We invite you to browse our online catalog for domestic small cars, focussing on Cavalier and Sunfire, and take a look at the standard by which all other performance parts for these cars are measured. We invite you to browse our online catalog for domestic small cars, focussing on Cavalier and Sunfire, and take a look at the standard by which all other performance parts for these cars are measured.
We invite you to browse our online catalog for domestic small cars, focussing on Cavalier and Sunfire, and take a look at the standard by which all other performance parts for these cars are measured.
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Iperformance has become distinguished as the world's top manufacturer and supplier of performance parts for Isuzu, Geo Storm, Asuna Sunfire, and Lotus Elan M100 cars, and we now bring that excellence to owners of all makes and models of cars, but we still offer nothing for trucks or suvs.


FREQUENTLY ASKED QUESTIONS

Can I buy the pre bent exhaust pipes without the muffler instead of the entire exhaust system?

Will you substitute a different brand muffler or different style of tip or do something custom to the exhaust system or header that I want to purchase?

Can I buy the Cavalier header without the catalytic converter?

Do you offer a dual exhaust system for the Cavalier/Sunfire?

Some people claim your exhaust system hits the rear axle, is that true?

Will the Cavalier/Sunfire header or exhaust system fit my non J body GM car?

I don't see a header or exhaust system for my car, will you make one for it?

What is the difference between ceramic coated and non ceramic coated exhaust products?

Are your headers legal in California?

You don't answer your telephone when I call?

Why didn't you return my email?

Are you still in business?

Are the prices in your online catalog current?

What are the customs fees on my order shipped outside the US?

What is the sales tax on my order?

I am in the US or Canada, how much is the shipping cost?

Will you offer a discount if I buy a header and exhaust system at the same time or a reduction in shipping costs?

What payment methods do you accept?

I mailed my check on such-and-such date: how come you say it arrived a week later?

My bank says my check cleared on such-and-such date, Why do you still wait 14 days from the date you deposited it before you will process my order?


Do you sell wholesale for resale by performance shops?

I bought my parts from another vendor who hasn't provided me with any installation instructions, will you tell me how to install these parts I bought from someone else on my car?

I'm trying to do some modification I found on some internet site and can't figure out how to get my car running? Some guy on the internet (not us) told me I should do make this modification to my car, can you tell me how to do the modification or how to get my car put back together?

Can you help me fix my car?

Can you tell me about the gear ratios, interchangeability, or how to repair the Isuzu 76 mm transmission in my GM car?

Can you answer my question that is not about parts or products that you sell?
 

Can I buy the pre bent exhaust pipes without the muffler instead of the entire exhaust system?
Please look at the bottom of the exhaust system pages, we are now offering stainless exhaust pipe sets without mufflers.

Will you substitute a different brand muffler or different style of tip or do something custom to the exhaust system or header that I want to purchase?
All of our exhaust systems are production made in production runs of all identical products. All are exactly the same. We will not substitute different brands of mufflers or styles of exhaust tips. We will not do custom work on exhaust products, such as add sensor fittings, change dimensions or design, or other custom modifications. Our exhaust products are made in production runs, and all are identical.
We do offer stainless exhaust pipe sets that you can customize yourself with whatever muffler or fitting that you desire. Please check the bottom of the appropriate exhaust system page for listings for this item.

Can I buy the Cavalier header without the catalytic converter?
The Chevrolet Cavalier Z24/Pontiac Sunfire GT header is sold only as a complete unit, including the catalytic converter. Because GM manufactured the original parts with the catalytic converter welded to the down pipe, it is a violation of US Federal law to sell a header and down pipe assembly without a catalytic converter as part of the assembly. It is illegal to sell this product without the catalytic converter and we will not break the law by doing so. It does not matter what country the customer lives in or what their local emissions laws are, we are in the US and the law prohibits us selling a product that eliminates any emissions control devices.

Do you offer a dual exhaust system for the Cavalier/Sunfire?
We are a performance parts company. We are not a cosmetic parts company. Dual exhaust on a four cylinder car is purely for cosmetic purposes and has absolutely no positive performance implications. In fact, the added weight will in fact make the car slower.
If you would wish us to have a dual exhaust system custom made for you, we would require an order for ten units. Ten prepaid means an order for ten paid in advance. We will not accept orders for less than ten. We will not collect deposits. We will not barter or arrange groups to purchase. You must deliver to us prepayment for ten units and it is your responsibility to arrange finances be it that you purchase ten units yourself or that you gather nine other people and collect money from them, then delivering payment to us. We will not at any time discuss or entertain any quantity less than ten and full prepayment there of. It is also your responsibility to deliver a car for prototyping to Seattle, Washington, upon which we will design and prototype the product.
Pricing for a dual exhaust system would be 1 1/2 to 2 times the price of one of our single pipe single muffler exhaust systems as listed in our online catalog.

Some people claim your exhaust system hits the rear axle, is that true?
Our exhaust system does not move when installed on the car, and can not hit either the underside of the vehicle or the rear axle.
However, if our exhaust system is installed on a vehicle that has been excessively lowered and the vehicle owner has modified the suspension through either the use of springs that are too soft or dampers (struts) that do not offer enough compression resistance or are not in proper working order, it is possible that in these cases where the owner has willfully and intentionally improperly modified their vehicle to cause the suspension to hit our exhaust system.
As can be seen in the above picture, the exhaust pipe tucks as high as physically possible against the floor pan of the vehicle where it passes over the rear axle. Note the frame rail is lower than the exhaust pipe, and the axle will strike the frame rail before it strikes the exhaust pipe.
Remember, the exhaust system does not move, the suspension moves, and it is actually the suspension hitting the underside of the car that has been reported in these cases where the suspension has been improperly modified.
The solutions to this situation are as follows:

  • Inspect and repair any damper (strut) that is leaking or has lost its gas charge.
     

  • With adjustable dampers, increase the compression resistance valving by turning the stiffness up.
     

  • Replace soft rear springs with stiffer rear springs that will not allow the rear suspension to strike the underside of the car.

One very recurring pattern has been that almost every one of the few people who have reported problems with their rear axle hitting the underside of the car has been that they have been using Eibach brand lowering springs. We had found previously with our work with the Isuzu and Geo Storm cars, that Eibach uses extremely soft rear springs that are not capable of preventing bottoming out the rear suspension. They choose these soft rear springs to soften the ride, but the result is increased understeer and increased movement of the rear suspension. It is easy to tell which cars are on Eibach springs when following them on the street, because the tail end of the car bounces up and down, over bumps in the road, twice as much as any other vehicle over the same bumps. If you are using these springs, our best suggestion is that you immediately contact the manufacturer of your suspension springs and explain to them that the rear springs they provided to you are not stiff enough to keep the rear suspension from bottoming out on your exhaust system and demand that they provide you with more suitable replacements.
Another consistent pattern has been that some Cavaliers and Sunfires have been found to have leaking or blown struts as delivered from the factory, new, and right off the show room floor, and that the OEM rear struts of these vehicles do not have a very long life and seem to go bad in six months or so. This is the case as illustrated one of our customers, Patrick Kelley, Phatcub on the J-Body.Org website. Mr. Kelley bought our exhaust system and installed it on his new 2002 model Cavalier in November of 2002. He later reported that his rear axle was striking the underside of his car and exhaust pipe. We exchanged some 30+ email messages with Mr. Kelley recommending that he examine the rear struts of his vehicle and determine if they had failed. Mr. Kelley refused, stating his car was brand new and that there was no possible way that his struts were bad. On August 13, 2003, Mr. Kelley posted this message on the public message boards on the J-Body.Org website:

Mr. Kelley was responding to another owner's question of why their rear axle was striking their stock exhaust system and stated the following:
    "...but I don't have shocks so I hit s really big bump and ripped off one of the hangers, so I'm gonna wait untill I get my shocks to get it fixed again."
and
    "Basically if you don't have good shocks in the rear it will NEVER be fixed."
Mr. Kelley states that as of August 13th, 2003, he was driving around with bad struts on the back of his car, a problem he had previously encountered because he had already replaced his rear struts once (between December of 2002 and August of 2003), that replacing his damaged rear struts had remedied his previous problem of his rear axle striking the underside of his car and his exhaust system, and that unless the vehicle has properly functioning struts on the back of it, there is no way to keep the rear axle from striking the underside of the car and the exhaust system.
We are very glad that Mr. Kelley did finally follow the technical advice that we provided to him, and that our technical advice was responsible for remedying his difficulty.
But, the real proof that our exhaust systems fit and fit well is the fact that not a single customer has returned one of our exhaust systems for poor fit.

Will the Cavalier/Sunfire header or exhaust system fit my non J body GM car?
We have not test fit our Cavalier and Sunfire headers or exhaust systems on any non J body GM cars. What is important to remember is that the engine model has less to do with whether or not a header will fit into a car, and the floor pan and sub structure that the exhaust piping must wind around has much more of an affect on fitment. If your GM car does not share a J body floor pan, it is doubtable that a header for a J body car will fit your car.
If you wish to try to fit our header to your non J body car, we will be more than happy to sell one to you, but we will not be able to accept the return of that product if you try to install it and find out that it will not fit, because installing a header will, in almost all cases, result in scratching and chipping of the finish of that header, even on cars it is designed for, but more so if the header is not designed for the car you are installing it on. We can not accept the return of any products which have been damaged or marred in any way such that they are not in new condition.

I don't see a header or exhaust system for my car, will you make one for it?
We require a prepaid order for ten units before we would consider developping and manufacturing any new header or exhaust system applications. Ten prepaid means an order for ten paid in advance. We will not accept orders for less than ten. We will not collect deposits. We will not barter or arrange groups to purchase. You must deliver, to us, prepayment for ten units, and it is your responsibility to arrange finances be it that you purchase ten units yourself or that you gather nine other people and collect money from them, and then deliver payment to us. We will not at any time discuss or entertain any quantity less than ten and full prepayment there of.
It is also your responsibility to deliver a car for prototyping to Seattle, Washington, upon which we will design and prototype the product.

Pricing will be as follows:
  • Single Pipe Cat Back Exhaust: $600 per unit
  • Dual Pipe Cat Back Exhaust: $1100 per unit

  • Upper Header Only, Ball & Socket Outlet (No Collector Pipe): $120 per cylinder per unit
  • Header and Collector Pipe to Cat Inlet Flange (For vehicles with seperate cat and down pipe only): $170 per cylinder per unit
  • Header with Collector Pipe And Catalytic Converter (For vehicles which have the OEM cat welded to the down pipe): $200 per cylinder per unit


What is the difference between ceramic coated and non ceramic coated exhaust products?
Our exhaust products are offered in both ceramic coated and non ceramic coated finishes. Ceramic coating offers both thermal insulation to keep the heat of the exhaust inside the pipe and also corrosion resistance. Keeping the heat inside the pipe reduces under hood temperatures and keeps exhaust gas velocity high, both of which enhance the engine's ability to produce more power. Corrosion resistance protects the product from rust and makes it last longer. For headers and down pipes, we recommend the ceramic coating to protect your valuable investment and protect it from corrosion. Ceramic coated headers and down pipes will outlast non coated products many times over. For cat back exhaust systems and after the catalytic converter, ceramic coating is more of a esoteric thing. This pipe does not see as extreme of a temperature fluctuation or as high of temperatures, and aluminized finish is adequate except for cases where the owner wants the cat back exhaust system to look like new for many years to come.

Are your headers legal in California?
California Air Research Board certification is an expensive and time consuming process for getting headers and other aftermarket parts legalized to pass visual inspection in California. That added cost would have to be passed on to the customer and headers would cost more than double what they do without CARB certification. Because of this, there are no headers for Cavalier, or Sunfire which have CARB certification, not from us and not from any other manufacturer. Our headers meet or exceed all emissions requirements and will have no problem passing emissions performance tests for tailpipe emissions.

You don't answer your telephone when I call?
Our office hours are from 10 AM to 6 PM Central Standard Time. If you call during that time period, and we do not answer the telephone, that is because we are at the machine shop building parts to fill orders, at the coating shop ceramic coating headers, or delivering and picking up parts at polishing shops, plating shops, or other subcontractors. We put the highest priority on filling the orders we have received, and if we are not here to answer the telephone, it is because we are busy filling those orders.
We return messages inquiring about our parts when messages are left on our answering machine. If you do not leave a message on our answering machine, or do not leave your telephone number, we can not return your telephone call. We do not return telephone calls for people asking for parts for trucks or SUVS, asking for OEM parts, or asking technical questions about building their own nitrous, turbo, or supercharger systems, as has been indicated in the FAQ above, we can not help with those topics. We get a dozen hangup messages on our answering machine every day. We can not return calls those calls because we have no telephone number to call or any message to respond to.

Why didn't you return my email?
We answer almost every email we receive. However, we receive a large number of email messages with fake return addresses. Nothing is more frustrating than spending half an hour typing out an answer for someone and then having that message returned as undeliverable. Please make sure that the return address on your mail program is accurate. We will not search the content of your message for an email address and will respond by hitting the respond box in our Netscape program. If you do not have a valid email address in your email program, do not blame us for responding to your faked address or for you never receiving our response.

Are you still in business?

I am not sure why this question is asked so frequently, other than that we specialize in parts for niche cars outside the mainstream.
We are still in business. We would not be paying the web hosting fees to keep this website on the internet and paying for advertising every month in the compact car magazines if we were not still in business.

Are the prices in your online catalog current?
Our online catalog is our master price list. Any changes in prices or products are made directly to the online catalog first and fore most. We work directly from the website catalog for all of our pricing questions. If you ask us if a price in the online catalog is correct, our reference is the online catalog, because that is our master price list.

What are the customs fees on my order shipped outside the US?
We do not collect any customs fees or duty taxes on any orders. Those fees and taxes will be determined by your government officials when the product passes into your country and you will be billed for those fees or taxes directly by your government.


What is the sales tax on my order?
Missouri State sales tax applies only to product which is delivered within the state of Missouri. If the product is to be delivered to you within the state of Missouri, multiply the total for all product costs, excluding any shipping costs, by the percentage indicated on the order form, and add that number to the total for your order. If the product is to be delivered outside the state of Missouri, there is no sales tax.

I am in the US or Canada, how much is the shipping cost?
Shipping costs for the US and Canada for almost every items in the catalog are listed below the product description. Please look at the end of the listing heading for the company or the product type on the catalog page.

Will you offer a discount if I buy a header and exhaust system at the same time or a reduction in shipping costs?
Prices for all items are as listed in the online catalog and those prices are as low as we can set them. As such, we do not offer any reduction in price for purchase of multiple items.
Headers and exhaust systems must be shipped in seperate boxes due to the size and weight restrictions by the shipping company and can offer no reduction in shipping costs for purchases of multiple items.

What payment methods do you accept?
As is stated on every main catalog index page, we accept only checks and money orders. We do not accept any other payment method. Checks and money orders must be made payable in US Dollars and drawn from a bank with a US office, indicated by the address of that US office printed on the face of the check or money order.

I mailed my check on such-and-such date: how come you say it arrived a week later?
The US Postal Service does not instantly teleport an envelope from the mail box that you drop your envelope into, to the mail box on the front of our building. Depending on the schedule for pickup from the box that you drop your envelope into and the day of the week that you drop your envelope into that box, that envelope may sit in that box or at that post office for several days over a weekend before the Post Office even puts it into the machinery to sort it and send it on its way. Any time within a week of a holiday, this delay will likely be even longer due to the days the Post Office is closed and the increased amount of letters mailed around holidays. Once the Post Office begins sorting and directing that envelope, it will take three or four days for it to be delivered to our local Post Office for delivery to us. If the letter requires a signature for delivery, if we are not happen to be standing at the door for our letter carrier to get a signature, he will simply leave a card for us to pick up the letter at the Post Office two days following his initial delivery attempt, and this will further delay delivery. Overall, we can realistically expect the Post Office to deliver your envelope seven days after you drop it into a mail box or present it at a Post Office counter, at the very earliest, and only after we receive your envelope can we begin to process your order.

My bank says my check cleared on such-and-such date: Why do you still wait 14 days from the date you deposited it before you will process my order?
Our bank's policy is that a check may be returned as refused by the bank that check is drawn from up to 14 days after that check has been presented to the bank. After 14 days time, our bank lawfully has the right to refuse the return of any check for insufficient funds or invalid account, and does so. So a check can be returned at any time within those 14 days after it is presented to the bank. Our bank, or any bank other than your own bank, has no mechanism to verify if that check has been honored and processed and cleared your bank. This is because that information is confidential to you and you alone. There is no mechanism for any bank to check if a check has cleared another bank. So we must wait out the 14 days and upon verification from our bank that the check has not been returned, then and only then do we know that the check has been honored by your bank, and only after that time will we process any order paid by check.

Do you sell wholesale for resale by performance shops?
We are not currently offering any of our products for wholesale sales.

I bought my parts from another vendor who hasn't provided me with any installation instructions, will you tell me how to install these parts I bought from someone else on my car?
Part of what you, as a consumer and customer, are paying for, is customer service, and the knowledge and expertise of the vendor to assist you with installing the products you purchase from them either through written instructions or by communicating with you. If your vendor can not provide you with this information for your particular vehicle, you have the right to take your business to someone who does. We encourage consumers and customers to seek out vendors who can offer them assistance and customer service for their specific vehicle.

I'm trying to do some modification I found on some internet site and can't figure out how to get my car running? Some guy on the internet (not us) told me I should do make this modification to my car, can you tell me how to do the modification or how to get my car put back together?
For liability reasons, we can not offer assistance in areas of performing modifications suggested by third parties or people other than us. We really suggest that if you have a question regarding someone's suggested modification, that you contact the author of that material directly.

Can you help me fix my car?
Our business is designing and manufacturing performance parts. Our specialty is not repairing or offering advice on repairing cars, because that is not really what we do.  Our best advice in most cases will be to follow the instructions and troubleshooting sections in the factory shop manuals, which can be obtained from Helm Publishing.

Can you tell me about the gear ratios, interchangeability, or how to repair the Isuzu 76 mm transmission in my GM car?
We do not offer technical assistance on these topics, please consult your local General Motors representative.

Can you answer my question that is not about parts or products that you sell?
We will answer only questions about the products we sell. We will not answer questions about any other topics.

Iperformance has become distinguished as the world's top manufacturer and supplier of performance parts for Isuzu, Geo Storm, Asuna Sunfire, and Lotus Elan M100 cars, and we now bring that excellence to owners of all makes and models of cars, but we still offer nothing for trucks or suvs.
We invite you to browse our online catalog for domestic small cars, focussing on Cavalier and Sunfire, and take a look at the standard by which all other performance parts for these cars are measured. Click Here to Go Back to the iperformance Main Page...