A lofty goal with a strut type suspension.   
         The weight distribution may require a re design  of nearly the whole car.   As for the rear, I would remove all the rear suspension, struts and all then start with a clean sheet approach.  The MR2 design was not purpose built for drag racing.  The suspension you want will have to be.  Most likely an equal length upper and lower control arm set up so there will be no camber change with wheel travel.  Being a parrellelagram  between the upper and lower control arms will not create a change in toe with wheel travel either.   Placing the control arms at a angle similar to the Viper might be a good place to start your initial lay out for anti-squat.
         Frankly having the majority of the weight over the rear tires is good for launch.  That puts you ahead of the weight transfer game and will give more grip at the instant the tree goes green.      IMO I would leave the weight distribution alone and use aerodynamic aids to keep the nose down and in control at 140+   Air dam with a splitter mounted as low to the track surface as possible would create some help.
      I am assuming you are going to install a cage  and gut the car to its bare essentials for weight reduction to even be a contender for the record, Right?  What record are you trying to beat?   What engine size engine does that class allow? Are you going to boost or are you going all motor?
         Good luck with that.     Records are not records because they are easy to beat.   Records are the target all racers aim at.!

Last edited by tyrellracing (1/29/2012 6:50 pm)

Good suggestions and many things I've already considered. I should've given more info on my car and about the state of mr2 drag racing to begin with. My car's previous best was a 10.85 @ 132mph 1.61 60-ft with full interior and a cage and radio making 557whp on a 2.0 liter @ 26 psi., but the power band was weak and the suspension setup was crude at best. The current record is set at 9.66 @ 144mph pulling 1.43 60-fts with the rear tires making only 20-40 more whp than me on 8.5" tires still with most of the front interior and street driven. I am currently building a 2.2 with a state of the art billet wheel, triple ceramic ball bearing,  twin scroll turbo system. Power will not be the problem. Although I'm not currently competing, If I ever were to, the class I'd fit in requires the use and non modification of all stock mounting points. So struts it is. I will be using a majority of the same suspension components as my competition this time around. It is essentially a set of tubular control arms (trailing arm and lateral control arm) that intersect by solidly bolting together with heims at the chassis points. I can't do a complete redesign of the suspension, only improvements on angles with relocation brackets, lengths, spacers, etc.
These are the Hux Racing arms I plan to use. The long arm is the trailing arm and the short arm is the lower control arm. They are factory dimensions.
http://a7.sphotos.ak.fbcdn.net/hphotos-ak-snc7/387569_166842410078214_100002573682094_278615_732000085_n.jpg
This is an image of the stock suspension
http://www.mr2turbo.info/pics/rearsuspension.html
This was my idea so far...
http://i785.photobucket.com/albums/yy138/fobangn/scan0001.jpg

I thought if I spaced the lower ball joint I could get more anti-squat angle on the trailing arm and if I spaced the subframe down or made a drop bracket for the inboard joint of the LCA, I could lower the car to the point of having the LCA level so that with a small amount of starting negative camber it would go positive to 0 when the rear was loaded and squatting a bit because of the dynamic of strut suspension going to positive once the LCA start moving upward at the outboard joint.
my car...
http://www.dragtimes.com/images/6344-1993-Toyota-MR2.jpg
http://www.youtube.com/watch?v=YoEgRxvpwwA
my competition...
http://www.jwracing-fab.com/forum/viewtopic.php?p=342&sid=f8b3ed0384995faf1a8293798545f901
http://www.youtube.com/watch?v=uUtSUApuuNo
http://www.youtube.com/watch?v=hmSF3LsShLg&feature=related

it should be noted that mr2s have very little problems with traction at the start. The problem is down track stability especially with gear changes. The rear weight distribution makes the car like trying to throw an arrow backwards. A short arrow in the case of an MR2. I'm trying to achieve a forward weight ratio by relocating the fuel cell, water cell, electronics, battery, etc. to the front trunk area even if I have to add weight ballasts.

Ralphy,
the alignment specs change depending on the years 91-92 are different the 93+. Mine is a 93. 93's also had a longer tie rod for more stability and less drop throttle over steer problems that caused so many 91-92 cars to get wrecked. The 8-9-10 on the diagram is the inner and outer tie rods and the turnbuckle for adjustment. The examples that I gave were of the lower control arm #3 and the trailing arm #4. My drawing is more reminiscant of the factory style pieces how the trailing arm intersects the LCA through a bushing.
This is a better image of the tubular setup that I will be using.
http://i207.photobucket.com/albums/bb248/MR2_Josh/ed163047.jpg

This is a picture of a lowered Mr2 from the rear . You can see how the tie rods and the LCAs aren't going to be moving in parrallel arcs through the travel. It seems like that needs to be corrected to keep there from being any toe changes. I think the factory intended to increase rear toe under certain conditions, but I'm not sure what exactly.
http://i207.photobucket.com/albums/bb248/MR2_Josh/7fda38be.jpg

Yea If your locked into the factory suspension lay out,  You will have to do a lot of trial end error testing to find the sweet spot that creates "0" camber and as close to zero toe at launch.  Ralphy is right  about the struts as well,  You need to get the best adjustable struts you can afford.  They will be taking a far greater load than any strut engineer ever thought the little car would  see.  If you have small diameter shaft type struts, you will have their flex involved in your suspension soup of undesirable traits.  The larger diameter shaft in your strut s, the less it will bend and become sticky under load.   With the horse power  you are making combined with racing slicks I am shocked you are able to keep transaxle's  together.  It would be very interesting to mount a camera under the car and film the rear suspensions flexing and distortion of the bushings under launch mode.  I think it might be revealing as well as a tuning aide.   If the rules allow, I would start by replacing all the soft rubber bushings with either urethane or anything with a higher durometer than oem rubber.  Soft bushings are difficult to tune with because they can sometimes be unpredictable .  They will always distort but seldom in the  same way or amount twice..

tyrellracing wrote:

Yea If your locked into the factory suspension lay out,  You will have to do a lot of trial end error testing to find the sweet spot that creates "0" camber and as close to zero toe at launch.  Ralphy is right  about the struts as well,  You need to get the best adjustable struts you can afford.  They will be taking a far greater load than any strut engineer ever thought the little car would  see.  If you have small diameter shaft type struts, you will have their flex involved in your suspension soup of undesirable traits.  The larger diameter shaft in your strut s, the less it will bend and become sticky under load.   With the horse power  you are making combined with racing slicks I am shocked you are able to keep transaxle's  together.  It would be very interesting to mount a camera under the car and film the rear suspensions flexing and distortion of the bushings under launch mode.  I think it might be revealing as well as a tuning aide.   If the rules allow, I would start by replacing all the soft rubber bushings with either urethane or anything with a higher durometer than oem rubber.  Soft bushings are difficult to tune with because they can sometimes be unpredictable .  They will always distort but seldom in the  same way or amount twice..

There is a lot that can be done within the confines of the factory layout by changing angles with spacers/relocating brackets etc. like changing toe/camber curves through travel. That's what I'm trying to figure out. The Mr2's were designed to have all kinda of toe changes under different cornering conditions to force understeer so they could reduce the amount of normal joe schmoes from wrecking their cars. I want 0 toe changes during squatting at launch or accell at shift points and during diving at shift points.
Here is the previous record holder. You can see how squirlley his car is. It's scary. This is what I'm trying to avoid. Getting traction at the line is easy, it's keeping from playing pin ball with the walls down track that is difficult.
http://www.youtube.com/watch?v=P6fB73OAwko&feature=results_main&playnext=1&list=PL749048DBE9390975

I will be using all solid heims everywhere. I don't have to worry about bushing deflection. As far as strength goes. The factory E153 transmission is indestructable. The fastest mr2 in the world has run a completely stock transmission and factory axles with upgraded CV cages for 4 years while tripping the 60ft beem with his back tires to a 1.4. I have the same setup. It's a combination of wheel hop and radials that seem to be the only thing that will break something. Slicks absorb the impact when they wrap up and I have all solid heims and solid chromoly motor mounts to keep things from hopping.

Last edited by Wolfenstein (2/03/2012 6:37 am)

Thats a damn good thing Toyota engineered the transaxel to withstand  the turbo engine you built.  I am still trying to find a affordable Tremec 5 spd for my stang.  The 408 I have breaks T5's like twigs and the top loader doesn't have a fifth gear.         A must with today's gas prices. 
         
       Good call on the heims,    That's the route I took with all my suspension linkages.      Most people shy away from them due to their lack of dust boots and how fast the non self lubricating heims can wear when exposed to road grit and grime.. 
    The issue with change in toe really can be narrowed down to avoiding toe out.     Toe in makes the tires push towards each other which tends to be a sum what stable condition.  However toe out is another thing entirely.  That will make the rear feel really  twitchy.     Since this will occur  with each gear change, in a 9 second car that would be down right   f...ng scary.      I am sure the MR2 rear can be adjusted to reduce toe out.   Do you know any one that owns an alignment rack with a  lazer alignment  computer?  If they can be bribed,   they could be very helpful right now.    The nice thing about this kind of device is you can watch what changes you make do to the alignment instantly.   You just cycle the suspension with out springs and the alignment heads zeroed in while watching the viewing screen.  Obviously the weight has to be supported by stands.    It is the simplest way to make a tough analyzing job into a no brainer.
   
       Just out of curiosity:
        Was your MR2 a factory turbo car?       I am guessing that to be able to use 26lb's boost with out detonating the mill you are not using a  Toyota  ECU.      If not  what brand controller are you using?  How big of injectors  what size T-body?    What type turbo, bearing type,compressor inlet size, a/r ratios , inter cooler type and size, and vehicle wet weight?   I have no intent of anything more than to see whats required to push the 2.0l to that level of out put.
            I have built,     turbo, Roots and Lysholm  super charged engines and only a few were stout enough to be boosted  to 25-27 lb's and that was dependent  on the inter coolers efficiency.     At that level of boost  the MSD ignition just could not make a hot enough spark to light the fire.   Back then it was a brick wall I could not get past.    If you are going to a higher boost ,   What are you using for a ignition?        It has been my experience that with the HP you are producing from a 16 valve DOHC 2.0l you are pushing the envelope to the limit.    Do you have a lap top interface to adjust your timing and fuel curve for the track conditions?
     
         I like how the record holder has his fuel cell in the passenger seat position for weight distribution,   or a lack of any where else to put it.   SCCA would never allow that little mod.  Rules demand an air tight  fire wall between the fuel tank and the driver.   No exceptions.

       You did not mention a posi in the trans axle. I don't  know if they came in any models.  I would have thought you would have a quaif or some method of limited slip for the carrier's equalization of the tire speeds.  Being transverse it has no left or right bias unless the half shafts are un equal length.  If you have no limited slip then you are doing pretty damn good on your rear weight distribution.

        Last of all
      With the stiff suspension approach you would need properly adjusted SPRUNG wheely bars set to allow the front tires aprox. 10 inches on the launch and shifts then maintain 3" of air  to smooth out the transitions.   That is if the rules allow such things.   You would  avoid the losses the guys on youtube could not.   My sand rail has a simple coil over built into the upper link of the wheely ski that allowed me to remain hooked in a wheel stand with the front wheels 12 in. above the track .   Then the trick is to power shift as fast as I could to keep the front aloft.   I was able to do that with practice.  By the time  I stopped racing  I had the lapse between shifts down to three feet.  When rails race on the sand its mandatory to groom the track after each run.   Its easy to see where the power lets off on sand by the tracks going from trench to paddle to trench every shift.    The reason I gave it up was I could no longer afford to buy a core Subaru transaxel to rebuild after each race.     First gear was the weak link and Mendeola's cost  between 15K and30K   That is the trans axel   Factory five has in their mid engine car.    Ralphy posted a image of the transaxel in the after market design thread.

Last edited by tyrellracing (2/04/2012 2:44 am)

tyrellracing wrote:

The issue with change in toe really can be narrowed down to avoiding toe out.     Toe in makes the tires push towards each other which tends to be a sum what stable condition.  However toe out is another thing entirely.  That will make the rear feel really  twitchy.     Since this will occur  with each gear change, in a 9 second car that would be down right   f...ng scary.      I am sure the MR2 rear can be adjusted to reduce toe out.   Do you know any one that owns an alignment rack with a  lazer alignment  computer?  If they can be bribed,   they could be very helpful right now.    The nice thing about this kind of device is you can watch what changes you make do to the alignment instantly.   You just cycle the suspension with out springs and the alignment heads zeroed in while watching the viewing screen.  Obviously the weight has to be supported by stands.    It is the simplest way to make a tough analyzing job into a no brainer.

I have access to an alignment rack at the school where my friend is an instructor. It's not laser, but it'll do the job. I want to get all of the toe changes out to limit friction, but if I have to have some at different times, I'll make sure it only toes inward. Yeah, toe out is scary.
   
     

tyrellracing wrote:

Just out of curiosity:
        Was your MR2 a factory turbo car?       I am guessing that to be able to use 26lb's boost with out detonating the mill you are not using a  Toyota  ECU.      If not  what brand controller are you using?  How big of injectors  what size T-body?    What type turbo, bearing type,compressor inlet size, a/r ratios , inter cooler type and size, and vehicle wet weight?   I have no intent of anything more than to see whats required to push the 2.0l to that level of out put.
            I have built,     turbo, Roots and Lysholm  super charged engines and only a few were stout enough to be boosted  to 25-27 lb's and that was dependent  on the inter coolers efficiency.     At that level of boost  the MSD ignition just could not make a hot enough spark to light the fire.   Back then it was a brick wall I could not get past.    If you are going to a higher boost ,   What are you using for a ignition?        It has been my experience that with the HP you are producing from a 16 valve DOHC 2.0l you are pushing the envelope to the limit.    Do you have a lap top interface to adjust your timing and fuel curve for the track conditions?

the new setup will consist of
Accell DFI stand alone laptop interface, 2000 cc injectors (for e85, the last motor used 960cc on 118 leaded), 80 mm oem infinity Q45 throttle body, Comp Turbo 62mm triple ceramic ball bearing billet cold wheel twin scroll T4 .84 ar 65mm hot wheel. (previous turbo was a simple 67mm journal bearing .82 t4 single scroll), Ice water filled air to water intercooler, MSD 6AL with blaster ss coil. I'm nowhere near the limit as people have made 1300whp+ and ran as much as 60+ lbs of boost on the same block and head. One of the biggest things people over look is gapping the plugs down. A lot of boost will blow out the spark even with a good ignition. My gap is in the 0.020's
       

tyrellracing wrote:

I like how the record holder has his fuel cell in the passenger seat position for weight distribution,   or a lack of any where else to put it.   SCCA would never allow that little mod.  Rules demand an air tight  fire wall between the fuel tank and the driver.   No exceptions.

       You did not mention a posi in the trans axle. I don't  know if they came in any models.  I would have thought you would have a quaif or some method of limited slip for the carrier's equalization of the tire speeds.  Being transverse it has no left or right bias unless the half shafts are un equal length.  If you have no limited slip then you are doing pretty damn good on your rear weight distribution.

That's just the water cell for his air to water intercooler. His fuel cell is is in the trunk behind the motor. My fuel and my water cell are both in the front trunk area for better weight ratio. That way when I crash, the water will put out the fire LOL. Stock, they have a viscous LSD, the record holder had a spool.

That sounds a lot safer.  I use to use a air to water heat exchanger that I would fill the system reservoir with ice then top off with water before each run. 
  As far as the alignment rack,  If you have a change in mind you can make temporary pivots or even hold the pivot point while experimenting and cycle the suspension to confirm weather or not the idea is sound.  If you stumble onto a reasonable geometry then you take notes as to the point location.   Fabricate  the strong version check and set alignment.  then,  head to the track and try to set records of your own.
   I was assuming you were using a stock Toyota block that has been built to the current level with forged pistons, h-beam rods, turbo oriented cams. and so on.   
In the end you have a car you can drive to work come monday morning.  Most of the Drag cars at the level of the Scion running Lenco's either have blocks filled to the top with epoxy or are whittled from billet and never had coolant passages at all.   Engines at this level can only be ran for short periods  and are not streetable.   This is the price paid to eliminate cylinder rupture from ultra high cylinder pressure created by high boost.   In your case if you can still drive your car to the track then you still have coolant in your block.  You will find that you can only push the cylinder walls so far until you rupture a cast iron cylinder from ext ream cylinder pressures.  That is what I ment by pushing the envelope. 
  Years ago I was faced with this same limit so I bored the cylinders out until I hit the coolant jacket. Then I made 4340  cylinder sleeves with a .250 wall that were hydraulically pressed in with loc tight green.  Similar to Darton MID sleeve system with a flange at the top and a step with o-rings at the bottom.   This proved to be as bullet proof as I could hope for in a factory cast Iron block.
     I always removed all the weight I could for street racing.  Electrical systems dont weigh very much.  I just didnt see any reason to pack around interior panel's or a  seat no one sat in.  The only glass was the windshield and rear view mirror.  Every thing else was Lexan.  Side windows had no regulators but were held up with nylon straps with snaps.  To raise window you pulled the strap then snapped it to the bottom of the door.  This was in a 72 240 Z with a 383 chevy that did 8's all the time and could dip into 7's every now and then.
     As for your engine:
  The ability to support the HP through superior bottom end components is pretty much down to a science.  The only limitation is where the stock toyota castings are used.
     Looks like you have built a fun little GO toy!     Good luck with breaking the record!   keep it as safe as possible.
    PS
    What did you mean by "twin motor"?    Eight cylinder Sport compact?
    That's cool your MR2 has a Viscous type limited slip.  I have ran spools on the street and they are very  hard on drivetrane parts like CV's

Damn thats squeezing the piss out of those little engines.  I am impressed that Toyota has high enough nickle content in their cast iron to make a significant difference.  I have witnessed 22re burst cylinders, as well as a few 240 Z blocks come apart which is probably ancient history but 25 lb's boost is still 25 lb's boost.  If detnation is avoided then it is purely up to the casting to retain the force of combustion.    Sounds like you could be a contender.   By your description you have the right equipment and a damn fine turbo.   Kudo's
     I have worked with Accell DFI before,  Good hardware!  I prefer FAST's hardware primarily because of their software and customer support. FAST has the same level of quality with Accell in fact they are near equal in most aspects except price.
       I have been rebuilding turbos for years. I have hundreds of cores that I rebuild when I have a customer with a deposit.   For small engines I mainly have Air Research  T-3 , T-4's,  hybrids and a few IHI's.   I have about a dozen new T-4 ball bearing cartrages. None of them are triple bearing race units.   but the lion share of what I rebuild are for semi's and big engine applications.They consist of  Holset ,Rotomaster's and AR's I have a friend who does my balancing for me. 
        I am shocked that people are getting 1000 hp from 2.0l engines.    My personal best was just shy of 2000 hp from a SBC bow tie block that was bored 4.060" over and used a bryant 4340 billet crank to provide a 3.8" stroke making 393.56 cid that  ran up to 27 lbs boost  from two rotomasters and river water to air inter coolers in a tunnel hull mini hydro boat I use to own.  Most boats dont fly,  This one did!

A buddy of mine who use to build turbos just called it quits due to a messy divorce. He is the guy who did my balancing so I am trying to scrape up the money to buy the balance machine  he just put up for sale.    He gave me two totes (3 feet cubed) of turbo cores.  roughly 100 or so,  Many of them Holset's.   I just hauled them home this morning.  I dont know what I have yet so give me a day or two to get a inventory taken of this  acquisition.  I am pretty sure I have a new Rayjay that would be close to your spec's.   Since all of the Holsets I have are for diesels, the exhaust turbines would be too big in relation to the compressor for gas engine use..  Most big diesels use exhaust turbine size alone to control boost.    I usually mix and match smaller exhaust turbines to go on a given compressor and make a hi bread.  This only works when I can find the right a/r ratio and size exhaust housing in the same series as the compressor.    This can sometimes be tough.  That is the only way it can make the boost desired for a high performance gas engine.  Even so, The combo would have to be balanced before I would even think of selling it as a runner.   Just to let you know,   I dont have any Holset turbine housings with built in waste gates.  I am assuming that your friend uses a divorced waste gate and would not want a crappy all in one housing any way.  They do a piss poor job of boost control.

I'm looking for an hx35 just like the ones that came on the later Dodge cummins. I'm not sure how big the compressors are, probably around 52-57mm. Holset goes by centimeters when  it comes to their exhaust housing terminology instead of A/R. I think they came in 9cm 12cm 16cm and maybe bigger. For reference I believe that the 9cm is a bit larger than the equivalent of a .63 a/r. Now that I think about it, a 9cm housing would probably be better for him. The real hot setup is an HX40/35 hybrid.

before you do too much leg work, let me get in touch with my friend and see what kind of money he wants to spend. He knows more about the specs he wants on the turbo as well. Apparently there are a few different variations on those turbos and I think he was looking for something kinda specific.