I know this is off the original topic, but why is it the the high H.P. supras, and 300z's run slower times? I have noticed this around my area.

 

high HP supras make all their power at the very top of their RPM band, not spread out like other cars.

also they get horrible traction, due to ****ty IRS.

as for 300zx's...........all the highly modded ones ive seen run respectable times if they have ET streets........they also have a crappy IRS that doesnt launch for ****.........but they have two turbos instead of supras that goto a single.........so the twins have better low end torque.

most 300zx's with aftermarket turbos run 11s........i just saw a vid the other day of one with stock internals, just upgraded turbos and manifolds/fuel.......runs low 11.2 @ 130.

 

errrmmmm most of the Newer Supra's you will see out and about ARE twin turbo. They are typically only SINGLE turbo if they owner upgraded to the single turbo setup......

 

The new Supras have twin turbos, but they are twin sequential, meaning they are in series instead of parrallel. They have one small and one large turbo. The small one spools up quick for response and the larger one comes in later.

They don't run good et's because they usually don't invest in an automatic / good converter / trans brake and a good rear end / slicks. If they could leave on boost, the et's would be awesome.

Some Supras have been built like that and they run in the 9's or better.

Mike

 

um, wow, Let me give you a Supra history lesson.

the MKII Supras didn't have turbo except the cartech kit
and an HKS aftermarket kit. 1982-1986

1986.5-1992 is the MKIII Supra it came with a single turbo.

the MKIV Supra (fast and the furious style) came twin turbo
one comes on then the other, sequential, both turbo are in fact
EXACTLY the same size, one is NOT bigger than the other, it is
a very common mistake as it FEELS like it, what actually happens
is the second turbo makes all its boost in a quick PUNCH so it
feels like a big turbo, but I promise, they are the same, both CT12

the 1JZ uses twin ct-12s as well, but they both come on at the same time.

Supras with bad 1/4 mile times are due to most of the MKIV
drivers not able to drive worth a hoot. A bad driver with a 900
rear wheel hp supra will make 11s fairly easy, a GREAT driver with
a 600rwhp can put the baby in the 10's easy. This is why almost
all supra owners will wanna race from a roll, as they can't launch
the car worth a crap.

I am one of the driver's that can't launch the car worth a crap, I
can easily drive our MKII (with the MKIII turbo engine) happily
into the mid 13's, where as my roomate and OWNER of the car
can put it at 12.3 @ 123, with only 400rwhp. and all this for less
than $5,000 in total cost. And HIS 60' times are 2.2 if he launched
better the trap speed is good for low 11s.

 

OWNED!!! Guess that article I read was incorrect. Are they even in series?

123 should be good for some high 10's with a 1.5 60'. But a 1.5 would be nearly impossible with a turbo / standard transmission combo -- unless you have a 2-step rev limiter.

 

ive seen lots of diff cars launch 1.5-1.6 and trap low 120-123............thats more like a low 11 time.

ordinarily i see 10s seem to start around 125+.

atleast thats here in florida........maybe its diff near you.




as for the mkiv supras.............driver error is only sometimes the problem.

an IRS is NOT great for launches. same reason corvettes dont launch as good as fbodies.
solid rear > irs

and the original question was why to HIGH power supras run crappy times for their power level. so the stock turbos are not in question here. he was talking about large single turbo setups. most of them are setup to be dyno queens, since thats what most of the owners care about (trust me, ive attended enough supra dyno days to know)........they run such large turbos that all the power is at the very top of the rpm band in a big spike.

so when they goto the track, the first half of the their run is usually slow as *****, then they get into their power band and go flying through the end at very high trap speeds.

that is why their trap speed never matches their ET.............for example running an high 11 second slip, but trapping 130mph (which should be easy 10s).

 

.......i thought that the supra came with ct-13 twins?

 

That is a lot of questions but I'll do my best to answer some.

If you look at the rear view picture of the Camaro, you can see the oil pump mounted on the RH side in front of the axle. It pumps back to the valve cover and through a quick disconnect fitting in a supplied oil cap.

Wastegate noise hasn't been any issue. All the exhaust has quieted down substantially by the time it gets to the back of the car. It sounds if anything, alot like a quiet BOV. You can hear air but nothing like the wastegate mounted on the xover pipe on my car (wow, now that is obnoxious).

We are currently upgrading our prototype to run more boost and are looking at putting a water/air intercooler in the spot where the original air box was removed.

Std low boost kit 5-7 psi seems to flow enough fuel to keep things happy just by raising fuel pressure with boost pressure, this is integrated into kit. We run hi/low boost on prototype with 10 psi being the high boost. We raise the fuel pressure with not boost pressure but with exhaust backpressure and are getting 75-85 psi fuel pressure out of a stock fuel system and it seems to work well. This isn't in the kit but we are working on developing this system as an option.

Everybody loves the sound of the exhaust on the car. It is real tough but not obnoxious. We put a resonator tip on the tail pipe to knock off some of the edge. There is room for a small muffler if you want it real quiet. On our suburban kits, we usually install a 9" (small) 3" ID muffler after the turbo and it sounds real close to stock.

Lag isn't bad. Turbo is sized for the amount of air (temperature and volume) that is at the back. A turbo from the front, moved to the back, would have excessive lag. With stock compression, you don't have a serious lack of low end power anyway. Car is great for street use because if it had full boost by 2000 rpm you would just blow the tires out from under it anyway.

Air filter location was a concern for us as well. We originally planned on building a shield around the filter but ended up driving the car in real wet weather before it got built and it never had any problems. We do offer a precharger that helps with dust and water conditions as well as a dry-charger that doesn't let water through if you are overly concerned. I wouldn't recommend backing your boat into the lake real far though. But, most of you probably tow your boat with your truck. (we build some killer truck kits too)

Turbo is TO4E 60 trim compressor, P trim turbine and runs a .81 A/R housing. This turbo is capable of a lot.

Wastegate is new TiAL 38mm and works great.

Hope I got most questions answered. One reason kit is fairly expensive is the oiling system. Just the oiling system alone is about $500.

I really appreciate your feedback and interest in our kit, we are building it for you guys and it helps to know what you want.

Talk to you all later, Rick @ STS

 

is it possible that you could run the car really hard, get the turbo nice and hot.................then run through a puddle, splashing water on the hot turbo and causing the housing to crack?

i mean........even though YOU guys drove it around in rain without a problem............florida rain is much different, and that turbo WILL get wet here.

 

Sorry, wrong. Same compressors, different exhaust housings. I swapped them w/ a buddy before. The second one doesn't come on in a flash, its designed to come on slower, to keep from ruining the turbo. Several different thigns will cause it to come on in a flash, which blows #2 in no time. A lot of the BPU supras run in TTC anyways.

 

got_hp, my last car ran 11.0's at 122 with 1.5 60' times, so I assume that 123 will get 10.9's.

Mike

 

like i said.........just in my experience around here.........i havent seen anyone clock a 10 with less than 125............but then again, its all about track conditions and powerbands.

 

got_hp?-
water wont hurt the turbo at all..

 

ok, just wondering...............id always heard that hot metal + cold water = bad things.