motorheaddown

Greetings!

After doing some web research on the Toyomoto and FMAX turbo kits, I've learned that the fuel required to support the turbo is delivered by additional fuel injectors (440cc or 550cc). This appears to be controlled by the Haltech F5 or F2 controller.

Here's the rub... How can these kits be improved on without completely redoing the fuel maps? Additionally, is there any risk of starving a cylinder because the additional fuel is inserted in the compressed airstream prior to entry into the intake plenum instead of being controlled by injection directly into the cylinder? Have any A/F ratios been plotted, after installation, to insure the engine isn't too rich or lean?

Has anyone tried to "tune" an aftermarket kit after installation to support increased boost? (Assuming of course things like a larger intercooler maybe required to handle the additional heat due to reduced compressor efficiency, etc.)

Here's my point. Once these kits are installed, does the process of tuning have to be performed all over again to support more boost?

(Please limit responses to turbo kit technical approach and upgraded performance; this thread is NOT about quality of materials or reliability.)

Thanks,
-scott

awj

Basically, yes. If you know how to tweak then you have an advantage - or you can learn. Best way - quality standalone (halltech, speedpro, aem, etc.) with wideband O2 - and all the other hoopla. I was looking at ease of use and software availability and requirements. (Speedpro was winning in my comparisons). Expect to always be tuning.

IMO - yes. That is why they say (f-max and the like) don't exceed x pounds of boost. Usually like 8 psi or something.

Fuel concerns? I'm not a fan of the 2 aux injectors in the intake a la f-max and the like. When I was going this route - I planned to get 6 new, high flow injectors to replace the stock squirters. Depending on power goals, 440 to 720cc.

edit:

Of course! Check out ebanks - with the assistance of the fellas out Sound Performance in the Chicagoland area. Ummm - oh yea, SC300T (Scott) out of Cincy - not sure where he stands at this point (haven't seen him round here in a while (I wonder why)).
.... pause to fix keyboard ....
The guys at Performance Factory/Rollhard have done it also. Lots of info on na/t conversions at the supra site too.

motorheaddown

Awj,

Thanks for the reply.

I know ebanks, sc300T, and the like have done outstanding jobs tuning their cars, but I doubt they did it with a kit that supplies additional injectors. It just doesn't seem like fine enough control over the a/f on a per cylinder basis.

My guess is that they'll go with a larger fuel rail/injectors plus fuel management. The kits I mentioned above only seem to control the added injectors; consequently, adding a larger turbo would require more fuel that the kit just can't provide.

The sc300 kits are great for a certain amount of hp and torque, but leave much to be desired in terms of real *tuning*. Maybe, that's were a stage 3 and up kit comes into play.

It seems all I read about on Supraforums are guys that tune their own car, and they have access to reasonably priced kits that *allow* them to do so.

-scott

awj

The guys there are great (some of them). Some of them are questionable though. Those that have done it and done it right have spent $$$ and saved on labor by knowing how to do it themselves. What is a reasonable price? Basically, kiss the kit idea good bye. That is what I was getting at. People have those kits and may or may not like them. Those aux injectors are not the best way to do it and I wouldn't. Get six injectors rated for your application and go from there.

Expect to spend 7 to 10k on turbo, manifold, dp, gate, piping, bov, injectors, gauges and all the controls including labor. You can use used parts in some areas - I had a used manifold, dp, rail and gate that were in great shape. I would not buy used turbo or injectors with a big fat unless.

motorheaddown

Well said... I'm working with PHR in the next month or so to install a turbo on my '95. I'm going to make sure that attention is paid to the fuel system so that I'm not handcuffed by limitations in fuel delivery when I want to increase the hp later on.

-scott

Hermosa

All things aside I think there is much less headache if you simply do a GTE swap. The engine is fine and easily upgradable to 430rwhp for an additional $1400. The swap canbe done at most shops for $10,500 including parts.

If you put together a kit and get it installed it will easily be that much plus uncertainty.

motorheaddown

Hermosa,

Through my experience of this effort, it's not cheap regardless of which way you go. The absolute best deal I've seen is an ebay auction where a JDM 2jz-gte motor, 6-speed tranny, driveline, and LSD went for a little over $4k. *That* was a deal.

I'm very confident with PowerHouseRacing, and I'm getting a good price because they're using my car to produce their own kit for the sc and NA supras.

However, the one thing that everyone under estimates is the driveline. Building one that holds 450+ hp *reliably* is almost as much as the turbo itself.

-scott

SC300T

I personally had very good luck with the Haltech F5. I ran fairly consistent air/fuel ratios, made good HP and got the car to run very well. That said, there was a slight hitch when the boost would cross from vacuum to boost. I got it to go away almost completely through advanced timing, MSD boost retard and different plugs. The VPC cars I've ridden in don't have any of this tendancy when tuned properly. I'd say on a budget, its still a viable way to go. My car has been out of action for most of 9 months. Tore it down for stem seals leaking last spring, got half way through an upgrade process and ran out of money. I've decided to put it together the same way, but its got hotter cams, valve springs, porting, etc-- so I doubt the stock ECU is going to like that very much. As always, I'll always be a fan of Lance's stuff. Toyomoto has helped me every step of the way. Hopefully I can get it together for this spring. I'm sort of tired of working and wrenching by myself, since I'm close to Chicago, it will probably go up there for any more upgrades. As far as the kit giving reliable power, I can say that its much quicker than any BPU Supra I've encountered. It dynoed 423rwhp on pump gas with less than $10k total engine upgrades, and would do 500rwhp on race gas. Compared to a BPU Supra, its stronger off the line, stronger around town, stronger up top, just plain STRONGER RUNNING. The GTE swap has its advantages, but the turbo kit IMO is the best way to get to the 400rwhp level. If your ultimate goal is above 400rwhp, the GTE swap starts to look better, in my mind, its still almost a wash unless you just want to build an 850rwhp monster from the ground up.

motorheaddown

Scott,

Thanks for your input. Please don't get me wrong. I'm not critical of the additional injector approach. I just want to understand its limitations.

If you go to SupraForums, additional injectors are rarely used to augment the fuel system; even for the guys going NA-T. Typically, a/f control is, as you mentioned, implemented using a vpc and s-afc. Unfortunately, the vpc is out of production.

I know the Toyomoto kit is great quality. In fact, I would much rather go with their log style manifold instead of an equal-length tubular header for reliability/durability reasons alone. However, it's obvious that once you get hooked with more power, more boost is close behind.

My objective is to get the infrastructure (turbo, header, bov, wastegate, FMIC, piping) set right the first time without swapping it out later. I'll concentrate on fuel delivery (larger injectors, engine management) to upgrade for more boost later.

Any other comments are greatly appreciated!

-scott

SC300T

Based on your post,
You're not a good candidate for the Haltech AIC and extra injectors. To the person looking for an eventual 600rwhp platform, the proper thing would just be to get the modded rail, the bigger injectors, AEM ECU, etc. This is basically where I am at for the moment. The AIC in my system won't go unused, though. I've got some plans (more like idea) to squirt a water-alchy solution through them.

motorheaddown

That's exactly the conclusion I've come to. I'm going with the AEM EMS and 550cc/min injectors on a single TT fuel pump. Beyond 22lbs of boost, it'll required two pumps, fuel lines, FPR, rail, etc.

My project got a little delayed which allowed me to do the necessary research to determine the pro's and con's of most of the after-market turbo kits. I figured the up front cost will be more than an off-the-shelf stage 2 by going with a larger turbo, larger injectors, and independent engine management, but in the end, I'll be saving money over the long haul by doing it the way I want the first time.

-scott