Going down the right path...

[coheed]

First off, thanks to anyone who stopped to read this post.

Well, I finally got a 240, like everyone else on the planet lol j/k. So, the thing is is that I want to of course go down the forced induction route. BUT, I don't know which would be better in the long-run, swapping to a SR or rebuilding a KA from the bottom up with forged internals. I'm not looking for a super amount of HP, just around 300+whp on high boost. Plus, I want to daily drive the car with whichever route I take. The question is is if it's really worth it or better in the long run to go with the KA-T or should I just go with the SR for that kind of HP goal? With the KA, I'd know what shape the internals are in, because they'd all be new, but I would not necessarily know the shape of the internals on the SR because I wouldn't be tearing it down to the block. Please help me out lol.

Any help or suggestions is greatly appreciated.

Thanks

[Nismo_Freak]

I give up.

[95 kat]

man you have to search and read eveyones opinions. I did and you will find out most people who have sr's rb's and whatever say they would raather blow ka's up all day long and be able to fix it soon. I went ka-t route becuse first sems pretty easy to make around 250 if you have the right turbo and ****. Then if it does blow I can get the parts to fix it petty quick and fix it and blow it up again. I just dont have the time to sit around waiting on parts. I wanted so bad to got eh rb route but if you read alot of posts everyone is happy with them it is just lot of headaches. Sr's eem to be easier than rb's but who knows They say if it takes you more than like 30 minutes to wire up the r33 rb in a s14 then you ar just thinking way to hard. Do what you want. Everyone has there experiences.

[Maverick7687]

*cough*cough*KA-T*cough*cough*.... Obviously...this is the KA-T forum..lol.....But seriously..I have looked at both..and I dont see the point in spanding the money..plus the PITA to put an SR in, when you could spend less money if you do it right and have the same power...Myabe a little more money to know what condition the motor is in (rebuild KA). But that is what I am doing..stock KA24DE rebuild and turbo...then later..when that gets to be normal for me..I will shell out some more cash for forged pistons, rods, valvetrain, etc...

Probably hasnt helped any...just my opinion on what I have read and what I am going to do.

Mav

[coheed]

I knew I would get the search smack hehe. I was just wondering about a couple of peoples' opinions on the KA-T. I really appreciate all of your replies, and if anyone has anymore input, that would also be greatly appreciated. I'm more than sure that I'm going to go the KA-T route...it sounds to be more logical. Thanks again guys.

[Florida240sx]

I just spun a rod bearing...As soon as I make a trip to pick up another KA for $300 I'll be boosting again...No need to order a new SR....And I have my old block to build with forgedness

[babowc]

modified cars arent the most reliable cars in the world.if you want reliability, stick to the KA, have someone build it up well with OEM parts.and it'll be like new..

but if you still want to take the modified route, i'd suggest ka-t, if you have minimal mechanical knowledge, its not too hard.. just the tuning part, thats the headache.

SR's are nice.. just a bish to get parts for them here. hence the downtime..

if you go either SR or KA-T, always time-efficient to build or keep another motor on the side, just in case your current one blows and its a DD.

at least thats what im planning.. ka-t and ka on the side for emergency

[95 kat]

I am still trying to find the rest of my parts for may ka-t. Dont need but intercooler piping, exhaust , fuel pump, and time. I cant wait.

[Craving4Boost]

moderators please make a sticky about asking this question

[Nismo_Freak]

zerothread?id=99647

[DammitBobby]

Wants: 300rwhp on high boost daily driven.

General rules of thumb:Stock KA24DE 200 - 240 hp stock injectors, stock maf, stock ecu .Stock KA24DE 250 - 300hp Upgraded injectors, z32 maf, ecu upgrade.Stock KA24DE 300hp and up same as above just iffy at this level.Rebuilt KA24DE 300hp and up have had issues with stock rods.

Since one of your goals includes reliable you will need to buy a turbo kit from a reliable source. Lets look at typical costs per hp goals using our sponsor IAP.

Stock KA24DE Stage I kit 200 - 240 hp = 3199.00Stock KA24DE Stage I+ kit 300 hp = 4599.00Cost could be more or lessStock engine rebuild 300 hp and below: 2000 and up.Performance engine rebuild 300hp and up: 3000 and up.

The next question you need to determine is your current motor capable of handling 300hp and will it be reliable?

To help in this decision you need to do a compression test. This should give you an idea of what shape your engine is in. Numbers you want to see is something close to stock

185 across all cylinders and not more then 10 difference between cylinders.Here is where it gets difficult. Lets say your engine shows good numbers across all cylinders. That still doesn`t tell you anything about the rest of the engine.

Things that could go wrong using your stock engine at 300hp:Wiped rod bearingSpun rod bearingthrow rodring landsvalves hitting piston

This will all depend on your current engine condition and how well you tune your setup.

Now my rule of Thumb

Power goals 200 hp to 240 hpAny 89 or 90 swap with SR.91 - 93 Stock rebuild.95 - 98 Hopefully it is in decent shape no rebuild.

Power goals 250 hp to 300 hpAny 89 or 90 swap with SR and upgrade.91 - 93 Stock rebuild purchase IAP kit.95 - 98 Stock rebuild purchase IAP kit.

300 hp and upAny 89 or 90 swap with SR and upgrade. Possible need to rebuild.91 - 93 Performance upgrade engine rebuild and purchase IAP kit.95 - 98 Performance upgrade engine rebuild and purchase IAP kit.

[Jookmasta]

its always a tough decision to see which path will take u to ur goal since both paths could get u to 300hp. the real question is whether or not u want to do an engine swap or not. seems like u have a good budget but its really an individualistic decision. if u want 300hp from the SR, the stock turbo on an SR wont be in its efficiency range if it is capable of gettin u to that power level. on the other hand, the KA-T might be less of a headache pending on the condition of ur engine. obviously the posts to this thread will support the KA-T cuz most of us are KA-T or are planning to do so. i can say though that altho i spent 2500 bux and dealt with some headaches, i can trounce any sr in stock form. 2500 is about the price of sr these days so from a wallet perspective, ka-t wins (in my case that is).

[C-Kwik]

General rules of thumb:Stock KA24DE 200 - 240 hp stock injectors, stock maf, stock ecu .Stock KA24DE 250 - 300hp Upgraded injectors, z32 maf, ecu upgrade.Stock KA24DE 300hp and up same as above just iffy at this level.Rebuilt KA24DE 300hp and up have had issues with stock rods.

I hope you are saying to use a FMU(RRFPR) for your 200-240HP level. The stock injectors will max out well before 240 and probably be dead lean or approaching it around 200.

And for the 300HP+ level, how is it simply iffy? 400 HP has been seen on stock rods before they started seeing deformation. And I know of several 350 HP KA's with stock rods. I would suspect most failures are a result of detonation. Tune detonation out and you no longer have to try and band-aid the problem with forged internals. And even forged internals can not withstand sustained detonation.

Things that could go wrong using your stock engine at 300hp:Wiped rod bearingSpun rod bearingthrow rodring landsvalves hitting piston

At 300HP these would likely be detonation issues. And how exactly does a valve hit a piston from simply adding a turbo? That's a clearance issue. Turbos do not add anymore lift to the valve. The only possible way to see that would be if you revved higher and caused valve float to the point the valve hit the piston. But the result would be the same on a NA motor and woujld be independent of a turbo.

Now my rule of Thumb

Power goals 200 hp to 240 hpAny 89 or 90 swap with SR.91 - 93 Stock rebuild.95 - 98 Hopefully it is in decent shape no rebuild.

Power goals 250 hp to 300 hpAny 89 or 90 swap with SR and upgrade.91 - 93 Stock rebuild purchase IAP kit.95 - 98 Stock rebuild purchase IAP kit.

300 hp and upAny 89 or 90 swap with SR and upgrade. Possible need to rebuild.91 - 93 Performance upgrade engine rebuild and purchase IAP kit.95 - 98 Performance upgrade engine rebuild and purchase IAP kit.

I would call this a very conservative approach to this. Not that it's necessarily a bad thing, but I think in many cases, it could be unnecessary. There are many factors that would need to be known to determine if a motor is in good enough condition to put a turbo on. And I'm curious as to the reasoning you simply say to swap to an SR for a 89-90? I'd have to guess it's an integrity issue since you suggest rebuilds for DOHC versions.

[DammitBobby]

I hope you are saying to use a FMU(RRFPR) for your 200-240HP level. The stock injectors will max out well before 240 and probably be dead lean or approaching it around 200.

I used a FMU but IAP kits are only using Walbro 255 at these power levels.

And for the 300HP+ level, how is it simply iffy? 400 HP has been seen on stock rods before they started seeing deformation. And I know of several 350 HP KA's with stock rods. I would suspect most failures are a result of detonation. Tune detonation out and you no longer have to try and band-aid the problem with forged internals. And even forged internals can not withstand sustained detonation.

Iffy is a stock motor that has not been rebuilt. Yes it is a crap shot mine messed up a rod bearing and I had no detonation issues. JWT ECU and SAFCII with wideband reading good AF.

At 300HP these would likely be detonation issues. And how exactly does a valve hit a piston from simply adding a turbo? That's a clearance issue. Turbos do not add anymore lift to the valve. The only possible way to see that would be if you revved higher and caused valve float to the point the valve hit the piston. But the result would be the same on a NA motor and woujld be independent of a turbo.

My engine had a rod knock and the valve hit the piston.

I would call this a very conservative approach to this. Not that it's necessarily a bad thing, but I think in many cases, it could be unnecessary. There are many factors that would need to be known to determine if a motor is in good enough condition to put a turbo on.

The reason for the conservative approach is this person wants a reliable Daily driver.

And I'm curious as to the reasoning you simply say to swap to an SR for a 89-90? I'd have to guess it's an integrity issue since you suggest rebuilds for DOHC versions

A SOHC has very few options and being the engine is over 16 years of age a reliable solution would be a rebuild. Since the SR will be cheaper to rebuild and have many more options why not? The other factor is if you get tired of the project car the SR will be a easier and more profitable to sale.

[coheed]

I didn't know this thread would get this many posts lol. Thanks guys for all your help. I'm going to purchase another KA that I can tear down and rebuild. I'll probably go with some forged internals, so I won't have to rebuild for any higher boost later. Here's another little question: Is it a better idea to buy JE pistons and drop the compression to 8.5:1 or just buy some CP pistons and keep the stock 9:1???

[Jookmasta]

personal decision...............some ka-t's kept the 9:1 for their rebuilds, others did 8.5:1, and even some couldnt decide and just went with 8.8:1. lol. costs wont change so its how u want ur setup that will determine it.

[frsh13]

buy an sr......this way the ka-t parts wont go up in price

[JDMEnthused]

eh.. im with ^^^.. alot of people are starting to do KA-T and we have brought this topic up alot over the past few months to years..

do whatever u want, its your car..

[DammitBobby]

buy an sr......this way the ka-t parts wont go up in price

Actually if you buy KAT parts it will help us in the long run. If you haven`t notice SR engine parts are cheaper, more options and more available. Why, because there are more people building SR engines rather then KA.

1 Example of this is Rods, KA there is only 2 choices and very expensive.

2 I went to a local shop that only sales engine parts. They had no performance parts for the KA but if I had the SR they had plenty of choices.

[coheed]

Yea, I'm just going to go KA-T. I'll rebuild another engine that I'll pick up from somewhere. Thanks for all of the replies fellas.

[C-Kwik]

I used a FMU but IAP kits are only using Walbro 255 at these power levels.

Really? Well since the Stock Fuel Pressure Regulator won't allow the Walbro pump to actually flow any more fuel trhough the injectors it would be a waste to simply slap on a Walbro and think that the motor will get enough fuel. For a given injector size, you have to increase pulsewidth or increase fuel pressure to increase flow. Do the math on this and you will very quickly see that stock fuel pressures with stock injectors will not be big enough to power 240 safely. 200 would be quite iffy as it is.

Iffy is a stock motor that has not been rebuilt. Yes it is a crap shot mine messed up a rod bearing and I had no detonation issues. JWT ECU and SAFCII with wideband reading good AF.

Don't equate your experience with others. As far as no detonation, how did you check yours for evidence of it. It's not always apparent. JWT ECU, SAFCII and a wideband don't make an engine detonation proof. I can also point out plenty of motors that have blown with forged internals. Rod knock generally occurs due to poor lubrication, over revving, or a high level of detonation. These can simply occur even without turbos. I'm not trying to dictate your experience either. I'm just pointing out that you are simply making an assumption on only your own experience. Each situation is different. The key to any turbo add-on is to determine the condition of the motor it's actually being installed on.

My engine had a rod knock and the valve hit the piston.

If the valve hit the piston, there was something else going on. Did they occur at the same time? Sounds a lot like an over-rev to me if it did. Or unless the rod-knock occurred first and it cause so much play that the piston went up high enough to hit the valve (not as likely, as I found there is a pretty good degree of clearance when shifting cam timing around a bit).

The reason for the conservative approach is this person wants a reliable Daily driver.

Well without knowing the condition of the motor in question, how would anyone know if a rebuild is actually warranted. Keep in mind doubling the HP would not double the peak loads on the parts. 200-240 HP would put a minimal increase of load on the motor if the turbo is reasonably well matched.

A SOHC has very few options and being the engine is over 16 years of age a reliable solution would be a rebuild. Since the SR will be cheaper to rebuild and have many more options why not? The other factor is if you get tired of the project car the SR will be a easier and more profitable to sale.

SR is cheaper to rebuild? Lets see, you have to buy the motor, put it in, make it work, and then add the cost to rebuild it? I have a feeling that rebuilding the KA will be cheaper no matter which KA you have.

[DammitBobby]

Really? Well since the Stock Fuel Pressure Regulator won't allow the Walbro pump to actually flow any more fuel trhough the injectors it would be a waste to simply slap on a Walbro and think that the motor will get enough fuel. For a given injector size, you have to increase pulsewidth or increase fuel pressure to increase flow. Do the math on this and you will very quickly see that stock fuel pressures with stock injectors will not be big enough to power 240 safely. 200 would be quite iffy as it is.

Not going to argue with you on this statement. If you remember I stated that I was using a FMU. I only stated that the IAP stage I kit does not come with a FMU.

Don't equate your experience with others.

Have to argue with you on this one. That is how I have learned is from other peoples experience. No I don`t think it was detonation I think it was old engine that the rod bearing failure. There are pictures of the engine in this forum if you care to look.

Well without knowing the condition of the motor in question, how would anyone know if a rebuild is actually warranted.

Won`t argue with this statement either. The original post stated he wanted a reliable engine. I don`t think reliable is pushing a 100k plus engine to 300hp.

SR is cheaper to rebuild? Lets see, you have to buy the motor, put it in, make it work, and then add the cost to rebuild it? I have a feeling that rebuilding the KA will be cheaper no matter which KA you have.

Engine parts for SR is cheaper then KA. Not only that but more abundant and more options. The SOHC is not a popular engine. I am looking at the whole picture here. The SR engine does not have to be rebuilt if you are shooting for 300hp goal. When it comes time to sell he will get a better resale value with a SR engine then a rebuilt SOHC engine.