lexcoupe

hey guys, i want to boost my horsepower, i dont want NOS, thats too crazy for me. i was wondering if anyone could tell me what mods would be the best for my money, and what the approx. cost would be. i would just like to hear about what some of you other guys did before i jump into anything.

Thanks,
Kevin (92 sc300 5 spd, stock)

Soarer-007

there are the basics:
synthetic engine oil
better more free flow mufflers (not a whole cat back)
K&N air filter
and then maybe a ECU (chip) upgrade.....maybe even in that order......not saying the chip upgrade is great...but for the $ not a bad option.....keep in mind you should be using 92 or better octane too.

midknight

How many additional hp can you squeeze out of it?:eek:

SC300T

You have the prime candidate for boost!
Only $4500 to $6000 for a turbo kit.
You'll be spanking everything from Supra TTs, M3s, C5s, modded Mustangs, etc. etc. etc.

In the Midwest, call Larry @ SP 603-893-5002. in the south Lance@ Toyomoto. 305-599-3050. Either of the two can convert your SC300 into a daily drivable beast.

Perhaps best of all, you don't sacrifice daily drivability to get this type of performance. Mine is used as a daily driver, and it performs like stock until you get into the boost... The clutch is only modestly heavier, the turbo lag is minimal, and fuel economy only suffers when you dig deep into the turbo. Your insurance company insured you for an SC300, when you've got Viper like performance.

If there is a downside to all this, its that you'll become addicted to the turbo rush and will want to spend every free penny on upgrading the car.

Lance built my kit, and it's been bulletproof, even on a 126k mile engine... He and Larry really do great work. I've stomped BPU Supras (approx 380rwhp) at the track on only 11psi boost, ran 12.73@116.9 on street all-season Dunlops and I've spent less than $7000 on hp related parts.

Ooops, I'm sorry for the long post... Can you tell I like the turbo?

www.datapathusa.com/scott/scott.html

Soarer-007

from just mufflers, filter and chip maybe 20hp....
..I agree, if its in your budget.....go turbo.....
my car came stock with turbos, so I was lucky...
...my car can still beat mildly modded out Supras and alot of other cars....it wont beat some GNs, Stangs and built Supras out there.......but that wasnt my goal when I got my car to be the fastest......but just to be one of the quickest....and do it from the right side while do so..!!

If a turbo is out of your budget....Nitrous is your best option (50-100shot) to make some horsepower......dg

Toan Nguyen

Hey Soarer-007

Why do you only suggest changing mufflers? They arent the real restriction to the exhaust as much as the whole exhaust system. Cat back is a good cheap way to get a couple more hp (certainly more than just the mufflers). If you have the dosh, get the whole exhaust replaced ie extractors, hiflow cat, etc.. good HP gains for a semi-modest outlay.

Toan.

Soarer-007

Thats a farce these companys would like you to believe..
You may only need new pipe from the cat back if you install some sort of forced induction (turbo etc...) on your car, other then that...the only hp gain a cat back will add is at rpms Over 3,000....while your normal driving range is from idel 800rpm to maybe 4,000 rpm. Larger pipe just isnt needed....and its a given fact that you'll lose more low end torque if you go larger pipe. Is everyone ready to lose that off the line push you back in the seat feel..? Usually.....No. As far as whats More restrictive...Do this, cut off your exhaust and take a look thru the Pipe....Ill bet $100 you can see straight thru it.....tell me how thats hurting your Hp..
On the other hand, try looking thru your stock muffler, gaurantee you wont see light on the other end.....its baffled to keep down the sound...THIS is more restrictive then the pipe........so now, you tell me whats more important to change. A good pair of "straight thru" performance mufflers "compliment" rest of the stock exhuast system w/o killing your low end torque AND w/o spending an arm and a leg! I think a Toyota enigineer has a good idea of what size is best for these cars with minor bolt ons included. But thier hands are tied when it comes to the mufflers, people higher up at Toyota make sure the car comes out quite...just as most Lexus owners prefer.

lexcoupe

well ive looked into the turbo and i decided that i want it ! it'll take me a while cause im still in high school, but ill get it soon enough. now with the f-max or toyomoto kit, what kind of psi am i looking at, cause i dont want to have to build up my engine. and can anyone point me to a garage that is good with turbos and that wont rip me off. Thanks, ill be sure to post pics and updates on how the project is coming. (should be in the late summer or so)

lexcoupe

Ps. i forgot to mention that i would need the garage in the chicagoland area, or midwest usa. man am i desperate. i want someone really good. thanks

SC300T

See above posts. Larry with SP is one of the best and he's in Chicago.

lexcoupe

oh thanks, but still what kind of psi are you running?

SC300T

The 12.73 @ 116.9 was run at 10-11psi on street all season Dunlop SP5000 tires with a 2.3x 60ft time and high density altitude conditions. Was slipping halfway down the track.

10psi at 10:1 (stock) compression is equivilant to around 14psi at 8.5:1 compression. So if you do the low compression head gasket mod, you'll have to raise the boost by around 4psi just to make the same amount of power. At 10psi, the car makes more power than BPU Supras running 18psi on their twin turbos. At 18psi, the Supras stock twins are starting to fade in their efficiency. At 10-11psi on a T60-1 your just reaching the point of best efficiency which is between 12-17psi. The 60-1 fades after 20psi... I haven't even began to explore the limits of boost with race gas or octane boosters. I'm hoping that I can reach 15psi on race gas, and run 12-13 psi on the street with a $4 bottle of off road octane booster. An MSD 6BTM ignition is a good idea as well, because you can dial in as much ignition retard as you want to compensate for varying boosts and fuel types.

Many people say to go directly to the 8.5:1 compression, but I think that unless you're looking for an 11.5 second timeslip, this may not be needed.

An engine at 10:1 will:

1. spool the turbo quicker
2. generate more power off boost
3. be easier to drive
4. have a milder off-boost / on-boost transition
5. will get better gas mileage
6. generate more torque off the line
7. save the driver $1250 dollars in labor and parts for the gasket.
8. generate higher EGTs, cylinder pressures, and has more tendancy to detonate, which can be a major problem
9. have less overall HP potential with larger turbos
10. I would guess a 10:1 engine would be limited to around 550rwhp max at around 15psi on race gas, assuming you do VPC, CAMS, good fuel control, G-force ECU, upgrade valve springs, port the head, etc. Compare that to the 800+rwhp for a fully modified large single turbo running 8.5:1.

For normal street driving, I run at 9psi and have no detonation problems on 93 octane.

MISURA

Scott.
Any ideas of putting on drag radials to see what she can do? Are you curious?
(I noticed the all seasons, great tires mind you, and the 60ft. time)

SC300T

Assuming I could pull a 1.6 60ft time on DRs , the 12.73 would have been a 12.07. Since I am spinning well past the 60ft point, I may pickup an extra few tenths past that, may be an 11.8@121 or so. Correct that to 60 degrees... Who knows? 11.5@123?

We didn't pickup any MPH or ET by adding a 50/50 race gas mixture, so we've got room to add boost/timing to get more out of it.

Jeff down in Miami gained well over a second switching from street Yokos to slicks, so there is probably a lot more to gain.

BTW... I am very curious what it could do on DRs. I haven't put DR's on it because I don't think the tranny and driveline would like it very much. Its much more fun seeing the Dunlops smoke than picking up axles. I may have to try it out, though... A friend of mine just traded his GS400 for a 2002 Z06 :eek: :eek:


BTW.... Will be posting some crappy videos of the run against a BPU Supra tonight!

Soarer-007

...I run my Soarer at 12psi around town, and when I race I use my BLITZ Dual SBC to adjust it up to about 20-23 psi.. My car came with the 1JZGTE and can handle it. Im also running a HKS F_CON, HKS Twin Power, 440 injectors, upgraded exhaust, intake and Blitz Intercooler and some odds and end....bolt on stuff. I also went from the stock twins to a single TO4X ungrade too recently...and have an Art Carr built trans and 2800 stall convertor......dayle