turbo advice needed

[karmagedon]

hey there people,Names Dave, I am building a lotus 7 and using a CA18 as the powerplant. I started this project 2 years ago when I was in my last year of high school. A link to my build website is : lotus 7 Just recently I've been considering turbo charging my car. Now I know that I could get flammed for even considering turboing a CA18DE, however due to budget constraints I am unable to buy a DET and do all the extra power mods.What I am planning is a t3/t4 with 8psi.I have a walbro 500hp fuel pumpAfter market fuel pressure regulatorLarger injectorsDET ECUBOV, wastegate etc

1 ) am I correct in saying that the only internal difference between the 2 engines is that the DET has oil squirters and a different cam?

2) Is the engine loom of the DET any different to the DE?

3) What extra sensors does the DET have over the DE?

4) what else will I need/to do in order to make this work?

Thanks for any help you guys can offerRegardsDave Slabbert

[ca18detgabby]

I know the DET is low imped injectors, he DE is high

the MAFs are the same

beyond that, I would reference dee for most of yoru questions.....

one thing I would say.... instead of a DET ECU, just have your DE tuned(as the DET will need to be anyways).

you will need a new exhaust mani, and if budget is a little strapped right now a T25 makes more sense to me and they are far cheaper and easy to find in good condition used. new DP will be needed as well, not to mention a IC or some sort......

[karmagedon]

I know the DET is low imped injectors, he DE is high

does this mean that I will have to run a different wiring loom?

Pardon my ignorance, but what is a DP?

BOV, wastegate etc

I tried to include the intercooler, boost controller into that senteance.

Reason that I'm going with the t3 is that i already have an aftermarket manifold for that flange, and the only top mount manifold I could get my hands on was a t3 one, the t25 was with a low mount, and due to space criteria, low mount is nearly impossible.

[Nicksemianiw]

DOWWWWWWWWWWWWWWN PIPE!!!!!!!!!! orrr double penetration what ever one works lol.

[karmagedon]

HAHA now there's a delema; which to choose but yes, so far the plan is to run a 3" straight through pipe with a resonator at the end. Will also plumb wastegate back into exhaust

[Buddyworm]

DE's compression ratio is 9.5:1 instead of 8.5 like the DET. The timing on the DE maps is advanced quite a bit over the turbo maps which also have more fuel.

DE uses single wire O2 sensor

I hear of lots of people turboing the DE's. I'm not sure what the knock threshold is with the higher compression ratio but seems to me with that turbo 8psi won't push things too hard as you'll be nowhere near its efficiency limit.

Sounds like you'd be fine with a DE chip with DET timing and fuel maps. The timing is really safe and the fuel maps are rich as hell so other than that you can just use your DE loom with high impedence injectors and slap the turbo on the side.

[karmagedon]

Thanks for that Buddyworm.

In regards to the O2 sensor, what gains would a wide band offer? Will gains only be gained if I'm using an aftermarket engine management?

If I was to push the boost to 1bar, will I be shooting myself in the foot?

[Buddyworm]

Some wideband units have a simulated narrowband output that you can splice into your stock ecu harness instead of using the stock narrowband. Narrowband is fine for closed loop, wideband is necessary for tuning.

Although I don't know if the motor will like 1bar with that compression ratio I'd definitely be tuning the ECU then. But in that teeny little tubeframe chassis this engine will not f*** around at any boost level. Death could be imminent with that kinda punch.

[karmagedon]

Death could be imminent with that kinda punch.

that is a very good point. Might just keep boost low then for a long while.

ok, so wideband if I intent to get it dyno tuned, and if I don't want to fork out for aftermarket management yet get one with a narrow band feature.Do widebands just screw into where the narrow band came out from?

[boost_boy]

that is a very good point. Might just keep boost low then for a long while.

ok, so wideband if I intent to get it dyno tuned, and if I don't want to fork out for aftermarket management yet get one with a narrow band feature.Do widebands just screw into where the narrow band came out from?

You will quickly crack the ringlands on the DE pistons. Unless you have a standalone or a programmable ecu and have someone skilled enough to time this engine correctly, you'll be up for a rebuild in no time. What you should do is get a stock CA18DET and engine harness with accessories. If you are truly on a budget, stay out of the boost ring until the funds healthy enough to play.

Dee

[Nissanclubman]

Hi Dave, Great to see another (LOCOST) Clubman builder venturing in with the plans to use Nissan harware. I'm a fellow builder and put mine on the road in 1999 and have been upping the performace limites ever since. I decided on the CA18DET for a number of reasons and looking at your shopping list you have similar intensions of developing some serious hoursepower for such a lightweight car. Great to see you also used teh Nissan R200 diff and asumed you also have gone with a wider chassic to cater for the wider track. Beautiful job and being a fellow builder know exactly what your going through. Anyway my thoughts:

If you haven't committed to a DE (appears you have however) and you can get your hands on a DET then I support that for sure, particularly if you end up like me, want more grunt and start cranking up the boost.... In the early days however tuning the DE won't be much of a problem and lots of suggestions already on offer on this thread. Stay with the standard JDM ECU. These can be tuned to do anything you want and are dirt cheep. The T25 or T25G would be my suggestion if using a DE, with some minor mods to the oil delivery these will live a long life pushing up to 15psi. They spool up nice and quick and will bring you buttom end torque on line nice and early. Mind you being a DE you will have quite a bit already. Once you start tuning beyond 10-12 PSI then you will need to replace the 50mm AFM, the Std unit run out of range at 12 PSI, after that then your ECU struggle to fuel the car correctly.I wouldn't worry about a wide band O2 other that what has been suggested for initial tuning. The motor only uses it during closed loop running in any case. Under any level of boost your ECU runs pretty much off the AFM, VQ profile, Injector opeing duty scale, latency setting then adds to that what it reads from the fuel map. The O2 sensor isn't involved at the business end of things.

From an exhaust point of view the standard DET header/dump pipe is more that enough for up to 230 HP (flywheel) before any detectable restrictions come into play and by then you will be needing to make some other changes in any case.

Your standard 370cc injectors like wise are pleanty good enough for early days tuning and if married with the Std AFM, T25(G) turbo, STD exhaust, you can certaily get to around 210-220 (Flywheel) HP.

Afer market fuel regulator..... can't see the point. All your tuning is based around an injector size which is asumed to being fed fuel at a standard pressure (range because it tracks with boost). If you go for biggish HP and upgrade to larger injectors (Skyline RB26... for eg) 440cc then they will operate very nicely on the std fuel rail preasure. If you up your rail pressure then you will need to retune for that and in the end if you select injectors wisely you will only be delivering fuel as per what the ECU decides it needs from what the AFM tells it. All of this asumes the fuel rail pressure to be standard, albeit tracks up and down with boost. A pretty simple job really and the Std regulator does just fine.

This would make it pretty cheep to build, give you losts of scope to tune up your HP and if you go beond that you will have to change a number of things. AFM, Intercooler, Injectors, Turbo, Exhaust so start saving your $.

Having said that you will already have a 0-100 kph in mid 4 sec car on standard hardware and that may very well suit you fine for a while.

Good luck with your project and will watch your progress. Keep your WEB site current because it is pretty exciting stuff you are doing.

These are just my thoughts and hope no one takes it too seriously. There are alway may ways to skin your question. Cheers for now Richard

[KEMP]

big turbo.... real big.. heheh im a boost adict