How was your car dynoed? Was it an eddy current dyno or was it an inertia dyno. Was the shop that dynoed your car the same shop that sold you the intake? Was the hood open? How many runs? Was there a cool down?

You would be surprised at how much the sound effects what you "feel". Being a speed freak and wanting my car to make power without compromise, I would NEVEr put a hot air intake like that on ANY of my cars. I challenge any of you with a hot air intake against a car with stock intake.

 

The stock intake for the GS and SC are very efficient. A simple pipe and a filter most likely won't be better than the factory design. That said, I have the Injen intake and I got it for the sound.

 

You need both data points. California hasn't gotten ridiculously hot to the point where ignition would retard due to intake air temperature.

 

HA HA What the hell are you talking about..

 

I find the results lack credibility, due to the huge change in performance. It's common knowledge that changing intakes does little for performance increases, and I would think the opposite true for performance decreases.
If I understand the your premise correctly, there is a 20 HP drop due to simple difference in intake air temp., even though you used a 70 mph fan (bad a$$ fan by the way).
If you had posted results of a 3 HP drop, similar to what many have posted as gains, I would have found those results more believable.
Doesn't matter to me, though. I'm gettin' flames put on which will make up for any loss of performance on my car....

 

Since some of you are still having a hard time believing the non-biased data gathered from the eddy current dyno, I asked Race Precision Inc. to elaborate on the results of this exam. Hopefully, this will clarify.


Designing an intake is a complicated thing and its not as simple as slapping on a steel or aluminum pipe with an induction filter. For several years, companies like Injen, Fujita, etc. have been making induction type intakes that are called “Cold Air Intakes (or Induction), when in all reality, many of them have no source of cold air. In the instance of your SC430, the intake filter location (under hood) was sucking in a LOT of hot air. We measured your IAT (intake air temperature) at 166+ when your Injen intake was on. With the stock air box/intake, your IAT was at 92. That is a difference of over 50 degrees. Any reputable tuner will tell you that IATs are extremely important and every 10 degree swing can be +/- 1% in power. As for dyno charts, most of the companies dyno with the hood open and a fan blowing at the induction filter. This is a very inaccurate way of testing an intake. The flow dynamics of the entire engine bay is changed when the hood is open as the car was NOT designed to be driven without a hood. I know you are going to be bashed on the forums but most of the bashing will come from people that are “forum educated” and don’t have a clue how to properly make/tune an intake. You should challenge any of those guys with similar mods to you to race. I can guarantee you that your car with the stock airbox will be faster than a car with the “hot air intake”.

Regards,

Eloy Way
Race Precision, Inc.
7029 Marcelle Street
Paramount, CA 90723
Tel: 562-630-5966
Fax: 562-630-5968

 

Actually I stand corrected (myself ). I had forgotten that the OEM intake is a ram air setup unlike most cars. Big difference!

 

Thanks for the info!!


What is the best way to achieve a true cold air intake?

 

I'm posting up my dyno results as soon as I can book time. For those who have dyno'd their cars, can you post them up as well? Unfortunately, until the [actual] results of dynos are compared, there really won't be an end to this discussion as one dyno result does not make a truth.

 

Here are my numbers,

Type of dyno: Dynojet
Run conditions:
Temp 76.3
Bars 1024.6
Humid 18%


MAX POWER = 262.5
MAX TQ = 279.1


But keep in mind that I modified my own intake and it ducts cold air in from the oem scoop above the radiator and another channel I made to divert air from the front grille.

 

That is certainly the correct way to do it. That said the stock system incorporates a helmholtz resonator that in many applications has proven performance gains. Aftermarket intakes do not offer this. Peter Scott of Planet Soarer did multiple tests with aftermarket and homemade large tube intakes and ultimately found the best power and performance by modifying his stock SC400/Soarer intake by ducting a large quantity of cool air to the filter of an otherwise stock system. I made a similar modification to my LS400 stock system and in back to back multiple runs testing at the dragstrip found a consistent 0.5mph gain which equals about 5rwhp.

As stated by others... testing with the hood OPEN is not the same as closed ESPECIALLY with open element designs.

 

For cat back systems this statement is pretty accurate.

HOWEVER... I can think of one exhaust mod that is most definitely a power maker and very noticeable in the cars performance

 

Planet Soarer was where got the idea from, after modifying my SC400's intake and having such good results I knew that I could do the same with my 430 and utilize both the oem scoop and a custom one I fabricated the radiator and another channel I made to divert air from the front grille.

 

Tommy - do you have any pics of this? I made a diverter out of aluminum and placed it behind the right side of the grill, then opened up the area in front of the air box location where I have a fiberglass heat shield. I think this is giving me better airflow, and hopefully keeping the intake air temp down. I'd like to see what you've done with the oem scoop. I've been trying to find an extra one of those to modify, too.
Thanks,
Cecil

 

The factory intake is the best design. The key is getting more cold air into the stock system.

Dyno results are really nothing. It all depends on the dyno and how it was dynoed.

This is false. If you design the exhaust correctly, you can make more power. Most companies will throw in larger pipes and say its "more free flowing". This is not always the case. The proper design will allow for more volume of exhaust gasses while maintaining exhaust gas velocity. This is not always acheived by going with larger than oem piping. Its a gimic.

Generally, heat shields are used to block radiant heat. With the sc430, the manifold is there but it has its own heatshield. The heat shields used for induction type cone filters dont help with underhood temperatures. You're not trying to block radiant heat now.