v8 240 suspension questions

[qwarnon]

alright i have a few questions about suspension for my project. its a s13 coupe from 93. Im swapping in a 355 gen 1 chevy small block.

now i know thats going to add around 150lbs or so upfront... basically my questions are

A) should i go for coilovers? (if so i would go for some cheapish ones.. megan is what i was looking it)

B) if not would shocks and springs do the job just as well? KYB and eibach or tien or something along those lines

C) what kind of spring rates should i be looking for here. i know the stock rates for a 240.. im just wondering what i should be looking for with the added weight.

i plan to use the car for occasional runs down the drag strip..but i am not looking for insane times here.. im just going to run it for fun and some occasional track day stuff. i'm just looking for some descent handling really. this car wont be a "daily driver" i guess but it will be on the streets more than the track. however comfort is not a big issue. im more concered with performance than ride quality and definetly more than looks.

thanks for all your help in advance,
chris

[Massimo Power]

I would suggest megan.. they arent that bad when it comes to their coilovers. i would also suggest to upgrade the front springs to around 10k just to support that extra weight...

Springs and shocks are all made for the car with its only specific motors.. handling would be comprimised..

Coilovers you would be able to adjust it to help you make the car do what you need..

good luck..!

[blu808]

Well just so you know you cant have a suspension that is good at everything.

You can find a happy medium, like something that is tolerable on the streets, and does well at the road course, or something that is great on the street and is tolerable on the road course.

If you want to drag race you will need a completely different setup.

I dont think you should be as concerned with finding the correct spring rate, because any spring rate that would be optimum for traction and handling will be too stiff for the street to be comfortable.

I would be more worried about the weight balance, and the cars tendancy to understeer, and rotate. With that said you will want to do whatever you can to balance the car. If you have a set of aluminum heads, intake manifold, and aftermarket headers then you can get within 50 lbs or so of the ls1's weight. Thats if your using a t5 to make up for some more weight as well.

If you are using a combo like that, then I think a set of 8/10 kg coilovers would work fine. I would also suggest to run some front tension rods to attain a good amount of caster, which will also move the weight balance rearward.

Other than that just shave weight on the front. Swiss cheese the front crash bar, ditch the AC, condenser, etc.


Luke

ps. The KA is heavy. You will be around 100lbs lighter in the front with a correct ls1 swap over the ka in factory trim.

[TUnity2]

i would suggest swapping an LS series aluminum block motor. that way you actually lose weight instead of gaining it with more efficient power.

[qwarnon]

well.. im using the gen 1 small block not the ls1. and im using an old 4spd tranny. a built super T-10.
the motor is already 90% built and its what i want to use.
but thanks luke for the excellent response. my original choice was the 10k/8k megan tracks. i think thats what ill go for.

im mainly looking for barely tolerable on the street but good on the track and in spirited driving.

i dont plan on much dragging.. just some for fun at a local raceway.. they have sportsman races just for fun sometimes. i just didnt want something so stiff in the rear that i cant put down any traction.

any more input is apprieciated

[racer98]

alright i have a few questions about suspension for my project. its a s13 coupe from 93. Im swapping in a 355 gen 1 chevy small block.

now i know thats going to add some serious weight upfront... basically my questions are

A) should i go for coilovers? (if so i would go for some cheapish ones.. megan, k-sport something like that)

B) if not would shocks and springs do the job just as well? KYB and eibach or tien or something along those lines

C) what kind of spring rates should i be looking for here. i know the stock rates for a 240.. im just wondering what i should be looking for with the added weight.

i plan to use the car for occasional runs down the drag strip.. and some occasional autox or scca stuff. but it will also be a daily driver.. im more concered with performance than ride quality and definetly more than looks.

thanks for all your help in advance,
chris

need to get the car corner weighed and make the adj you need from there.

[g6civcx]

now i know thats going to add some serious weight upfront...

What is "serious" weight? It all depends on your mounts. I disagree with your premise so your questions are hard to answer.

There are few v8 240s that are daily driveable so you won't get much more than speculation.

I will assume arguendo that your premise is correct for the purposes of answering your questions.




A) should i go for coilovers? (if so i would go for some cheapish ones.. megan, k-sport something like that)

B) if not would shocks and springs do the job just as well? KYB and eibach or tien or something along those lines

C) what kind of spring rates should i be looking for here. i know the stock rates for a 240.. im just wondering what i should be looking for with the added weight.

i plan to use the car for occasional runs down the drag strip.. and some occasional autox or scca stuff. but it will also be a daily driver.. im more concered with performance than ride quality and definetly more than looks.



That's a tall order. You're not going to get everything you want even if you throw out comfort.

For street driving, I want to throw out all coilovers except for Megan due to price. I think Megan Street would serve you well for the most part.

[chitosdr]

I am using kyb agx/ eibach pro kit with my ls1/t56 combo. It handles fine, just need to add the sway bars back on. Very comfortable on the street, and just low enough here in DC. BTW its a s14.

[qwarnon]

ok i edited my original post to change my goals a little bit. those were fairly unrealistic.

and ive done a little more research on the weight.. i think i should be looking at only a 150 lb weight gain or so.. with the battery relocation and other things as well as my light tranny i may be looking at less.

anyway im thinking about megan track coilovers. i may see if i can get a 10k front with an 8k rear though.

[FloridaRacing]

well.. im using the gen 1 small block not the ls1. and im using an old 4spd tranny. a built super T-10.
the motor is already 90% built and its what i want to use.
but thanks luke for the excellent response. my original choice was the 10k/8k megan tracks. i think thats what ill go for.

im mainly looking for barely tolerable on the street but good on the track and in spirited driving.

i dont plan on much dragging.. just some for fun at a local raceway.. they have sportsman races just for fun sometimes. i just didnt want something so stiff in the rear that i cant put down any traction.

any more input is apprieciated


4 speed is a bad idea. 4th is probably 1:1 which means with the 4.08 rear gear on a 240 you will be turning 4500-5000rpm at interstate speeds.

[qwarnon]

yes 4th is 1:1 i will end up with an aftermarket lsd rear in the end. and ill be going with a different gearing (probably between 3.25-3.75 depending on whats available. that part im not worried about.

[FloridaRacing]

why do all that instead of just buying a 5 speed?

[qwarnon]

i was going to go with a t-5 but i dont believe they can handle much torque. i havent seen many other descent options. besides even with the stock rear end im going to be at about 3900rpm at 70

[g6civcx]

i was going to go with a t-5 but i dont believe they can handle much torque

Search my threads if you want to see my opinion. You probably found the same thing I did. Only Camaro 2.95 1st gear T5s are worth anything. Everything else is weak.

I putting 315 ft-lbs to the wheels on that T5 and so far I'm ok. I guess it depends on how you drive and maintain your stuff.

I have to seriously consider if I want to keep the T5 when I go to the 383 which should put down over 450 ft-lbs.

How much torque are you looking to put down?

i havent seen many other descent options.

Probably the only option you have is a T56 or aftermarket, but = $$$.

besides even with the stock rear end im going to be at about 3900rpm at 70

On which gearbox?

[SoSideways]

3900rpm for a motor that only revs to like 6000rpm, or if you built it for high revs, 7000rpm or 8000rpm.

But on a V8.

First gen SBC no less.

That's a lot of fuel.

[g6civcx]

First gen SBC no less.

That's a lot of fuel.

You need to lean out your carb on cruise mode, but I'd rather take a few mpgs drop than detonation.

[jmauld]

ok i edited my original post to change my goals a little bit. those were fairly unrealistic.


Your goals aren't unrealistic.

You can get a great handling car and still keep it civil on the street. The extra weight you're adding up front isn't going to make that large of a difference. You're looking at 75lbs per tire at most. Which in the grand scheme of things, is nothing, especially if you're not an experienced racer/autocrosser.

The first thing to do is get rid of the idea of the JDM coilovers. Instead look at getting a set of Koni or Bilstein shocks. Then get a set of GC (or similar) coilover sleeves and use ~350-400lb springs up front and ~250-300lb springs in the rear. Get a big front bar* and leave the factory bar in the rear. You'll need to avoid upgrading the rear bar due to the amount of power you're going to have. A big rear bar is going to make it more difficult to put power down.

You can't slam the car with this setup, but you should be able to easily lower it 1.5-2" with the mods you can do to get additional shock travel.

*Tanabe or Largus are the two that I would look at.


P.S. Any of you SBC guys interested in a Super T-10, with a Tex Racing tail housing? It has the W gearset, and a hurst super shifter.

[qwarnon]

thats what ive got the super t-10. it wont be "daily driven" but it will be on the streets.. MPG is no concern for me. the life of the motor is though and spinning a 6500-7000 rpm motor at 4000 for an hour or 2 is a little rough on it.

anyway thanks for all the help. i think im going to be switching up the rear end or gears to a taller ratio (3.15 from a pathfinder i believe)

[jmauld]

anyway thanks for all the help. i think im going to be switching up the rear end or gears to a taller ratio (3.55 from a pathfinder i believe)

The automatic 350z has a 3.3 if that 3.55 isn't tall enough. I don't know if it will fit.

[qwarnon]

oops its accually a 3.15 that was a typo.

[jmauld]

thats what ive got the super t-10. it wont be "daily driven" but it will be on the streets.. MPG is no concern for me. the life of the motor is though and spinning a 6500-7000 rpm motor at 4000 for an hour or 2 is a little rough on it.

anyway thanks for all the help. i think im going to be switching up the rear end or gears to a taller ratio (3.15 from a pathfinder i believe)

Do you already have the T10 in the car? If so, can you take some pictures of how you have the shifter setup? I bailed on my T10 because I didn't think there was going to be room to mount that offset shifter.


I didn't know the Pathfinder came with a 3.15. That should actually work fairly well with the T10. Cruising at 65 will put you at 2800rpm, a little lower if you can get some big tires in there.

What 1st gear ratio are you using? If I used that 3.15, I could hit 60mph in 1st. :D

[qwarnon]

i'll have to go look at the numbers again. its obviously a 1:1 final drive which was my main concern.. i forgot what gearset it was.. maybe the "W" set. ill look later on today.

i dont have it in yet.... i hadn't thought a lot about that offset shifter.. i could possibly use a bent shifter to center it more.. i dont know has anyone else done it?

btw what tranny are you using?

[g6civcx]

has anyone else done it?

btw what tranny are you using?

T5 with the offset shifter. Had to cut another hole.

[jmauld]

i'll have to go look at the numbers again. its obviously a 1:1 final drive which was my main concern.. i forgot what gearset it was.. maybe the "W" set. ill look later on today.

i dont have it in yet.... i hadn't thought a lot about that offset shifter.. i could possibly use a bent shifter to center it more.. i dont know has anyone else done it?

btw what tranny are you using?

Yeah, a bent shifter would be simple to move the shift point over. My concern is the actual space that the shifter assembly takes up sitting over to the side.

I don't have mine installed yet. I've got a T10 and a T56, I just have to decide which one that I want to use. You would think the obvious choice is the T56, but when you see the two side by side, that tiny T10 looks awfully appealing.

[qwarnon]

yeah the t-10 is really small and light. id like to have the 6spd.. but its huge .. and pretty complicated lol. i like the t-10's simplicity... and i got it cheap

[g6civcx]

With the stock 195/60-15 and 4.083 diff, 1:1 top gear = 3250RPM @ 55mph, 3800RPM @ 65mph.

[qwarnon]

yeah i have 17" wheels with lo profile tires.. so a 24.5" tire height but im going to go with the pathfinder rearend i believe

[FloridaRacing]

i was going to go with a t-5 but i dont believe they can handle much torque. i havent seen many other descent options. besides even with the stock rear end im going to be at about 3900rpm at 70

TKO 600 or T56, all in the $1500ish new mark. Will handle 600+ FTTQ

[jmauld]

TKO 600 or T56, all in the $1500ish new mark. Will handle 600+ FTTQ


Link please!!!

[qwarnon]

yes both of those handle alot of torque.. but are quite costly (i have seen them higher than $1500) and quite heavy and a small pain to install. the t-56 anyway

[g6civcx]

yes both of those handle alot of torque.. but are quite costly (i have seen them higher than $1500) and quite heavy and a small pain to install. the t-56 anyway

When you're putting out over 700 ft-lbs at the crank, you don't really have a choice ;)

[qwarnon]

that would be the truth lol.. thats gotta be one crazy 240. btw thanks for all ur help in my other threads