Dealing with extra horsepower and torque

[SynthDesign]

I've spent the last year building and tweeking a heavily modded and built tercel and have come to many points of frustrations. So far the car is tuned and 2wd dyno'd to 84HP with 92ftlbs of torque @5600rpm's and getting an average of 24mpg.
See post http://www.tercel4wd.com/forums/viewtop ... f=6&t=4934
The 4AGE swap is still in process and I gotta be prepared to prep another rig.


Yesterday, I happened to see Petros in my neighborhood and got him to take a look as well. He concurred a few things as well as pointed out a few others. I think it's time to ask for more help.

At this point my main issues are how to deal with an UP'd HP range and high amount of toque.

The problem: Under heavy acceleration and deceleration, the engine and trans jump violently. Enough to make a few loud clunks. One being the 4wd lever slamming into the tunnel. Over the past two months, I've replaced almost everything on the front end or anything possibly allowing movement and haven't been able to correct it. I thought it my be a front Dif but Petros dismissed it. The vehicle has a little over 2k miles since restoration.

So far I've destroyed:
3x used trans mounts, now replaced with a new Toyota unit.
1 set of barely used left and right reman'd CV axle, new reman'd units installed now.
1 carrier bearing(used) replaced with with New KOYO bearing and balanced driveline.
1 New engine dampener, replaced with used unit and springs till other fix.

So far I've replaced
New ball joints, tie rod ends and rack freshly serviced.
Installed new T4WD Toyota engine mounts, swapped to AE86 Toyota mounts.
New Toyota swaybar and tie end bushings.
Front struts have been completely serviced with new parts.
Both hubs are new up front with silky smooth new bearings.

Through this process I've been able to tune out a lot of the engine movement and noise but I still feel I have much more movement than a stock operating T4WD. Also much more torque. Is this my main problem? Overpowering?

Petros noted that my custom 2" exhaust will hit the frame when we where exploring it. I have about and inch of clearance otherwise. This tells me that I'm still getting more than an inch of movement from the trans and engine. He also saw that it looks like my sway bar tie ends may have loosened up too. Tomorrow I'll go back through the front end, but fear I won't find the problem

Anyone have any ideas or maybe something I've missed?

I'm thinkin I may swap back to stock new T4WD engine mounts, but fill the spaces with urethane. Maybe do the same with the trans mount.
Maybe another engine dampener to prevent engine lift tied to the strut tower?
Could this all be caused by weak stock engine dampeners?

I'll shot a video later this weekend to give you guys a better idea of what's happening.

[takza]

Do what the hotrodders do...add some chains? Figure where the engine is lifting and add a length of chain with some slack.

[danzo]

Jeez it must be such a drag having all that extra hp strewn about cluttering up the place . I would follow takza's advice and be like the big hp boyz - in general (no pun) do whatever it takes to keep the driveline from moving. Of course the extreme example of this would be solid mounts/no movement at all, but that would make for a very harsh driver. I've seen many dedicated autox cars go this route, but of course the owners don't have to live with it for 80 miles every day. Five miles a month not a biggie.

The trick is getting your desired balance between harshness and driveability, but I'm sure you realise this. It's difficult to make suggestions without seeing the car in person. If your exhaust is made of aluminized piping you can heat/lower it fairly easily to get more clearance. It's not too difficut to see what's hitting what, but if in doubt just spray some paint on suspected surfaces to clarify. Maybe fab up a solid engine dampner?

It's almost strange you're having problems like this, it's not like your motor is putting out 200hp. Look at the bright side! Good luck and keep us posted.

[ARCHINSTL]

While I'm hardly qualified to run with the bulls at Pamplona like some (most) of you guys do with T4WD mods...after the installation of the three new and OE mounts (whether Windoweld-modded or not), my first inclination would be to make a really stiff engine damper along the lines of the one I did - and if that helps, maybe even another one toward the back of the motor.
Tom M.

[SynthDesign]

I've thought about the chain limiter idea used in drag cars and it seems so like such overkill. Plus I think it would just add another clank and stress the frame or engine more. I spoke a bit today with a fellow at Energy Suspension and he recommended installing a new vertical dampener and adding a horizontal dampener along the top of the engine to a strut tower. He also recommended trying polyurethane bushings and maybe a dampener mounted to the trans horizontally to the tunnel or undercarriage as well.

@Danzo, It truly has been a horrible drag. In over 5 months I've barely put on a 1,000 miles due to things constantly breaking. The feeling of an unsafe car you've spent a over a year and thousands of $$$ building has been quite a downer. Especially since it's my only running vehicle since my MR2 threw a rod last month.

I've been pretty impressed with how the trans and clutch hold the power. I feel like all this needs to get sorted out as I'm a few months away from installing a 4A-GE in a silver 85 SR5 and I'll be looking at bit more hp but less torque at the low end. The same platform should work for that setup hopefully, but i need to get it all sorted and ordered soon.

Thx for all your thoughts and ideas!

[Petros]

I want to add my own observations: while in 2wd I stood on the brakes and in first and reverse, engine reving, I jabbed the clutch out and in while watching the engine. The engine of course moved some, tilted forward in reverse, and back in first. But it did not look excessive to me. In revese gear we got a "clunk" somewhere in the area of the tail shaft of the trans. Possible from the exhaust pipe, or the drive shaft area (remember it was not in 4wd).

When Snyth did the same thing while I watched: the most noticeable thing was the wheels moved either forward or reverse what looked excessively. But watching the front suspension it appears all of the movement came from the normal rubber parts flexing. And all of these are new. I saw no movement in the ball joints or steering linkage at all.

It appears to me two things are in order: stiffer engine mounts, stiffer front suspenion rubber parts. Toyota always choose to make the ride soft and quiet compared to other imports (one reason I suspect they were popular with American drivers), so it appears just going "factory" is too soft for all that torque.

Are there any really large engine mounts (from a larger engine Toyota perhaps, like the v6 truck) that might bolt into the Tercel mount? IF not you might have to adapt something else, or make your own. Engine mount failures are not unusual when you do engine swaps or get more power out of the stock engine, so this just might be expected with a car that already had soft engine and suspension mounts. You might also add several of Tom's home made engine mount dampers on both sides of the engine, or something similar. I would not go with solid mounts on a daily driver, they will cause not just noise and vibration, but also fatigue cracking of the mounts and cross members. We just needs stronger/stiffer rubbers ones.

The largest culprit in the suspension I suspect is the sway bar to lateral strut mount. The sway bar forms a tension/compression bar to locate the front wheels in the fore and aft direction, and they use large rubber donuts to locate it. This is a really bad way to locate a wheel, every car that I have owned that used such a method always felt imprecise and vague. On my T4wd, I cut extra rubber washers from 1/4" sheet rubber (a piece of tire might also work) and put them in with the doughnuts to compress them and make them stiff.

The rwd Ford truck front suspension uses such a method on the radios rod (they go backwards from the hub, and mount at the frame with large rubber donuts). Our one-ton Ford van was impossible to control when towing a trailer, I replace most of the front rubber with viton bushings, with little help. There is an inexpensive kit to replace the Ford truck radios rod donuts with a plastic ball and cup (about $18 each side from NAPA), it transformed the van to being safe and pleasant as a tow vehicle (Ford really blew it, and they needed to fix this problem 30 years ago). This I think might be worth exploring to adapt to our sway bar mount at the lower arm. Ideally we should junk the whole factory sway bar, go with a tension rod like on the rwd Corolla or MR2 front suspetion, and use a separte anti-sway bar. But that means major changes and new parts fab.

Snyth, try the nylon ball and cup designed for the Ford truck front radios rod mount. IT might take some modifications to the plastic ball and cup, but it should not be too difficult to adapt. Get to a NAPA store and take a look at one, they always have them in stock.

[takza]

The largest culprit in the suspension I suspect is the sway bar to lateral strut mount. The sway bar forms a tension/compression bar to locate the front wheels in the fore and aft direction, and they use large rubber donuts to locate it. This is a really bad way to locate a wheel, every car that I have owned that used such a method always felt imprecise and vague. On my T4wd, I cut extra rubber washers from 1/4" sheet rubber (a piece of tire might also work) and put them in with the doughnuts to compress them and make them stiff.

If you look at the control arm where the swaybar mounts...you see that you already have a ball/socket setup...just need to replace the rubber with polyurethane lubed with axle grease. But you also need to allow some lengthwise flex in this part so you don't put too much sideways stress on the threaded bar end.

Maybe some polyu roller skate wheels that you could turn down and shape on a drill if needed? Then some soft rubber spacers on both sides to allow some flex...MAIN THING is to make these small enough in diameter that they won't hit the control arm when the suspension is either extended UP or DOWN at it's extreme.

Problem being that the polyu won't flex any...which puts a bind on the control arm end when the suspension travels up and down?

[SynthDesign]

Spent the last few hours checking through the front end. Every thing was tight. There's a bit of deflection but nothing compared to my roommates well running 86 SR5. I re-adjusted the exhaust so it has close to two inches of clearance and went for a drive. I eliminated the exhaust flex clunk, one down, but still have all the other noises and play to deal with.
I think Pertros is right along the lines of a lot of rubber bushing movement and Takza has a great idea about making new bushings. Looks like most skate wheels start around 72 durometer and got up to 120, so there's a bit of range to play with. Adding a radial bearing to each end of the sway bar might help with any binding issues.

Another thought is that the lift might of changed the output shaft angle on the diff's mount, so when the engine is lifted under rpm, the drive shaft u-joints bind and make noise. What would the easiest way to test this theory? Just remove the back half of the driveshaft?

[takza]

When you lift it...you change the angles for everything....when they design cars I'd guess they account for all angles...drives and suspension...carefully. Not that it's not fixable....I'd try making an engine shock absorber using the threaded rod and some rubber bumpers to allow just a small amount of movement.

Of course this is advice from someone who has only seen the shock absorber one time when I decided to see if I had one.... At times I've driven the crap out of my wagon offroad and in 2WD, but have noticed no slop issues...and that's with 260K on it. Using my 25 to 60 mph timing test I got around a 20% gain in "power" from changing the timing...meaning going from 62 hp to 74 hp...in theory. Recently I found my toe was way off...but not in the direction you'd expect...it was toed IN...and as far as I can tell it only got that way from enthusiastic acceleration in first gear over rough ground in 2WD.

[Barto]

Sorry I did not have time to read all of this but have you lowered the engine since the suspension lift? Those 5/8' shims I put in mine made almost all of the noises you speak of go away. If nothing else have a look at the bottom of the unibody where the motor cross member bolts in and see if it has indented upward at all. Mine was like that so the 5/8" plates acted as a super beefy washer/load distributer. Making everything there alot stronger. Then I jacked up the motor with it all bolted in to tighten up the mounts and welded a piece of chain in tight. That way when you relax the mount there is still some movement but it is caught by the chain before it gets bad. I also had the idea of running a large fabric Strap of some sort like a semitruck tie down. under the bell housing area of the trans. and up to the Fire wall something not hard mounted but hard mounted if you know what I mean. Hope that might help sorry for the horrible typing im in a rush lol

[Petros]

I have been thinking about this some more, and part of your problem is the angles the lift has put on the cv and U-joints. As Barto recommends, you need to lower the engine with fairly large shims under the cross member to reduce the angles somewhat. You also might run the maximum positive camber on your front wheels. This will tilt the wheel hub upwards towards the trans giving you another degree or two less angle as the front cv joints. You could go past the factory specs Camber angle of course but your tires will wear more on the outside shoulder, this might affect hard surface traction and stopping distance some too. Of course, the reason you are lifting it is to get more ground clearance, so you loose some of the advantage of the lift when you shim down the cross member.

Also, you have to either find a strut with longer travel, or lift the car by spacing the strut downward to allow the strut to rest near the center of its travel. That way you avoid topping out the struts when the suspension extends downward and damaging your the strut seals.

On the rear axle you need to get or make some adjustable upper trailing links and adjust them so the front of the differential tilts upward to reduce the angle on the rear u-joint. They make these adjustable links for use on the rwd Corolla GTS with TRD hard rubber bushings, they should fit in the Tercel. It would not be hard to make the existing upper links adjustable if you have a welder handy.

Here is a web site that sells MR2 bushing kits, in the image at the link, I suspect the ones listed as 6 (rear track control arm bushing) should be almost identical to the front Tercel sway bar to radius arm bushing:

http://store.powerflexusa.com/mr2-1991- ... s-p67.aspx

As an aside, it appears the first gen MR2 lower ball joint and the front upper strut mount are interchangeable with the Tercel, so if you can find these in a performance upgrade for the MR2, they should work in the Tercel as well.

Check out these radius arm bushings for Ford trucks, these might be too large for our cars, but I am sure we can find something similar for a smaller vehicle:



http://www.carparts.com/details/Ford/E- ... 2681190509

Or this Thermoplastic radius arm bushing kit, notice the ball and cup kind of pivot:



http://www.carparts.com/details/Mevotec ... Suspension

[Barto]

I forgot to ask if you run a strut spacer I run a 2 or 3 inch I can't remember but it puts everything back where it should be.

[takza]

What I was trying to say in my last post is they design a car as a unit...you lift one a lot and everything is "out of center" and far as loads...torque... etc. Probably why Toyota backed out of the special offroad version of the T4WD? Easiest fix is to lower it again?

[SynthDesign]

Sorry got sick and wasn't able to shoot video this weekend. Been holdin down food and hoping to get back in the shop soon.

@Barto, No spacres on the strut tops nor the engine crossmember.

I have a crossmember bolt set for a corolla which are an inch longer. I think I'm gonna try Barto's recommendation. I haven't had much topout issues since I swapped to the Corolla All-trac springs. They ride much firmer and I've been pretty gentle on the car recently.

@Petros, The AW11 mr2 bushing bits are pretty different but I haven't looked the the SW20 bits yet. I'll talk with Josh from Nix99 and see if he has something handy for me to look at. He's quite versed. Pics if possible

So if the spacers solve the clunking noise, them most of the noise is from the CV axle position Correct? That would explain why it happens during engine lift/drop. Would it make sense to make the engine crossmemebr spacers out of block Aluminum and just drill two holes instead of using 4 spacers?

I also found out Jeggs supposedly sells kevlar engine straps, which sound better than chain if it comes to that.

I did a bit of searching for after market engine dampeners and it seems 99%of them use elastomers which to me, is outdated materials. This makes the home brew spring option sound better. Really, I'd like fluid dampened.

[Barto]

Would it make sense to make the engine crossmemebr spacers out of block Aluminum and just drill two holes instead of using 4 spacers?

.

I used some 5/8's x2 1/8 Aluminum flat bar that I had left over from my welding/fab Days. drilled two holes and If i remember correctly they were about 8" long. I realized that there are no pics of the strut spacer I used. It was crafted out of cutting boards from walmart stacked up to make 2" then sandwiched with new grade 8 hardware. They have never loosened off and are not sketchy at all. The mechanic who did the alignment was blown away at how close it was to stock after doing all of the lift. Camber bolts were the only ones that were out of adjustment and only 5* of change was needed.

Hope that helps. Mine still has a small vibe from the front left CV shaft under hard acceleration on left had turns. But I have yet to see a tercel that does not have the same vibe all 4 of mine have done this with old worn out CV'S and new remans. If you could find new old stock CV's I bet they would be a lot better seeing as they don't come off of the shelf with new boots and 100,000 miles on them.

Good Luck I have not been on here much but will try to check back to see if I can Help

Cheers Bart