how to get beter tq?

[corey240]

whats a good way to get reliabel torque on an sr? i dont plan on massive hp numbers, i wana keep it between 280-350 later on. but i want my tq up there nice with the hp, i dont want 350 hp and like 260 tq. what mods could get that there? i would have exhaust, fmi, 300 maf, injectors, havnt decided on turbo because im gathering info on best one to get equal tq and hp numbers, possibly cams if it will help the tq number get up there.

[Deadrodent]

4.36 or 4.4:1 rear end from a 180sx/skyline and a nice clutch to transfer the power

[DuckyD]

Keep the stock intake manifold. Aftermarket manifolds (like the Greddy) use shorter runners which result in less torque (like a 10% drop in torque, but 10% gain in horsepower). Go with a small and responsive turbo like a GT28RS or GT2871R in .64 a/r. That should put you 300hp / 330hp respectively, with equal amounts of torque.

It's also in the tuning.

[AmoebAssassin]

Increase boost pressure.

Boost pressure increase = torque increase.Compressor flow rate increase = power increase.

I always see these SRs making 350whp and 275 lb-ft. It's because nobody knows how to properly size a turbo. Buying a GIANT turbo an boosting 10lbs to make 350whp gets you nowhere. You will not have the combustion force to make proper torque numbers on low boost.

[corey240]

this is all in an s14 btw, as in. s13 redtop in s14 if its any difference. il also have greddy profec bspec 2. so basicaly, proper size turbo, stock intake mani....

now i want this to be so i can have good tq all the way through the power band. what i mean is i want this car to be responsive from the start all the way through a nice smokey drift or a down the quarter mile, or out of a road course turn. i dont want to have to wait a year for spool up and tq, i want instant tq so the car is as fast from the start as it is in say 4th gear at 6k. exageration but you know what i mean. im trying to get this a a good search reference for future people and my own knowledge. thanks for the help so far.

[DrifterProdigy85]

Large turbo, Stock Intake Manifold.

[vutony]

aluminum driveshaftunorthodox underdrive pulleybigger tbarc or s15 smicsplitfire ignition system

[corey240]

old thread but would the tomei throttle body help? i was reading the modified mag with silvia tech (older one) and they swape din an s14 srdet but swaped in the s14 sr rwd de (not det) throttle body because its bigger. if i have to get the size i will go check through the mag pile and find it. what about exhaust manifold? keep it stock? slight port/polish it? or would it be ok to use like a megan or ssac reinforced? i just want the bling of an aftermarket but if it would help that much more to use stock i could deal with it.

[doridori23]

aluminum driveshaftunorthodox underdrive pulleybigger tbarc or s15 smicsplitfire ignition system

Did you just recommend a Side mount intercooler? slap yourself please

Seriously though the SR is an inline motor which will produce wonderful amounts of torque when selecting the proper turbo/power mods. The easiest thing in the world to do is just look at other setups and see what they are running. For your application the best setup would be the Garret GT2871R(S) with .64 ar. This will produce 325-375 hp and 325-350 torque with the supporting mods. you can play around with diff cam combos to alter the hp/torque numbers but Brian Crow 264/264 with a set of springs, retainers and RAS (Rocker Arm Stoppers), Front Mount Intercooler (GReddy M Spec is a great deal and flows great for your needs), with 550+ injectors and either a fuel computer or reflashed ecu is all you need to make nice numbers. I would recommend the GReddy Emanage Ultimate as the program is easy to run, reflash as you upgrade free (DIY) and you can eliminate that stupid maf.

[doridori23]

I forgot to mention your TB! The SR20de came with a 60mm Throttle body but our SR20deT came with a 50mm for some unknown reason. The Tomei wi a wonderful unit and its simplicity will actually make your life easier as you can remove some items but you will have to mess with the TPS, IACV, cables/brackets etc etc. An easier and stealthy move is to get a hold of a tb from a SR20de. I have used Ebay in the past but i would recomend going to a junkyard and looking for some older sentra's. Just so you know the last one we did was from Ebay (already picked the local yards clean of atleast 15 sentras ) and we did not need to swap out the TPS or anything as it was from a SR20de equiped Silvia. This was by far the easiest install and you can notice a bit of a diff at 3000 rpm and up. Cheap and since its already dirty looks stock.
Modified by doridori23 at 11:58 AM 6/20/2007

[corey240]

so your saying the fwd sr20de tb will work from like a b13 sentra? as in it is a 70mm? or are you in japan ? i cant believe that though. so 100%. the b13 sentra ser tb is a 70mm direct bolton piece? if so im getting my friends today

[doridori23]

First off a correction in sizing. The stock TB is 50mm and the upgrade from SR20de is 60mm.

To answer your question yes we have used sentra tb with success you will just have to checkout the TPS voltage BEFORE you take the old one off and make sure it matches the new one after you install it. You might have to loosen 2 small bolts/screws to move the TPS to achieve the correct voltage.

IF you want to run a HUGE turbo and are running a equally huge manifold you can actually use a TB from a Q45. This is a 90mm TB!! It is too large for most applications and might actually adversely effect performance. If your running 700+ hp though I highly recommend it. This tip was received from a friend at Z1. They really turned that place around (it used to be a camper/RV sales facility).

[corey240]

awsome i can pick up an sr20de tb off my friend for 15 bucks. so what about exhaust manifold? and exhaust syetem? would it be beter to run my straight through like i have or get a different muffler and/or highflow cat installed? or is that just an na thing?

[corey240]

i already planed on doing this but, would it help if i set my intercooler at the top likea vmount, only im not vmounting the radiator. so the pipes are shorter, im doing to protect it but i might not do it, maybe just have it so i can swap it up for the track

[doridori23]

The "log" type (stock) manifolds are good for spoolup but lack in both pulse formation and overall flow compared to a tubular manifold. When swaping out to a cheaper tubular (Megan's or Ebay) you will typically lag 200-300 rpm from where you were before BUT you can pick up 25 hp on the top end. A good manifold Will have a 4-2 design (4-2-1 is not what you want) This will put cylinders 1 and 4 on the same leg and cyl 2 & 3 on the other leg. The flange that mounts onto the turbo will have a double port design not just a big hole. This will allow the individual pulse of air from each cylinder to impact the turbine wheels with greatest force giving excellent spool up AND top end flow. When we installed a beautifully crafted manifold with said design on a 2871 w/ .64 ar we actually spooled 17psi 400 rpm sooner and made 45 WHP increase at peak. Granted this was a $1400 unit there are good knockoffs of the design. The best knockoff of the pulse manifold is Ichiba. We have used it with similar results and for half the cost of an HKS/Tomei/etc etc

I wouldn't v-mount anything unless your budget is high. This will require a fair amount of time and money to do it right. Only a few pro teams v-mount and it is mostly for bragging rights. If you want to protect that FMIC then get Stainless mesh and attach it to the front facia.

[corey240]

stainless mesh wont stop a wall or cone from smashing it in, all id have to do is make a couple pipes and brackets to "upper mount" the intercooler, not really vmounting it

[elgarvo616]

stainless mesh wont stop a wall or cone from smashing it in, all id have to do is make a couple pipes and brackets to "upper mount" the intercooler, not really vmounting it

youll have shorter pipes, but itll be real ineffiecient. a v-mount works because there is ducting driecting air to the intercooler. you cant do one without the other.
Modified by elgarvo616 at 5:27 PM 6/20/2007

[corey240]

ok thanks for the help everyone

[DrifterProdigy85]

First off, Stock Manifold isnt Log. Its a cast divided unequal length manifold. Far from the short 90* runner log style manifolds. Stock TB is big enough to make over 450whp. Going larger with only 350whp isnt gonna do anything. As far as making high torque and matching HP, that just means that the TQ peaks high at full boost and makes a huge nosedive afterwards. HP is calculated by "Torque x RPM / 5252". Your always better with a flat torque curve to give a constant pull rather than a peaky curve that falls like a brick giving all mid range pull but no top end. But if thats what you want then go for it. Best setup i can say is 2871R .64, 256/264 cams, and stock intake manifold for mid range or greddy for more top end.

[DrifterProdigy85]

To get a better idea of what a matched HP and TQ SR Dyno looks like. The numbers 312whp 325tq sound good but the powerband sucks. This was my old 2871R .64 setup with a serious boost problem. Was running HKS 264 Step 1 Cams and Stock Intake Manifold. Whats funny was that setup out ran a C5 Z06 from 80mph to 160mph so it wasnt horribly bad.

[Deadrodent]

To get a better idea of what a matched HP and TQ SR Dyno looks like. The numbers 312whp 325tq sound good but the powerband sucks. This was my old 2871R .64 setup with a serious boost problem. Was running HKS 264 Step 1 Cams and Stock Intake Manifold. Whats funny was that setup out ran a C5 Z06 from 80mph to 160mph so it wasnt horribly bad.

k i'm kinda confused...is this an example of a good matched hp and tq sr dyno or a bad one?

[TchouikoS13]

doridori23 You are talking about a good 4-2 exhaust manifold right? Would This also work for a stock sr??

Also would someone explain to mean the difference between 256/264 and 264/264 or 256/256 (basicly)?

[CoupedUp]

doridori23 You are talking about a good 4-2 exhaust manifold right? Would This also work for a stock sr??

Also would someone explain to mean the difference between 256/264 and 264/264 or 256/256 (basicly)?

It will but not as much as say a 300WHP car.

256 is the Cam Duration of the Intake cam and 264 is the Cam Duration of the Exhaust cam. The duration denotes how long a Valve will stay opened(and closed) Enabling your motor to suck more air in and push more exhaust out.

[karmakaze]

Bore it out 2.2LKeep VTC the sr20de throttle body does make a noticable difference in response

[corey240]

thanks for all the replys this is a good thread, hows your motor coming along karmakaze? how much is a stroker kit?

[DrifterProdigy85]

k i'm kinda confused...is this an example of a good matched hp and tq sr dyno or a bad one?

Its a generalization of how a matched Torque and HP SR looks like. I personally dont like a matched HP and TQ powerband cause the car feels doggy at high rpm from the lack of tq. Even if you get an SR making 400hp and 400tq, its gonna have a similar power curve. If that 400tq held steady past the 5252rpm point, the HP would climb higher then the TQ. Some calculated numbers of what i mean 400tq @ 5500rpm = 418hp 400tq @ 6000rpm = 456hp400tq @ 6500rpm = 495hp400tq @ 7000rpm = 533hp400tq @ 9000rpm = 685hp (Calculated Just For ****s)

Only way for torque to climb higher as RPM increases is usually from Boost Creep. Otherwise it holds fairly steady or falls off. If you didnt get the calculation before its

TQ x RPM / 5252 = HP

[Deadrodent]

so a peaky combo would be better for high rpm?

[DrifterProdigy85]

peaky combo?

[TchouikoS13]

So can someone give me an example of one of these 4-2 manifolds? Link or something.

[DrifterProdigy85]

Look at Full-Race for there Twin Scroll Manifold. Thats a 4-2 Design. Has 4 Runners with a Divided Collector/Flange. Only benefits with Twin Scroll Turbine Housings. The stock SR manifold might have that 4-2 design inside but not too sure. Too bad no T2 turbos have a divided turbine housing.