how much boost on non intercooled ca18det

[lotusCA18DET]

I have seen jdm ca's on pic's without intercooling, but I can't find any information how much boost they are running.
I have to run my ca without a intercooler for a short time (testing work on the car) will 5-7psi be ok?
thanks

[sjbsuperman1425]

Its not recommended, but if its for a short time and only street driving (no highway) i'd say you could get away with it if you have to. My friend ran his RB without an intercooler for a month and didn't have problems...but not he has half his piston in the oil pan soooo lol

[roast]

Why would the highway make a difference? I wouldn't run high load without cooling the compressed air...

[Amays U G37S]

If you seen a CA18 that was JDM in pics without a FRONT MOUNT INTERCOOLER

You may of seen them hiding a SIDE MOUNT intercooler.

Make sure you have one bolted up, Lol.

[lotusCA18DET]

If you seen a CA18 that was JDM in pics without a FRONT MOUNT INTERCOOLER

You may of seen them hiding a SIDE MOUNT intercooler.

Make sure you have one bolted up, Lol.

no, they have a crossover pipe strait from the turbo to the inlet. early CA's in FWD 87-88? gazelle's
so I know it can be done, the question is how much boost!
I have a nice chargecooler (engine is mid mounted) but want to test the car first for handling ext. without much extra work for the chargecooler and NO I do not have any room for an IC because the piping will be to long

[ILOVESILVIA(S13)]

And why would you want to run w/o an intercooler? Does not sound smart to me. But that's my opinion I guess.

[roast]

And why would you want to run w/o an intercooler? Does not sound smart to me. But that's my opinion I guess.

I'd love to reduce the amount of piping between my turbo and intake... less lag, less pressure drop from air-to-air intercoolers, etc...

For the OP:

I haven't run without an intercooler, I can't see you having a problem, enrichen the fuel mixture to keep your combustion temperatures down.

My concern is heat-soak on the charge pipe, you'll have higher intake air temperature however I don't know how to control that except for reducing load (step off the gas) and add more fuel.

If you have an EGT sensor, watch combustion temperature, use that as an indicator as to how much boost you can run. If you put the car under load and you start climbing into the 1900F+ range... get off the throttle...

oh, and run high octane fuel....

RE: the s12 silvia/gazelle, ca18et that had the direct pipe into the intake... I think...

[sjbsuperman1425]

i dont think most will recommend this. if its a bandaid thing until you can find an intercooler for a week or two, just dont boost if at all possible.

[float_6969]

You'll be fine on stock boost and high octane. You might throw 5 gallons of Toluene in the tank just to make sure it doesn't detonate.

[ganma_ca]

Or you could take your turbo off and run n/a jk jk. buy a Nos bottle and have a jet just constantly "seep" into your intake manifold, and add another jet to the front of your radiator, and everytime it starts to get a little hot just spray lmao(it's like 1,200* - blast to chill things out) Then you can run w/out an intercooler. There was a guy who used to have this crazy setup in australia without an intercooler/bov/or wastegate, and never ran into any crazy problems, he just ran water injection(direct injection) straight into his intake manifold, of course he had a secondary 9 gallon fuel cell full of water but it worked. Not suggesting any of this but you could run without an intercooler, but it would just be cheaper to buy one lol.

[float_6969]

Guys, LOTS of cars were made from the factory with out intercoolers. And honestly, the stock side mount did very little for the intake temps. And that was with all of the appropriate ducting. without the air ducting, it does very little.

You can build a water injection setup pretty easily and not have to worry about an intercooler at all. Or you can run 93 octane and 7psi and probably not have a problem either.

[lotusCA18DET]

Hi float_6969 you seems to understand the question, 7 psi sounds fine to me, I run euro 98 octane, think this is like US 93 octane
and it is only for testing the car,and as soon as I trust the car I go for 15psi and a chargecooler
so many people do not read the post and just shout a bit
thank you for your reply

[s13drifter88]

you shouldnt have any problem on stock boost or maybe a little bit more. Me and my best friend used OE turbo and manifolds to turbo his 86 N/A 300zx which had a freshly rebuilt 9:1 compression engine. We also used the stock 86 300zx turbo ecu/injectors/fuel rail/pressure reg as well. Z31's were not intercooled and stock boost is 6.8psi but he went as high as 13psi and still no intercooler, just slightly retarded timing and premium fuel (93 octane). Car ran for over a year like that until the turbo decided that it didnt wanna spin anymore lol

[MeanGreenS13]

Guys, LOTS of cars were made from the factory with out intercoolers. And honestly, the stock side mount did very little for the intake temps. And that was with all of the appropriate ducting. without the air ducting, it does very little.

You can build a water injection setup pretty easily and not have to worry about an intercooler at all. Or you can run 93 octane and 7psi and probably not have a problem either.

Ryan, if i remember correctly, the older 200sx with the CA18ET was one of these cars that came without an intercooler. Someone correct me if I am wrong?

[RM12577]

I have a 200 at my house and I definitely don't remember seeing any kind of intercooler... They actually run an over the top style intake straight off of the turbo.

[float_6969]

Yea, no intercooler at all on the S12 ca18et's, or the Z31 vg30et's, or the old fj20', or the Merkur's, or just about ANY turbo car from the early 80's.

[s13drifter88]

I think the only turbo cars that actually did come intercooled in the 80's was the Supra, RX7 and the Grand National and that was only after 87. Hell even my 87 toyota pickup wasnt intercooled. You can actually get away with a pretty good bit with no intercooler as long as its on the stock turbo and your not blowing it past its efficiency range. Any kind of a turbo upgrade tho and you'd prob be knocking on troubles door with both hands.

[float_6969]

I've seen in multiple places that you can run 7-10psi on water/alky injection alone and that removes enough heat from the air to fight off detonation.