$250 Chinese turbo crew checking in. $200 used FM log mani, rx7 460's etc. Having more fun than my brakes can handle in HPDE. There is no reason to spend too much for fun.

 

Having just driven the Wootton's car this past weekend in Blytheville, new turbo tech is certainly much better than old tech. They're running whatever the new hot **** Borg-Werner EFR is, and it would run circles around the setup on my old Alltrac.

However, around the really slow corners (~3kish, like you said), it's still night and day. At speed (4k+), the throttle was still pretty much a rheostat to boost. I can definitely give it that. Unfortunately, in autocross, performance around 3k matters a lot, especially in slowass bus stops like they seem to love to put on nationals courses these days. :(

Especially driving around on the street, I love pulling out to pass at 2000 RPMs in 5th gear and having gobs of torque. I would definitely have to downshift to get anything out of even a newer turbo down there.

 

Horsepower for your dollars, nothing will beat a turbo setup, fer sure. The question is, if you're looking for the "right" setup for your wants, and you're willing to pay a bit more for it, what is wanted? I think that question is often looked over.

 

Why are you doing 2k in 5th? How slow is that, I cant remember. I do know that on the wastegate only I hit positive pressures at 45mph in 5th, and it definitely scoots more than the engine did before the turbo went on. I think our cars must be geared drastically differently though. I'm still in boost going through a 17in/12out chicago box (which is under the legal size limit but was in the evo school course).

 

My gears are long -- I'm on the Quaife box. 1st goes to 51, 2nd goes to 75 (at 8k RPMs). 2k in 5th is ~40mph. If I'm cruising around town, I put it in 5th there, since it's quieter and gets better mileage, and I can still accelerate quite well if I need to.

 

I know autocrossers have different needs, but if I am at WOT below 4000 RPM then I'm a dumbass who should have downshifted and everybody is getting my point by on the straightaway.

 

It is different needs, it comes down to, is the time spent downshifting to first, just to spin the tires off the car , then upshifting back to 2nd worth it. Or is it faster to bog for a few tenths. 9 times out of 10 downshifting to 1st wont be worth it because nailing that heel toe short braking zone is damn hard to do when you only have 3 tries to get it right.

 

For a track car I'd go turbo. For track, more power is always better, and you can always get more max power with a turbo than a supercharger (no parasitic loss). If you're below 4000 RPMs there, you either need a closer ratio transmission or you fucked up good.

 

Yeah, I never go below 3rd gear on the track except in the paddock.

 

Ha And I had you longing for more power last weekend. Don't think you're going to get to my 380 rwhp 315 ft-lbs with a supercharged miata motor but I still question weather it is needed for autocross. I think there might have only been two very short points where I could touch full throttle and with over three times the power on tap I could barely out pace well driven CSP car.

On the track is where my car shines. Never lower than 3rd instead of never higher than second is quite a different application.

 

I'm incrementally working my way up there. I have no doubt I can reach those numbers, if it turns out that that power level is useful on course. I was able to fully use first gear in two places on each course this weekend, so I obviously need more power.

 

Damn. I can do that but I dont make enough torque to break 5 speeds, on purpose.

Bundy, you need aero. It was glorious to have a CSP driver be like, "you have twice as much power as I do and in your car I dont have the lift here."

 

1st gear for me only last 15 feet off the start line. rolling at all means second gear. first and second are both fairly traction limited in a straight line.

 

Yeah, I wound out first gear at both the start and the finish on sunday... It goes to 51, it's almost like your second gear.

 

FRT,
Hope you are doing well and still check this thread from time to time. I installed the M45 you sold me. You included a coupler and oil with the unit as it was making some noise on deceleration when I first installed it. I assumed this was the coupler being worn. Well I changed the oil and coupler, the grinding noise on deceleration is still present. I am beginning to think that the unit you sold may have a bad bearing. Were you aware of this when you sold it?

 

Yes I still check this. I did not have any issues with a grinding noise. If the bearing is bad, or beginning to go bad, I had no prior knowledge. According to the manufacture they shouldn't need any major maintenance until after 100k. When I had it on my car it ran fine with no issues.

 

Oh it does run fine and makes about 5.5 pounds of boost as it should, it just a growling kinda noise on low rpm deceleration. Its quiet at idle and only does it under load really.I think its coming from the rear of the blower, but its hard to tell as it only makes the noise under the conditions I described above.

 

So load or deceleration? Because those are the opposite
Are you absolutely sure everything is bolted down and not loose?

 

Very sure everything is bolted down. I generally hear the noise from 3,000 rpm downwards if I'm off the gas and letting the car coast down. The 'rattle' is not present under acceleration that I can hear nor at idle.

 

That is very odd. I would think a bad bearing would be present under most conditions. A rattle that becomes pronounced under certain frequencies seems like more of the issue. It may not be the SC at all. Are you sure something else near/around it isn't loose, or touching something causing a rattle?