

That is part of the proper functioning of the kit. The kit was made to run 7 psi across the rev range, & taper off to 5 psi at redline. That was Greddy being conservative & preventing detonation. That being said I will have a boost controller installed & mess with the Greddy EManage map (I have gotten the support tool), & a few other things to hopefully get to 9 psi across the board.

SAFD1450

I contacted Blitz by email and I was told

First Email:
"Hello,

Thank you for your interest in our company. We greatly appreciate it. We have had the RX-8 kit for awhile now. Special order only.

Regards,
Info@Blitz-na.com

Blitz North America, Inc.
626-839-8350
626-839-8340 fax
www.blitz-na.com"

Second email:
"All that we know at this moment for the kit is about a 40hp gain but we are making a better tuned fuel management system so we are expecting a little more horsepower gain. On our Scion xA supercharger we made a extra 10-15 horsepower with the new ecu fuel management system. Thank you for your time."

Final email:
"Estimated around $4500-$5000"

So there you have it Blitz is done and they are selling it but not much info and I think the AFM needs a little tuning

IZoomZoomI

hmm, wonder whats included with there kit. Not saying much at least that 4500-5000 is including fuel management :p. I would rather wait for petitts kit to be release. But I don't think a lot of people are going to bite on this one when then can buy a turbo for half the price with better gains. I think the only thing going for this kit is that switch that would allow you to adjust the level of power.

the-jewish-rx8

well i like the sound of a turbo better because it gives more hp and the greddy kit sounds good and its alot cheaper than a super

WestCoastFun

I can only speak to the Miata... having driven both supercharger and turbocharger, I felt the throttle response was noticably nicer on the supercharger. Could be different with a rotary - although I don't know why it would be.

WestCoastFun

The Turbo's are often less expensive to purchase, but much more involved to install. If like me, you are paying someone to install, the supercharger could work out to be a better deal than it may first appear to be.

Fanman

This isn't necessarily the case. It really depends on the turbo that you install. Generally speaking if you have a big turbo, you have more mid-& high range power but you have more lag on the bottom end. If you have a smaller turbo (like the one on the Greddy kit) you get good/fast spool up but the increase on the top end is more limited. Now, if Greddy had gone to a 20G (for example) we would have had more power on the top end, but boost lag would have been more noticeable. The turbo that you tested on the Miata may have been a larger unit, hence more lag. The unit on the RX8 delivers very good hp & tq. from just off idle.

A good example/explanation of this is the 93-95 FD cars. The original twin sequential setup had a smaller turbo for low to midrange power & a 2nd, larger turbo for mid to high range power.

Nemesis8

iTrader: (3)

I'm going to be the brother that went Supercharger one day! :D

I'm looking to modify my purchase so I can make use of both the Racing Beat Ram Air Ducted Intake and Feed Equal Length Runner Exhaust Headers. That should help me with more flow and HP first, then I'll add the blower to the mix. But this will take place late summer or this winter. I want to see Richard Pauls finished axial flow SC. So for now it's intake and headers!

the-jewish-rx8

i was wondering what my 0-60 would be around with the greddy kit

the-jewish-rx8

also unrealated to this thread is it possible to one day be able to put in an aftermarket rotary thats bigger i know u can put in a lighter one

StealthFox

mostly likely a 13bt from an FC. or a 13b-REW would be awesome as those engines have been known to tune up out 750hp with single large turbo units(even though not realistic...its possible)

Nemesis8

iTrader: (3)

The Renesis can take 13B-REW rotors. RE Amemiya is going to try this next with their turbo test mule in Japan. They want to lower the compression of the engine before the turbo is added.

the-jewish-rx8

still wondering what my 0-60 would be with a greddy turbo kit