Jump to content
SAU Community

Recommended Posts

  • Replies 43
  • Created
  • Last Reply

Top Posters In This Topic

Oh, and to give a comparison, I could have babied mine around like a grandma, but all of my Kays were driving to and from driving events and at the events. I did 2 track days on one bottom end (Well, actually 3 sessions at half pace each day) and then one texi.

The other one managed to get tuned on the dyno, then make the 3rd session at a track day and everything let go.

Slappers on big turbos do NOT last long...

I've broken 2 now... With a max of 1000KM on them... Pushing 1Bar (14PSi) through TD07S housings, t66 front and a t04r rear wheel.

Nothing below 4000/4500RPM, then everything ramps in over 200/300RPM...

Rev limited at 6600RPM.

On the dyno it made "250RWKW" wheel spinning like a spastic... Using fuel consumption and AFR it would be making around 360RWKW... (69% inj duty on 880cc injectors)

so they were used bottomends not refreshed or anything with twin cam head and big turbo on them?

could i expect anything different considering its got new pistons and bearings?

what exactly let go on them? rods bend or pistons break or the bearings finally had enough or what?

wanna get more than 1000kms out of my rebuilt one hey. if it was a full slapper i wouldnt give a rats. it was meant to be cheap as shit then i decided to go new rings and bearings to refresh it then found i had to bore it out and new pistons. also got the rb25 head full rebuilt so spent extra $750 more than i planned to there. probably just gunna put standard rb25 turbo on it for now but to get some use then il put the big shit on it and wont feel so bad if it lets go.

The bearings will not let go as they are the3 same as the bearings used in aftermarket rods

The rods will not bend until about 600hp or if the tuner detos the engine

the pistons will crack if deto is present but so will forgies they just have a bit more tolerance.

Its all down to your tuner if he is good then your not going to have issues

so they were used bottomends not refreshed or anything with twin cam head and big turbo on them?

could i expect anything different considering its got new pistons and bearings?

what exactly let go on them? rods bend or pistons break or the bearings finally had enough or what?

wanna get more than 1000kms out of my rebuilt one hey. if it was a full slapper i wouldnt give a rats. it was meant to be cheap as shit then i decided to go new rings and bearings to refresh it then found i had to bore it out and new pistons. also got the rb25 head full rebuilt so spent extra $750 more than i planned to there. probably just gunna put standard rb25 turbo on it for now but to get some use then il put the big shit on it and wont feel so bad if it lets go.

It comes down to the tune and how you drive it.

My first one let rip with oil surge on a track, mixxed with an over rev when it stepped out in second gear. Well that was the initial thought. Now it appears that the thrust bearings had worn out massively allowing the crank to float and just annhilate everything.

The second motor let rip with what appears to be a cracked oil pump. But this motor spent a shit load of time living life on the hard rev limiter at a motorkhana (Big turbo, very hard to get it to keep the tyres spinning at part throttle without hitting the limiter, if it didn't hit the limiter it bogged and died).

If I drove these motors peacefully, I'm near on 100% sure the second one would still be together today (The first one, probably not... It was a PITA from the get go)

If you can break rods, you're going well. Pistons may let go if it's not tuned properly.

The biggest killer is normally oil control, get a good oil pump on there and doa winged/baffled sump especially if you plan to do ANY form of drivig events (Even if you only do one!!!)

My first one let rip with oil surge on a track, mixxed with an over rev when it stepped out in second gear. Well that was the initial thought. Now it appears that the thrust bearings had worn out massively allowing the crank to float and just annhilate everything.

IMO that's the biggest risk with a slapper. My first 30, even though it had forgies, was a slapper crank and rods and the thrust clearance was out.. destroyed an oil pump and almost the block :(

Second pass, I got the crank ground for oversize bearings and it lived a much healthier life (only pulled it apart to upgrade rods and other stuff).

The bearings will not let go as they are the3 same as the bearings used in aftermarket rods

The rods will not bend until about 600hp or if the tuner detos the engine

the pistons will crack if deto is present but so will forgies they just have a bit more tolerance.

Its all down to your tuner if he is good then your not going to have issues

thats it, GOOD tuner

  • 1 month later...

469rwkw on a 3l slapper is the current record in my shop, nothing like a time bomb :/

Slappers FTW if their mates cars who can deal with the consequences if it lets go... a no no for customers :P

Dont just say a figure like that and not give us the details

Sounds awesome I want to know more

std rb30 na bottom end, 26 head and t04z.

about to kill it with a std 1.5jz thats in the shop atm, we matched the output of 469 last thursday... shooting for 500 by the end of the week.

btw both on e85.

  • 2 weeks later...

looks like i got the only genuine slapper here, 285kw@14psi 6800 rev limit

Rb25 s2 Head Fresh Mill clean slapped on to..

Rb30 s11 Bottom end 70,000kms. Un opened.

ACL 1.3mm Metal Head gasket.

GT35r,

and other stuff but not important here.

not daily driven but 6 dyno tunes, 1 sau dyno day, 2 wakie days, 1 hill climb and 1 motorkhana. love it

i'll let you know how long it lasts...

you have a metal head gasket, not a slapper :down:

i've just got myne running a few backs, still tuning atm but i'm running 23psi from a 1.06 gt3076 through an unopened 150k bottom end, standard nissan gasket etc. will get it on the dyno after tuning to see how much power its making

  • 2 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Yeah I've had too many issues with knock off's on the BMW's. I don't want to do a job twice or more because the parts are shit.
    • I read this and thought "ah! I will do this scissor jack on the tow point thing!" I just use my floor/low profile/costco jack and lift the car up by the tow hook itself, then slide jack stands under. Never thought about using scissor into floor jack combo :p
    • Well, my new WMI system took much longer to finalize. I actually missed my dyno appointment last Friday and lost my 150$ deposit. I'll be going back in the next week or two.  To sum it up. I only kept the AEM tank from my old setup. I replaced the AEM pump with a higher flow/pressure ProMeth 30GPH pump. I also swapped over to a 6AN low pressure feed line to the pump from the tank. There's also a pressure switch you cannot see on the pump high pressure line.    This is feeding 6x 200CC direct port nozzles and 1x 500CC Pre Throttle body nozzle. All fittings are Swagelok, because well why not. I also have a 300PSI pressure sensor up front.    I now have my Haltech ECU controlling everything. I start my pump with a basic relay at 5PSI and deadhead it. I then PWM a 3000CC methanol Injector to control flow starting around 10psi. The pressure switch in the trunk, along with my tank level are safeties before I ever get to 10PSI, and then I use my pressure sensor upfront as a secondary safety to cut the WMI and corrections in case the injector blocks or a line ruptures.  Wish me luck on the dyno!    
    • So, I'm back with bad news. There's no jack long enough on this planet that will reach the front subframe. If by some chance there is, it would weigh 200lb's.  I purchased a long reach jack... The damn thing weighted 120lb's and was massive. Didn't even come close, was still short at least a foot. It was a pain, but I brought it back. Next I decided HA! No problem, I'll get an Extra long reach jack. Well, I couldn't lift the box... It must have weighed 160LB's and luckily there was an open box in store. I took measurement and was still nowhere close.  Sadly I've lost hope and have accepted defeat. 
    • Thanks for that tip, niZmO_Man. I think the battery is OK. It's quite a new one, but I'll check. Last time I needed a new battery, everything electronic was fine, except that there wasn't enough current to turn over the starter. I decided to order one of the partial AV system translation CDs from Car Audio Workshop in NZ. That might have some effect, or help me diagnose the date problem. 🤞
×
×
  • Create New...