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Modifications for about +70HP from L98!

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Old Jan 5, 2011 | 09:21 AM
  #1  
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From: Serbia - BELGRADE
Modifications for about +70HP from L98!

I was reading a lot of threads and topics about increasing engine power, but I'm not sure which components to buy for it

I have stock 1988 GTA 350ci L98 without catalysator, with 3" pipe straight to the muffler with two 2,5" pipes.
As I can see this engine has 230HP and my goal is 300HP. I saw that stock injectors and TPI intake are enough for this power.

What modifications I need to get 300HP on this engine?

I know that Headers, heads, cam, roller rockers... will increase power, but could someone tell me what exactly to buy, for example: Hooker headers 2210, Edelbrock heads 60869...

I'm from other continent and here we don't know much about USA muscle cars, so my questions are maybe very stupid for you

I tried to read as much as I could, but there are so much informations and technical terms and my english is not good enough so I couldn't figure it out what to buy

Thank you all in advance.

Nenad.
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Old Jan 5, 2011 | 10:53 AM
  #2  
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Re: Modifications for about +70HP from L98!

One more question , is it better/cheaper to go with turbocharger instead of this modifications?
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Old Jan 5, 2011 | 11:27 AM
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Modifications for about +70HP from L98!

Do you have emissions requirements?

Can get hedman shortys with 3" collectors and then fab a y pipe as i dont think they come with one, or can run hooker 2055's with y pipe and just open up the collector alittle bit. Not sure if the design has changed but in the past, they were ball and socket flange, and the ball on the header was only 1.9" diameter...pathetic... Can open it up to 2.25 without much difficulty and still seal well.

So do headers, keep your 3" catback, and then replace the TPI system with aftermarket BIG tube large base stuff if you want TPI. IF not, go proflow xt, HSR, or others depending on budget.

Get 1.6 ratio rockers.

Set base timing to 8-10 deg and run it. OR get tuning equipment and put in a much better timing curve and fine tune the WOT fuel. May have to tune the setup with the 1.6 rockers, it does change fueling abit..my car leaned out alittle but I think it was due to new injectors that had a different spray pattern

That will get you 250-260whp on a strong running L98, which is 310-320hp on motor.
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Old Jan 6, 2011 | 08:34 AM
  #4  
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Re: Modifications for about +70HP from L98!

I just called my friend who is familliar with USA cars and he told me that have one Vortech V-1 supercharger He had plan to put it into one of his four C4 corvette but he dropped that idea. He will sell V-1 to me for 300 euros (about 370$) because he don't need supercharger at all. Also, he will help me in process of supercharger installation, when I bought all the necessary things for installing.

Thank you all.
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Old Jan 6, 2011 | 04:23 PM
  #5  
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From: Milwaukee WI
Car: 88 IROC
Engine: L98 HCI
Transmission: T-5
Axle/Gears: 3.27 9 bolt
Re: Modifications for about +70HP from L98!

The exhaust manifolds are very restrictive on a stock engine, and they will be even worse for a supercharged engine.

Headers will help that blown L98 to breathe and the sound will put a big smile on your face.
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