limits of jzx81 intercooler?

[pete05]

Anybody know the limits of the factory jzx81 intercooler in terms of boost and HP on a 1jz

[EldarO]

dunno about jzx81, but Michael Beetle just hit 299.5 through and auto with a factory JZA70 one, i guess the x81 would be similar.

Elmo.

[pete05]

dunno about jzx81, but Michael Beetle just hit 299.5 through and auto with a factory JZA70 one, i guess the x81 would be similar.

Elmo.

the reason i ask is lately at 15psi im get engine knock under load, was not doing it in the colder weather, and i havent had it runnning in warm weather, this is the first year, sorry who is Michael Beetle?
Also the car runs on 98 fuel all the time, was using shell but switched to bp and still doing the same thing.

[chris davey]

Are jza70 the FMIC type or are they side mounted?

From older reviews, (when china wasn't making intercoolers), the chaser type were mentioned as one of the better ones.

For the price of a china spec intercooler these days, you may as well upgrade at some stage.

Beatle is his username on here.

How do you know it is knocking? Audible? Or are you feeling like it is pulling timing?

I would try some v power racing 100ron and see if that makes a difference. It will naturally lean your car out a little but if it is stock ecu then that won't matter. Otherwise, slap some octane booster in there and see how that goes.

[pete05]

Are jza70 the FMIC type or are they side mounted?

From older reviews, (when china wasn't making intercoolers), the chaser type were mentioned as one of the better ones.

For the price of a china spec intercooler these days, you may as well upgrade at some stage.

Beatle is his username on here.

How do you know it is knocking? Audible? Or are you feeling like it is pulling timing?

I would try some v power racing 100ron and see if that makes a difference. It will naturally lean your car out a little but if it is stock ecu then that won't matter. Otherwise, slap some octane booster in there and see how that goes.

I can hear it knock and yes its running the factory ecu, i havent seen any V power around here at all so far
im think of fitting one of the just jap bar and plate intercoolers that are 450 wide and 100mm deep, the interesting thing is when i first put the boost controller on it would do 16/17psi no problems, now it doesnt seem to like much better than 14psi

[EldarO]

jza70 is front mount.

you should probably look at some form of timing control...

Elmo.

[pete05]

Hmm im all updated on Beatle now .
im fairly sure my front mount is the same as the jza70 one, really need to get it on a dyno and see whats going on. I notice you were talking about dump pipes in his member ride, check out the ones in my members rides, these are what i have been running on mine, notice the length of the duel pipes.

Just had a thought maybe im ramping the boost up to hard

[EldarO]

i dunno if the pipes being sepearted for that much longer will really make that much difference, not as bad as your describing (my opinion yo).

id further consider the chance of water getting into your tank, fuel pump not working well, blocked injectors, filters etc.

Elmo.

[1JZ.747]

you sure your not hitting boost cut? is it poping and farting only at full noise, or in different load levels.

a lot of guys when they put the twin dump pipes on free up the exhaust so much it then over boosts hits boost cut and people wonder what the fugg just happened.

[pete05]

definately not boost cut, i know what that is, its definately knock (or ping), if your on the freeway and you feed the power on hard but not so it drop back a gear and you can hear it knock as it hits full boost, so do you think the stock jzx81 intercooler is up to the task of 15psi?

[fatboy13]

my MA70 one dealt with 14psi... and its a smaller version of the JZA70 one....

im planning of running 16 through the stock cooler on high boost for the moment until i can afford piping for my china cooler

[1JZ.747]

i would be suprised if it was your intercooler, the intercooler would possibly make a restriction, although i have seen guys put 17psi through them for years with no dramas,

if its knocking i would be looking at fuel or spark as your problem. the intercooler would simply get really hot is it was out of efficiency which i doubt you are testing its limits at 15 psi.

[pete05]

im running the bcpr6es plugs but it was ok with these before, might put the factory plugs back and see what happens

[chris davey]

I think it would be. Considering they run basically 10psi stock. Does it feel cooler on the outlet than the inlet pipe?

Pull the plugs out: google for "reading plugs" by dragstuff. Check for any detonation marks on the plugs and you can also tell if the heat range is correct. I personally run BCPR7e's at .7mm in my tr44 1jz at 15psi (and also with nitrous) although I know Shane always used the 6's. I chose the 7's as the previous bkr7e's showed correct heat range as per the above article

Might just be time for a colder plug.

If your fuel system is up to the task then you will be running rich and that basically leaves octane and igntion to look at. As others have been fine at 15psi on 98RON you "should" be also.

What are the coils like? Any hairline cracks? May pay to pull em out and PVC glue or shrink wrap them up just in case

[EldarO]

check your cooler, might be clogged up with oil, but people are slamming 15-17psi through stock JZA70 cores, much the same as the JZX81, without problems, so i suggest you look elsewhere.

Elmo.