I was wondering if anyone on the boards has run any of the eaton series superchargers on there e28? Im looking at a few but dont know what would be best for my application. Im not going to be buying this setup for quite some time "waiting for college this summer" before I start on it.
I was looking at the older m90's, the ones without the GM 3.8 lower intake mani bolt-up but rather the older ones without that.
Also I do have a newer MSD ignition "not sure on the model" but I know its not the fuel economical one. Dont know if this helps.
Also would I have to make the supercharger mounts or is there someone on the boards that knows how to make some quality mounts?
1) Older Eatons are not the path to power. Twin screw/Lysholm technology is where it's at for supercharged street cars. Roots blowers are for diesels and Top Fuel classes that don't allow the twin screw.
2) As a supercharger fan, it pains me to say this - go turbo with this car. There's way more support and experience. Going the supercharger route will mean going it alone and, not meaning to be rude, you don't appear to have the experience or skill set to do that. Having said that - patience, perserverance, tenacity and a willingness to re-do things may result in a successful supercharger install, but it's going to be an incredibly steep learning curve that would thwart most people.
3) At a minimum, find Corky Bell's "Supercharged" book and study it to death. There are errors in it but the basic science is sound.
4) Read and study every technical document, write-up, post, textbook, SAE paper (that aren't barely-disguised ads) you can find.
The thing is though. The only reason I wanted to go with a supercharged setup is it looks cleaner and more organized than a turbo'ed setup and theres no lag.
Takedownrcm wrote:The thing is though. The only reason I wanted to go with a supercharged setup is it looks cleaner and more organized than a turbo'ed setup and theres no lag.
I would argue the point that a SC is inherently cleaner than a turbo setup. Either one properly designed should be very clean and well packaged. Also, as Corky says, "if you have no lag, you have no turbo." A small amount of lag is very acceptable. Have you driven a turbo car with a properly sized turbo? There is even a very real possibility that the turbo may make more boost at a lower rpm than a roots SC. The torque curves of each type of engine are very differently shaped and each suits people differently so make your choice accordingly.
There is no free lunch with forced induction. Supercharger systems can be designed to produce instant power but at the cost of efficiency. The same amount of boost produced by a turbocharger will make more power.
turbodan wrote:The same amount of boost produced by a turbocharger will make more power.
Especially on a true roots unit. Just take the compressor maps for instance. Below is the 5th gen Eaton M90 plot, which is the best version of that blower. Earlier units had far worse efficiencies.
The best it can do is a small window of 62% adiabatic efficiency.
Now, lets compare that to a GT35 compressor wheel.
The worst spot on that map is still better than the best efficiency the M90 can offer. The peak here is a nice meaty 79%. That's a big difference and is due to the M90's lack of an internal compression ratio. This is why a twin screw can achieve much higher efficiencies.
For example look at this TS map. It achieves 75% and is much better at higher pressure ratios than a roots.
Takedownrcm wrote:Hmmm... Well now I guess I have to save up for a turbo setup. Could you guys help guide me once I get started and have the cash on hand?
Dont rely too much on the board. We've had at least the one good thread recently about what happens when someone doesn't fully understand what they're doing when they attempt to turbocharge thier e28. The best course of action in the mean time is to read everything you can on the subject. Educate yourself on things like ignition timing, fuel systems, general turbocharging. Good places to go other than the archives on this forum are homemadeturbo.com and turbobygarrett.com.
I agree with Dan. Make sure to read as much as you can and actually understand what is going on with the many facets of turbocharging. The turbo FAQ here is a decent resource but also check out the books and links that are referenced within it. There is so much information on the web and in books about turbocharging, it should not be difficult to source good information.
Scottinva wrote:Tuning without a wideband o2 sensor, is like tuning blind.
Sure, if you've never jetted a carb before. Its not that hard. A wideband will help if you have no idea, but its not essential.
I'd guess that the OP in this case doesn't know much of anything about carb tuning. I know more than a lot of people today, and even at that it's not a whole lot.
Scottinva wrote:Tuning without a wideband o2 sensor, is like tuning blind.
Sure, if you've never jetted a carb before. Its not that hard. A wideband will help if you have no idea, but its not essential.
Dan,
My first turbo e28 was never tuned using a wideband. This was prior to Innovate offering them at an affordable price. It went years at high boost without blowing up. Even went 109mph non intercooled.
The only other way, is if you were to use like an SAF-C on a stock ecu, so you wearn't the one truely making the fuel table. The car I daily drive is carbed, I do understand it to a point. I think the wideband is something extremely recommended for tuning non the less. I have tuned my low load range of MS using simply map and other inputs, and I don't have a wideband (it failed me again). So to a certain point tuning is possible I guess.
I tuned my 240sx's PowerFC ECU without a wideband. Ripping off a 292hp pull with a wideband I found my fueling was at worst 5% off. With that being said, I'd much rather have on to tune with.
Do you guys know where I could pick up a wideband o2 sensor? Still looking threw some sites trying to find one but dont know exactly what company/model I should be looking into.
That's probably the minimum of what you need. If you don't plan on using something with datalogging abilities (like Megasquirt), the I recommend something like an LM-1/LM-2 or a TechEdge product that allows multichannel logging with a speed input in addition to the wideband input.
LC-1 = best money I ever spent on a car. I simply don't have the time to beat around the bush by ear and feel, let alone the consequences. Too bad they don't have something like this for women.
