BOOSTALMIGHTY7

iTrader: (1)

Well today i just got back from the dyno the car dynoed at 408 whp and 305 lbs of tq. My motor is large streetported with a t66 and i'm running 850 primaries and 1600cc secondaries. Can anyone tell me why it dropped off at 7k? Oh yeah this was at 15 psi you guys think its too low for that amount of boost? If anyone could help me i would appreciate it. thanks

Busted7

Thats about right in my opinion! Go to 20# and see!

Dudemaaanownsanrx7

iTrader: (23)

what is the rest of the setup. A/R hotside, exhaust size, cat or midpipe and what kind of dyno?

rx72c

iTrader: (8)

Maybe your porting is crap?
Seen alot of mild ports that dont actually make the engine peak any higher..

ErnieT

iTrader: (2)

Check your ignition system, especially the leading coil. Make sure it firing up high. Our stock coils are crap.

BOOSTALMIGHTY7

iTrader: (1)

i would scan the dyno but my scanner is messed up man. Thanks guys for the input. I bought the car from a friend of mine it was built by bryan smith at rotorsportsracing. I think its still using stock ignition. As for the turbo i ask the guy whom i bought it from and he said he didn't know. It was dynoed on a dynojet.

BOOSTALMIGHTY7

iTrader: (1)

3 inch from the turbo back no cat

arghx

iTrader: (3)

what turbo manifold, turbine wheel (P trim?) and turbine housing A/R ? even with aggressive street porting my HKS cast manifold didn't like to make power much over 7000rpm

BOOSTALMIGHTY7

iTrader: (1)

the turbo manifold was a custom turbo manifold, the turbine wheel he told me it was a q trim and the turbine housing a/r he didn't remember. Everything was fine till 7k hmm i dunno i'm new to the rotary community.

Dudemaaanownsanrx7

iTrader: (23)

how fast does it spool, like what rpms make 5 - 10 then 15 psi? that might be an indicator of what kind of a/r is on the hotside, or at least if it's more setup for top end power or faster spooling.

BOOSTALMIGHTY7

iTrader: (1)

5 psi by around 3.5k 10 psi at 4k and 15 psi around 4500k

thewird

iTrader: (8)

I'm not sure how big a T66 is but thats some laggy turbo right there and would make more power I think? This is said under the assumption that a laggy turbo is a bigger turbo ^_^

thewird

RXHEAVEN_WA

That is NOT laggy and its pretty A Typical of an average porting job in most peoples experience.

T04Z 1.15 A/R *actual* on road pull in 3rd gear to give "real" boost response curve and power generated!
This is a average street port, with unknown timing specs, but when testing compression figures were high so its not anything like the one pictured below that makes power much higher and makes much more power per boost pressure used

3" exhaust with no cat will not be your issue, it is more to do with the porting specification than anything else. A really well done street ported block will peak at around 7500rpm (no higher with stock inlet manifolding) and a medium sized turbocharger. So you are in the ballpark. But the ports need to be like this *see link* for that to happen... https://www.rx7club.com/showthread.p...29#post9078029

RXHEAVEN_WA

A properly done street port will only return around ~105psi compression or so on a 100% brand new engine @ 250rpm test speed on std temp and pressure day. *this is with 9.0:1 ratio rotor set and 2mm factory apex seals or equivalent sealing ability.

If your engine measures much higher compression than this then it does not posses the late timing and overlap qualities of a maximum effort street port and will not deliver the Ve increase nor the peak power speed increase or be able to make power to 8.5k+rpm either.

BOOSTALMIGHTY7

iTrader: (1)

I figure it should be making around 420 or 430 around 15 psi. well imma try to scan the dyno sheet at work and upload it and tell me what you guys think.

R-R-Rx7

iTrader: (24)

+1

RXHEAVEN_WA

There is a ton of variables involved here, but you are in ball park of honest power. There is an extensive running thread of actual engine power these things do make in reality in this thread here http://www.fdrx7.com/forum/showthread.php?t=182&page=2 from some of the most credible sources in the world.

You can use a simple *estimation multiplying factor of 1.15* to estimate your engine power as see how it compares to the median results listed here. Remember your dyno measures need to be reconciled with reality too............ something lots of people forget (not saying you have).

Go get yourself a Race Logic Performance Box and run your own tests of 90kph to 140kph acceleration in 3rd gear (great tests are pulls from 2k rpm to 8k rpm) and that will tell you when you run a speed report where you sit on power band quality and power quantity

BOOSTALMIGHTY7

iTrader: (1)

thanks for the inputs and advice guys i appreciate it.

RXHEAVEN_WA

Totally not true, people forget history all to readily sadly.

Heaps of cars over a decade ago have run from 600bhp to 700bhp on the stock FD3S coils! all be it with ign booster, a Crane Hi-6 on leading coil or a HKS DLI works and always has.

I have seen them listed in the above thread.

327kph on stock coils
10 sec and 135mph on stock coils

^ Both basically road cars

http://www.fdrx7.com/forum/showthread.php?t=182 327kph and 700+bhp 1999
http://www.riceracing.com.au/13B-REW-engines.htm A&L rx7 stock coils 1997

BOOSTALMIGHTY7

iTrader: (1)

see the attachment for the dyno!! the 410 hp run was from a recent rx7 he done with a smaller turbo at the same 15 psi. My runs were the top and bottom. The bottom was at 12 lbs and top was at 15 psi.

dregg100

iTrader: (34)

are you sure the engine is ported? meaning have you physically seen the ports? and for that size turbo on a streetported engine, id say its pretty lagy. that even seems pretty laggy for stock ports. on my old 35r setup(yes i know its bb) i was on a bone stock reman hitting 18 psi by 3700rpms, the above just doesnt make much sense.

look on the turbine housing to see what a/r it is. also, who tuned it?

BOOSTALMIGHTY7

iTrader: (1)

well i got the invoice from the guy whom i bought it from saying it was street ported. And Ed Senf tuned it.

RXHEAVEN_WA

100% it's street ported looking at the Tq curve

BOOSTALMIGHTY7

iTrader: (1)

The tuner was asking me the same question cause it idles at around 900 and it idles so smooth. He was like you sure its streetported i was like well he said it was lol.

BOOSTALMIGHTY7

iTrader: (1)

i heard the only true way to test power was on the street!!! right? dynos were used to tune cars and problem solve?