Force Fed RACE 4A (blown 94 GZE)

[GUN METAL]

I need some help with what to do with my SEIZED supercharger.

Sorry but your going to need a bit of history first.

The beloved AW11 has just had a large chuck of money spent on it in the last 12 months. The whole idea was to set it up as a fun car to take on the track to do hill climbs and supersprints once a month and for the short drive to work a couple of times a week.

When i purchased the car it allready had a very low k AE101 GZE transplant with pleanty of goodies including Motec M4 bigger valves, ported , cams, extractors, 175 pulley etc etc and was making a healthy 140 kw at the wheels. Only prob was on the track the IC was heat soaking, inlet temps skyrocket and motec finally shuts down the fun at 85 degrees C.

So an ST205 intercooler set up has been plumbed in to overcome this problem.

So it was on the dyno getting a retune when the SC seized

The SC was in top condition was always making 13 PSI, wasnt noisey oil always checked / changed (minamal usage). Unfortunately i still dont know exactly why it seized.

So what i need some help with is choosing another blower for my application, keeping in mind the track punishment it will get (and i want it reliable and tractible), so

WHO HAS TRACK RACED FORCE FED 4A ???

heres some of the ideas i have:

OPTION 1 Put back an SC12, getting an AE101 SC is next to impossible let alone getting any SC12 in decent condition. Some people say that overdriving them this much kills em pretty quick, obviously on a track (mainly supersprints so 4-5 laps FLAT OUT) puts a much bigger demand on them than on the road. i dont really want to run less boost but this is the lowest cost option until i have to replace it again.

OPTION 2 Get an SC14, decent ones in pleantiful supply and seem in better nick. Probs are the associated mods to make it fit and what sort of boost it will make and the associated extra costs involved. Plus if it were set up to run 13 PSI presumably to make similar power would it ultimately suffer the same death as the SC12 (presuming it had just had enough rather than something being sucked into it ?????)

OPTION 3 Aftermarket SC ? There are a few out there but i have heard of HEAPS of probs with them and dont know anyone that has put one in a race car.

OPTION 4 Turbo ? I always had in the back of my mind that if the SC failed then it would be time to turbo. The reason why its last on the list is because i love the tractibilty and the drivability of the SC (i am very much the novice on the track), not to mention the sound and the just to be different factor.

But at the end of the day more people seem to know more about turbos and say if its selcted correctly will be just as drivable and make more power than the SC and be more reliable ? Its just that the turbo 4As i have been in just havent impressed me and there has been some pretty hi powered ones in that lot.

So if the consensus is that an SC12 or 14 is living on borrowed time making 140 kw on the track what turbo should i use keeping in mind its got to make good torque from at least 3 grand and be reliable on the track using the factory AE101 GZE bottom end. If it ends up making 150 -160 kw with a flat torque curve like the SC i will be happy.

Any words of wisdon experiences or thoughts appreciated

[30psi 4agte]

It wasnt an over tight belt (trying to stop slip at 13 psi) that caused the SC to fail ???


Anyhow i would want to uprade at this point if this happened to me. Just how far/ big of an upgrade only you can decide.

I like the idea if the SC14 . It will give you a little more hp and isnt too much of a "major" upgrade. Plus wont cost you as much as going turbo.

A correctly sized turbo will provide great down low power and beable to match the low end power of the SC plus have the topend to put the SC away. It will however cost you anywhere from $1000 - 2000 to do.
( turbo + manifold + modifying exhaust + oil drain in sump + reworking cooler pipes etc etc)

If cost and time permit id go turbo...... but the SC14 sounds like it will be your best option.


IN the end its your decision

[ToySprinta]

Sprinterboy has done a SC14 conversion, look up his members ride, lots of pics and info.

Also somewhere on this forum, there is a fellah from the US selling screw-type chargers for the 4a. On his car it made approx 200rwkw at 20psi ( i think). will have to search for this one too...

I have gone turbo, but only cos of budget. I have been hillclimbing, circuiting and drifting for the past year and a half. Seized one SC but that was due to me not tightening the sump plug properly. Other than that has been pretty reliable, except for an appetite for belts.
Also i found it to strangle the engine a bit higher in the rev range. So at eastern creek and wakefield, it was great through the corners, but felt really wheezy on the straight.

[GUN METAL]

Thanks for the reply, was the belt too tight.......dont know ? maybe but it was that tension for like 2 years and never had any probs, but by the same token i never had and belt slip issues which seem to be the bane of many SC owners.


you obviosly have a bit of turbo experience what turbo you suggest for my application and what max PSI on the track with a stock bottom end ?

you got any links to some of your work please and make model / prices for:

inlet manifold

turbo

Exh manifold

Boost controller


A few people have said about and s15 turbo what you think ?

[MWP]

Was the SC12 running with an oversized pulley?
Maybe the continuous work on the track had the SC turning too fast for too long and cooked it?

Have you got room to fit in a centrifugal supercharger like a Vortech?
Itll be better for track work than a roots style.

[GUN METAL]

Yep it was overdriven to the MAX, and its certainly likely, thats what i am trying to esablish with some feedback from similar users

Maybe it was coocked but i thought they lost boost if they were cooked BEFORE they seized ?

Its running a 175 Nevo and because its the AE101 it also has the smaller SC pulley .

Oh plus because it has some bigger cams valves etc etc it loves to rev unlike the stock SCc so it was happy to rev to 8 grand.

On the track tho because of its great mid range as well was usually only revving it to 6500 maybe hold it to 7 but mostly between 3-6 grand is where it spent most of its time.

I know a bit about the vortech i know someone who has one on thier M3 makes like 250 kw at the wheels.......easy.....then BANG !!!!!. It certainly crossed my mind but like i said all aftermarket SC i dont know anyone with the experience

[oldcorollas]

look into twin screws.
expensive but...
takes less power to drive them,
can get higher pressure ratios (can order whatever pressure ratio you want),
doesn't choke or overheat the air at high rpm,
does make heat at idle tho, due to internal compression...

you can ask Ron, but he may not be able to answer too many questions otuside of "buy my kit"... which might be a very good option anyway

[dandan]

Go grab another sc12 (cheap) for now, have some fun with the car and then plan the turbo conversion properly whilst the car's still running.

[TooF]

i think before you go looking at new blowers you need to loko at WHY and HOW the current one failed. they dont fail bang overnight without some good reason, they usually melt off the coating and stop producing proper boost as opposed to siezing.

before you go looking for blowers that one needs to come off to be investigated.

[Joshstix]

Just buy Koffee's turbo kit and get a decent dump pipe made up for it.

A S15 turbo should be nice and tractable and make 170-180rwkw on your setup. You should be able to run some pretty decent boost with the water to air cooler even for full on track sessions as long as there is enough thermal mass in the water system.

[deviant]

Agree with TooF....I doubt an SC would just instantly seize like that. You need to get yours off and pulled down...maybe something got left in a pipe somewhere that made its way in and jammed it up, as mentioned before maybe the guys working on it did the nice thing of stuffing rags in your pipework to stop a foreign body entering the system but then forgot about said rag?

Obviously you need to be planning ahead slightly incase it really is fubared....in which case for cost and ease of getting you back on the road/track quickly I would find an SC12 or 2. Put new bearings and seals in where you can and run with that for the time being.
Hopefully that will last you the rest of the season until the wallet recovers and then go for the turbo set up....I think a turbo might be easier than an SC14 to do???

[Ben Wilson]

Borrow my SC12 and throw it in there while you build up a turbo setup....

[Drifty Midship]

Yeah I agree it is a bit suss that it failed while at the mech's.
But also agree that you were overdriving to the max prolly well past what the SC was designed to spin happily at esp if they were revving it out to 8k+ rpm on the dyno. Good chance it could have failed on it's own.
I would get an older SC12 with the big pulley and just run at a lower boost. not spinning the SC so fast. I think the old SC and the Nevo175 is pretty tried and true combo. Or I got a Nice HKS pulley I'll trade ya back ha ha.
Just stick with the old SC12's they are cheap and easy to change over... just keep blowin' em up and replacing them.

[GUN METAL]

Kids,

Thanks for all the feed back

Sprinterboy so how often do you track yours and how much boost was the SC making ? i assume you are now turbo ? if so what the specs

Old corrolas, Yep done some investigation on the twin screws, certainly more efficient etc. iwas waiting on benjimin getting his up and running to see how it went, but he has had a lot of probs with his and is reverting back to SC12 in the short term.


dandan, its obviously the cheapest option but like you say it should buy me some time for researh. THATS THE MAIN THING I AM TRYING TO ESTABLISH IF WHAT I AM DOING IS SIMPLY GOING TO KILL THEM ON A REGULAR BASIS THATS WHY I AM KEEN TO HEAR WHAT OTHER PEOPLES EXPERIENCE IS WITH THEM OVERDRIVEN ON THE TRACK.

Toof, as per our convo last night i totally agree, well it should be out today so hope to have a better idea then. i can tell you right now if there is something fallen in there i will be out with a baseball bat

Josh, Yep i am seriously considering the s15 route, the mechanic has pretty well reiterated what you say. I may be able to pick up one with an NA intake manifold exh manifold dump oil lines etc etc for 1400. Hey can you send me the details of the enginner who did your car please, before i go turbo i want to know what i am getting myself in for .

my hope is with the current intercooler set up the inlet temps should be stable, that is the heat will be rejected sufficiently so that its not a matter of thermal mass but total heat rejection. There is a 4a tubo clubman running t3 from memory with a W2A IC the ic and radiator are smaller than mine and he did all sorts of endurance races with it all day and the ST205 used this set up extensively so it should / better work. by my calculations the current set up is 100% more efficient than my old system and should be able to reject at least twice the total heat, so it should shyte in a supersprint.

Deviant, yep agree with that as well. the thing is the car has been of the road for so long now (7 weeks) i have misssed 2 rounds of the championship allready (so there goes the championship this year) i want to do it once and do it properly, well at least as to the best of my knowledge and $$$ i am waiting on the mechanic to give me the exact prob with the blower and some prices for the various options.

Ben i really appreciate the offer but i would hate to kill your charger, how much would you sell it for ? toof had offered me his but it needs some work. how much boost was yours running 10 wanst it ? and what do you think about the longevity issue running 13 PSI up to 7000 rpm. also i havnt compared the small port to large port for the intake but would it be possible to make an adaptor and sell the whole of your kit. i am 99% sure mine is small port unles its had ahead swap ???? is there any way of telling externally ?

Drifty, yep the 175 is tried and tru, have no hesitation with the set up on the road but on the track its a totally different story. if you had a look at the data logging from the motec you would know what i mean, temps, throttle position, RPM everything is maxed out, you would be lucky to get that on the road for 30 seconds while on the track in a SS it could be up to 10 mins. Nice HKS pulley HAHAHAAH, GLAD YOU ARE ENJOYING IT well its certainly an option just to whack back on a stock crank pulley, may get a fair bit more life out of it but it will be difficult to take a drop in power. I want to have a look at the weekend what my competition is running so i plan on going out there and do some reasearch if i cant race at least i can do something positive. There is a blown CRX that is cutting some VERY quick times so ultra keen to see how.

so who else is running the SC on the track keen for feed back

[ToySprinta]

Here is the link to Sprinterboys sc14 conv. http://toymods.net/forums/showthread.php?t=855

My SC had a HKS pulley i think, pulled around 11-12psi. BUT my redline is set to 8500rpm.
Last year i hit the track at least once everytwo months, from hillclimbs to drifting to the dutton rally.
As i said, the only problem i had was when i siezed one cos the sump ran dry cos i didn't check the plug....
At the local hillclimb, i normally sit on the limiter, cos it uses too much time changing to 3rd, also 3rd gear sychros are fucked.
Drifting ure sitting at the redline most of the time anyway.
I think its the luck of the draw, ive heard of chargers popping real quick, whereas mine has lastet a year of hard abuse. I did change the oil everytime i changed the engine oil as well.